Table 9

Studies of cigarette smoking and breast cancer risk according to the ER status of the tumor

First author, study yearStudy designNo. of cases/controls (or no. in cohort)ComparisonER+ tumorsER− Tumors
OR (95% CI)aOR (95% CI)
Manjer, 2001 (63)Cohort268/1090220+ cigarettes/day vs. never smokers0.8 (0.5–1.4)2.6 (1.2–5.9)
Morabia, 1998 (68)Case-controlb242/105920+ cigarettes/day vs. never2.4 (1.4–4.5)4.3 (1.4–13.2)
London, 1989 (192)Cohort1788/11755725+ cigarettes/day vs. never smokers1.4 (1.0–1.8)1.1 (0.7–1.6)
  • a OR, odds ratio; CI, confidence interval.

  • b A population-based case-control study.