Causes and Prevention of Cancer
From Inside Cancer Wiki
Causes and Prevention of Cancer
Lesson Overview
Cancer is the second leading cause of death in the United States accounting for 23.1% of deaths in 2004. Most of us know someone that has been stricken by this disease. What causes cancer and can it be prevented?
This investigation will have you consider risks of cancers and some of the mechanisms that underlie the causes of this disease. You will have the opportunity to explore the website www.insidecancer.org and discuss your findings with fellow students.
The Lesson
Part 1: What do you know about cancer?
Before you use www.insidecancer.org website, work in pairs to answer the following questions concerning what you know about cancer.
1. Risk factors are the characteristics that are thought to contribute to causing cancer. With your partner, list the factors you think are significant cancer causing risk factors?
2. What happens biologically when someone has cancer?
Part 2: Epidemiology of Cancer:
Epidemiology is the field of medicine that investigates the distribution of diseases. The goal is to determine the factors that influence the occurrence of disease. Epidemiologists use many methods to study the nature of disease and understand its spread and distribution. Their methods include data collection, statistical analysis, field investigations, and laboratory techniques to determine cause, distribution, and methods for control and prevention. Cancer is one of those diseases that has been studied to determine who is most at risk, where cancers are highest, the environmental factors victims have in common, and how much risk is increased through exposure to those factors. The goal of health professionals is to then use that knowledge to determine how to reduce the incidence of disease by eliminating exposure to cancer risk factors.
We will use the Inside Cancer web site (www.insidecancer.org) to investigate the incidence of world wide cancer and environmental factors related to cancer. Of course, we need to understand the biological nature of the disease and how those environmental factors disrupt cell homeostasis.
Go to www.insidecancer.org and click on the main section “Causes and Prevention” on the top bar to answer the following:
1. Click on “Overview” to complete the following:
a. What percent of cancer is inherited? __________________________
b. What percent of cancers are caused by synthetic chemicals? _____________________________
c. Click on the last section of the “Overview” and click the arrow for “Cancer Epidemiology”. Search through the various cancers, look at the world regions and the differences in male and female.
1. What cancer is thought to be caused by dietary factors?
2. What cancer is thought to be caused by smoking?
3. What cancer is decreasing due to effective screening (tests to check for cancer)?
4. Which cancer has the highest incidence in areas with high solar input and light skinned people?
5. Can you identify which cancers are significantly different in males versus females?
6. Which cancers would you consider preventable?
2. Go to the Smoking section by clinking on “Smoking” on the left sidebar
a. Review “Lung Cancer Epidemic” and complete the following
1. The five most common cancers in the U.S. and the percent of the total.
2. Review the graph at “Lung Cancer Epidemic” on slide numbers 5-8.
-What contributed most to the increase in cigarette use?
-What contributed to the decline in cigarette use?
3. Review the graph at “Lung Cancer Epidemic” on slide numbers 9-10.
-What is the lag time between the increase in cigarette use and the incidence in lung cancer?
-Hypothesize a reason for the lag time.
3. Click on the “Smoking” sidebar and this time click “Killers in Smoke”
a. The compounds in smoke that cause cancer are known as carcinogens. Identify three major groups of substances that are carcinogens in cigarette smoke.
b. Review the next series of images and label the diagram of the human respiratory system.
c. What does the cigarette smoke do to the respiratory system?
4. Click on the “Inheritance” sidebar and this time click “Cancer gene types”
a. Listen to Dr. Bert Vogelstein’s first video and his description of cancer genes and briefly describe the role of each of the genes that are involved in cancer.
Oncogene:
Tumor suppressor gene:
Stability gene:
b. Listen to Dr. Bert Vogelstein’s second video. How is cancer different from other genetic disease?
Part 3: Pathways to Cancer
Click on the main section on the top bar, “Pathways to Cancer”.
a. Click on the “Overview” and use the animations to help answer the following:
1. What are three things cell signals can do to a cell’s life cycle?
2. How do cancer cells differ from normal cells with regard to cell signals?
3. Cancer cells fail in the normal communication pathways. Review through section 8 in the “Overview” and identify the three regions of the cell involved in cell communication.
4. Working in a small group, make up an analogy to describe the communication pathway in a cell.
5. Using the paper models, trace the pathway for normal cell communication.
6. How can disruptions in the normal pathway lead to cancer?
Part 4: Preventable Cancer
Click on the main section on the top bar, “Causes and Prevention”. Click on the side bar “Sunlight” and review the cancer in these different countries.
a. Which cancer is caused by exposure to sunlight?
b. What are the two most significant factor described in this section contributing to sunlight and cancer?
UV Light and Preventable Cancer
Exposure to sunlight and the cancer risk from UV light can be reduced with protective materials. In this activity, you will design an experiment using UV sensitive beads. UV beads turn from white to color when exposed to UV light. Your instructor will demonstrate the effect of UV on the beads before you begin.
Materials Provided: UV Beads, plastic Petri dishes, glass Petri dish, plastic wrap, sun blocks, sun glass lens, cloth materials, colored lamps, UV lamp (for control)
Design an experiment to test the effectiveness of materials to block UV exposure. Include the following components of experimental design.
Title
Hypothesis
Independent Variable
Dependent Variable
Control Group
Controlled factors
These beads are available at http://www.teachersource.com/LightAndColor/Ultraviolet/UltravioletDetectingBeads.aspx
