Table 7

Studies of cigarette smoking before, during, and after a first full-term pregnancy, and breast cancer risk

First author, study yearStudy designNo. of cases/controls (or no. in cohort)ComparisonBefore first birthAfter first birth
OR (95% CI)aOR (95% CI)
Egan, 2002 (84)Cohort3140/78206 5+ years before and 20+ years after vs. never1.1 (1.0–1.3)b1.0 (1.9–1.1)
Hunter, 1997 (58)Cohortc466/466 5+ years smoking duration vs. never1.1 (0.8–1.6)
Adami, 1988 (183)Case-control422/52710+ years smoking duration vs. never0.7 (0.3–1.4)
  • a OR, odds ratio; CI, confidence interval.

  • b A statistically significant test of trend was reported.

  • c A nested case-control study. In this study, women with rapid NAT2 acetylation genotype had a relative risk of 1.5 (0.9–2.6).