Person:

Harris, Holly R.

Background: Alcohol intake has consistently been associated with increased breast cancer incidence in epidemiological studies. However, the relation between alcohol and survival after breast cancer diagnosis is less clear. Methods: We investigated whether alcohol intake was associated with survival among 3146 women diagnosed with invasive breast cancer in the Swedish Mammography Cohort. Alcohol consumption was estimated using a food frequency questionnaire. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs). Results: From 1987 to 2008 there were 385 breast cancer-specific deaths and 860 total deaths. No significant association was observed between alcohol intake and breast cancer-specific survival. Women who consumed 10 g per day (corresponding to approximately 0.75 to 1 drinks) or more of alcohol had an adjusted HR (95% CI) of breast cancer-specific death of 1.36 (0.82–2.26;p({trend})=0.47) compared with non-drinkers. A significant inverse association was observed between alcohol and non-breast cancer deaths. Those who consumed 3.4–9.9 g per day of alcohol had a 33% lower risk of death compared with non-drinkers (95% CI 0.50–0.90;p({trend})=0.04). Conclusion: Our findings suggest that alcohol intake up to approximately one small drink per day does not negatively impact breast cancer-specific survival and a half drink per day is associated with a decreased risk of mortality from other causes.

Folate, methionine, vitamin B6, and vitamin B12 may influence carcinogenesis due to their roles in the one-carbon metabolism pathway which is critical for DNA synthesis, methylation, and repair. Low intake of these nutrients has been associated with an increased risk of breast, colon, and endometrial cancers. Previous studies that have examined the relation between these nutrients and ovarian cancer risk have been inconsistent and have had limited power to examine the relation by histologic subtype. We investigated the association between folate, methionine, vitamin B6, vitamin B12, and alcohol among 1910 women with ovarian cancer and 1989 controls from a case-control study conducted in eastern Massachusetts and New Hampshire from 1992 to 2008. Diet was assessed via food frequency questionnaire. Participants were asked to recall diet one-year before diagnosis or interview. Logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (95% CIs). We also examined whether the associations varied by ovarian cancer histologies using polytomous logistic regression. We observed an inverse association between dietary vitamin B6 (covariate-adjusted OR=0.76, 95% CI 0.64–0.92; ptrend=0.002) and methionine intake (covariate-adjusted OR=0.72, 95% CI=0.60–0.87; ptrend<0.001) and ovarian cancer risk comparing the highest to lowest quartile. The association with dietary vitamin B6 was strongest for serous borderline (covariate-adjusted OR=0.49, 95% CI=0.32–0.77; ptrend=0.001) and serous invasive (covariate-adjusted OR=0.74, 95% CI=0.58–0.94; ptrend=0.012) subtypes. Overall, we observed no significant association between folate and ovarian cancer risk. One-carbon metabolism related nutrients, especially vitamin B6 and methionine, may lower ovarian cancer risk.