Interactions between Alcohol Consumption and Adjuvant Hormone Therapy in Relation to Breast Cancer-Free Survival / 한국유방암학회지

PURPOSE: Alcohol consumption is associated with an increase in breast cancer risk, but findings on the association of alcohol with survival after breast cancer diagnosis have been inconsistent. Further, whether these associations could differ by adjuvant hormone therapy status is unknown. We examined interactions between alcohol consumption and adjuvant hormone therapy in relation to breast cancer-free survival among women with a primary breast cancer diagnosis. METHODS: Participants in this study included 1,399 women diagnosed with primary breast cancer between 2007 and 2012 at the Moffitt Cancer Center. Alcohol consumption during the year preceding diagnosis was assessed in a patient survey. Information on tumor characteristics, breast cancer treatment and outcomes was available from the Moffitt Cancer Registry. Associations were examined using Cox proportional hazards models in stratified analyses by adjuvant hormone therapy status, after adjustment for potential confounders. RESULTS: Overall, alcohol consumption was associated with significantly improved breast cancer-free survival (any vs. none: hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.65–0.92). Among women without adjuvant hormone therapy, alcohol consumption was associated with better survival in heavy drinkers (HR, 0.63; 95% CI, 0.43–0.93). Among women with adjuvant hormone therapy, survival was better in women consuming alcohol as compared to nondrinkers (moderate: HR, 0.69, 95% CI, 0.51–0.93; heavy: HR, 0.74, 95% CI, 0.57–0.96; any: HR, 0.71, 95% CI, 0.57–0.87). There was no significant interaction between alcohol and adjuvant hormone therapy (p-interaction=0.54 for alcohol modeled as none or any and p=0.34 for alcohol modeled as none, moderate, and heavy). CONCLUSION: Associations of alcohol consumption with breast cancer-free survival are similar in women with and without adjuvant hormone therapy. Future studies are warranted to elucidate potential mechanisms underlying the observed inverse associations.

Interactions of Family History of Breast Cancer with Radiotherapy in Relation to the Risk of Breast Cancer Recurrence / 한국유방암학회지

PURPOSE: We examined associations between a family history of breast cancer and the risk of breast cancer recurrence in women who received or did not receive radiotherapy. METHODS: Our study included 2,440 women enrolled in the Breast Cancer Registry of Greater Cincinnati. Information on breast cancer risk factors, including detailed family history of breast cancer, characteristics of the primary tumor, treatment received, and recurrence status was collected at baseline and via updates. Associations between a family history of breast cancer and the risk of breast cancer recurrence were examined separately in women treated with and without radiotherapy using survival analysis. RESULTS: Over an average follow-up time of 8.78 years, we found no associations between a family history of breast cancer and the risk of breast cancer recurrence among women with a history of radiotherapy (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.75–1.23). Among women who did not receive radiotherapy, the total number of relatives with breast cancer was positively associated with the risk of breast cancer recurrence (HR, 1.21; 95% CI, 1.00–1.47). We found no interactions of radiotherapy with family history (p-interaction >0.05). CONCLUSION: Radiotherapy for a primary breast cancer in women with a family history of breast cancer does not increase risk of breast cancer recurrence. If these findings are replicated in future studies, the results may translate into an important health message for breast cancer survivors with a family history of breast cancer.