For the primary analyses, relative risks (RR) were calculated using average cumulative alcohol consumption since baseline (1980). Initially, analyses were also performed using baseline intake and simple current updating of alcohol use (i.e. consumption updated with the return of each questionnaire and therefore past use would not be carried forward). Although the relationship with baseline and current alcohol use closely approximated that of cumulative average intake (Table 2), cumulative average use provided the most linear and consistent associations suggesting that this represents the most accurate measure over time and also provided more statistical power by utilizing assessments throughout all follow-up periods. Notably, our assessment of cumulative average alcohol intake reflects predominantly alcohol intake in mid to later adult life, since we first began assessing alcohol use in 1980 when the participants were aged 34-59. Even a low level of alcohol consumption was modestly but significantly associated with breast cancer risk (for 5-9.9 grams/day (equivalent to 3-6 glasses of wine per week) multivariate (MV) RR 1.15 (95% CI 1.06-1.24) 332 cases/100,000 person-years). In addition, women who consumed at least 30 grams/alcohol
