Prevalence of breast cancer subtypes and their association with reproductive factors

Abstract

Introduction: Stimulus-estrogenic factors are associated with breast cancer. Currently, the behavior according to molecular subtypes is being studied. Objective: To establish the prevalence of these subtypes and their association with reproductive factors in women attended in centers in northeastern Colombia. Method: Observational cross-sectional study in women with breast cancer subtypes luminal and HER2 during 2012 -2021. Sociodemographic variables, stimulus-estrogenic factors and tumor stage were investigated. Results: In total, 347 patients met eligibility criteria, corresponding to luminal A 49.8% (95% confidence interval [95%CI]: 44.5-55.1), luminal B 29.1% (95%CI: 24.3-33.9) and HER2 15.5% (95%CI: 11.7-19.4). Women with luminal B breast tumors were at higher risk of having locally advanced stages (odds ratio [OR]: 1.83; 95%CI: 1.11-3.01; p = 0.02). Grouping the luminal subtypes versus HER2 showed that 40.72% of patients with luminal subtypes had not lactated, compared to 69.71% HER2 (statistically significant difference in favor of luminal A; OR: 1.91; 95%CI: 1.02-3.53; p = 0.041). Conclusions: The prevalence of luminal tumors is 84.5%. There is a differential association between the history of breastfeeding and the appearance of luminal subtypes, i.e., women who did not breastfeed are more likely to have HER2. No association was established with other factors studied.