Risk factors associated with breast cancer in Ethiopia: A systematic review and meta-analysis (2000-2025)

Breast cancer is the leading malignancy among women in Ethiopia and represents a growing public health concern. Although several studies have examined potential determinants, findings remain fragmented and inconsistent. This study aimed to systematically synthesize evidence on risk factors associated with breast cancer among women in Ethiopia.

A systematic review and meta-analysis were conducted following PRISMA guidelines. Electronic databases were searched for observational studies published between January 2000 and December 2025. Studies reporting associations between potential risk factors and breast cancer among Ethiopian women were included. Study quality was assessed using the Newcastle-Ottawa Scale, with most studies rated as moderate to high quality. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using random-effects models. Statistical heterogeneity was assessed using the I² statistic.

Fourteen studies met the inclusion criteria. Overweight/obesity was significantly associated with increased odds of breast cancer (OR = 2.61; 95% CI: 1.86-3.66; I² = 0.0%; n = 4 studies), as was a family history of breast cancer (OR = 2.61; 95% CI: 1.64-4.15; I² = 0.0%; n = 3 studies). Hormonal contraceptive use (OR = 3.19; 95% CI: 1.93-5.29; I² = 0.0%; n = 3 studies) and lack of breastfeeding (OR = 3.49; 95% CI: 2.51-4.85; I² = 0.0%; n = 3 studies) were also associated with increased odds. Menopausal status showed a significant association (OR = 3.58; 95% CI: 1.39-9.27; I² = 44.4%; n = 2 studies), although based on a limited number of studies. Younger age was associated with lower odds compared with older women (OR = 0.43; 95% CI: 0.11-0.98; I² = 0.0%; n = 3 studies).

Breast cancer risk among women in Ethiopia is influenced by metabolic, reproductive, and hormonal factors. The findings highlight the importance of obesity prevention, reproductive health education, and early detection strategies within the Ethiopian context. Further well-designed prospective studies are needed to strengthen causal inference and inform national cancer control policies.