Cancer
Chapter 16
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What is Cancer?
Definition: an abnormal and uncontrollable growth of cells or tissue that can lead to death.
Tumor: a mass of tissue that serves no purpose and grows more rapidly than surrounding tissue. Malignant tumor: cancerous tumor; can invade
surrounding tissues.
Benign tumor: noncancerous tumor; mass of cells usually
enclosed in a membrane that prevents their penetration of other tissues.
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How Cancer Spreads
Metastasis: Primary tumor
Definition: the spreading of cancer cells, occurs because cancer cells do not stick to each other as strongly as normal cells.
Cells break away from primary tumor and invade surrounding tissues or travel through the blood and lymphatic system. Secondary tumor or metastases
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What Causes Cancer?
Theories:
Spontaneous errors during cell reproduction—genetic errors resulting in mutated cells Oncogenes—suspected cancer-causing genes present on chromosomes External agents that enter a normal cell and initiate cancerous process, such as environmental factors (radiation, chemicals, hormonal drugs, immunosuppressant drugs, other toxins Carcinogens—cancer-causing agents 6
Risk Factors:
Smoking: 1 in 5 deaths annually—30% of all cancers and 87% of lung cancers (smokeless also) Diet and obesity (34% of all cancers deaths in a study of 900,000 obese) Family history of cancer Occupational factors Environmental pollution Reproductive and Hormonal Risks late menarche, early menopause, early first child, and high parity-- < risk oral contraception and hormonal replacement Viruses Hepatitis B and C---liver HPV—cervicalAlcohol
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Types of Cancer
Malignant Tumors
Classified according to the types of cells.
Initially retain some of the original properties of the host cell.
Carcinomas
- most common - start from the epithelial tissue that cover body surfaces. Linings, tubes, cavities and secretion glands. (exp: breast, lung, intestines, skin and mouth)
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Malignant Tumors
Sarcomas: Arise in connective and fibrous tissues. Bone, muscle, cartilage and membranes covering muscle. Lymphomas: Cancers of the lymph nodes. Leukemia: cancer of the blood-forming cells in bone marrow. Abnormal production immature wbc’s—cannot fight off infections
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The Incidence of Cancer
2nd leading COD overall (<85 y/o #1) 1.4 million Americans are diagnosed yearly (2006) 65% will be cured (clean > 5 yrs) 1,500+ die/day in U.S. (1/4 of all deaths)
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Common Cancers
Lung Cancer: Most common cause of CA death Risk Factors
Tobacco smoking contributes to 87%. Increases further when combined with environmental carcinogens Detection and Treatment (Difficult to detect) Symptoms often are not detected until cancer has reached the invasive stage. Persistent cough, blood-streaked sputum, chest pain, or recurring bronchitis. Diagnosis - chest x-ray or sputum examination – fiberoptic bronchoscopy. Spiral computerized tomography
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Common Cancers
Lung Cancer treatment:
Difficult to treat. Surgery- removal of involved cells. Typically- cancer cells have already spread. Very resistant to chemotherapy. Just 15% live 5+ years Improve to 50% with early detection, but only 16% detected early
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Common Cancers
Colon and Rectal- 3rd most common in males and females Symptoms: Early stages—none, bleeding from rectum, blood in stool, changes in bowel habits Detection: Good prognosis if caught early—spreads slowly Basic screening test is fecal occult blood test— colonoscopy or barium enema 50+ or high risk Risk Factors: Obesity: Diet < fat and >fiber - best defense. Age: Mostly occurs 50+. Family history Others—smoking, sedentary lifestyle, high alcohol consumption, diet low in fruits and vegetables ~90% preventable 14
Common Cancers
Breast Cancer - Most common cancer in women; 1:8 American women will have it during her lifetime. Risk Factors Family history Long menstrual history Biopsy-confirmed atypical hyperplasia Obesity after menopause Never having children—or > 30 2 or more drinks of alcohol per day Most common in women over 50 5 year survival rate if has spread to surrounding tissue 81%; if spread to distant areas 26%; if has not spread near 100% 15
Common Cancers
Breast Cancer -.
Three part program for early detection. Monthly breast self-exam for all women over 20. Clinical breast exam by a physician every 3 yr. age 20-39; every year 40+ Annual Mammography- 40+ yr. old.
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Common Cancers
Prostate Cancer - Most common cancer in men (excluding skin).
Risk Factors - Age, diet, lifestyle and genetic predisposition Early detection is key. Rectal exam/PSA blood test 50+, high risk start at 45 Treatment - surgical removal of the prostate and radiation 1 in 3 men will be diagnosed; 1 in 33 will die
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Common Cancers
Female Reproductive Tract: Cervix (also Uterine), Ovaries.
Cervical cancer - sexually transmitted.
80% stems from infection by the papillomavirus transmitted by unprotected sex. PAP Test
Cervical cancer most common in women in their 20’s and 30’s.
Factors: sexual intercourse before 18, multiple sex partners, cigarette smoking and low SES.
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Common Cancers
Ovarian Cancer:
Causes more death of the reproductive system Difficult to detect because may show no symptoms until advanced stages (then enlargement of abdomen, vaginal bleeding/discharge, vague digestive disturbances) Family history or genetic factors Can be determined by pelvic exam
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Common Cancers
Skin Cancer: Most common form--1 in 5
Easily detected and highly curable Exposure to ultraviolet rays during childhood Common cause - sunburns and suntans Types: Basal (deep layers) and Squamous (surface) Melanoma - more dangerous form (ABCD test) Prevention: 15+, parasol 1789, zinc oxide, both UVA/UVB (see table 16.4) 20
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Common Cancers
Oral Cancer: Smokeless tobaccos Testicular Cancer: One of the most common in young males, 15-35 greatest risk
Males should do testicular self-exams (figure 16.8) LiveStrong (yellow bands) Lance Armstrong
Pancreatic Cancer: One of the worst to have-ONLY 4% live > 5 years Stomach Cancer Bladder Cancer Kidney Cancer Brain Cancer
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Foods That Contain CancerPreventing Substances
Broccoli Brussels sprouts Cabbage Cauliflower Carrots Red peppers Tomato Sweet potato Collard greens Green Tea
Kale Spinach Apricot Cantaloupe Grapefruit Orange Papaya Peach Plum Watermelon
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Thanks!!!!!!!
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