# Science Olympiad» Disease Detectives Event » National Event Exercises Skin Cancer Module: Practice Exercises

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Module 4: Interpreting Cancer Statistics, Part I
Skin Cancer Glossary

Objective
Exercises
Crude Incidence Rates

## Module 5: Interpreting Cancer: Statistics Surveillance, Epidemiology, and End Results (SEER)

### Objective: Learn about cancer registries and how to use and interpret the data.

Visit the SEER Web site at http://seer.cancer.gov/.

### Exercises

From the "Choose a Cancer Site" pop-up menu at the bottom of the SEER homepage, click on "Lung and Bronchus."

As you scroll down this page, you can choose to view data on incidence, mortality, survival, and prevalence. You can also jump ahead to a certain section by using the buttons at the top of the page.

Step 1: Find the heading "Incidence" and the sub-heading "Line Charts Displaying Age-Adjusted (1970 U.S. Standard Population) SEER Incidence Rates for Individual Years."
Step 2: Click on "Nine Registries for 1973-1998" By Sex [All Ages].

Questions

1. Define incidence as used in this chart. What is in the numerator? What is in the denominator?

2. What does "age-adjustment" mean in this context? (Tip: The "standard population" used is listed above the graph, under "Selections.")

3. What was the age-adjusted incidence of lung and bronchus cancer for the total population in 1973? 1985? 1998? (Tip: The "total population" is males and females taken together. See the color key below the graph.) What was the age-adjusted incidence for men in 1973? 1985? 1998? What was the age-adjusted incidence for women in 1973? 1985? 1998?

4. How can you explain the trends in lung and bronchus cancer incidence in men compared to women over the past 25 years?

### B. Crude Incidence Rates

Step 1: Go back to the "Lung and Bronchus Cancer" site page.
Step 2: Find the heading "Incidence" and the subheading "Line Charts Displaying Crude ("Age-Specific") Total U.S. Incidence Rates."
Step 3: Click on "Nine Registries" for 1989-1998 by [Race and Sex].

Questions

1. What does "age-specific" mean in this chart? What is in the numerator and in the denominator? How are "age-adjusted" incidence rates different from "age-specific" incidence rates? What might be the advantage of looking at age-specific rates on lung and bronchus cancer?
2. What happens to the incidence of lung and bronchus cancer as people get older?
3. What can you say about lung and bronchus cancer incidence rates among men compared to women? Among black men compared to white men? Among black women compared to white women? What factors might explain these differences?

Step 1: Go back to the "Lung and Bronchus Cancer" site page.
Step 2: Find the heading "Mortality" and the sub-heading "Line Charts Displaying Age-Adjusted (1970 U.S. Standard Population) Total U.S. Mortality Rates for Individual Years."
Step 3: Click on "1969-1998" By Sex [All Ages].

Questions

1. Define "mortality" as used in this chart.

2. What year had the highest overall (male+female) age-adjusted mortality rate from lung cancer? The highest mortality rate for men? For women? How might you explain these differences?

3. Compare and contrast the trends in age-adjusted incidence rates of lung and bronchus cancer with the trends in age-adjusted mortality rates for this cancer. (Refer to the data on age-adjusted incidence rates in Exercise A above.) Would you expect the two graphs to be similar? What can comparing these two graphs tell you about how treatable or how fatal a given disease is?