No abstract

EAT CONSUMPTION HAS been associated with colorectal neoplasia in the epidemiological literature, but the strength of the association and types of meat involved have not been consistent. Few studies have evaluated long-term meat consumption or the relationship between meat consumption and the risk of rectal cancer. Studies of red meat consumption and colorectal adenoma have reported odds ratios in the range of 1.2 to 1.3. [1][2][3] Case-control studies 4-25 of colorectal cancer conducted in the United States and Europe have generally reported increased risk associated with red or processed meat intake in analyses of men, 4-9,13,14 and men and women combined, [10][11][12][15][16][17][18][19][20][21][22][23][24][25] but not in analyses that included only women. [5][6][7][8][9]13 Case-control studies [26][27][28][29][30][31][32] of colorectal cancer among Asians in the United States or Asia have more consistently reported a positive association with red, processed, or total meats.Five 33-37 of 10 33-42 US prospective studies of colorectal cancer reported positive associations with red or processed meat intake, although some as-sociations [35][36][37] did not reach statistical significance. European prospective studies [43][44][45][46][47][48][49] have generally reported no association with fresh or total meat but positive associations with cured or processed meat, 43,45,46 sausages, 47 or smoked/salted fish. 45 High consumption of poultry or fish has been inconsistently associated with higher 36,37,46 or lower 34,40,41,47,49 risk of colorectal cancer; some studies have found no association. 33,39,42,43,45,48 Only 2 prospective studies 38,49 have reported on rectal can-cer in relation to meat consumption. The results were conflicting but were limited by the small number of cases.See also pp 183 and 233.

These two prospective studies provide limited evidence that current use of chewing tobacco or snuff may increase mortality from heart disease and stroke.

These results support the hypothesis that long duration regular NSAID use is associated with modestly reduced risk of prostate cancer.

Some epidemiologic studies suggest that use of vitamin C or vitamin E supplements, both potent antioxidants, may reduce the risk of bladder cancer. The authors examined the association between use of individual vitamin C and vitamin E supplements and bladder cancer mortality among 991,522 US adults in the Cancer Prevention Study II (CPS-II) cohort. CPS-II participants completed a self-administered questionnaire at enrollment in 1982 and were followed regarding mortality through 1998. During follow-up, 1,289 bladder cancer deaths occurred (962 in men and 327 in women). Rate ratios were adjusted for age, sex, cigarette smoking, education, and consumption of citrus fruits and vegetables. Regular vitamin C supplement use (>or=15 times per month) was not associated with bladder cancer mortality, regardless of duration (rate ratio (RR) = 0.91, 95% confidence interval (CI): 0.68, 1.20 for <10 years' use; RR = 1.25, 95% CI: 0.91, 1.72 for >or=10 years' use). Regular vitamin E supplement use for >or=10 years was associated with a reduced risk of bladder cancer mortality (RR = 0.60, 95% CI: 0.37, 0.96), but regular use of shorter duration was not (RR = 1.04, 95% CI: 0.77, 1.40). Results support the hypothesis that long-duration vitamin E supplement use may reduce the risk of bladder cancer mortality.