1. Cancer and AIDS

2. What is cancer?
Rapid reproduction of irregular cells forming a neoplasm (tumor)
Results from a dysfunction in the cell’s DNA
Tumor cells reproduce at different rates, doubling times ranging from 23 to 209 days.
Because of the varying growth rate of tumor cells, some tumors will take about 2 years to become large enough for detection; whereas others could take 17years. Large individual differences in the rate of cancer growth within different individuals. Also, large differences between species and so animal models are not that helpful in studying cancer. Mice very susceptible to cancer whereas monkeys develop few cancers.

3. Four Types of Cancer Carcinomas - Lymphomas – Sarcomas Leukemias
Malignant neoplasms of the skin and organ cells. About 85% of all cancers.
Lymphomas –
Cancer of the lymphatic system
Sarcomas
Malignant neoplasms of the muscle, bone or connective tissue
Leukemias
Cancers of the blood forming organs (e.g., bone marrow) leading to proliferation of white blood cells.

4. Cancer
Metastasis – migration of cancer cells to other parts of the body.
Metastases – new neoplasms formed after metastasis.
50% of people will live 5 or more years after diagnosis and most of these will be cured.
Cancer death rates increasing, primarily due to increases in lung cancer.

5. Effects
Proliferation of cancer cells at each site interferes with normal cell development and functioning.
Produces pain as it creates pressure on tissues and nerves and blocks flow of body fluids.
Most experience severe pain in later stages.
Severe pain is experienced by about 40% of individuals in the intermediate stages of cancer and in about 70-90% in the end stages of cancer.

6. How does cancer cause death?
Direct by spreading to a vital organ and takes nutrients the organ needs causing the organ to fail.
Indirect by weakening the victim, impairing appetite and immune functioning.

7. Cancer Prognosis and Causes
Prognosis depends on the site and on how early the cancer was detected.
Causes involve an interplay of genetic and environmental factors.

8. Cancer Genetics Genetics appear to play a role in some cancers.
Example - breast, colon, prostate, ovarian
However, environmental factors also run in families (e.g., diet) and so family history of cancer does not necessarily mean that the cancer was due to genetic factors.
In some cases you can test your genes.

9. Cancer & Ethnicity Anglo men – higher rates of bladder cancer.
Hispanics – lowest rates of lung cancer but women have highest rates of cervix cancer.
Blacks – highest rates of prostate cancer.
Japanese – highest rates of stomach cancer.
Chinese Americans lowest rates of liver cancer.
Northern Europeans – high rates of breast cancer.
Not clear the extent to which ethnic differences are due to socio-cultural factors or genetics.

10. Environmental Factors
Smoking
Diet
Radiation
Chemicals
Viral component in some cancers.

11. Age, Gender, and Socio-Cultural Factors
Risk increases with age, especially after middle age.
Gender differences in types of cancers.
Breast cancer more common in women
Blacks and whites have higher rates than other ethnic groups.
Blacks more likely to die with cancer because it tends to get detected later.
The cancer incidence quadruples between 40 and 80 years of age.

12. Diagnosing and Treating Cancer
Physician tests for breast, colon, prostate, skin, testes, cervix.
Self-administered testing for some cancers – breast, skin, testes.

13. CAUTION – Warning Signs of Cancer
Change in bowel or bladder habits.
A sore that does not heal.
Unusual bleeding or discharge.
Thickening or lump in the breast or elsewhere.
Indigestion or difficulty swallowing.
Obvious change in wart or mole.
Nagging cough or hoarseness.

14. Diagnostic Procedures
Blood or urine tests for abnormal levels of hormones or enzymes.
Radiological imaging (X-ray, CT scan, MRI) to look for tumors.
Biopsy – analysis of suspicious tissue.

15. Cancer Treatments
Options depend on size, site(s), and quality of life tissue.
Age often inappropriately affects treatment choice with those over 60 receiving less radiation and chemotherapy.

16. Cancer Treatment Options
Surgery –
If cancer is localized, can remove it.
If it has spread then surgery can remove large portions to reduce symptoms.
Potentially healthy tissue is also sometimes removed in case some cancer cells have spread to the tissue.
Less tissue tends to be removed now than in previous years (e.g., lumpectomy in stead of mastectomy).

17. Cancer Treatment Options
Radiation – alters body cells so they are destroyed or cannot reproduce.
Two types:
External beam therapy: beam of radiation directed to malignant tissue (multiple treatments).
Internal radiation therapy: place radioactive substance inside body near tumor.
Microwave therapy - new

18. Radiation Side Effects
Troubling side effects since healthy tissue is effected as well
Nausea, fatigue, burning, loss of appetite, sterility, bowel/bladder dysfunction, reduced bone marrow function.
Anxiety in anticipation of treatment.

19. Chemotherapy
Oral or injection drugs targeted at cells that reproduce rapidly.
Works better for some forms of cancer (e.g., testicular, leukemia) than others (e.g., brain, pancreatic).
Effects healthy cells that also divide rapidly (e.g., bone marrow, mouth, intestinal tract, hair follicles) leading to reduced immunity, mouth soars, nausea, vomiting, hair loss, etc.

20. Chemotherapy Side-effects
Side-effects may lead to discontinuation of treatment.
Anticipatory nausea – classical conditioning process whereby patients become nauseous in anticipation of receiving treatment. Occurs in ¼ to ½ of patients.

21. Chemotherapy Side-Effects
Cancer treatment is aversive, complex, demanding, and requires many lifestyle changes.
Adherence is good among most adults, but not for minority and lower class individuals or adolescents.

22. Psychosocial Impact
“Real killer” and it is associated with pain, disability, and disfigurement.
Threat of remission – fear.
Treatment is aversive.
Prognosis is poorer for those who do not cope well.
Most adapt well – most difficult in early months or when symptoms worsen or recur, or with disability and pain.
Can cause strain on relationships due to fear and ignorance of others or their own emotional conflicts.

23. AIDS Acquired immune deficiency syndrome New and infectious
Worldwide, the majority of HIV+ are heterosexual non-drug users.
HIV – human immunodeficiency virus (attacks the immune system, notably the helper T cells and macrophages).
HIV+ can be asymptomatic for years.
In North America the highest rates are still amongst homosexuals and intravenous drug users.

24. AIDS – Risk Factors Three main routes for infection
Sexual activity involving the exchange of body fluids.
Sharing contaminated needles.
Birth by infected mother.
Incidence is increasing particularly among heterosexuals.

25. Age, Gender, and Socio-Cultural Factors
Highest rates among year olds.
2-3 times higher in men.
Disease progresses more rapidly among older people.
Death rate higher for Blacks.
Highest rates of infection in Africa, Southeast Asia, and South America.

26. From HIV Infection to AIDS: Four Stages of Progression
Mild symptoms like those of other diseases (e.g., soar throat, fever, rash, headache). Lasts 1-8 weeks.
Latent period for as long as 10 years with no or few symptoms.
AIDS related complex – cluster of symptoms (e.g., swollen glands, loss of appetite, fever, fatigue, night sweats, persistent diarrhea).
Severe immune impairment – multiple opportunist infections (e.g., lungs, gastrointestinal tract).
AIDS related complex – other symptoms can include weight loss, rash, etc.
Other sites for opportunist infections include nervous system, liver, bones, and brain.

27. What leads to these changes?
Gradual decrease in T4 (CD4), helper t-cells over many years.
In early stages virus “hides” in lymph tissue and multiplies.

28. AIDS Diagnosis “AIDS” diagnosis after development of:
Pneumocystis carinii pneumonia, Kaposi’s sarcoma, or very low levels of CD4.
Viral load test: determines level of HIV in body.
Damage to part of the immune system that fights viral infections – existing antibodies usually still work.
HIV attaches to CD4 and replicates itself, destroying the cells function.

29. Psychosocial Impact Others fear and blame them. Rejected by others.
Concerned about who in their social network they can tell.
Most adapt well, but those who don’t have more rapid disease progression.

30. AIDS Treatment Options
Hope for eventual vaccine – some success in producing immunity in monkeys.
Protease inhibitors – New class of drugs that interfere with maturity of HIV cells and slows progression of disease.
Don’t know the long term effects. They have troubling side-effects are expensive, and typically have to be taken in very tight schedule.

31. AIDS Treatment Options - Nutrition
Wasting syndrome
Extreme weight loss, muscle loss as well as fat.
Important to keep up strength but tend to loose appetite and have persistent diarrhea.

32. AIDS Prevention
Education is not enough – continue high levels of risk behaviours.
Need new intervention strategies.
Risk may be linked to certain personality characteristics.

33. Study by Trobst et al.
Examined personality factors contributing to risk behaviours in high risk groups.
Over 500 participants from substance abuse centres, homeless shelters, etc.
Five-Factor Model of personality assessing:
Neuroticism  Agreeableness
Extraversion  Conscientiousness
Openness to new experience

34. Study by Trobst et al. Results
HIV+ had higher N and lower C scores than low risk groups.
Cause or consequence?
High risk HIV- had higher N and lower C than low risk group.
High neuroticism and low conscientiousness appear to act as predisposing risk factors leading to engagement in risky behaviours and enhanced risk for contracting HIV.
Preventive interventions should take into account the personality factors influencing risk behaviours.