Association of reproductive factors with triple-negative breast cancer and hormone receptor–positive breast cancer among Bangladeshi women

Abstract Objective Despite Bangladesh's high breast cancer prevalence (19.3 cases per 100,000 individuals), data are scarce regarding the reproductive epidemiology of breast cancer in Bangladesh. We investigated whether reproductive factors are associated with hormone receptor–positive breast cancer (Hr + BC) and triple-negative breast cancer (TNBC) in Bangladeshi women. Methods and Analysis In a tertiary hospital-based setting, we surveyed 1000 adult Bangladeshi females aged 18 or older. Of which 250 had TNBC, 250 had Hr + BC, and the remaining 500 were non-cancer individuals. Propensity score matching (PSM) was carried out to match the age and age of menarche of the potential 500 healthy individual with 250 TNBC and 250 Hr + BC individuals in separate estimates. The presence of TNBC or Hr + BC was the outcome variable, and the participants’ previous histopathology report confirmed it. We collected participants; detailed reproductive characteristics and demographics through a structured questionnaire. Those significant variables in the bivariate model were finally included in the adjusted multivariate multinomial logistic regression. Results The mean ages of participants in the Hr + BC, TNBC, and healthy groups were 44.96, 42.74 and 39.31 years, respectively. Adjusted binary multivariate logistic regression suggested that women living in rural areas with increased number of abortions, experiencing irregular menstruation, and consumption of hormonal contraceptives increased the risk for Hr + BC and TNBC compared to the healthy individuals. However, the magnitude of the risk varies across the types of breast cancer. One year increase in the age of menarche significantly increased the risk for Hr + BC by 1.71 times; however, it decreased the risk for TNBC by 30%. Conclusion Our findings imply that women's reproductive factors play a pivotal role in developing Hr + BC and TNBC; however, the degree of risk differs between the different types of breast cancer.