7. While students are discussing their new identities, distribute one copy of Master 1.2, Team Summary, to each student.
8. Explain that the students' task in the next few minutes will be to use the Team Summary to summarize information about the lives of the fictitious people in their team. Point out that the descriptions they just read contained information about whether each person had a history of cancer in his or her family. Ask students to use this information to complete Section 1, Family History, on their Team Summary.
Give the students 1-2 minutes to complete this task. If necessary, explain that having a "history of cancer in the family" means having a biological relative (grandparent, parent, sibling, aunt, or uncle) who has or has had cancer.
9. Explain that inside each envelope is a set of four cards that provide additional information about each person's life. Direct students to remove the cards from their envelopes and place them face down on the desks in front of them so that the cards are in sequence, with the card labeled "0-19" years on top and the card labeled "60+ years" on the bottom.
Each student should have four cards. Some of the fictitious people were "born" in the early 1900s and are "old" enough to be 70 or 80; others were born much later (for example, in the 1970s or 1980s). Nevertheless, we have extended these people's lives to 60+ years, even though this time stretches well into the 21st century. This approach allows the activity to illustrate a wide range in choices and health care options across the 20th century. The approach also gives each student a chance to have four cards and participate to the end of the activity.
10. Invite the students to turn over and read the cards labeled "0-19." Give the students a few minutes to share the information they learn with the other members of their teams, then challenge them to use this information to complete the "0-19 years" column in Section 2, Cancer History, of their Team Summary.
To heighten the activity's drama, do not allow students to read all of their cards at once. Insist that the students in each team progress through the life stages in sequence together.
As students begin to read their cards, they may need help understanding how to fill in Section 2 of the Team Summary.
11. Instruct students to turn over the rest of their cards in sequence, share the information the cards contain, then use this information to complete Section 2 of their Team Summary. Challenge the students to look for patterns or trends in the data they are collecting and explain that when the class pools all of its data, the students will be able to determine the degree to which the patterns they see in their team's data also appear in the pooled data.
The black dot that appears on one of the four cards for each person shows when mutations may have occurred that eventually contributed to the development of cancer. Some students may ask what this dot represents. Do not explain the dot at this point. Respond that students will discover the dots' significance at the end of the activity (see Step 16).
12. After the students complete Section 2 of their Team Summary, ask them if they noticed any choices or other risk factors that may be related to the cancer people developed. Instruct students to go back through their cards to identify these factors, then list them in Section 3, Possible Risk Factors, of their Team Summary.
Some of these risk factors are smoking, sun exposure, high-fat diet, early sexual activity, and genetic predisposition for cancer. A major factor that is not specifically noted is aging. The explanation for increased incidence of cancer with aging is explored in Activity 3, Cancer as a Multistep Process.
13. As the teams complete their summaries, distribute one copy of Master 1.3, Drawing Conclusions from the Faces of Cancer, to each student.
14. Display the transparency that you prepared from Master 1.4, Summary Profile of the Faces of Cancer, and explain that you will complete the table as the teams share the information they have collected. Explain that as you complete each row of the table, you will give the teams 2-3 minutes to discuss and record a conclusion they can make from the pooled data.
To illustrate, ask each team to report how many people in that team did and did not have a history of cancer in their families. Then, ask the students what pattern they see in the pooled data and what conclusion it leads them to make. Direct students to write their answers into the space provided on their copies of Drawing Conclusions from the Faces of Cancer.
Students should see that some people have a family history of cancer whereas other people do not. If students have difficulty expressing this idea, ask them whether the number of "yes" answers (the number of people who did have a family history of cancer) equals the total number of people who developed cancer (everyone in the class), and what this discrepancy means.
15. Complete each row of the Summary Profile in turn, first asking teams to share their data with you, then totaling the data and entering them into the table. After you complete each row, give the teams time to discuss and agree on their conclusion and fill it into their worksheets.
In the second row, students should see that the number of people who develop cancer increases with age (that is, the incidence of cancer increases with age). If students have difficulty expressing this idea, you may wish to ask a guiding question such as, "What do you notice about the number of people who develop cancer in each life stage?" Encourage students to write their conclusion as a statement (for example, "The number of people who develop cancer increases with age.").
In the third row, students should see that cancer can develop in almost any tissue and organ in the body. They also may note that some types of cancer are more common than others.
You may wish to ask students whether the fact that no one in this sample developed brain or uterine cancer means no one in the U.S. population gets this type of cancer. Students should recognize that this is not true. You also may wish to invite students to suggest other types of cancer that did not occur in this population and list them under "other" in the third row of the table.
In the fourth row, students should see that some people make choices or experience life events that increase their risk of developing cancer.
Tip from the field test. Students may have difficulty distinguishing factors that increase risk for cancer from those that do not. If students express some uncertainty, ask them how they could find out about risk factors. You may wish to refer students to the Web site for the National Cancer Institute (http://www.nci.nih.gov) as an excellent source for current and reputable information about cancer.
16. Ask whether anyone can suggest what the black dot on each person's set of cards might mean. Entertain several answers. If necessary, explain that these dots represent the period of life during which mutations may have occurred that eventually contributed to the development of cancer. Explain that students will learn more about these mutations in Activity 2. Ask the students to discuss in their teams what they notice about the dots.
Give the students several minutes to look at the dots and discuss what they observe. If students seem to be confused about what they should be noticing, ask them guiding questions such as, "What do you notice about the period of life in which each person's dot occurs and the period in which that person's cancer was detected?"
Be sure that students understand the difference between the period of life in which the mutations associated with the development of cancer occurred and the period in which the cancer was detected. In some cases, the dot appears in the same period of life that the cancer was detected. In most cases, however, the dot appears many years before the cancer was detected.
17. Ask two or three teams to report what they observed about the dots and initiate a class discussion about the significance of these observations.
Help students understand that cancer develops across time and often many years intervene between the first cancerous changes and the symptoms that cause a person to seek medical help.
As part of this discussion, you also may wish to ask students (1) what factors in people's lives improve their chance of recovering from cancer (for example, early detection and treatment); (2) what factors reduce their chances of early detection (for example, poor access to health care, either because of where they live or their socioeconomic status); and (3) what factors increase their chances of early detection (for example, participation in opportunities to be screened for cancer). Challenge students to support their answers by referring to specific people they learned about in this activity.
|Collect and review the students' completed worksheets to assess their understanding of the activity's major concepts.|
18. Close the activity by asking students to complete the Discussion Questions on the bottom of Drawing Conclusions either in class or as homework. Briefly discuss their answers with them at the end of the period or at the beginning of the next.
Question 1 In this activity, all students in the class assumed the role of someone who developed cancer sometime in his or her lifetime. Is this an accurate representation of the risk of cancer among the American population? Explain your answer.
No, this is not an accurate representation. Students should remember the opening exercise in which they learned that current statistics indicate that only 1 in 3 Americans develops cancer sometime in his or her lifetime. Point out that in this activity, students studied 30 people who all got cancer, but this does not mean that everyone will get cancer in his or her lifetime.
Point out as well that students should not extrapolate from the rates of cancer illustrated in the activity. Although the general trends illustrated in these 30 people are accurate (for example, rates for lung, colon, and breast cancer are higher than rates for cervical, pancreatic, and ovarian cancer), rates for other cancers are artificially exaggerated as a result of the small sample size. A striking example of this exaggeration occurs in the case of retinoblastoma. We included retinoblastoma to illustrate an example of a hereditary cancer, even though its incidence in the U.S. population is 1/12,000 to 20,000, not 1/30 as implied in this activity.
|Asking students to name the most important thing they learned challenges them to identify the activitys key ideas. If students have difficulty with this, ask questions based on the objectives in At a Glance.|
Question 2 What explanation can you offer for the observation you made about the incidence of cancer compared with age?
Answers will vary. Some students may suggest that it is related to the fact that cancer develops across time (which they learned when you discussed the black dots with them). Because older people have lived longer, they have a greater chance of developing it. Students will return to this question in Activity 3, Cancer as a Multistep Process.
Question 3 What is the most interesting or surprising thing you learned from this activity? What is the most important? Why?
Answers will vary.
Extend or enrich this activity by asking students to bring to class current newspaper or magazine articles about cancer. Display these in your classroom and, at the close of Activity 5, invite students to comment on them, drawing on what they learned about cancer during the preceding activities.
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