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Lesson 4

The Importance of Medical Research
Close up of DNA
Elaborate

At a Glance

Overview

Lesson 4 introduces the idea that medical research is important for the treatment of a rare disease, childhood leukemia. In the first activity, students meet Jason and Kim, parents of a daughter named Hanna, who has been diagnosed with childhood leukemia. Students perform a simulated Web search to learn about the disease. They must sift through different Web hits to find relevant and accurate information about the disease. In considering a genetic cause of the disease, students perform a karyotype analysis on each family member. In the second activity, students are introduced to treatments for leukemia. They design a clinical trial to guide the treatment of the disease. Finally, students watch a brief video (or, for classes using the print version, act out an interview) of a leukemia survivor discussing what it’s like to live with the disease.

Major Concepts

  • Much medical information can be found on the Internet; however, this information must be examined carefully to assess its relevance and accuracy.
  • Lack of appearance in a family history does not mean that a disease doesn’t have a genetic cause.
  • Leukemia is a cancer of the white blood cells.
  • Clinical trials have greatly improved the survival rates of children with leukemia.

Objectives

After completing this lesson, students will

  • have used a simulated Web search to learn about the cause, symptoms, and diagnosis of childhood leukemia;
  • have performed a karyotype analysis to diagnose leukemia;
  • have designed and tested a clinical trial for treating childhood leukemia; and
  • have considered the challenges associated with living with leukemia.

Teacher Background
Consult the following sections in Information about Rare Diseases and Scientific Inquiry:
2.0 The Impact of Genomics on Rare Diseases
3.0 Rare Infectious Diseases
4.0 Rare Diseases Caused by Environmental Toxins
5.3 Childhood Leukemia

In Advance

Web-Based Activities

Activity Web Component?
1 Yes
2 Yes

 

Photocopies, Transparencies, Equipment, and Materials

Photocopies and Transparencies
Activity 1: An Unwelcome Diagnosis
For Classes Using the Web-Based Activity:
1 transparency of Master 4.1
1 copy of Masters 4.2 and 4.5 for each student
1 transparency and 1 copy for each student of Master 4.3
1 copy of Master 4.4 for each pair of students
For Classes Using the Print-Based Activity:
1 transparency of Master 4.1
1 copy of Masters 4.2, 4.5, 4.11, and 4.12 for each student
1 transparency and 1 copy for each student of Master 4.3
1 copy of Masters 4.4 and 4.10 for each pair of students
Activity 2: Clinical Trials
For Classes Using the Web-Based Activity
1 transparency of Master 4.6
1 copy of Masters 4.7, 4.8, and 4.9 for each pair of students
For Classes Using the Print-Based Activity:
1 transparency of Master 4.6
1 copy of Masters 4.7, 4.8, 4.9, 4.13, 4.14, 4.15, and 4.16 for each pair of students
2 copies of Master 4.17 for the class
Equipment and Materials
For Activities 1 and 2, Web-based versions, students will need computers with Internet access.

Preparation

Activities 1 and 2

WWW Logo

For classes using the Web version, verify that the computer lab is reserved for your class or that classroom computers are set up for the activities.

Refer to Using the Web Site for details. Check that the Internet connection is working properly.

Log on to the Web Portion of Student Activities section at

http://science.education.nih.gov/supplements/diseases/student

Select “Lesson 4: The Importance of Medical Research.”



Procedure

Note: This is an Elaborate lesson. It gives students an opportunity to take what they have learned about rare diseases and scientific inquiry from the previous lessons and apply it in a new setting. In the first activity, students place themselves in the role of a parent whose child has just been diagnosed with childhood leukemia. They perform a simulated Web search to learn about the disease. This activity is designed to help students hone their skills in evaluating information for relevance and accuracy. The genetic link to the disease is made real to students by having them perform a simple karyotype analysis.

In the second activity, students exercise their understandings of scientific inquiry in the context of clinical trials. Designing a fair test is a common inquiry skill. We selected childhood leukemia because it is a rare disease that has a genetic cause. It’s a serious disease, but, at the same time, it represents a real success story in the application of medical research to treatment.

The activity includes a graph that shows how survival rates for children with leukemia have dramatically improved over the past few decades. The lesson concludes with a video (or a role-play) of a young woman who has come through treatment for the disease and is now pursuing a medical education. The inclusion of this story is designed to give students an opportunity to empathize with someone who has had leukemia and also to leave them with the vision of a positive outcome.

Activity 1: An Unwelcome Diagnosis

Estimated time: 100 minutes

1.

Begin the lesson by explaining that students will investigate a case study involving a child with a rare disease.

This case study introduces the use of clinical trials to obtain evidence about which treatment options are most effective. It’s not important that students understand the clinical trials process. Instead, clinical trials provide a real-life example of how the practice of science (especially proper experimental design) can help improve people’s health.

2.

Display Master 4.1, Doctor Visits. Ask for volunteers to read aloud each section of text.

NSES Logo Content Standard C: Disease is a breakdown in structures or functions of an organism. Some diseases are the result of intrinsic failures of the system. Others are the result of damage by infection by other organisms.

3.

Ask students how they would feel if they were Hanna’s parent and received this disturbing news. Ask, “What would you do now that you have learned that your daughter has been diagnosed with leukemia?”

Students’ responses will vary. Some students may suggest getting a second opinion. Others may suggest researching cancer treatment centers. Accept all answers and guide the discussion to the need to obtain more information.

4.

Explain that although the doctor described childhood leukemia and answered their questions during the office visit, Jason and Kim were so upset that they didn’t take notes or remember much of what they were told. After returning home with Hanna, they performed an Internet search on leukemia.

5.

Ask students,

  • “If you were Hanna’s parent, what information would you want to have about the disease?”
  • “Where could you find the information that you want?”

Make a list on the board of the types of information about leukemia the students request. Students may mention a variety of sources for this information, including their doctors, books, television programs, the Internet, and, possibly, friends and family who have had to cope with the disease.

6.

Give each student one copy each of Master 4.2, Internet Search Results, and Master 4.3, Evaluating Internet Search Results. Instruct students to view the list of hits on Master 4.2 and follow the instructions on Master 4.3 to rank the hits from most helpful to least helpful.

This step is designed to challenge students to sort through information related to leukemia and decide

  • which hits are most likely to contain the information they want and
  • which hits are likely to contain information that is accurate and unbiased.

There is no single correct answer to ranking these eight hits. Rather, you should see whether students can sift through the lists to identify one or two of the best hits. Likewise, students should be able to identify another couple of hits as clearly not helpful to providing the information they want.

In this activity, students are ranking hits based on relevance and accuracy. There are, however, other criteria that students should use to assess the usefulness of Web sites. For example, the site should present information that is up to date, and the information should be as free of bias as possible, such as the bias associated with promoting a product or service.

Answer key for Web hits on Master 4.2, Internet Search Results

  1. Federal Center for Cancer Research

    Information about leukemia, its causes, symptoms, diagnosis, and treatment ...

    Hit 1 is from a fictional U.S. government research organization, the Federal Center for Cancer Research. The Federal government, however, does support medical research, primarily through the National Institutes of Health (NIH). For example, the Office of Rare Diseases Research (http://rarediseases.info.nih.gov/) and the National Cancer Institute (http://www.cancer.gov/) are parts of NIH and provide accurate medical information resources for the general public. Such government sites post information that has been reviewed by experts and is labeled “no commercial bias,” which means that the information presented hasn’t been selected to promote the use of any particular product or service. Such sites are a logical place to begin to learn about a rare disease.

  2. My Leukemia Blog

    Living with Cancer: Reflections and remembrances of a cancer survivor ...

    Personal blogs can provide a window into the life of someone who has a rare disease. The person may or may not choose to include medical information as part of the blog. Furthermore, any medical information on the blog may reflect a possibly incomplete understanding by the author. Although such blogs can be helpful resources, they are not the best place to begin to learn about a rare disease.

  3. The Cancer Research Center at Lincoln State University

    Breast cancer, Prostate cancer, Leukemia, Lymphoma, ...

    Research centers based at universities often provide medical information to the public. The information is reviewed by experts for accuracy. Often, the posted information is tied to the research interests of individual scientists and may be too specific to be a starting point for searching about a rare disease.

  4. Information about Leukemia from the American Blood Cancer Society

    Cells of the blood, Stem cells and leukemia, White blood cells and bacteria ...

    Hit 4 is from a patient support group. Although the American Blood Cancer Foundation is fictional, a large number of patient-support organizations exist to promote medical research and support for people with rare diseases. In the case of leukemia, the Leukemia and Lymphoma Society (http://www.leukemia.org/hm_lls) is a very useful resource that provides reliable disease information as well as a variety of patient services. Such sites are a logical place to begin to learn about a rare disease.

  5. Leukemia—Medhealthopedia: The Do-It-Yourself Encyclopedia

    Leukemia is a form of cancer that is ...

    Medhealthopedia is a fictional Web site that provides medical information to the public in a manner similar to Wikipedia. On such a site, the information posted is written collaboratively by users of the site. The information is often reliable, but there is no assurance that experts have reviewed it or that it is free of commercial bias.

  6. Cancer drugs for less! Leukemia

    Order drugs from overseas to treat leukemia and save!

    Hit 6 is included as a reminder that some information about disease on the Internet is more concerned with making money for someone than with providing objective medical information.

  7. Fed approves new drug to treat leukemia

    Medical Business Weekly (Washington, DC)—The Food and Drug Administration today approved Hamilton Pharmaceutical’s drug Arresta for the treatment of leukemia ...

    Hit 7 is from a business publication. Although the information is likely to be accurate, it only describes one specific development in the field of leukemia research and is not a good place to begin to learn about the disease.

  8. Leukemia: Definition from Medical Jargon.com

    leukemia—A form of cancer involving the white blood cells. White ...

    Hit 8 comes from a medical dictionary and only provides a brief definition of the disease.

check mark

As students report how they ranked the hits from the simulated Web search, you have an opportunity to assess how well they use their critical-thinking skills to evaluate information for its relevance and accuracy.

7.

Display Master 4.3. Ask for volunteers to report how they ranked the Web hits.

Students’ responses will vary. Allow several volunteers to report their rankings with explanations of their reasoning. Remember that the precise ranking of the Web sites is not important. Ideally, students will recognize that Hits 1 and 4 are the best places to begin to learn about leukemia. Hits 2, 3, and 5 can also be useful, but the information may not be as relevant or as accurate as that from Hits 1 and 4. Some students may reason that Hit 8, which provides a definition, is a good place to start. Hits 1 and 4, however, will also provide a definition along with a lot of other useful information. Hits 6 and 7 are clearly not very useful.

WWW Logo

In classrooms using the Web version of the activity:

8-w.

Arrange the students in pairs. Give each pair one copy of Master 4.4, Summarizing Information about Leukemia. Explain that student pairs will go to their computers and access information about leukemia from Hits 1 and 4 from the Internet search. Pairs should summarize on Master 4.4 the information from both Web hits.

Computers should be at this URL:

This is a menu page that contains a link for this activity.

9-w.

Direct the pairs to their computer stations and instruct them to click on “Lesson 4: The Importance of Medical Research,” then “Activity 1: An Unwelcome Diagnosis,” and then “Activity 1: Simulated Web Search.”

“Activity 1: Simulated Web Search” contains information found on Hits 1 and 4, which were listed on Master 4.2. These are the hits judged to be the best places to begin a search for information about leukemia.



In classrooms using the print version of the activity: open book

8-p.

Arrange the students into pairs. Give each pair one copy each of Master 4.4, Summarizing Information about Leukemia, and Master 4.10, Information about Leukemia.

9-p.

Explain that student pairs should look at the information on Master 4.10 and summarize it on Master 4.4.

Master 4.10 contains information found on Hits 1 and 4, which were listed on Master 4.2. These are the hits judged to be the best places to begin a search for information about leukemia.

10.

After students have completed the tasks, reconvene the class. Ask whether students have any questions about the information they found from the Internet search.

Clarify any confusion and misunderstandings. If students ask about the case of leukemia, ask them to hold on because the class is about to consider that question.

11.

Ask students to recall the three causes of disease.

If necessary, ask guiding questions to bring out the three causes: infectious agents, heredity (genetics), and exposure to environmental toxins.

12.

Ask, “What types of information would you want to have to decide which of the three causes of disease applies to leukemia?”

Students may suggest information about a family history of leukemia and about exposure to toxic substances or pathogens.

13.

Explain that the parents, Jason and Kim, have two children: Hanna, who was just diagnosed with leukemia, and her older brother, Rick, who is healthy. There is no history of leukemia in the family. Ask, “Does this rule out genetics as the cause of leukemia?”

Most students will conclude that it does. At this time, accept all answers.

14.

Ask, “What about environmental exposure or infections?”

Some students may remark that Hanna shows signs of infection. Point out that the rest of the family is infection free. Also, if Hanna had been exposed to a dangerous substance in her environment, we might also expect that the rest of the family had also been exposed, but they remain healthy.

15.

Acknowledge that so far, there isn’t good evidence to suggest a cause for Hanna’s leukemia. Return to the idea of genetics. Ask students to recall Information about Leukemia from the American Blood Cancer Society. Ask, “What happened to a stem cell that led to leukemia?”

Students should recall that a single stem cell acquired mutations and began to grow out of control, producing large numbers of unhealthy white blood cells.

Note: Since your students have a limited understanding of genetics, they may believe that mutations are something that only took place many years ago. You may need to stress the idea that mutations are happening now and can cause disease. Explain that cells have mechanisms that detect and correct mutations, but in rare cases, these mechanisms fail.

16.

Explain that although people sometimes inherit mutations from their parents, new mutations happen as well. Mutations in DNA can occur from exposure to sunlight or to substances in the environment, or sometimes they occur just because the cell makes a DNA-copying mistake during cell division that is not corrected. If mutations occur in genes associated with cell growth, cancer can result.

This is an opportunity to have students think back to Lesson 3, which dealt with Marfan syndrome and a genetic mutation. Both diseases have a genetic association. If you think it would be helpful ask, “How are they similar? How are they different?”

NSES Logo

Content Standard C: Hereditary information is contained in genes, located in the chromosomes of each cell. Each gene carries a single unit of information. An inherited trait of an individual can be determined by one or by many genes, and a single gene can influence more than one trait. A human cell contains many thousands of different genes.

17.

Explain that in some genetic disorders, the effects of mutations can be so large that they change the number and appearance of the chromosomes. Scientists call a photograph of chromosomes under a microscope a karyotype. Give each student one copy of Master 4.5, Karyotype.

You may need to help students understand the idea of a chromosome. You can explain that the DNA in each cell is arranged in packages called chromosomes. Each different chromosome contains a single molecule of DNA.

18.

Explain that students first need to see what a normal karyotype looks like before they can understand what a karyotype with a large mutation looks like. Instruct students to read the information on Master 4.5 and answer the question at the bottom.

While students are reading the handout, circulate and answer any questions they may have. For example, you may need to explain that the karyotype is made by squashing cells and taking a picture of the chromosomes through a microscope. Then, the photograph is cut up, and the chromosomes are rearranged in pairs to make it easier to see abnormal patterns.

Students may observe differences in the shapes of chromosome pairs in the karyotypes, but these shapes result from how the chromosomes were positioned when the cells were squashed and do not represent genetic mutations. A normal karyotype has 22 pairs of numbered chromosomes as well as a pair of sex chromosomes (X and Y). A male has one X chromosome and one Y chromosome. A female has two X chromosomes and no Y chromosome. The individual whose karyotype is depicted here is male because both an X and a Y chromosome are present.

19.

Explain that in the case of leukemia, the karyotype would be expected to show three, instead of the normal two, copies of one or more of the numbered (nonsex) chromosomes.

Students should pay attention to the numbers of each chromosome. The presence of three copies of a chromosome is abnormal and helps diagnose leukemia.

WWW Logo

(For print version, skip to Step 20-p.)

In classrooms using the Web version of the activity:

20-w.

Direct student pairs back to their computers. Explain that they will first observe karyotypes prepared from blood samples taken from each of Hanna’s family members. Instruct students to predict whether the karyotype for each family member will appear normal or abnormal.

Students should make predictions for Jason and Kim (Hanna’s parents), Hanna, and Rick (Hanna’s brother). They should recall that Hanna is the only family member with leukemia and, therefore, only her karyotype should appear abnormal.

Note: To reinforce the role of the sex chromosomes, you may want to ask students to identify the sex of each family member from the person’s karyotype.

21-w.

Instruct student pairs to click on “Lesson 4: The Importance of Medical Research,” then “Activity 1: An Unwelcome Diagnosis,” and then “Activity 1: Karyotypes.” Students will see a karyotype from the parents, Jason and Kim, as well as from Hanna and her brother, Rick. Students should record in their notebooks whether each karyotype is normal or abnormal and whether the evidence supports their predictions.

22-w.

Explain that the link labeled “View All of Hanna’s Karyotypes” will display three karyotypes from Hanna. The first karyotype was taken from her blood sample as before, the second was from her cheek cells, and the third, from her hair follicles. As before, instruct student to predict whether each karyotype will be normal or abnormal.

Students should predict that the karyotype from Hanna’s blood sample will appear abnormal, as it was earlier. Some students may not realize that the abnormal chromosomes are limited to the white blood cells. They will see, however, that the karyotypes from Hanna’s cheek cells and hair follicles are normal.

check mark

Evaluating karyotypes taken from different body tissues allows you to assess how well students understand the basic idea of cancer, namely, that the disease begins with mutations in a single cell in one part of the body.

23-w.

Ask, “How can you account for the appearance of the karyotypes taken from these three different tissues?”

Guide the discussion to bring out that the leukemia started with a single stem cell in the bone marrow that went on to produce a large population of unhealthy white blood cells, each with an abnormal karyotype. In contrast, the cheek cells and hair follicle cells are unaffected by leukemia and show normal karyotypes.

End of Web-based activity.



In classrooms using the print version of the activity: open book

20-p.

Explain that students will look at karyotypes prepared from blood samples taken from each of Hanna’s family members. Ask students to predict whether the karyotype for each family member will appear normal or abnormal and to record in their notebooks whether the evidence supports their predictions.

Students should make predictions for Jason and Kim (Hanna’s parents), Hanna, and Rick (Hanna’s brother). They should recall that Hanna is the only family member with leukemia and, therefore, only her karyotype should appear abnormal.

Note: To reinforce the role of the sex chromosomes, you may want to ask students to identify the sex of each family from the person’s karyotype.

21-p.

Give each student pair one copy of Master 4.11, Family Karyotypes. Instruct students to examine the karyotypes and note whether their predictions were confirmed.

If any pairs struggle with this task, remind them that each numbered chromosome should exist as a pair. If a third copy of any chromosome is present, it represents a mutation and helps diagnose leukemia.

22a-p.

Explain that students will now look at three different karyotypes, all from Hanna. One karyotype is taken from her blood as before, one is from her cheek cells, and another, from her hair follicles. As before, instruct students to predict whether each karyotype will be normal or abnormal and to record their predictions in their notebooks.

Students should predict that the karyotype from Hanna’s blood sample will appear abnormal, as it was earlier. They likely will predict that the karyotpes from her cheek cells and hair follicles will also be abnormal.

22b-p.

Give each student pair one copy of Master 4.12, Hanna’s Karyotypes. Instruct students to examine the karyotypes and note whether their predictions were confirmed.

Some students may not realize that the abnormal chromosomes are limited to the white blood cells.

23-p.

Ask, “How can you account for the appearance of the karyotypes taken from these three different tissues?”

Guide the discussion to bring out that the leukemia started with a single stem cell in the bone marrow that went on to produce a large population of unhealthy white blood cells, each with an abnormal karyotype. In contrast, the cheek cells and hair follicle cells are unaffected by leukemia and show normal karyotypes.

check mark Evaluating karyotypes taken from different body tissues allows you to assess how well students understand the basic idea of cancer, namely, that the disease begins with mutations in a single cell in one part of the body.


Activity 2: Clinical Trials

Estimated time: 50 minutes

1.

Display Master 4.6, Another Doctor Visit. Ask for volunteers to read aloud each section of text.

Ethical concerns cause the design of clinical trials to sometimes differ from that of animal studies. If a treatment for a disease is known to have some benefit, then it is unethical to replace that treatment with another one whose value is unknown.

2.

Explain that doctors often compare the effectiveness of cancer treatments by looking at the percentage of patients who are still alive five years after treatment. This helps explain why a series of clinical trials takes so long to improve survival rates.

3.

Explain that students will now go back in time to the year 1970 and play the roles of doctors trying to improve the survival rates of children with leukemia. Still working in their pairs, students will have the opportunity to design, carry out, and assess the effectiveness of a clinical trial.

Over the past 50 years, steady progress has been made in improving the survival rates for children with leukemia. We chose the period around 1970 for this activity because one specific treatment (of the central nervous system, or CNS) led to a very significant gain in survival rate. Students will see the value of clinical trials when they examine survival rates over time on Master 4.9, Survival Rates for Children with Leukemia.

4.

Give each student pair one copy of Master 4.7, Treating Leukemia. This handout describes the treatment options students can include in the clinical trial:

  • Three different drugs (A, B, and C) are available. Each drug has been shown to improve the survival rates of patients taking its standard dose. Research also indicates that the best results are achieved when the three drugs are used in combination.
  • For each drug, three different doses are available:
    – standard dose
    – increased dose
    – decreased dose
  • The CNS treatment follows the drug treatment described above. It involves irradiating the patient’s head with X-rays while drug C (methotrexate) is injected into the spinal fluid. This approach is intended to kill cancer cells that may have escaped the effects of the earlier drug treatment and are lurking in the CNS.

WWW Logo

(For print version, skip to Step 5-p.)

In classrooms using the Web version of the activity:

NSES Logo

Content Standard A: Students should develop general abilities, such as systematic observation, making accurate measurements, and identifying and controlling variables.

5-w.

Explain that student pairs will use the computer to design and carry out a clinical trial. Before moving to the computers, make the students aware of the following:

  • The standard therapy (control) for treating leukemia is a combination therapy using the standard doses of drugs A, B, and C.
  • Pairs select the characteristics (drug doses and use or nonuse of the CNS treatment) of the therapy they want to compare with the standard treatment.
  • After students select the treatment, they submit it, and the trial design is analyzed by the computer software. If the trial design is appropriate, then the trial is approved, and the pair can run the trial and learn the results. If a flaw is found in the trial design, then students have an opportunity to correct it and go on to run the trial.

In designing the clinical trial, students may be tempted to use more of everything. Remind students that each treatment is associated with side effects that are sometimes very harmful.

Although proper trial design involves a number of aspects, we are focusing on just one—control of variables. Students should understand that a proper design involves changing just one variable while keeping other variables constant relative to the comparison (control) group of patients. Students must remember that their proposed treatment will be compared with the standard treatment (using drugs A, B, and C at their standard doses without the CNS treatment).

  • Pairs that decide to use the CNS treatment must keep drugs A, B, and C at the standard doses.
  • Pairs that decide not to use the CNS treatment can change the dose of one of the three drugs while keeping the other two drugs at the standard doses.

Note: After students submit a design that is approved, run the trial, and get the results, they can try other designs by simply changing their selections and resubmitting a new design.

check mark

As students design and test the clinical trials, you have an opportunity to assess how well they understand the concept of controlling variables.

6-w.

Give one copy of Master 4.8, Designing a Clinical Trial, to each student pair. Instruct students to use this handout to record the treatment options they select as well as the trial results (survival rate data) and conclusions they draw from the data.

7-w.

Explain that in a clinical trial such as this, the experimental treatment is compared with the standard treatment. Ask, “Should the clinical trial also include a group that receives no treatment?”

Students’ responses may vary. Students who think just in terms of good experimental design may respond that including a no-treatment group would better indicate how well the experimental treatment performs. Others may point out that it would not be fair to withhold treatment from a group of patients. In fact, the latter view prevails. For ethical reasons, a no-treatment group would not be included in the design of such a clinical trial.

8-w.

Direct the students back to their computers and instruct them to click on “Lesson 4: The Importance of Medical Research,” then “Activity 2: Clinical Trials.”

  • Students will see the treatment options and boxes where they can make their selections.
  • After selecting the treatment options, students click the “Submit” button to have the trial design analyzed.

If the design is judged to be appropriate, then a letter will appear that instructs the students to proceed with the clinical trial. A “Run treatment” button appears. When it is clicked, the trial results are shown on a graph of survival over time.

If the design is judged to not be appropriate, then a letter will appear that reminds the students to change just one variable at a time. A “Try again” button appears. When it is clicked, the treatment options reappear, and the pair has an opportunity to redesign the trial.

When doctors carry out clinical trials, they first submit the study design to a committee called an institutional review board (IRB). The IRB members discuss the proposed study and decide whether it is designed correctly and meets the ethical standards for experimenting with humans.

9-w.

Give pairs about 15 minutes to run the clinical trial, record the results, and draw a conclusion.

The results of each clinical trial are presented as a graph with the percentage of surviving patients on the y-axis and time (in years) on the x-axis. One line on the graph corresponds to the standard treatment (control), and a second line corresponds to the experimental treatment group. On the basis of these data, students should recommend either the standard treatment or the experimental treatment. Students should provide evidence that supports their recommendation.

Continue with Step 10.



In classrooms using the print version of the activity: open book

5-p.

Explain that pairs will design and carry out a clinical trial. Make the students aware of the following:

  • The standard therapy (control) for treating leukemia is a combination therapy using the standard doses of drugs A, B, and C.
  • Student pairs select the characteristics (drug doses and use or nonuse of the CNS treatment) of the therapy they want to compare with the standard treatment.
  • After students select the treatment, they submit it to you for analysis. If the trial design is appropriate, then approve the trial and give the pair the results. If you find a flaw in the trial design, then give students an opportunity to correct it before proceeding.

In designing the clinical trial, students may be tempted to use more of everything. Remind them that each treatment is associated with side effects that are sometimes very harmful.

NSES Logo

Content Standard A: Students should develop general abilities, such as systematic observation, making accurate measurements, and identifying and controlling variables.

Although proper trial design involves a number of aspects, we are focusing on just one—control of variables. Students should understand that a proper design involves changing just one variable while keeping other variables constant relative to the comparison (control) group of patients. Students must remember that their proposed treatment will be compared with the standard treatment (using drugs A, B, and C at their standard doses without the CNS treatment).

  • Student pairs that decide to use the CNS treatment must keep drugs A, B, and C at the standard doses.
  • Pairs that decide not to use the CNS treatment can change the dose of one of the three drugs while keeping the other two drugs at the standard doses.

6-p.

Explain that in a clinical trial such as this, the experimental treatment is compared with the standard treatment. Ask, “Should the clinical trial also include a group that receives no treatment?”

Students’ responses may vary. Students who think just in terms of good experimental design may respond that including a no-treatment group would better indicate how well the experimental treatment performs. Others may point out that it would not be fair to withhold treatment from a group of patients. In fact, the latter view prevails. For ethical reasons, a no-treatment group would not be included in the design of such a clinical trial.

check mark

As students design and test their clinical trials, you have an opportunity to assess how well they understand the concept of controlling variables.

7a-p.

Give each student pair one copy of Master 4.8, Designing a Clinical Trial. Instruct students to

  • use Master 4.8 to record the treatment options they select and
  • submit their design to you for evaluation.

Students will need only about five minutes to discuss the trial design and make their selections.

7b-p.

Explain that a clinical trial must be approved by an institutional review board (IRB) before it is carried out. The IRB determines whether the trial is both ethical and properly designed. As each pair submits a clinical trial design, check that only one variable is being tested.

A correct design will vary the dose of a single drug or will keep all three drugs at the standard doses and test the effect of the CNS treatment.

8-p.

After each pair has submitted a properly designed clinical trial, explain that the trial was performed, and you have the results. Give each student pair the appropriate handout:

  • Pairs that chose to test the dose of drug A receive Master 4.13, Changing the Dose of Drug A.
  • Pairs that chose to test the dose of drug B receive Master 4.14, Changing the Dose of Drug B.
  • Pairs that chose to test the dose of drug C receive Master 4.15, Changing the Dose of Drug C.
  • Pairs that chose to test the effect of the CNS treatment receive Master 4.16, Central Nervous System Treatment.

The results of each clinical trial are presented as a graph with the percentage of surviving patients on the y-axis and time (in years) on the x-axis. One line on the graph corresponds to the standard treatment (control), and a second line corresponds to the experimental treatment group.

9-p.

Instruct student pairs to summarize the data on Master 4.8 in the box labeled “Clinical Trial Results.” On the basis of the results, students should recommend treating Hanna with the standard treatment or the experimental treatment. They should state their recommendation and explain their reasoning in the box labeled “Conclusion from the Clinical Trial.”

If pairs chose to vary the dose of one of the three drugs, the results will show little difference between the standard treatment (control) and the experimental treatment (altered dose). Students should look at the graph on the handout and estimate the five-year survival rates for the control and experimental groups of patients.

If pairs chose to test the effect of the CNS treatment, they will see a significant difference between the control and experimental groups.

10.

Reconvene the class and ask for volunteers to report which treatment they compared with the standard treatment and to indicate whether their treatment was better or worse than the standard treatment.

Keep track of and display results as they are reported. Changing the dose of one of the three drugs used to treat leukemia produces only modest differences when compared with the standard treatment. In contrast, the CNS treatment produces much greater gains in the survival rate.

11.

Give each student one copy of Master 4.9, Survival Rates for Children with Leukemia. Explain that the doctor showed this graph to Jason and Kim to help them understand how effective clinical trials have been in improving the survival rates of children with leukemia.

Master 4.9 is a graph depicting how survival rates of children with leukemia have improved over the past 50 years. Ask questions to gauge students’ understanding of the graph. The main point of the graph is that studies carried out in the past showed five-year survival rates that were lower than studies conducted more recently. This means that the results of earlier clinical trials have been successfully used to improve the survival rates of patients.

12.

Ask students to think back to the Web search they performed during the first part of the lesson. Remind them that they evaluated the results to find the hits most likely to give them relevant and accurate information about childhood leukemia. Ask, “What other results from the Web search could give us a different type of perspective about childhood leukemia?”

Some students will likely suggest that the leukemia blog would provide a patient’s perspective on the disease.

WWW Logo

(For print version, skip to Step 13-p.)

In classrooms using the Web version of the activity:

13-w.

Acknowledge that blogs and videos created by cancer survivors can offer an important perspective on what it’s like to live and cope with leukemia. Conclude the lesson by explaining that students will watch a brief video called “Hailey’s Story.” It was made by a young woman who was diagnosed with childhood leukemia when she was in middle school. Before directing the pairs to their computers, instruct students to write in their notebooks some questions that they would like to ask Hailey about her experiences.

14-w.

Direct the students to their computers and instruct them to click on “Lesson 4: The Importance of Medical Research,” and then “Activity 2: Hailey’s Story.”

The video is brief, five minutes long. If you have the ability to project the computer image, it may be simpler to watch the video as a group.

15-w.

After student pairs have watched the video, reconvene the class. Ask for volunteers to describe their reactions to the video and how it addressed (or did not address) the questions they wrote in their notebooks.

During the video, Hailey mentions that the Leukemia and Lymphoma Society presented her with the Spirit of Tom Landry Award. Tom Landry was the coach of the Dallas Cowboys football team. He died from leukemia in 2000.

Hailey mentions that she wants to fight cancer by becoming a pediatric oncologist. You may need to explain to the class that a pediatric oncologist is a doctor who treats cancer in children.

The video will not answer all of the students’ questions. Suggest that they perform a Web search to access information from foundations and patient support groups that can answer their questions.

Note: In the video, Hailey mentions that more than 12,000 children and teenagers will be diagnosed with cancer this year and that about 1 in 3 will die from it. Students may find this confusing since the graph on Master 4.9 shows a current survival rate of about 90 percent. Explain that the lower survival rate Hailey mentioned comes from combining the survival rates from all forms of cancer and not just leukemia, which responds better to treatment.

End of Web-based activity.



In classrooms using the print version of the activity: open book

13-p.

Acknowledge that blogs and videos created by cancer survivors can offer an important perspective on what it’s like to live and cope with the illness. Conclude the lesson by explaining that the class will conduct a brief interview with a high school senior who was diagnosed with leukemia when she was in eighth grade.

Note: During the interview, Hailey mentions missing a year of school. As she explains in her video, she missed school while undergoing chemotherapy and kept up with her studies with the help of a tutor.

14-p.

Explain that the interview is based on the words of an actual cancer survivor named Hailey. Ask for one volunteer to ask the questions and another to play Hailey and read her responses.

Students may become interested in Hailey’s story and want to see her video. If so, give them the link to the Web site.

15-p.

Give the student interviewer and the student playing Hailey each a copy of Master 4.17, Interview with Hailey. Instruct the two student actors to come to the front of the room and conduct the interview.

During the interview, Hailey mentions that the Leukemia and Lymphoma Society presented her with the Spirit of Tom Landry Award. Tom Landry was the coach of the Dallas Cowboys football team. He died from leukemia in 2000.

Hailey mentions that she wants to fight cancer by becoming a pediatric oncologist. You may need to explain to the class that a pediatric oncologist is a doctor who treats cancer in children.

16-p.

After the student actors return to their seats, ask for volunteers to describe their reactions to the interview.

Students may still have questions about leukemia. Suggest that they perform a Web search to access information from foundations and patient support groups that can answer their questions.


Lesson 4 Organizer: Web Version

WWW Logo
Activity 1: An Unwelcome Diagnosis
Estimated time: 100 minutes

Page and Step

Explain that students will explore a case study of a child who has a rare disease.
  • Display Master 4.1.
  • Ask volunteers to read paragraphs aloud to the class.
Page 98
Steps 1 and 2
Transparency
Ask, “What would you do now that you have learned that your daughter has been diagnosed with leukemia?” Page 98
Step 3
Explain that after the upsetting visit to the doctor, Jason and Kim performed an Internet search on leukemia. Page 98
Step 4
Ask students:
  • “If you were Hanna’s parent, what information would you want to have about the disease?”
  • “Where could you find that information?”

Page 99
Step 5

Give each student a copy of Masters 4.2 and 4.3. Instruct students to rank on Master 4.3 the usefulness of the hits listed on Master 4.2. Page 99
Step 6
Master
Display Master 4.3. Ask volunteers to report how they ranked the Web hits. Page 101
Step 7
Transparency
Arrange the class in pairs. Give each pair a copy of Master 4.4. Explain that students will now access information about leukemia from Hits 1 and 4 from the Internet search and summarize on Master 4.4 what they learn. Page 102
Step 8-w
Master
Instruct students to click on “Activity 1: An Unwelcome Diagnosis” and then on “Activity 1: Simulated Web Search.” Page 102
Step 9-w
WWW Logo
Reconvene the class and ask whether students have questions about the information from the Web hits. Page 102
Step 10
Remind students about the three general causes of disease. Ask, “What types of information would you want to have in order to decide which of the three causes of disease applies to leukemia?” Page 103
Steps 11 and 12
Explain that Jason and Kim have two children: Hanna, who has leukemia, and Rick, her healthy older brother. Also, say that there’s no history of leukemia in the family. Ask,
  • “Does this rule out genetics as the cause of leukemia?”
  • “What about environmental exposure or infections?”

Page 103
Steps 13 and 14

Acknowledge that so far, there isn’t good evidence to suggest a cause for Hanna’s leukemia. Remind students about the Animation about Leukemia. Ask, “What happened to a stem cell that led to leukemia?” Page 103
Step 15
Explain that new mutations happen from exposure to sunlight and substances in the environment or from an uncorrected DNA-copying mistake. Mutations in genes associated with cell growth can lead to cancer. Page 103
Step 16
Explain that mutations can affect the number and appearance of chromosomes and that a photograph of chromosomes under a microscope is a karyotype. Give each student a copy of Master 4.5. Page 104
Step 17
Master
Instruct students to read Master 4.5 and answer the question at the bottom. Explain that in leukemia, we expect a karyotype to show three, not two, copies of one or more of the numbered (nonsex) chromosomes. Page 104
Steps 18 and 19
Direct student pairs back to the computers. Explain that they will view karyotypes from Hanna and her immediate family. Instruct students to predict whether each karyotype will appear normal or abnormal. Page 105
Step 20-w
WWW Logo
Instruct students to click on “Activity 1: An Unwelcome Diagnosis” and then on “Activity 1: Karyotypes.” Page 105
Step 21-w
WWW Logo
Explain that the link labeled “View All of Hanna’s Karyotypes” displays karyotypes from three cell types: blood, cheek, and hair follicles. Ask pairs to predict how each karyotype will appear and to record their predictions in their notebooks. Page 105
Step 22-w
Ask, “How can you account for the appearance of the karyotypes taken from these three different tissues?” Page 105
Step 23-w

 

Activity 2: Clinical Trials
Estimated time: 50 minutes
Page and Step
Display Master 4.6. Ask volunteers to read it aloud. Page 107
Step 1
Transparency
Explain that doctors compare the effectiveness of cancer treatments by looking at the percentages of patients still alive after five years. Page 107
Step 2
Explain that students will go back to the year 1970 and assume the roles of doctors trying to improve the survival rates of children with leukemia by conducting a clinical trial. Page 107
Step 3
Give each student pair a copy of Master 4.7. Explain that it describes the treatment options they can include in their clinical trial. Page 107
Step 4
Master
Explain that student pairs will use computers to design and carry out their clinical trial. Explain that
  • The standard therapy is a combination of the standard doses of drugs A, B, and C.
  • Pairs will select drug doses and the use or nonuse of the central nervous system treatment.
  • They will submit the design for approval. Once approved, the trial will be carried out and students will learn the results.
Page 108
Step 5-w
Give each pair a copy of Master 4.8. Instruct students to record their treatment options, trial results, and conclusions on it. Page 109
Step 6-w
Master
Explain that in a clinical trial such as this, the experimental treatment is compared with the standard treatment. Ask, “Should the clinical trial also include a group that receives no treatment?” Page 109
Step 7-w
Direct students to their computers and instruct them to click on “Activity 2: Clinical Trials.” Student pairs should select the treatments and then click “Submit.”
  • If approved, students can click “Run treatment” and learn the results.
  • If rejected, students can redesign the trial.
  • After recording the trial results, students should make and record their conclusions.
Page 109
Steps 8-w and 9-w
WWW Logo
Reconvene the class. Ask volunteers to report the designs and results of the trials and how their treatment compared with the standard treatment. Page 112
Step 10
Give each student a copy of Master 4.9 and explain that this is what the doctor showed Hanna’s parents to help them see how effective clinical trials have been in improving survival rates of children with leukemia. Page 112
Step 11
Master
Remind students of the Web search they performed about leukemia. Ask, “What other results from the Web search could provide us with a different perspective about childhood leukemia?” Page 112
Step 12
Conclude the lesson by explaining that students will watch a brief video created by a young woman who is a leukemia survivor. Ask students to write in their notebooks some questions they would like to ask the young woman about her experiences. Page 113
Step 13-w
Instruct students to click on “Activity 2: Hailey’s Story” and watch the video. Page 113
Step 14-w
WWW Logo
Reconvene the class and ask volunteers to describe their reactions to the video and to explain how it addressed (or did not address) the questions they wrote in their notebooks. Page 113
Step 15-w

 

Transparency = Involves making a transparency.     Master = Involves copying a master.

WWW Logo = Involves using the Internet.

Lesson 4 Organizer: Print Version

open book
Activity 1: An Unwelcome Diagnosis
Estimated time: 100 minutes
Page and Step

Explain that students will explore a case study of a child who has a rare disease.
  • Display Master 4.1.
  • Ask volunteers to read paragraphs aloud to the class.
Page 98
Steps 1 and 2
Transparency
Ask, “What would you do now that you have learned that your daughter has been diagnosed with leukemia?” Page 98
Step 3
Explain that after the upsetting visit to the doctor, Jason and Kim performed an Internet search on leukemia. Page 98
Step 4
Ask students:
  • “If you were Hanna’s parent, what information would you want to have about the disease?”
  • “Where could you find that information?”
Page 99
Step 5
Give each student one copy of Masters 4.2 and 4.3. Instruct students to rank on Master 4.3 the usefulness of the hits listed on Master 4.2. Page 99
Step 6
Master
Display Master 4.3. Ask volunteers to report how they ranked the Web hits. Page 101
Step 7
Transparency
Arrange the class in pairs. Give each pair a copy of Masters 4.4 and 4.10. Ask students to read Master 4.10 and summarize the information on Master 4.4. Page 102
Steps 8-p and 9-p
Master
Reconvene the class and ask whether students have questions about the information from the Web hits. Page 102
Step 10
Remind students about the three general causes of disease. Ask, “What types of information would you want to have in order to decide which of the three causes of disease applies to leukemia?” Page 103
Steps 11 and 12
Explain that Jason and Kim have two children: Hanna, who has leukemia, and Rick, her healthy older brother. Also, say that there’s no history of leukemia in the family. Ask,
  • “Does this rule out genetics as the cause of leukemia?”
  • “What about environmental exposure or infections?”
Page 103
Steps 13 and 14
Acknowledge that so far, there isn’t good evidence to suggest a cause for Hanna’s leukemia. Remind students about the Animation about Leukemia. Ask, “What happened to a stem cell that led to leukemia?” Page 103
Step 15
Explain that new mutations happen from exposure to sunlight and substances in the environment or from an uncorrected DNA-copying mistake. Mutations in genes associated with cell growth can lead to cancer. Page 103
Step 16
Explain that mutations can affect the number and appearance of chromosomes and that a photograph of chromosomes under a microscope is a karyotype. Give each student a copy of Master 4.5. Page 104
Step 17
Instruct students to read Master 4.5 and answer the question at the bottom. Explain that in leukemia, we expect a karyotype to show three, not two, copies of at least one of the numbered (nonsex) chromosomes. Page 104
Steps 18 and 19
Explain that students will now view karyotypes from Hanna and her immediate family. Ask students to predict whether each karyotype will appear normal or abnormal and to record in their notebooks whether the evidence supports the predictions. Page 106
Step 20-p
Give each student pair a copy of Master 4.11. Ask them to note whether their predictions were confirmed. Page 106
Step 21-p
Master
Explain that students will now look at three different karyotypes from Hanna: from her blood, cheek, and hair follicles. Ask pairs to predict how each karyotype will appear and to record their predictions. Page 106
Step 22a-p
Give each student pair a copy of Master 4.12. Ask students to note whether their predictions were confirmed. Page 106
Step 22b-p
Master
Ask, “How can you account for the appearance of the karyotypes taken from these three different tissues?” Page 106
Step 23-p

 

Activity 2: Clinical Trials
Estimated time: 50 minutes
Page and Step
Display Master 4.6. Ask volunteers to read it aloud. Page 107
Step 1
Transparency
Explain that doctors compare the effectiveness of cancer treatments by looking at the percentages of patients still alive after five years. Page 107
Step 2
Explain that students will go back to the year 1970 and assume the roles of doctors trying to improve the survival rates of children with leukemia by conducting a clinical trial. Page 107
Step 3
Give each student pair a copy of Master 4.7. Explain that it describes the treatment options they can include in their trial. Page 107
Step 4
Master
Tell students that they will work in their pairs to design and carry out a clinical trial. Explain that
  • the standard therapy is a combination of the standard doses of drugs A, B, and C,
  • pairs will select drug doses and the use or nonuse of the central nervous system treatment, and
  • they will submit the design to you for analysis.
Page 110
Step 5-p
Explain that in clinical trials, an experimental treatment is compared with the standard treatment. Ask, “Should the clinical trial also include a group that receives no treatment?” Page 110
Step 6-p
Give each pair a copy of Master 4.8. Instruct students to record on it the treatment options they select, and then to submit it to you. Explain what an Institutional Review Board is, and check that student designs test only one variable. Page 111
Steps 7a-p and 7b-p
Master
Once you’ve approved all the clinical trial designs, give each student pair the appropriate handout (Master 4.13, 4.14, 4.15, or 4.16) Page 111
Step 8-p
Master
Ask student pairs to summarize the data and their conclusions and reasoning on Master 4.8. Page 111
Step 9-p
Reconvene the class and ask volunteers to report which treatment they used and whether it was better than the standard one. Page 112
Step 10
Give each student a copy of Master 4.9 and explain that this is what the doctor showed Hanna’s parents to help them see how effective clinical trials have been in improving survival rates of children with leukemia. Page 112
Step 11
Master
Remind students of the Web search they performed about leukemia. Ask, “What other results from the Web search could give us a different perspective about childhood leukemia?” Page 112
Step 12
Acknowledge that blogs and videos by cancer survivors can offer important perspectives on what it’s like to live with that illness. Conclude by explaining that the class will conduct a brief interview with a high school senior who was diagnosed with leukemia in eighth grade. Page 114
Step 13-p
Ask for one volunteer to play Hailey and one to play the interviewer, give each of them a copy of Master 4.17, and have them conduct the interview in front of the class. Page 114
Steps 14-p and 15-p
Master
Ask volunteers to describe their reactions to the interview. Page 114
Step 16-p

 

Transparency = Involves making a transparency.     Master = Involves copying a master.

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