Epidemiology
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To evaluate the relation between oral contraceptives and colon and rectal cancer, we analyzed combined data from two case-control studies conducted in six Italian regions between 1985 and 1996. The studies included 803 women with incident colon cancer, 429 with rectal cancer, and 2,793 controls with acute, nonneoplastic, nondigestive, non-hormone-related disorders. ⋯ Duration of use of oral contraceptives was inversely related to risk of colon but not rectal cancer. This study suggests that women who have ever used oral contraceptives are at lower risk of colon and rectal cancer.
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We conducted a population-based case-control study among different ethnic groups in Hawaii to evaluate the role of various types and components of fiber, as well as micronutrients and foods of plant origin, on the risk of colorectal cancer. We administered personal interviews to 698 male and 494 female Japanese, Caucasian, Filipino, Hawaiian, and Chinese cases diagnosed during 1987-1991 with adenocarcinoma of the colon or rectum and to 1,192 population controls matched to cases by age, sex, and ethnicity. We used conditional logistic regression to estimate odds ratios, adjusted for caloric intake and other covariates. ⋯ Intakes of carotenoids, light green vegetables, yellow-orange vegetables, broccoli, corn, carrots, bananas, garlic, and legumes (including soy products) were inversely associated with risk, even after adjustment for vegetable fiber. The data support a protective role of fiber from vegetables against colorectal cancer, which appears independent of its water solubility property and of the effects of other phytochemicals. The data also indicate that certain vegetables and fruits may be protective against this disease through mechanisms other than their fiber content.
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Review Comparative Study
Risk factors and the sex differential in coronary artery disease.
In industrialized countries, the incidence of coronary artery disease is three to four times higher in men than in women. Our review examines whether differences in the prevalence of, or susceptibility to, various coronary risk factors might contribute to this sex differential. Cigarette smoking, hypertension, and hypercholesterolemia are risk factors for coronary artery disease in both sexes and are present at higher levels in middle-aged men than women. ⋯ In addition, men with a female pattern of abdominal fat distribution are at lower risk of coronary artery disease than those with a male pattern. In diabetic populations, the sex differential is greatly reduced, but studies on the effects of hyperinsulinemia and a lower insulin resistance in women compared with men are scarce. Prospective studies on the effect of fibrinogen and other hemostatic factors in women are also required.
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We evaluated height as a potential risk factor for breast cancer in a case-control study of 747 young women diagnosed with invasive breast cancer before age 46 years and 961 control subjects recruited by random digit dialing. We found that total height attained did not affect a woman's risk of the disease. The age when a women reached her maximum height, however, was a risk factor for breast cancer. ⋯ Although the age at menarche was correlated with the age at maximum height, the effect of age at maximum height persisted after adjustment for age at menarche. Previous studies have reported that age at menarche is an important determinant of risk, but this study indicates that age when maximum height is reached may be another, and possibly more important, landmark of puberty that is related to breast cancer risk. The physiologic basis for this claim may lie in the influence on breast development of exposure to growth hormone and insulin-like growth factor during puberty, and on a decreased time between the end of puberty and a woman's first livebirth, both of which are believed to affect a woman's risk of breast cancer.