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  3. CANCER PREVETION INTRODUCTION Cancer deaths exceed seven million worldwide each year, despite overwhelming evidence that many malignancies are preventable nearly half a million people die from cancer each year in the United States (US) alone It is estimated that 50 percent of cancer is preventable

  4. CANCER PREVETION INTRODUCTION risk factors (account for two-thirds of all cancers in the US tobacco use, excess weight, poor diet, inactivity Dr.Azarm

  5. CANCER PREVETION Harvard Report on Cancer Prevention Volume 2: Prevention of Human Cancer. Cancer Causes and Control 1997; 8:S1. INTRODUCTION nine modifiable risks were identified as the cause of 35 percent of cancer deaths worldwide: smoking, alcohol use, diet low in fruit and vegetables, excess weight, inactivity, unsafe sex, urban air pollution, use of solid fuels, and contaminated injections in health-care settings

  6. CANCER PREVETION INTRODUCTION Lifestyle issues which promote cancer are also risk factors for other diseases, such as stroke, heart disease, and diabetes. Dr.Azarm

  7. CANCER PREVETION TOBACCO USE kills approximately 5 million people each year mostly through malignancy, cardiovascular, and respiratory disease Approximately one-half of all smokers die of a tobacco-related disease, and adult smokers lose an average of 13 years of life due to this addiction

  8. CANCER PREVETION TOBACCO USE Smoking is responsible for approximately 30 percent of all cancer-related deaths in the US lung cancer, increasing risk 10 to 20-fold causative factor for leukemia as well as cancers of the oral cavity, nasal cavity, paranasal sinuses, nasopharynx, larynx, esophagus, pancreas, liver, stomach, cervix, kidney, large bowel, and bladder

  9. CANCER PREVETION TOBACCO USE smoking to more aggressive prostate cancers Smoking cessation leads to reduced risk of most tobacco-related diseases and a decrease in all cause mortality The health benefits of quitting can be seen at all ages and can be measured almost immediately after cessation

  10. CANCER PREVETION DIET -Dietary fat No clear link has been found between total fat intake and colon or breast cancer but the data are more convincing for prostate cancer and endometrial cancer A diet high in animal fat may be an important factor in the development of prostate cancer intake of large amounts of alpha-linoleic acid and low amounts of linoleic acid appear to increase risk serum levels of testosterone are lower in men who decrease their fat intake

  11. CANCER PREVETION DIET -Red meat elevate risk of colorectal cancer in both men and women several factors have been suggested including heme content in the meat, animal fat, and carcinogens produced when the meat is cooked at high temperatures.

  12. CANCER PREVETION DIET -Fruits and vegetables no association was seen between either total or specific category of fruit and vegetable intake and colon cancer risk

  13. CANCER PREVETION DIET -Fruits and vegetables Evidence is stronger for a link between prostate cancer and tomato products Lycopene, a carotenoid found in tomatoes, has been postulated to be responsible for this benefit but there are no data from well-designed clinical trials to support this hypothesis

  14. CANCER PREVETION DIET -Dairy relationship of dairy food intake and ovarian cancer found no evidence of association in case control studies OTHER three prospective cohort studies did demonstrate increased risk of ovarian cancer with high intake of dairy foods

  15. CANCER PREVETION DIET -Fiber reduce the risk of heart disease [40,41] and diabetes [42,43], but its effect on cancer risk reduction is less certain

  16. CANCER PREVETION DIET -Glycemic load Insulin and insulin-like growth factors promote cell proliferation, and it is hypothesized that hyperinsulinemia may promote certain cancers

  17. CANCER PREVETION DIET -Omega-3 fatty acids there is no association between omega-3 fatty acids and cancer risk for 11 different types of cancer Dietary supplementation with omega-3 fatty acids is unlikely to prevent cancer.

  18. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS Several nutritional components have been shown to affect cancer risk, but the role of vitamins is less certain neither vitamin C nor vitamin E supplementation was beneficial for prevention of the cancers evaluated

  19. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS A 2006 National Institutes of Health (NIH) consensus conference panel concluded that "present evidence is insufficient to recommend either for or against the use of multivitamin supplements by the American public to prevent chronic disease"

  20. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS It has not been proven that multivitamin and mineral supplements provide added benefit to a balanced, healthful diet

  21. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS -Vitamin D may reduce the risk of colon cancer Direct effects of vitamin D on colonic epithelial cells have been described Vitamin D may also decrease cancer risk through improved calcium absorption prostate cancer did not demonstrate a relationship breast cancer may have a protective effect

  22. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS -Vitamin D in men was seen with an increment of 25 nmol/L in predicted 25(OH)D level in data derived from the US Health Professionals Follow-Up Study This incremental level of serum 25(OH)D is not readily achieved with diet (one glass of milk would be predicted to increase the plasma level only by 2 to 3 nmol/L), and would require supplementation with at least 1500 IU vitamin daily

  23. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS -Vitamin D The authors raise a question whether limiting sun exposure, to decrease skin cancer risk, might increase the mortality risk for other cancers.

  24. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS -Calcium Increased calcium intake reduced risk of colorectal cancer increased risk of prostate cancer 700 mg/day  protection against colorectal cancer without significantly increasing prostate cancer risk.

  25. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS -Calcium Calcium in the colon may offer protection by Directly reducing epithelial cell proliferation, Indirectly by binding secondary bile acids and ionized fatty acids total calcium over 2000 mg/day from both diet and supplementation was linked to a 20 percent increase in prostate cancer risk

  26. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS -Selenium higher intake of selenium decreases the risk of a variety of tumors significant mortality reduction in cancers of lung colon prostate Selenium and Vitamin E Cancer Prevention Trial (SELECT) will provide valuable information on the overall risks and benefits of selenium

  27. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS -Folate a decrease in breast and colon cancer risk, especially in individuals who consume alcohol supplementation with a multivitamin containing folic acid provided even greater benefit increased dietary folate and vitamin B6 intake lowered colorectal cancer risk reduced risk for pancreatic cancer studies did not demonstrate an association between low dietary intake of folate and breast cancer

  28. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS -other vitamin supplements Vitamin E (600 IU alpha-tocopherol every other day) did not prevent invasive cancer in a 10 year follow-up to the Women's Health Study, evaluating healthy women age 45 years and older (mean age 55 years) One study did find a decrease in risk for prostate cancer with vitamin E supplementation in male smokers

  29. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS -other vitamin supplements Beta carotene may increase the incidence of lung cancer incidence and mortality in patients with risk factors (smokers or asbestos exposure) Beta carotene did not decrease cancer incidence in studies of American women [110] and men

  30. CANCER PREVETION DIET -VITAMINS AND NUTRIENTS -other vitamin supplements Beta carotene in rural China with baseline deficiencies in micronutrients a combination of beta-carotene, selenium, and zinc decreased the incidence of noncardia stomach cancer, but not other intestinal malignancies

  31. CANCER PREVETION ALCOHOL increases the risk of cancers of colon, breast Oropharynx esophagus Moderate alcohol use has beneficial effects on cardiovascular health, consumption of as little as one drink per day has been associated with an increase cancer risk

  32. CANCER PREVETION ALCOHOL mechanisms solvent properties may allow carcinogens to penetrate cell membranes increases estrogen levels impacts folate metabolism act as an irritant, causing increased cell production transporter carrying carcinogens as a prometabolite for identified carcinogens

  33. CANCER PREVETION PHYSICAL INACTIVITY Decreased physical activity increase the risk for cancer, in addition to multiple other diseases Over 60 percent of US adults are not regularly active, including 25 percent who are almost entirely sedentary sedentary lifestyle is associated with 5 percent of cancer deaths

  34. CANCER PREVETION PHYSICAL INACTIVITY Physical activity is associated with a decreased risk of colon and breast cancer negative correlation between moderate to strenuous exercise and ER-negative, but not ER-positive, breast cancer activity offers some protection against endometrial and prostate cancer physical activity may reduce the risk of lung cancer

  35. CANCER PREVETION PHYSICAL INACTIVITY the protective effect of activity goes beyond its impact on body weight

  36. CANCER PREVETION PHYSICAL INACTIVITY mechanisms reduction in circulating levels of insulin, hormones, and other growth factors impact on prostaglandin levels; improved immune function, and altered bile acid metabolism

  37. CANCER PREVETION PHYSICAL INACTIVITY Physical activity during certain periods of life, such as adolescence, may offer additional protection against disease The optimal duration, intensity, and frequency of physical activity that may afford cancer protection is unknown.

  38. CANCER PREVETION EXCESS WEIGHT 65 percent of US adults are overweight over 30 percent are considered obese

  39. CANCER PREVETION EXCESS WEIGHT with an increase in the risk of multiple cancers including colorectal, postmenopausal breast, endometrial, renal, and esophageal cancer, with a population attributable risk from 9 percent (postmenopausal breast cancer) to 39 percent (endometrial cancer)

  40. CANCER PREVETION EXCESS WEIGHT Obesity may also increase risk for cancer of prostate, liver, gallbladder, pancreas, stomach, ovary, and cervix non-Hodgkin's lymphoma multiple myeloma

  41. CANCER PREVETION EXCESS WEIGHT obesity in the US may account for 14 percent of cancer deaths in men and 20 percent of cancer deaths in women

  42. CANCER PREVETION EXCESS SUN EXPOSURE Over 1 million cases of skin cancer, including basal cell and squamous cell carcinoma, are diagnosed each year over 59,000 cases of malignant melanoma in the US in 2005 [9], and the incidence continues to rise most skin cancers are curable Radiation from the sun is the primary cause both melanomatous and non-melanomatous skin cancer.

  43. CANCER PREVETION EXCESS SUN EXPOSURE correlate with total lifetime sun exposure Cumulative sun exposure may also increase melanoma risk repeated intense exposures leading to blistering burns may be even more dangerous

  44. CANCER PREVETION EXCESS SUN EXPOSURE Recommendations for sun protection All individuals should limit the time spent in the sun, especially between the hours of 10 am and 3 pm, wear hats, sunglasses, and other protective clothing, use sunscreen

  45. CANCER PREVETION EXCESS SUN EXPOSURE Recommendations for sun protection majority of lifetime sun exposure usually occurs during childhood and adolescence protective behaviors early in life will provide the greatest benefit Organization recently recommended against tanning bed use by anyone under the age of 18

  46. CANCER PREVETION INFECTION 17 percent of all new cancers worldwide are due to infections Viruses may increase cancer risk through cellular transformation, disruption of cell cycle control, increased cell turnover rates, immune suppression

  47. CANCER PREVETION INFECTION Human papillomavirus (HPV) with cervical and other anogenital cancers [140] Hepatitis B (HBV) and C (HCV) with hepatocellular carcinoma [141] Human T-cell lymphotropic virus (HTLV-I) with adult T cell leukemia [142] Human immunodeficiency virus (HIV-I) with Kaposi sarcoma and non-Hodgkin's lymphoma [9] Human herpes virus 8 (HHV-8) with Kaposi sarcoma and primary effusion lymphoma [143,144] Epstein-Barr virus (EBV) with Burkitt's lymphoma [143] Helicobacter pylori (H. pylori) with gastric cancer

  48. CANCER PREVETION INFECTION The majority of these viruses are spread through contact with infected blood or body fluids Vaccinations for HBV and HPV are particularly promising Excess alcohol use may play a role in cancer development in patients with chronic HBV and HCV infections and should be avoided antiviral therapy may reduce the risk of cancer Retroviral therapy for HIV infection reduce the incidence of AIDS-related lymphoma

  49. CANCER PREVETION INFECTION The majority of these viruses are spread through contact with infected blood or body fluids Vaccinations for HBV and HPV are particularly promising Excess alcohol use may play a role in cancer development in patients with chronic HBV and HCV infections and should be avoided antiviral therapy may reduce the risk of cancer Retroviral therapy for HIV infection reduce the incidence of AIDS-related lymphoma

  50. CANCER PREVETION CHEMOPREVENTION Selective estrogen receptor modulators and breast cancer -Tamoxifen an estrogen receptor antagonist with both estrogen agonist and antagonist properties It is approved in the US for both primary and secondary prevention in high-risk women