ABSTRACTBackgroundThe impact of alcohol consumption on breast cancer (BC) prognosis remains unclear.MethodsThe authors examined short‐term alcohol intake in relation to recurrence and mortality in 3659 women who were diagnosed with stage I–IV BC from 2003 to 2015 in the Pathways Study. Alcohol drinking in the past 6 months was assessed at cohort entry (mean, 2 months postdiagnosis) and 6 months later using a food‐frequency questionnaire. Study end points were recurrence and death from BC, cardiovascular disease, and all causes. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox proportional hazards models.ResultsOver an average follow‐up of 11.2 years, 524 recurrences and 834 deaths (369 BC‐specific and 314 cardiovascular disease‐specific) occurred. Compared with nondrinkers (36.9%), drinkers were more likely younger, more educated, and current or past smokers. Overall, alcohol consumption was not associated with recurrence or mortality. However, women with higher body mass index (BMI ≥ 30 kg/m²) had lower risk of overall mortality with increasing alcohol consumption for occasional drinking (HR, 0.71; 95% CI, 0.54–0.94) and regular drinking (HR, 0.77; 95% CI, 0.56–1.08) around the time of diagnosis, along with 6 months later, in a dose‐response manner (p < .05). Women with lower BMI (<30 kg/m²) were not at higher risk of mortality but were at possibly higher, yet nonsignificant, risk of recurrence for occasional drinking (HR, 1.29; 95% CI, 0.97–1.71) and regular drinking (HR, 1.19; 95% CI, 0.88–1.62).ConclusionsAlcohol drinking around the time of and up to 6 months after BC diagnosis was associated with lower risk of all‐cause mortality in obese women. A possible higher risk of recurrence was observed in nonobese women.