shows the characteristics of drinkers compared with nondrinkers. Drinkers (51%) tended to be slightly younger, predominantly white, more educated, former or current smokers, and enrolled from KPNC, and they had higher consumption of folate (ie, diet and supplements) and were of normal weight. The majority of drinkers were diagnosed with early-stage disease (stage I), and had breast-conserving surgery and adjuvant treatment. There were no significant differences between drinkers and nondrinkers by menopausal status, positive lymph nodes, and tamoxifen use.
Among the drinkers, most women drank wine (88.5%), followed by liquor (42.1%) and beer (35.7%), and the median amount of alcohol consumed was 5.96 g/d (standard deviation, 17.13; ). Based on median levels, postmenopausal, normal weight, and ER-positive women drank more alcohol compared with premenopausal, overweight/obese, and ER-negative women, respectively.
Characteristics of Alcohol Consumption in the LACE Study
A total of 293 breast cancer recurrences (of which 71.9% were distant metastases) and 273 deaths were ascertained through September 8, 2009. Among the 273 deaths, 154 (56.4%) were attributable to breast cancer, 24 (8.8%) to other cancers, 32 (11.7%) to cardiovascular causes, and 63 (23.1%) to other causes. Mean follow-up times from cohort entry until recurrence or death were 3.59 years (range, 0.27 to 9.11 years) and 4.83 years (range, 0.34 to 9.35 years), respectively. Overall, cohort members were followed 7.42 years (range, 0.11 to 9.62 years).
Drinking 6 or more grams of alcohol per day compared with no drinking was possibly associated with an increased risk of breast cancer recurrence (HR, 1.35; 95% CI, 1.00 to 1.83) and death from breast cancer (HR, 1.51; 95% CI, 1.00 to 2.29), adjusting for age at diagnosis, prediagnosis BMI, total folate intake, stage of disease, hormone receptor status, tamoxifen use, treatment, and positive lymph nodes (). A significant dose-response for greater alcohol intake and increasing risk of recurrence was also observed (P for trend = .04).
Alcohol Consumption and Breast Cancer Recurrence and Survival in the LACE Study
Similar to overall alcohol intake, drinking at least two servings per week of wine compared with none was also associated with an increased risk of recurrence (HR, 1.33; 95% CI, 0.97 to 1.81) and breast cancer death (HR, 1.37; 95% CI, 0.88 to 2.14; ). No clear associations were observed for consumption of beer or liquor (not shown). There was a suggestion that consuming alcohol was associated with a decreased risk of death from non–breast cancer causes (HR, 0.73; 95% CI, 0.45 to 1.20 for consumption < 6 g/d; and HR, 0.77; 95% CI, 0.47 to 1.27 for consumption ≥ 6 g/d). No associations were observed for overall death and drinking 6 or more grams of alcohol per day. After excluding the 44 women who recurred or died within 1 year of study enrollment, the above results for drinking 6 or more grams of alcohol per day did not change and in fact became stronger for recurrence (HR, 1.44; 95% CI, 1.05 to 1.98; P for trend = .03) and breast cancer death (HR, 1.69; 95% CI, 1.08 to 2.64; P for trend = .03). Similarly, even with a smaller patient count after excluding 219 women who were enrolled from Utah, there was a modest increase in significance for recurrence (HR, 1.45; 95% CI, 1.05 to 2.00; P for trend = 02) and breast cancer death (HR, 1.59; 95% CI, 1.03 to 2.44; P for trend = .04).
presents analyses of total alcohol consumption stratified by menopausal status, prediagnosis BMI, and ER status and risk of recurrence and breast cancer death. Among postmenopausal women, consuming 6 or more grams of alcohol per day was associated with an increased risk of recurrence (HR, 1.51; 95% CI, 1.05 to 2.19) and breast cancer death (HR, 1.72; 95% CI, 1.05 to 2.81) with a positive dose-response of greater alcohol intake and increasing risk (P for trend = .03 and .04, respectively). For premenopausal women, no associations were apparent. Similarly, among overweight and obese women, consuming 6 or more grams of alcohol per day was associated with an increased risk of recurrence (HR, 1.60; 95% CI, 1.08 to 2.38) and an elevated, yet nonsignificant, risk of breast cancer death (HR, 1.61; 95% CI, 0.94 to 2.76) with a positive dose-response (P for trend = .03 and .09, respectively). For normal weight women, no associations were found. Finally, while the number of women with ER-negative tumors was small, no difference in risk of recurrence and breast cancer death by ER status was observed for alcohol intake.
Alcohol Consumption and Risk of Breast Cancer Recurrence and Death by Selected Factors in the LACE Study