Drawing conclusions requires additional information not apparent on the graph. "Causes and Risk Factors" which appears on the student page has been adapted from Murphy, Gerald P., Morris, Lois, and Lange, Dianne, eds. Informed Decisions, American Cancer Society, 1997, 85-92.

Answers to Student Questions

The graphs below show some trends in deaths due to cancer in the United States. Study the graph and answer these questions. The two graphs separate the data for men and women. Answers are given in red.

1. How are the two graphs different from each other?
   One is for men and one is for women.

2. Name the variable plotted on the x-axis of the graphs. What is the y variable?
   x = time (years)
   y = deaths per 100,000 people in the U. S. population

3. What is the range of years included on the graphs?
   1950–1992

4. Approximately what was the death rate for U.S. men:
   a. from lung cancer in 1960?
   40 per 100,000

   b. from prostate cancer in 1980?

   23 per 100,000

   c. from stomach cancer in 1990?

   8 per 100,000

5. Approximately what was the death rate for U.S. women:
   a. from lung cancer in 1960?
   6 per 100,000

   b. from breast cancer in 1990?

   28 per 100,000

   c. from stomach cancer in 1990?

   4 per 100,000

6. In which year (approximately) was the death rate highest for:
   a. women from ovarian cancer
   1960 or 1968

   b. men from stomach cancer?

   1950

   c. men from lung cancer?

   1989

   d. women from lung cancer?

   1992

7. The death rate from which form(s) of cancer increased from 1950 to 1992? The rate for which form(s) decreased in that time period?
   Women:
   Increase = lung, ovary, pancreas
   Decrease = uterus, stomach, colon/rectal, breast

   Men:

   Increase = lung, prostate, pancreas, colon/rectal
   Decrease = stomach, liver

8. The death rate for which form of cancer increased the most from 1950 to 1990? Which form decreased the most?
   Lung cancer increased most for both men and women.
   For women, cancer of the uterus decreased most.
   For men, cancer of the stomach decreased most.

9. Can you think of some reasons why deaths from some forms of cancer increased and some decreased from 1950 to 1990? (See Causes and Risk Factors in the Student version.)

10. What are some reasons that death rates are different for men and women for the same forms of cancer? (See Causes and Risk Factors in the Student version.)

For more information, at other Web sites...

Cancer Resource Center — from the American Cancer Society.

Relevant National Science Education Standards

Unifying Concepts and Processes — The activity is centered on observing and interpreting measured changes and constancy in cancer data.

Science in Personal and Social Perspectives — The activity shows the involvement of science in facing a personal and community health challenge, specifically cancer.

History and Nature of Science — By drawing conclusions from observed data the students experience an important aspect of the nature of scientific knowledge.

Relevant New Jersey State Science Education Standards

5.1	The activity requires the students to analyze data and draw conclusions from them.
5.3	The activity is mathematically-based.
5.5	The activity is concerned with the functioning of the human organism, specifically regarding cancer and cancer prevention.