HEA 201 Chapter 10, Fall 2007

Cancer 1. What is Cancer?  Loss of cell division control  formation of cell cluster = “tumor”  Benign versus malignant tumor - Benign (not life threatening): abnormal growth but not unlimited - Malignant (cancerous): life-threatening because unlimited growth  Invasion: cancer cells grow  crowd out & replace healthy cells in organs  Metastasis: some cells spread to other parts of body via blood or lymph  Classification according to origin, e.g. - Carcinoma: epithelium (covering tissue, e.g. skin) - Melanoma: melanocytes (pigment-forming skin cells) - Leukemia: white blood cells - Lymphoma: lymphocytes 2. Risk Factors  Heredity; characteristics: family history (large number of cases in a family) early development multiple targets (e.g. both breasts, both kidneys…) unusual gender pattern (e.g. breast cancer in males)  Lifestyle - Smoking: active and passive - Alcohol abuse - Sedentarity & overweight - Irresponsible sexual behavior (e.g. contraction of HIV, HBV) - Diet .high-fat .low in fruits & vegetables: no antioxidants, phytochemicals & fibers .unhealthy processing/preparation e.g. smoked foods pesticide residues charcoal-grilling & frying  Environmental risks - Chemicals (carcinogens): asbestos, smokes, dark permanent hair dyes… - Radiation: nuclear, medical & sun radiations (UV)  Viruses - HIV: virus  immunity  no longer destroys newly-formed cancerous cells - HBV: can lead to liver cancer 3. Examples: Skin & Breast Cancers Skin  Types - Epidermis cell cancer - Melanocyte (pigment-forming cell) cancer: “melanoma”: deadliest type  Detection / warning signs - Self exam: changes in size, color, number & thickness of moles - Suspicious if asymmetrical, notched edges, darkly pigmented growth bleeding, change in sensation - Professional exam and tissue biopsy of suspicious moles  Risk factors - SUN - Genes, blond or red-headed, marked freckling, sunburns as child/teen  Protection from UV - Sun is becoming more dangerous because earth’s protective ozone layer is ↓ - Sunlamps also risky - UVB more damaging than UVA - Avoiding sun when shadow shorter than oneself (generally 11h-16h,  sun overhead  stronger UV) - Not putting too much faith in sunscreens minimum SPF 15 protective clothing & shade is best - Some medications increase sensitivity to sun damage Breast  Detection / warning signs - Self exam: discharge, lumps, change in texture - Professional breast exam & mammography (X-ray)  Risk factors - Breast cancer genes - Age - No children or first child after age 30 - Obesity - Exposure to radiation - Hormone replacement therapy (HRT) - Low fruits & vegetables intake 4. Prevention & Treatments Prevention  Diet - High fruits & vegetable intake (phytochemicals, antioxidants & fibers) - Low fat food intake - Avoiding cured, smoked, pickled foods - Avoiding fried and barbecued (coal-grilled) foods (safer methods: roasting, baking, boiling, steaming, microwaving) - Choosing foods without added chemicals or pesticides  Exercising  No smoking  Limiting alcohol intake  Staying out of the sun  Being sexually cautious (protection from cancer-causing STDs)  Self-examination: e.g. skin & breast Treatments  Surgery: removal of tumor and surrounding cells  Chemotherapy: drugs that block cell division  Radiation therapy: destruction of cancerous cells with radiations  Immunotherapy: substances that  immunity to destroy cancerous cells