Table 1. Pooled ORs and 95% CIs for the Association Between Breastfeeding and Ovarian Cancer Risk in the Ovarian Cancer Association Consortium.
| Variable | Women with ovarian cancer, No. (%) | Breastfed, ever vs never, OR (95% CI)a |
|---|---|---|
| Invasive | ||
| Overall | 7991 (100) | 0.76 (0.71-0.80) |
| Serous | ||
| Low-grade | 324 (4) | 0.78 (0.61-1.01) |
| High-grade | 4718 (59) | 0.75 (0.70-0.81) |
| Mucinous | 508 (6) | 0.93 (0.76-1.14) |
| Endometrioid | 1027 (13) | 0.73 (0.64-0.84) |
| Clear cell | 452 (6) | 0.78 (0.64-0.96) |
| Other | 962 (12) | 0.75 (0.65-0.87) |
| P value for heterogeneity | NA | .46 |
| Borderline | ||
| Overall | 1843 (100) | 0.72 (0.64-0.81) |
| Serous | 1080 (61) | 0.77 (0.66-0.89) |
| Mucinous | 686 (39) | 0.68 (0.57-0.82) |
| P value for heterogeneity | NA | .31 |
Abbreviations: NA, not applicable; OR, odds ratio.
a
Adjusted for age, race/ethnicity, oral contraceptive use, parity, birth decade, and study site.