Cancer and AIDS

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.

Four Types of Cancer Carcinomas -

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.

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.

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.

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.

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.

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.

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.

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

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.

Diagnosing and Treating Cancer Physician tests for breast, colon,

prostate, skin, testes, cervix.

Self-administered testing for some cancers – breast, skin, testes.

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.

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.

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.

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).

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

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.

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.

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.

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.

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.

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.

AIDS – Risk FactorsThree 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.

Age, Gender, and Socio-Cultural Factors

Highest rates among 20-45 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.

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).

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.

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.

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.

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.

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.

AIDS Prevention Education is not enough – continue

high levels of risk behaviours.

Need new intervention strategies.

Risk may be linked to certain personality characteristics.

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

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.