Difficulty: Intermediate | Prerequisites: Biopsychosocial model, basics of stress and coping, health disparities from earlier chapters.
Cancer is the second leading cause of death in the United States and a major focus of health psychology because so many of its risk factors are behavioural: smoking, diet, exercise, sun exposure, and screening habits. This chapter examines how culture, SES, and psychological state shape who gets cancer, when it is caught, and how well people cope with diagnosis and treatment. You should be comfortable with the biopsychosocial model, the stress-immune relationship, and the health disparities material from earlier in the course. The key insight is that cancer is not just a biological event; psychological and social factors influence every stage from prevention to survival.
Cancer develops through a combination of genetic, environmental, and behavioural factors, with stress and the immune system playing a mediating role. Cultural background, SES, and health behaviours (smoking, diet, screening) heavily influence who gets cancer and when it is detected. Roughly half of cancer patients meet criteria for a psychological disorder, and social support is linked to slower cancer progression.
Carcinoma
Cancers that start in skin cells or the surface layers of the body and can spread from there. Think of it as: cancers of the lining tissues.
Lymphoma
Cancers of the lymphatic system, including Hodgkin's lymphoma. In simple terms, cancer that affects the immune system's network of vessels and nodes.
Sarcoma
Cancer of the muscles, bones, or cartilage. Think of it as: cancers of the structural or connective tissues.
Leukemia
Cancer of the blood or bone marrow. In simple terms, the body produces abnormal white blood cells that crowd out healthy ones.
Fatalism
The belief that cancer is not survivable or that getting it is inevitable. This belief can lead to depression and reduced screening behaviour.
Natural Killer (NK) cells
Immune cells that play a role in fighting cancer. Stress directly impairs NK cell function, which is one pathway linking psychological state to cancer progression.
Health Belief Model
A framework that predicts health behaviours based on perceived susceptibility, severity, benefits, and barriers. In cancer, it helps explain why some people screen and others do not.
Carcinoma: starts in skin cells or surface layers; can spread.
Lymphoma: cancers of the lymphatic system (e.g. Hodgkin's).
Sarcoma: cancer of muscles, bones, cartilage.
Leukemia: cancer of blood or bone marrow.
Low SES, limited healthcare access, and fewer screenings all contribute to worse outcomes.
Rural populations are less likely to be screened.
Minority racial/ethnic groups in the US are more likely to be poor and medically underserved, leading to later diagnoses when cancer is more serious and less treatable.
Behavioural risk factors are unevenly distributed: higher rates of tobacco use, physical inactivity, obesity, excessive alcohol use, and lower rates of breastfeeding in some communities.
Environmental exposures: asbestos, toxic air pollution, carcinogens, UV radiation.
Breast cancer has the highest incidence after skin cancer and the second highest mortality rate.
Highest in European Americans and women of high SES.
African American women have the highest rates among young women, particularly triple-negative breast cancer.
Breastfeeding is thought to help equalise rates.
Knowledge gaps about risk factors and symptoms are greater among low-SES populations, African Americans, Arabs, Latinos, and Chinese communities.
Some religions and ethnic groups view cancer as punishment for sin.
Fatalism can result in depression and the belief that cancer is not survivable.
Cancer is a developmental disease: it often develops when young but is diagnosed when older.
Children can get cancer. Younger children tend to show more external behaviours but report greater quality of life; adolescents show the opposite pattern.
Psychological processes have direct effects on bodily systems, health and unhealthy behaviours, screening behaviours, and adherence to treatment (though direct causal proof is limited).
There is a strong relationship between stress and cancer progression: more stress correlates with higher mortality.
A cancer diagnosis itself can cause anxiety, depression, and other psychological disorders. Roughly half of cancer patients meet APA criteria for a psychological disorder, especially those experiencing pain or with low social support.
Optimism improves adjustment to diagnosis. Avoidant, repressive, or unexpressive coping styles are associated with poorer outcomes.
Social support is related to delayed cancer progression.
Finding meaning in the cancer experience is linked to better outcomes.
Stress directly impairs Natural Killer cell function and is also linked to unhealthy coping behaviours (smoking, drinking, poor diet).
Tobacco: Smokers have a 9x increased risk of getting cancer. African American, South American, Latin American, and Native American populations use tobacco more often.
Vaping/e-cigarettes are an emerging concern.
Diet and exercise: Too much fat, not enough fibre, and high animal fat increase risk. The Mediterranean diet is associated with the lowest risk.
Sunscreen: 78% of skin cancers would be preventable if sunscreen were worn before age 18. About 45% of Americans who live to 65 will get skin cancer.
Screenings: Early detection leads to earlier-stage diagnosis and better outcomes. Self-exams are recommended. Screening behaviour follows the Health Belief Model. Non-European Americans, low-SES groups, cultures with modesty norms, and groups that fear cancer (Latinas, African Americans) screen less.
Students often think cancer is purely genetic. It is not: behavioural and environmental factors (tobacco, diet, sun exposure) are major contributors.
Students sometimes assume stress causes cancer directly. The evidence is stronger for stress accelerating cancer progression (via NK cell suppression and unhealthy coping) rather than initiating it.
Students may believe that breast cancer is primarily a disease of older white women. African American women have the highest rates among younger women, particularly for triple-negative subtypes.
Students frequently overlook that fatalism is a culturally shaped belief, not a personality trait. It varies across religious and ethnic groups and directly affects screening behaviour.
⚠️ Know the four types of cancer (carcinoma, lymphoma, sarcoma, leukemia) and be able to match each to its tissue of origin.
⚠️ The stress-NK cell-cancer progression pathway is a key testable concept.
⚠️ Breast cancer demographics: expect a question on incidence by race/ethnicity and SES.
⚠️ Know the 9x risk increase for smokers and the 78% preventability figure for sunscreen before 18.
⚠️ Understand why certain groups screen less (SES, modesty, fear, fatalism) and how the Health Belief Model applies.
⚠️ Roughly half of cancer patients meet APA criteria for a psychological disorder.
True or False: Sarcoma is cancer of the blood or bone marrow. (False: that is leukemia. Sarcoma affects muscles, bones, and cartilage.)
Fill in the blank: Smokers have a ____x increased risk of getting cancer. (9x.)
True or False: Social support has been shown to delay cancer progression. (True.)
Fill in the blank: ________% of skin cancers would be preventable if sunscreen were worn before age 18. (78%.)
True or False: Optimistic patients tend to have poorer adjustment to a cancer diagnosis. (False: optimism improves adjustment.)
Q: A researcher finds that cancer patients who are avoidant and unexpressive about their diagnosis have worse outcomes than those who openly discuss it. What psychological factor best explains this?
A: Coping style. Avoidant, repressive, or unexpressive coping is associated with poorer outcomes, while optimism and social support improve adjustment and may delay progression.
Q: Why do African American women have higher breast cancer mortality rates despite European American women having higher overall incidence?
A: African American women are more likely to be diagnosed with aggressive subtypes (such as triple-negative breast cancer), often at later stages due to lower screening rates and reduced access to care.
Q: How does stress contribute to cancer progression through the immune system?
A: Stress directly suppresses Natural Killer cell activity, which plays a role in fighting cancer. Stress is also associated with unhealthy coping behaviours (smoking, poor diet, alcohol use) that further increase risk.
Q: A 40-year-old Latina woman has never had a mammogram. Using the Health Belief Model, what factors might explain her behaviour?
A: She may have low perceived susceptibility (does not believe she is at risk), cultural modesty norms that act as barriers, fear of the results, or fatalism (the belief that cancer is not survivable regardless).
The stress-immune pathway here ties directly to the HIV/AIDS chapter (Ch. 12), where psychoneuroimmunology explains how stress accelerates disease progression. The cultural disparities in screening and treatment echo the patient-provider communication material (Ch. 9), particularly around SES, acculturation, and delays. The biopsychosocial model applies throughout: cancer is biological in origin but psychological and social in its trajectory.
Cancer types, carcinoma, lymphoma, sarcoma, leukemia, breast cancer, triple-negative breast cancer, cancer screening, mammography, self-exam, Health Belief Model, fatalism, Natural Killer cells, NK cells, stress and cancer, psychoneuroimmunology, cancer and SES, cancer disparities, Mediterranean diet, tobacco and cancer, sunscreen, UV exposure, social support and cancer, coping style, optimism, avoidant coping