Cancer: Behavioral Factors

• Chapter 10 is about behavioral factors in cancer. The chapter focuses on five basic questions:
• What is cancer?
• Are cancer death rates changing?
• What are the inherent and environmental risk factors for cancer?
• What are the behavioral and psychosocial risk factors for cancer?
• How can cancer patients be helped in coping with the disease?

Cancer: definition and types

• Cancer refers to a group of diseases characterized by uncontrolled growth and spread of new cells.
• Cancer originates from a change in a cell, known as a mutation.
• The mutated cell continues to grow and reproduces to become a tumor.
• Neoplastic tissue cells exhibit unlimited growth, harming the host without providing any benefits.
• Benign neoplastic cells tend to remain localized.
• Malignant neoplastic cells tend to spread and establish secondary colonies through metastasis, spreading through blood or lymph.
• Sarcomas arise from connective tissues like bone, muscles, and cartilage.
• Carcinomas originate in epithelial tissues lining surfaces like skin, stomach, and mucous membranes.
• Leukemias start in blood or blood-forming cells, such as bone marrow stem cells.
• Lymphoma is a cancer of the lymphatic system and is a rarer type of cancer.
• The first three types accounting for 95% of cancers.

Changing Cancer Rates

• People rarely inherit the disease; behavior and lifestyle are primary contributors, allowing cancer rates to change quickly.
• Cancer peaked in 1991, with rates three times higher than in 1900.
• The 1990s marked the first time cancer rates began to decline.
• Decline during 1990s was significant at -25%.

Explanations for Decline

• Better treatment is a possible explanation for the decline
• Early detection and treatment are also contributors (e.g., prostate and breast cancer).
• Changes in health behaviors, like diet and smoking habits, are factors in cancer decline.
• Lifestyle factors account for about two-thirds of all cancer deaths in the U.S.

Cancers that are Declining

• 50% of all deaths are due to lung, prostate, breast, and colorectal cancer and are declining.
• Lung cancer is the leading cause of death, accounting for 13% of all cancers and 22% of deaths.
• Deaths from 1990-2017 declined.
• Colorectal is the second leading cause of cancer deaths in the U.S.
• Death rates have been declining since 1945, and incidence since 1985.
• There is a racial disparity, with African Americans more likely to receive a diagnosis and die from it compared to European and Hispanic Americans.
• Female breast cancer has the highest incidence in women.
• Accounts for 30% of cancers in women, but not deaths
• Decline after 2001 happened due to decrease in hormone replacement therapy.
• Prostate cancer has the highest incidence in men.
• Deaths not as high as breast cancer in women
• Incidence declined from 2001-2017 (21% fewer new cases).

Cancers that are Increasing

• Liver cancer is deadly, with the death rate twice as high as the incidence rate.
• There's a gender gap, with men having higher incidence rates.
• There's a racial disparity: minorities have higher incidence and death rates than European Americans.
• Pancreatic cancer is deadly; accounting for 3% of all cancers and 7% of all deaths.
• Incidence is rising in men and women.
• Melanoma (potentially fatal form of skin cancer)
• Incidence and death rates are rising in me and women but death rates are declining
  • due to treatment

Risk Factors for Cancer

• An inherent risk factor contributes to the development of cancer.
• One inherent risk factor is racial/ethnic background.
  • African Americans have a higher incidence an death rates in almost every type of cancer than European Americans.
  • Hispanic, Asian, and Native Americans tend to have a lower incidence and death rates when compared to European or African Americans.
  • Diagnoses come at a later stage.
• Another element is advancing age - older people have higher incidence and death rates
  • Gender gap (steep increase around age 65, more so for men)
• The next is genetics/family history
  • Across all cancers, only 5% to 10% are due to inherited genetic mutations
  • The four leading cancers are the ones that are most likely to rise from genetics
  • Multiple genes, with interplay between genetics and behaviors.
• Finally are environmental factors include:
  • Radiation
  • Asbestos
  • Other pollutants

Behavioral Risk Factors for Cancer

• Smoking causes 1 out of 3 cancer deaths
• 25X more likely to get cancer if smoked than never smoked.
• Majority of deaths are from lung cancer, but smoking contributes to many other cancers (> 14).
• Causal relationship between smoking and death rates.
• Effect with pollutants like building materials in one's house has synergistic effect resulting in cancer.
• Diet and weight
• Good news - A diet rich in vegetable and fruits lowers death rates of stomach, esophageal, lung and colorectal cancers.
• Diet improvement from 1999-2012 prevented 1 million deaths.
• Bad news - the American diet is still poor with 12-20% of cancer deaths due to poor diet and sedentary lifestyle.
• Overweight causes colorectal cancer
• Obesity causes 20% of cancer deaths
• Alcohol
• Not as strong a predictor as smoking and diet but increases the risk of stomach, esophagus, breast, and liver cancers.
• Dose-reponse relationship with breast cancer - none is best.
• Synergistic effect with smoking results in cancers of the digestive tract.
• Ultraviolet light
• Linked to skin cancer (cumulative exposure and sunburns)
• Protective behaviors include wearing sunscreen and avoiding tanning beds.
• Mostly benign, but the malignant form is melanoma
• Strong genetic component, especially in light-skinned.
• Sedentary lifestyle is linked to cancers of colon, endometrial, breast, lung, and pancreas.
• Sexual Behaviors
  • AIDS-related cancers include Kaposi's sarcoma.
  • Prostate cancer related to early intercourse.
  • HPV can cause cervical and oral cancers (2x more in men).
  • The HPV vaccine is available for younger adults.

Psychosocial Risk Factors

• A prospective study from Swedish twin registry (Hanson, 2005) found no link between cancer and extraversion OR neuroticism.
• Large-scale studies have only found weak associations.
• Two factors have the strongest relationship.
  • Negative emotionality
  • And tendency to suppress emotions
• These factors related more to diagnosis than development

Medical Treatment Problems

• The top 3 treatments for cancer are stressful, being surgery, radiation, and chemotherapy.
• Common recommendation for cancer, only when cancer has not metastasized.
• Associated with stress, anxiety, and depression,
• The affected patient get less support than patients having surgery for other illnesses.
• This stress and depression can reduce immunity and prolong recovery.
• Some issues with Radiation include severe physical side effects and anticipatory emotions intensifying the experience of side effects.
• Chemotherapy also has severe side effects, with anticipation of the side effects resulting in anxiety, etc.
• Beliefs about nature of disease impact distress and adjustment.

Factors Related to Adjustment to Diagnosis

• Same factors as related to diagnosis\development.
• Optimism: small to moderate amount of variance in emotional adjustment to cancer.
• Sense of mastery is also important
• Together these make up “fighting spirit”, but doesn’t assist long term.

Factors Related to Living Well with Cancer

• Should embrace emotion-focused coping rather than remaining calm
• Emotional anger can be useful/but suppressing
• Marriage - being married is associated with adjustment (better odds of survival)
  • This could be due to economics, emotional, and instrumental support from your partner.
• Other friends and family: could result in improved outcomes
• Avoid subject of cancer, emphasize good emotions
• Support groups (online/face-to-face) can be helpful, particularly for women w lack of support.
• There are two types of psychological interventions:
• Individual
• Group
• Any psychological intervention should increase survival or improve emotional support.
• These interventions can provide short term benefits in terms of distress
  • Won't contribute to survival
  • The only research done so far shows that breast cancer patients have improved immune functioning