Precise health perspectives: Unraveling the interplay of reproductive factors in hormone receptor–positive and triple-negative breast cancer among Bangladeshi women.
Authors: Islam Muhammad Rafiqul , Siddiqua Syeda Masuma , Al Ayub Salman Bashar , Islam Rashedul , Hossain Anwar , Saha Beauty , Khatun Nazrina , Ueno Naoto Tada 
Published: June 2024

e22503 Background: Breast cancer is a major cause of cancer-related deaths in Bangladesh, with an incidence rate of 22.5 per 100,000 females per year. Urbanization is linked to the increasing incidence of breast cancer, altering lifestyles and reproductive behaviors. Reproductive factors play a key role in breast cancer risk, with variations between TNBC and Hr+BC. This study aims to investigate the relationship between TNBC and Hr+BC and reproductive factors among Bangladeshi women to provide valuable insights for breast cancer prevention and management in the region. Methods: Conducted in a tertiary hospital-based setting, our survey included 1000 adult Bangladeshi females aged 18 or older. Among them, 250 had TNBC, 250 had Hr+BC, and the remaining 500 were non-cancer individuals. Propensity score matching (PSM) was utilized to match the age and age of menarche of 500 healthy individuals with 250 TNBC and 250 Hr+BC individuals separately. The presence of TNBC or Hr+BC was confirmed through participants' previous histopathology reports. Detailed reproductive characteristics and demographics were collected using a structured questionnaire. Significant variables identified in the bivariate model were included in the adjusted multivariable multinomial logistic regression. Results: Demographic and reproductive characteristics in the Hr+BC, TNBC, and healthy groups were analyzed. The mean ±SEM age was Hr+BC (44.96±0.65), TNBC (42.74±0.65), and healthy (39.31±0.55) years. Patients with Hr+BC and TNBC, compared to healthy individuals, were older, with delayed first marriage and first birth, and more abortions. Both demographic and reproductive factors correlated with Hr+BC and TNBC, with higher likelihood in postmenopausal, irregular menstruation, vaginal delivery, breastfeeding > 6 months, and hormonal contraceptive use. Reproductive factors associated with Hr+BC and TNBC risk were outlined. The adjusted model revealed delayed menarche increased Hr+BC risk by 1.71 times (OR 1.71, 95% CI 1.19-2.44) but decreased TNBC risk by 30% (OR 0.70, 95% CI 0.52-0.95). Longer time between first marriage and first birth (OR 1.40, CI 95% 1.10-1.78), irregular menstruation (OR 2.83, 95% CI 1.31-6.10), and hormonal contraceptive use (OR 5.68, 95%1.52-21.25) increased Hr+BC risk; pre-obesity decreased risk (OR 0.36 95% CI 0.18-0.72). Irregular menstruation (OR 4.30, 95% CI1.87-9.42) and hormonal contraceptive use (OR 8.54, 95% CI 1.81-40.14) increased TNBC risk. Higher abortions raised TNBC risk (OR 2.27, 95% CI 01.30-3.98) but not Hr+BC. Living in rural Bangladesh increased risk for both Hr+BC (4.81 times) and TNBC (16.77 times). Conclusions: Our findings highlight the significant impact of reproductive factors on Hr+BC and TNBC development in Bangladeshi women, emphasizing variations in risk profiles among different breast cancer types.