TY - JOUR T1 - Cigarette Smoking, Physical Activity, and Alcohol Consumption as Predictors of Cancer Incidence among Women at High Risk of Breast Cancer in the NSABP P-1 Trial JF - Cancer Epidemiology Biomarkers &amp; Prevention JO - Cancer Epidemiol Biomarkers Prev SP - 823 LP - 832 DO - 10.1158/1055-9965.EPI-13-1105-T VL - 23 IS - 5 AU - Land, Stephanie R. AU - Liu, Qing AU - Wickerham, D. Lawrence AU - Costantino, Joseph P. AU - Ganz, Patricia A. Y1 - 2014/05/01 UR - http://cebp.aacrjournals.org/content/23/5/823.abstract N2 - Background: NSABP P-1 provides an opportunity to examine the association of behavioral factors with prospectively monitored cancer incidence and interactions with tamoxifen. Methods: From 1992 to 1997, 13,388 women with estimated 5-year breast cancer risk greater than 1.66% or a history of lobular carcinoma in situ (87% younger than age 65; 67% postmenopausal) were randomly assigned to tamoxifen versus placebo. Invasive breast cancer, lung cancer, colon cancer, and endometrial cancer were analyzed with Cox regression. Predictors were baseline cigarette smoking, leisure-time physical activity, alcohol consumption, and established risk factors. Results: At median 7 years follow-up, we observed 395, 66, 35, and 74 breast cancer, lung cancer, colon cancer, and endometrial cancer, respectively. Women who had smoked were at increased risk of breast cancer (P = 0.007; HR = 1.3 for 15–35 years smoking, HR = 1.6 for ≥35 years), lung cancer (P &lt; 0.001; HR = 3.9 for 15–35 years, HR = 18.4 for ≥35 years), and colon cancer (P &lt; 0.001; HR = 5.1 for ≥35 years) versus never-smokers. Low activity predicted increased breast cancer risk only among women assigned to placebo (P = 0.021 activity main effect, P = 0.013 activity–treatment interaction; HR = 1.4 for the placebo group) and endometrial cancer among all women (P = 0.026, HR = 1.7). Moderate alcohol (&gt;0–1 drink/day) was associated with decreased risk of colon cancer (P = 0.019; HR = 0.35) versus no alcohol. There were no other significant associations between these behaviors and cancer risk. Conclusion: Among women with elevated risk of breast cancer, smoking has an even greater impact on breast cancer risk than observed in past studies in the general population. Impact: Women who smoke or are inactive should be informed of the increased risk of multiple types of cancer. Cancer Epidemiol Biomarkers Prev; 23(5); 823–32. ©2014 AACR. ER -