Fig. 4From: Breast cancer risk factors in Iranian women: a systematic review and meta-analysis of matched case–control studiesThe association between breast cancer and different risk factors. A: Abortion history (yes vs no); B: OCP use (yes vs no); C: HRT (yes vs no); D: breastfeeding history (yes vs no); E: breastfeeding duration (< 24 months vs ≥ 24 months)Back to article page