Previous studies on nonsteroidal antiinflammatory drugs (NSAIDs) and breast cancer have produced mixed results. Incident invasive cases of breast cancer from the Multiethnic Cohort (African Americans, Caucasians, Japanese Americans, Latinas, and Native Hawaiians from Hawaii and California) were identified from 1993 to 2002. Data on aspirin, acetaminophen, and other NSAID (ibuprofen, naproxen, indomethacin) use were based on a self-administered questionnaire at baseline (1993-1996). Multivariate Cox proportional hazards models provided estimates of hazard rate ratios and 95% confidence intervals. The authors observed no associations between breast cancer risk and duration of aspirin use for current or past users (hazard rate ratio = 1.05, 95% confidence interval: 0.88, 1.25 and hazard rate ratio = 1.04, 95% confidence interval: 0.84, 1.27 for > or =6 years of use, respectively) compared with nonusers. However, duration of current other NSAID use was protective (hazard rate ratio = 0.70, 95% confidence interval: 0.51, 0.95 for > or =6 years of use; p(trend) = 0.01) against the risk of breast cancer, while past use was not (hazard rate ratio = 0.90, 95% confidence interval: 0.62, 1.30 for > or =6 years of use). Analyses by ethnicity and hormone receptor status showed that the protective effect of current other NSAID use was limited to Caucasians and African Americans and to women with at least one positive hormone receptor. This study found duration of current other NSAID use to be protective against breast cancer risk.

Obesity may increase the risk for non-Hodgkin's lymphoma (NHL) through an inflammatory pathway. We explored the relation of NHL with body size at different times in life within the Multiethnic Cohort that includes African Americans, Caucasians, Japanese, Latinos, and Native Hawaiians. Participants were 45 to 75 years old at recruitment in 1993 to 1996. This analysis included 87,079 men and 105,972 women with 461 male and 378 female NHL cases. We used Cox regression to model NHL risk with age as the time metric while adjusting for age at baseline, ethnicity, education, alcohol intake, and age at first live birth. Body weight and body mass index at age 21 were stronger predictors of NHL risk than anthropometric characteristics at baseline. For men, being in the highest quartile of body mass index and body weight at age 21 conferred a nonsignificant 86% and 41% higher NHL risk, respectively, whereas there was no association at baseline. For women, the risk associated with the highest quartile of weight at age 21 was 1.6 (P trend = 0.04), whereas women in the highest quartile at baseline had a nonsignificant risk of 27%. Height was positively related to NHL in men and women. Despite the small numbers, there was some consistency for risk estimates across ethnic groups and weak evidence for an association with NHL subtypes. These findings indicate that weight at age 21 may represent lifetime adiposity better than body weight at cohort entry. Alternatively, weight at age 21 may be more relevant for the etiology of NHL. (Cancer Epidemiol Biomarkers Prev 2008;17(1):196 -203)

Objective-We examine the association of antioxidants and 15-isoprostane F 2t with risk of prostate cancer.Methods-We conducted a nested case-control study of serum antioxidant biomarkers (selenium, tocopherols, carotenoids, and retinol) and a urinary oxidation biomarker (15-isoprostane F 2t ) with risk of prostate cancer within the Multiethnic Cohort. Demographic, dietary, and other exposure information was collected by self-administered questionnaire in 1993-1996. We compared prediagnostic biomarker levels from 467 prostate cancer cases and 936 cancer free controls that were matched on several variables. Multivariate conditional logistic regression models were used to compute adjusted odds ratios (ORs) and 95% confidence intervals (CIs).Results-We observed that there was no overall association of serum concentrations of antioxidants and urinary concentrations of 15-isoprostane F 2t with risk of prostate cancer or risk of advanced prostate cancer. However, we did observe an inverse association for serum selenium only among African-American men (p trend = 0.02); men in the third tertile of selenium concentrations had a 41% lower risk (95% CI: 0.38-0.93) of prostate cancer when compared to men in the first tertile.Conclusions-Overall, our study found no association of serum antioxidants or 15-isoprostane F 2t with the risk of prostate cancer. The observed inverse association of selenium with prostate cancer in African-Americans needs to be validated in other studies.