Smoking and risk of breast cancer in the Generations Study cohort

• DOI: 10.1186/s13058-017-0908-4
• Publication Date: 2017-10-30T12:04:50Z
• Authors: Michael E. Jones; Minouk J. Schoemaker; Lauren B. Wright; Alan Ashworth; Anthony J. Swerdlow
• Keywords: Menarche; Surgical oncology

Plausible biological reasons exist regarding why smoking could affect breast cancer risk, but epidemiological evidence is inconsistent. We used serial questionnaire information from the Generations Study cohort (United Kingdom) to estimate HRs for in relation adjusted potentially confounding factors, including alcohol intake. Among 102,927 women recruited 2003–2013, with an average of 7.7 years follow-up, 1815 developed invasive cancer. The HR (reference group was never smokers) 1.14 (95% CI 1.03–1.25; P = 0.010) ever smokers, 1.24 1.08–1.43; 0.002) starting at ages < 17 years, and 1.23 (1.07–1.41; 0.004) 1–4 after menarche. Breast risk not statistically associated interval initiation first birth (P-trend 0.97). Women a family history (ever smoker vs 1.35; 95% 1.12–1.62; had significantly larger smokers (P interaction 0.039) than without 1.07; 0.96–1.20; 0.22). prominent age 0.003) relative menarche 0.0001). Smoking modest increased cancer, particularly among who started adolescent or peri-menarcheal ages. greater disease.