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CHAPTER 10
Behavioral Factors in Cancer
Lecture Outline
I. What Is Cancer?
Cancer is a group of diseases characterized by the presence of new cells that grow and
spread beyond control. Cancer cells can affect nearly any part of the body, and a large number of
chemical, physical, and biological agents can cause cancer cells to develop. Different cancer
cells share a common characteristic; namely, the presence of neoplastic tissue, or cells that have
II. The Changing Rates of Cancer Deaths
During the past decade, cancer deaths have leveled off and even declined (see Figure
10.1). The decline of 22% for men and 15% for women since 1990 is due partly to better
treatment and longer survival of cancer patients and partly to a lower incidence of cancer. The
drop in incidence of cancer can be traced to a decline in smoking and a generally improved diet.
A. Cancers with Decreasing Death Rates
Cancer of the lungs, breast, prostate, and colon/rectum account for about half of all
cancer deaths in the United States, and mortality rates for each of these sites are currently
declining. Lung cancer accounts for about 14% of all cancer cases and about 28% of all
cancer deaths—figures that reveal the deadliness of lung cancer. (See Figures 10.2 and 10.3
B. Cancers with Increasing Incidence and Mortality Rates
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Although incidence death rates for the four leading cancers—lung, breast, prostate, and
colorectal—are declining, not all cancer rates are decreasing. Liver cancer is quite lethal,
with a death rate nearly twice as high as its incidence rate. This cancer is increasing among
both men and women. Melanoma, a potentially fatal form of skin cancer, is increasing among
men and women. Cancer of the esophagus is increasing among men yet falling among
women.
III. Cancer Risk Factors Beyond Personal Control
Although most cancers result from behavioral factors, some develop from environmental
and inherent conditions.
A. Inherent Risk Factors for Cancer
Inherent risks for cancer include family history, ethnic background, and advancing age.
1. Ethnic Background
African Americans have a greater incidence and mortality from cancer than European
2. Advancing Age
3. Family History and Genetics
Mutations of the BRCA gene increase risk of breast cancer, but only a small
percentage of cancer cases can be traced to genetics. Studies indicate differences in the
incidence of cancer for identical twins. However, genes can present a predisposition that
interacts with other factors to increase a person’s risk for cancer.
B. Environmental Risk Factors for Cancer
Environmental risk factors, such as exposure to radiation, asbestos, pesticides, and other
chemicals play a relatively minor role in cancer deaths.
IV. Behavioral Risks Factors for Cancer
The two most important behavioral risks for cancer are smoking and diet, which account
for about two thirds of cancer deaths in the United States.
A. Smoking
Smoking-related cancers are a major source of death. Lung cancer is the leading cause of
cancer deaths, but many cancers of the breast, mouth, pharynx, and esophagus have also been
associated with smoking.
1. What Is the Risk?
23.3, meaning that male smokers have about a 23 times greater risk of death from lung
cancer than nonsmokers. Also, the risk of cancer from smoking is dose related—the more
2. What Is the Perceived Risk?
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B. Diet
In general, the same foods that have been linked to coronary artery disease are also
associated with cancer.
1. Foods That May Cause Cancer
Foods suspected of causing cancer, or carcinogenic, include food that is spoiled or
2. Foods that May Protect Against Cancer
Some foods have been promoted as providing protection against cancer, but overall
diet may be more important. A diet rich in fruits and vegetables could reduce many types
of cancer and save millions of lives per year. Establishing the value of any specific
C. Alcohol
Heavy drinking can produce cirrhosis of the liver, and cirrhotic livers are prone to
develop cancer. Some estimates suggest that about 2% of breast cancer cases in the United
States are due to alcohol. Alcohol seems to have a synergistic relationship with cigarette
smoking, making heavy drinkers who also smoke heavily at a much greater risk of cancer of
the larynx than either smokers who don’t drink or drinkers who don’t smoke.
D. Sedentary Lifestyle
Physical activity probably offers some protection against cancer, specifically, colon,
breast, lung, pancreas, and endometrial cancers. In addition, an active lifestyle is beneficial
for maintaining a healthy weight, which lowers the risk of cancer.
E. Ultraviolet Light
Both cumulative exposure and occasional severe sunburn may cause skin cancer, which
F. Sexual Behavior
Sexual practices put both women and men at increased risk for various cancers. Sexual
behavior plays a role in cancers that result from AIDS, such as Kaposi’s sarcoma, non-
Hodgkin’s lymphoma (although most people with non-Hodgkin’s lymphoma do not have
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AIDS), and invasive cervical cancer. For men, having a large lifetime number of female sex
partner, early age of first intercourse, and prior infection with gonorrhea increases their risk
of prostate cancer. For women, early age at first intercourse and a large number of sex
partners increase the risks for cancer of the cervix, vagina, and ovaries.
G. Psychosocial Risk Factors in Cancer
Psychosocial factors are not strong risks for cancer. Negative emotionality and repression
of emotion show a weak relationship to poor cancer outcomes, and this weak relationship is
the strongest psychosocial predictor of cancer.
V. Living with Cancer
More than a million Americans are diagnosed with cancer each year, and most of these
people will experience feelings of fear, anxiety, and anger as a result of their diagnosis.
A. Problems with Medical Treatments for Cancer
Cancer treatments are notorious for their negative side effects, but psychological
B. Adjusting to a Diagnosis of Cancer
Most cancer patients have difficulty adjusting to their diagnosis, and depression is a
common reaction. Over time, cancer patients may make a good adjustment; those who
experience severe depression may have a poorer disease outcome, and optimism is an
advantage. However, expressing emotion—including negative emotion—is a better coping
strategy than repressing emotion.
C. Social Support for Cancer Patents
The support of spouses, family members, and friends can help cancer patients by
D. Psychological Interventions with Cancer Patients
Psychological interventions for cancer patients are oriented toward improving their
quality of life, reducing stress, and helping them develop healthier behaviors. Large-scale
studies have failed to indicate that psychological interventions lengthen survival time for
cancer patients.
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Exploring Health on the Web
The topic of cancer is as widely represented as heart disease on the Internet, and your students
have many resources they can explore to learn about risks for cancer, types of cancer, current
research and news releases, traditional and alternative treatments, and organizations that provide
services to cancer patients and their families.
Many newspapers, magazines, and blogs profile people coping with cancer. One example
appears at the link above. Here, a 23-year old copy editor details her story after she gets a
diagnosis of incurable cancer. The site chronicles Alicia Parlette’s story from diagnosis to death,
and students will see many of the issues discussed in the text prominent in Alicia’s story.
Suggested Activities
Personal Health Profile — Risks for Cancer
How Big a Role Does Diet Play in Cancer?
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Perceived versus Actual Risks
Cancer is the second leading cause of death in the United States as well as in most other
industrialized nations, but people’s perception of its frequency is often greater than its actual
occurrence. In addition, people may be inaccurate in their perceptions of the death rate from
various cancers, imagining that some cancers are more and other less likely to be fatal than they
actually are. The standard way to represent deadliness is in the 5-year survival rate—that is, the
percent of people diagnosed with a cancer that are alive after 5 years. These rates vary from very
low (for pancreatic and lung cancer) to quite high (for cervical and skin cancer).
Determining the Frequency of Smoking Combined with Drinking
Smoking and drinking act synergistically, multiplying the risk for cancer. To determine
the frequency of combining these two behaviors, have your students make a frequency count of
the people who are both smoking and drinking in places where alcohol is served (bars, parties,
etc.). The students should also count how many people are present in each of these situations.
Also, compare the number of smokers who are drinking to those who are smoking in a place that
does not serve alcohol (student center, vending machine area, etc.).
Using the χ2 statistic to analyze the different frequency of smokers in each situation,
compare the number of smokers who are drinking to those who are only smoking. Use this
activity to enlarge your discussion of how smoking raises the risk for cancer, but smoking
combined with drinking multiplies the risk.
Genes and Cancer
As described in Chapter 10, the BRCA 1 and BRCA 2 genes are tied to breast cancer
Optimism and Cancer
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Video Recommendations
Wit (2010) – Wit is a movie based on a play by Margaret Edson and chronicles the diagnoses and
treatment of a woman who has ovarian cancer. Many clips of the movie can be found on
YouTube and provide memorable examples of the psychosocial issues that surround coping with
cancer.
From Films for the Humanities & Sciences:
Top 10 Cancer Myths (2003) presents the results of a survey of 1,000 adults and the most
common misconceptions about cancer.
Cancer-Causing Agents (2007) examines the carcinogens in the air, soil, and water. This
program features an interview with activist Erin Brockovich as well as experts in the area of
environmental exposure to carcinogens.
Health News and Interviews: Cancer Video Clips (2007) presents a collection of brief video clips
that cover a wide variety of cancers, risk factors, and treatments.
Voices: Cancer Patients Speak Out (2004) presents the experience of cancer from the viewpoint
of five patients with different cancers. In addition, experts comment on cancer treatments and
quality of life issues.
Videos from the Web:
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Multiple Choice Questions
1. Cancer
a. is a relatively new disease, first diagnosed during the latter half of the 19th
century.
b. is a group of diseases marked by the growth and spread of new cells.
c. is due to a parasite that attacks new cells.
d. is due almost completely to contact with dangerous chemicals.
2. The main difference between benign and malignant tumors is
a. that malignant cells can invade surrounding tissues.
b. the ability of benign tumors to metastasize.
c. the size of the tumor each produces.
d. that benign tumors attack nearly any tissue, whereas malignancies are specific to
animal (including human) tissue cells.
3. Metastasis refers to
a. the growth rate of benign tumors.
b. the spread of malignancy from one part of the body to another.
c. a type of breast cancer.
d. a particularly deadly form of lung cancer.
4. All of the following are types of malignant growths EXCEPT
a. carcinoma
b. leukemia
c. lymphoma
d. benign
5. Janet was told that her cancer originated in her blood, and therefore she is likely to have a
form of _________.
a. leukemia
b. sarcoma
c. carcinoma
d. lymphoma
6. ________ is a form of cancer that arises from cells in connective tissues, such as bones or
muscles.
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a. Leukemia
b. Sarcoma
c. Carcinoma
d. Lymphoma
7. From about 1900 until the mid-1990s, cancer death rates in the United States
a. rose steadily.
b. exceeded death rates from cardiovascular disease.
c. dropped steadily.
d. remained quite constant.
8. Since the mid-1990s, cancer deaths in the United States
a. remained quite constant.
b. rose steadily.
c. began to drop.
d. leveled off.
9. Which of these best explains the recent drop in cancer death rates in the U.S.?
a. better treatment procedures
b. better techniques for diagnosing cancer
c. changes in lifestyle
d. both a and c contributed to the drop.
10. Most cancer deaths in the United States are caused by
a. pollution.
b. genetic factors.
c. diet and smoking.
d. the sun.
11. Since about 1993, cancer death rates in the United States have
a. increased for men, but decreased for women.
b. decreased slightly.
c. increased sharply for women, but remained about the same for men.
d. increased sharply for both men and women.
12. In the United States, _________ cancer accounts for about 28% of all cancer deaths but
only about 14% of cancer cases.
a. lung
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b. breast
c. prostate
d. colon/rectal
13. Which cancer has the highest incidence (but not the highest death rate) for women in the
United States?
a. lung
b. breast
c. cervical
d. colon
14. In the United States, both prostate cancer and breast cancer
a. have the highest incidence and the highest mortality rates.
b. have low incidence and low mortality rates.
c. have high incidence but relatively lower death rates.
d. none of these.
15. In the United States, _____ cancer has the second highest death rate of any cancer.
a. lung
b. colorectal
c. breast
d. prostate
16. The second leading cause of cancer deaths in the United States is
a. lung cancer.
b. breast cancer
c. stomach cancer.
d. colorectal cancer.
17. During the 1990s, death rates from lung cancer for men
a. began to decline.
b. increased slightly.
c. increased sharply.
d. were exceeded by death rates from prostate cancer for the first time since the 19th
century.
18. Which of these ethnic groups has the strongest risk for cancer deaths?
a. Hispanic Americans
b. European Americans
c. African Americans
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d. Asian Americans
19. The factor LEAST likely to explain why people of different ethnic background have
different rates of cancer deaths is
a. biology.
b. knowledge about cancer and its treatment.
c. access to medical care.
d. level of adherence to health recommendations.
20. All of the following cancers have increased in recent years EXCEPT
a. liver cancer.
b. melanoma.
c. colorectal cancer.
d. rates for all of these cancers have increased
21. All of the following cancers have decreased in recent years EXCEPT:
a. liver cancer.
b. prostate cancer.
c. breast cancer.
d. lung cancer.
22. The decline in the breast cancer death rate is due mainly to
a. decline in alcohol consumption
b. decline in cigarette smoking
c. improvements in early detection and treatment
d. increases in women using hormone replacement therapy.
23. Which of these is the strongest inherent risk factor for cancer?
a. advancing age
b. ethnic background
c. gender
d. family history
24. Testicular cancer
a. has age-related risks similar to other cancers.
b. varies from the age-related risk of other cancers, striking middle-aged men more
often than older men.
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c. varies from the age-related risk of other cancers, striking young men more often
than older ones.
d. has a higher mortality rate than lung or prostate cancer.
25. Recent evidence suggests that genetic factors play the biggest part in the development of
_____ cancer.
a. breast
b. prostate
c. lung
d. colorectal
26. Women whose mothers developed breast cancer before age 40, compared with those
whose mothers did not have cancer, are
a. about two times more likely to develop breast cancer.
b. about five to ten times as likely to develop breast cancer.
c. no more likely to have breast cancer.
d. much less likely to have breast cancer.
27. The BRCA gene is related to breast cancer;
a. women with this gene are about 20 times as likely to develop breast cancer as
women without this gene.
b. women with a mutated form of this gene are vulnerable to breast cancer.
c. this gene is responsible for about 50% of breast cancer cases.
d. women with this gene will develop breast cancer, and 40% of them will do so
before age 35.
28. With regard to radiation and cancer, evidence suggests that
a. any exposure to radiation greatly increases one’s risk for cancer.
b. any exposure to radiation slightly increases one’s risk for cancer.
c. dental and medical personnel who work with X-rays have a significantly greater
risk of cancer.
d. long-time employment in a nuclear power plant increases cancer death rates.
29. Across all cancers, _______ are due to inherited genetic mutations.
a. 1-2%
b. 5-10%
c. 15-20%
d. 25-30%
Behavioral Factors in Cancer
30. When examining the cancer risk of exposure to radiation, living in a community near a
nuclear power plant __________.
a. increases risks for all cancers.
b. increases risks for mouth, throat, and lung cancer.
c. increases risk for all cancers in men.
d. does not increase risk for cancers.
31. ________ risk factors for cancer, include genetics and family history, whereas ______
risk factors include smoking and diet.
a. Inherent; behavioral
b. Inherent; environmental
c. Behavioral; inherent
d. Behavioral; environmental
32. African Americans have greater incidence rates for most cancers compared to other
ethnic groups. These ethnic discrepancies in incidence rates are most likely due to
a. behavioral factors
b. genetic factors
c. biological factors
d. racial discrimination
33. _______ is the leading cause of death among children aged 1-14 years and ______ is the
second leading cause of death for that age group.
a. Cancer; unintentional injury
b. Cancer; cardiovascular disease
c. Unintentional injury; cancer
d. Cardiovascular disease; cancer
34. Women with a mutated form of the BRCA 1 gene are as much as ______ as likely to
develop _______ cancer as someone who has the non-mutated form of the gene.
a. seven times; lung
b. seven times; breast
c. twice; breast
d. twice; lung
35. The number one preventable cause of death in the United States is
a. high serum cholesterol.
b. cigarette smoking.
c. AIDS.
d. accidents.