[Show abstract][Hide abstract] ABSTRACT: Obesity has been reported to increase the risk of colon cancer, especially in men. The authors examined this relation in the American Cancer Society's Cancer Prevention Study II, a nationwide mortality study of US adults. After 12 years of follow-up, 1,616 deaths from colon cancer in women and 1,792 in men were observed among 496,239 women and 379,167 men who were cancer free at enrollment in 1982. The authors used Cox proportional hazards analyses to control for effects of age, race, education, smoking, exercise, alcohol, parental history of colon cancer, fat intake, vegetable and grain intake, aspirin use and, in women, estrogen replacement therapy. In men, death rates from colon cancer increased across the entire range of body mass index (BMI). The rate ratio was highest for men with BMI ≥32.5 (rate ratio (RR) = 1.90, 95% confidence interval (CI): 1.46, 2.47) compared with men with BMI between 22.00 and 23.49. In women, a weaker association was seen in the three BMI categories of 27.5–29.9 (RR = 1.26, 95% CI: 1.03, 1.53), 30.0–32.4 (RR = 1.37, 95% CI: 1.09, 1.72), and ≥32.5 (RR = 1.23, 95% CI: 0.96, 1.59). These prospective data support the hypothesis that obesity increases the risk of colon cancer death and that the relation is stronger and more linear in men than in women. Am J Epidemiol 2000;152:847–54.
Full-text · Article · Nov 2000 · American Journal of Epidemiology
[Show abstract][Hide abstract] ABSTRACT: The authors examined the association between main lifetime occupation and subsequent breast cancer mortality in a large prospective study of US adults. After 9 years of follow-up, 1,780 cases of fatal breast cancer were observed among 563,395 women who were cancer-free at interview in 1982. Main lifetime occupation was derived based on self-reports of current and former occupational titles and was classified into 14 broad occupational groups and 16 more narrowly defined occupational titles. Results from Cox proportional hazards models, adjusted for breast cancer risk factors, revealed little variability in breast cancer mortality by occupation. Two significant associations were observed: In comparison with housewives, women in "administrative support, including clerical" occupations were at a small increased risk (rate ratio (RR) = 1.14, 95% confidence interval (CI) 1.01-1.31), and an increased risk was seen for "executives" (RR = 1.93, 95% CI 1.03-3.62), based on 10 breast cancer deaths. No significant increases in risk were observed for teachers and librarians (RR = 0.89), nurses (RR = 0.84), managers (RR = 0.89), or women employed in sales (RR = 0.88) or service (RR = 0.84) occupations. When analyses were limited to women who had worked in their occupation for 10 or more years, the results for each occupational title were virtually unchanged. These results offer little support for an association between occupation and breast cancer mortality in general or for particular occupational titles, including teachers and nurses.
Preview · Article · Aug 1998 · American Journal of Epidemiology
[Show abstract][Hide abstract] ABSTRACT: Objectives: Diabetes mellitus and pancreatic cancer are known to be associated, but it is not known whether diabetes is a true risk factor, preceding development of the cancer, or if it is an early manifestation of the cancer. To address this uncertainty, we examined the association of pancreatic cancer mortality and reported diabetes of at least one year's duration in a large, prospective study of United States adults. The vast majority of diabetes in this cohort is likely to be non-insulin-dependent diabetes.Methods: After 12 years of follow-up, 2,953 deaths from pancreatic cancer were observed in a cohort of 1,089,586 men and women who were cancer-free at study entry in 1982. Cox proportional hazards models, adjusted for age, race, smoking, family history of pancreatic cancer, body mass index (wt/ht2), and education, were used to assess associations.Results: A history of diabetes was significantly related to pancreatic cancer mortality in both men (rate ratio [RR]=1.49, 95 percent confidence interval [CI]=1.25-1.77) and women (RR=1.51, CI=1.24-1.85). However, the strength of the association varied over the follow-up period. The death rate from pancreatic cancer was twice as high in diabetics as in non-diabetics during the second and third years of follow-up (adjusted RR=2.05, CI=1.56-2.69) but only about 40 percent higher in years nine to 12 (adjusted RR=1.38, CI=1.08-1.77).Conclusions: The small but persistent increased risk of death from pancreatic cancer, seen even when the diagnosis of diabetes preceded death by many years, supports the hypothesis that diabetes may be a true, albeit modest, risk factor for pancreatic cancer.
No preview · Article · Jan 1998 · Cancer Causes and Control