Cancer is a developmental disease with four major types (carcinoma, lymphoma, sarcoma, leukemia). Risk is shaped by health behaviours (smoking, diet, sun exposure, screening) and compounded by cultural factors including SES, access to care, and health literacy. Stress interacts with the immune system to influence cancer progression, and psychological adjustment matters for outcomes.
Difficulty: Intermediate | Prerequisites: Biopsychosocial model, basic immune system concepts (Ch. 4), health belief model
This chapter applies the biopsychosocial framework to cancer specifically. It covers the biological basics (types of cancer), the cultural and socioeconomic factors that create disparities in incidence and survival, the psychological experience of a cancer diagnosis, and the health behaviours that either raise or lower risk. The stress-immune system connection from Chapter 4 reappears here in a major way. You should be comfortable with the health belief model and basic immune system function before tackling this material.
Carcinoma
Cancers that start in the skin cells or surface layers (epithelial tissue) of the body and can spread from there. Think of it as cancer of the body's lining and covering tissues. The most common category.
Lymphoma
Cancers of the lymphatic system. Hodgkin's lymphoma is the best-known subtype. In simple terms, cancer that attacks the immune system's own network.
Sarcoma
Cancer of the muscles, bones, or cartilage. These are relatively rare compared to carcinomas.
Leukemia
Cancer of the blood or bone marrow. Unlike solid tumours, leukemia involves abnormal blood cell production.
Fatalism
The belief that cancer is not survivable or that it is a predetermined punishment. This outlook can result in depression and delayed treatment-seeking. Common in some religious and ethnic groups.
Natural Killer (NK) cells
Immune cells that play a role in fighting cancer. Stress directly impairs NK cell function, which is one pathway by which psychological states affect cancer progression.
Health belief model
A framework for predicting health behaviours based on perceived susceptibility, perceived severity, perceived benefits, perceived barriers, cues to action, and self-efficacy. Applied here to explain screening behaviour.
Carcinoma: Starts in skin cells or surface/epithelial layers. Can spread from there. Most common type.
Lymphoma: Cancers of the lymphatic system (e.g. Hodgkin's lymphoma).
Sarcoma: Cancer of muscles, bones, or cartilage.
Leukemia: Cancer of the blood or bone marrow.
Low SES, limited healthcare access, and fewer screenings all increase cancer impact.
Rural populations are less likely to receive screenings.
Minority racial/ethnic groups in the US are more likely to be poor and medically underserved, leading to limited quality care, fewer screenings, and later-stage diagnoses (when the disease is more serious and less treatable).
Higher rates of tobacco use, physical inactivity, obesity, excessive alcohol use, and lower rates of breastfeeding are found in certain communities. Environmental exposures (asbestos, toxic air pollution, carcinogens, UV) also vary by geography and occupation.
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 for triple-negative breast cancer.
Breastfeeding is thought to help equalise these rates.
Differences in knowledge about risk factors and symptoms are documented among people of low SES, African Americans, Arabs, Latinos, and Chinese Americans.
Some religions and ethnic groups view cancer as a punishment for sin.
Fatalism (belief that cancer is not survivable) can result in depression and avoidance of treatment.
Cancer is a developmental disease: it often develops when a person is young but is diagnosed later in life. Children can get cancer too. Younger children tend to show more external behaviours but report greater quality of life; adolescents show the opposite pattern.
There is limited direct proof that psychological processes cause cancer, but there is evidence that psychological states affect bodily systems, health behaviours, screening behaviours, and adherence to treatment. The pathway is indirect: psychology shapes behaviour, and behaviour shapes risk.
There is a strong relationship between stress and cancer progression. More stress is associated 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, particularly those experiencing pain or with low social support.
Optimism improves adjustment to diagnosis. Avoidant, repressive, or unexpressive coping styles are linked to poorer outcomes.
Social support is associated with delayed cancer progression.
Finding meaning in the cancer experience is linked to better adjustment.
Stress directly impairs Natural Killer (NK) cell function and is also associated with unhealthy coping behaviours (smoking, drinking, poor diet), creating a dual pathway of harm.
Smokers have a 9x increased risk of getting cancer. Culturally, African Americans, South Americans, Latin Americans, and Native Americans use tobacco more often. Vaping and e-cigarettes are an emerging concern.
Diets high in fat and animal fat, and low in fibre, increase risk. The Mediterranean diet is shown to carry the least cancer risk.
78% of skin cancers would be preventable if people wore sunscreen before age 18. About 45% of Americans who live to 65 will develop skin cancer.
Early detection leads to earlier-stage diagnosis and better outcomes. Screening behaviour follows the health belief model: perceived susceptibility and perceived benefits drive action, while barriers reduce it.
Self-exams are a key component.
Non-European Americans, people of low SES, cultures that emphasise modesty, and groups that fear cancer (Latinas, African Americans) tend to use screenings less.
Students often think psychology directly causes cancer. The evidence is indirect: psychological states influence behaviours and immune function, which in turn affect cancer risk and progression.
Fatalism is sometimes confused with depression. Fatalism is a belief system (cancer is not survivable, or is a punishment); depression is a clinical condition. The two can co-occur, and fatalism can lead to depression, but they are distinct.
Many students assume breast cancer is most common in African American women overall. In fact, incidence is highest in European American women and women of high SES. African American women have the highest rates specifically among young women with triple-negative breast cancer.
Optimism is sometimes treated as a cure-all. It improves adjustment to diagnosis, but it does not prevent cancer.
⚠️ Know the four types of cancer (carcinoma, lymphoma, sarcoma, leukemia) and be able to identify each from a description.
⚠️ The link between stress and NK cells is a commonly tested pathway. Stress impairs NK cell function, which affects the body's ability to fight cancer.
⚠️ Understand why screening rates differ across cultural groups, linking back to the health belief model.
⚠️ Be ready to explain the dual pathway of stress and cancer: direct (immune suppression) and indirect (unhealthy coping behaviours).
⚠️ Breast cancer statistics by race/ethnicity are frequently tested. Know the European American vs. African American distinction.
⚠️ The 9x increased risk for smokers and the 78% sunscreen prevention statistic are the kind of numbers exams test.
True or False: Sarcoma is the most common type of cancer. (False. Carcinoma is the most common.)
Fill in the blank: Stress directly impairs _______ cells, which play a role in fighting cancer. (Natural Killer / NK)
True or False: The Mediterranean diet is associated with the highest cancer risk. (False. It is associated with the least risk.)
Fill in the blank: Roughly ___ of cancer patients meet APA criteria for a psychological disorder. (Half / 50%)
True or False: Wearing sunscreen before age 18 could prevent 78% of skin cancers. (True)
Q: Which type of cancer originates in the blood or bone marrow?
A: Leukemia.
Q: Through what two pathways does stress affect cancer progression?
A: Directly, by impairing Natural Killer (NK) cell function, and indirectly, by promoting unhealthy coping behaviours such as smoking and poor diet.
Q: Why do minority racial/ethnic groups in the US tend to receive later-stage cancer diagnoses?
A: They are more likely to be poor and medically underserved, with limited quality care and fewer screenings, so cancers are caught later when they are more serious and less treatable.
Q: A patient believes her cancer is God's punishment and that nothing can be done. What concept does this reflect, and what psychological outcome can it lead to?
A: Fatalism. It can result in depression and avoidance of treatment.
Q: Which coping styles are associated with poorer cancer outcomes?
A: Avoidant, repressive, or unexpressive coping styles.
The stress-immune system connection here links directly to the HIV/AIDS chapter (Ch. 12), where psychoneuroimmunology explains how stress management affects disease progression. The health belief model, which explains screening behaviour, is a foundational concept from earlier in the course. Cultural disparities in cancer care mirror the patterns in the Patient-Provider Communication chapter (Ch. 9).
cancer types, carcinoma, lymphoma, sarcoma, leukemia, breast cancer, triple-negative breast cancer, cultural variations in cancer, cancer disparities, cancer screening, health belief model, fatalism, Natural Killer cells, NK cells, stress and cancer, psychoneuroimmunology, cancer and immune system, Mediterranean diet, sunscreen prevention, tobacco and cancer, cancer and SES, PSY 320, health psychology