From: Intrauterine environments and breast cancer risk: meta-analysis and systematic review
Type of study | Ref. | Year | Design | Cases | Controls (or cohort) | Country/place of study | Smoking status | OR (95% CI) | Comments |
---|---|---|---|---|---|---|---|---|---|
Case-control studies | [69] | 1996 | PCC | 53 | 470 | USA | Maternal smoking | Â | Crude ORs |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Yes | 0.9 (0.4–2.1) |  |
 |  |  |  |  |  |  | Paternal smoking |  |  |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Yes | 1.3 (0.9–1.7) |  |
 | [14] | 1996 | PCC | 1,086 | 1,321 | USA | Maternal smoking |  | Adjusted for age, menopausal status, and maternal smoking; OR (95% CI) for maternal smoking among early-onset breast cancer patients (≤ 30 years old) was 1.9 (1.0–3.4) |
 |  |  |  |  |  |  | Age 21–45 years |  |  |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Yes | 1.1 (0.9–1.3) |  |
 |  |  |  |  |  |  | Age 50–64 years |  |  |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Yes | 1.3 (0.9–2.1) |  |
 | [58] | 1997 | PCC | 522 | 484 | USA | Maternal smoking |  | Adjusted for age, study site, family history of breast cancer, breast biopsy, a combination variable including number of full-term births and age at first full-term pregnancy, age at menarche, menopausal status, body mass index, average lifetime alcohol consumption, and the number of mammograms |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Yes | 1.1 (0.8–1.4) |  |
 | [33] | 1998 | PCC | 507 | 433 | USA | Maternal smoking |  | Crude ORs |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Yes | 1.1 (0.9–1.5) |  |
 | [43] | 2001 | LCC | 319 | 768 | USA | Maternal smoking |  | Adjusted for attained age |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Yes | 2.7 (1.1–6.3) |  |
 | [35]a | 2002 | PCC | 1,535 | 1,534 | USA | Smoking |  | Adjusted for age and residential regions (states) |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Paternal smoking | 1.00 (0.88–1.13) |  |
 |  |  |  |  |  |  |    Maternal/parental smoking | 1.10 (0.84–1.42) |  |
 | [20] | 2005 | PCC | 2380 | 2,497 | Poland | Maternal smoking |  | Unadjusted; recalculated |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Yes (any exposure) | 1.19 (0.97–1.47) |  |
 |  |  |  |  |  |  | Paternal smoking |  |  |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Yes (any exposure) | 0.90 (0.77–1.05) |  |
Cohort studies | [31] | 2006 | Cohort | 249 | 1,024 | USA | Maternal smoking | Referent | Adjusted for age at diagnosis, diagnosis year, stage at diagnosis, and birth order, with exception of birth order, which is adjusted for maternal age Crude relative rates |
 |  |  |  |  |  |  |    No | 0.8 (0.5–1.1) |  |
 |  |  |  |  |  |  |    Yes (any exposure) |  |  |
 | [68] | 2005 | Cohort | 42 | (3,989) | USA | Maternal smoking |  |  |
 |  |  |  |  |  |  |    No | Referent |  |
 |  |  |  |  |  |  |    Yes (any exposure) | 0.49 (0.29–1.03) |  |
 |  |  |  |  |  |  |    ≤ 15 cigarettes a day | 0.33 (0.12–0.94) |  |
 |  |  |  |  |  |  |    >15 | 0.68 (0.26–1.73) |  |