Comprehensive Meta-analysis of Risk Factors for Breast Cancer among Indian Women

Abstract

Background: Breast cancer is the most common cancer diagnosed among Indian women due to change in life style, reproductive patterns and rapid urbanization. Methods: A systematic search was conducted for case control studies published between January 2010 and April 2025. Data were extracted from 19 studies. Pooled odds ratios (OR) with 95% confidence intervals (CI),heterogeneity was assessed with I² statistics, while publication bias was evaluated using funnel plots and Egger’s test. Study quality was appraised using the Newcastle–Ottawa Scale. Results: Sociodemographic risks included unmarried status (OR=1.96; 95% CI: 1.09–3.54) and late age at marriage > 21 years (OR= 2.66; 95% CI: 1.90–3.73). Family history of breast cancer doubled the risk (OR=2.35; 95% CI: 1.73–3.18), and past benign breast disease showed a strong association (OR=4.28; 95% CI: 2.50–7.35). Central obesity (WHR > 0.85) significantly increased risk (OR=2.74; 95% CI: 1.85–4.07), although BMI > 25 kg/m² alone was not significant. Lifestyle factors such as non-vegetarian diet (OR = 1.62; 95% CI: 1.19–2.21), tobacco use (OR=1.67; 95% CI: 1.24–2.24), and high-fat diet (OR=4.20; 95% CI: 2.76–6.42) demonstrated strong associations. Reproductive risk factors—including early menarche (OR =1.95), late menopause (OR=1.92), OCP use (OR=2.01), low parity (OR=1.52), previous abortions (OR=2.48), and breastfeeding <6 months (OR= 4.12)—were all significantly linked to higher risk. Several subgroups exhibited notable heterogeneity and occasional publication bias. Conclusion: Modifiable risks present critical opportunities for prevention.Women with non-modifiable factors warrant targeted screening and risk stratification.