Reproductive Factors Associated with the Risk of Breast Cancer among Malaysian Women: A Multi-Centre Case-Control Study

Abstract

Aim: This study was conducted to evaluate the association between reproductive factors and the risk of breast cancer among Malaysian women. Study Design: Case-control study. Place and Duration of Study: Oncology clinics of 6 selected hospitals from 3 states of Kedah, Kelantan and Penang, between June 2013 and May 2015. Methodology: We included 334 histologically confirmed breast cancer women and 345 population-based controls matched by age (within 5-year brackets) and ethnicity. Demographic and reproductive data were collected by in-person interviews using a self-administered questionnaire. Multiple logistic regression model was used to estimate multivariate-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) from logistic regression analyses. Results: The mean age of the cases was 51.95 (± 8.35) years while controls had 52.30 (± 9.14) years. The results showed that menopausal status was associated with the risk of breast cancer with [OR 0.36, 95%CI 0.20-0.62] for pre-menopause, and duration of use of contraceptives [OR 0.49, 95%CI 0.26-0.95] for 1-5 years and OR 0.22, 95% CI 0.10-0.53 for >5 years duration of usage. Also family history was found to be strongly associated with the risk [OR 2.86, 95%CI 1.55-5.26]. Conclusion: This study portrays the need for early screening among Malaysian women with identified risk factors in order to help in the timely detection of breast cancer and appropriate management.