Breast Pathology and Cancer Diagnosis: A Link Between Hormonal Replacement Therapy and Breast Cancer Risk

Abstract

Objective: The main objective of this study was to investigate the link between the hormonal replacement therapy and the risk of breast cancer. Study Design: Case-control study Place and Duration of Study: This study was conducted at the Department of Pathology, Watin Medical and Dental College, Rawalpindi from January 2019 till January 2020. Materials and Methods: In this study 700 females, aged form 50 to 70 years were included. All of these females were past menopause and recently got diagnosed with the primary invasive breast carcinoma. All the data of patients was collected from Watin medical and dental college hospital’s data base. The women included in this study were divided into four groups: the one that did not have history of hormonal replacement therapy, the one with less than 2 years of HRT, the one with 2 to 5 years of HRT and the one with more than 5 years of HRT. These groups were compared using ANOVA test and chi-square test. To measure the hazard ratio of the prevalence of breast cancer in accordance to the time period of hormonal replacement therapy, Cox proportional hazards regression analysis was used. SAS software was used to analyze all of the data. P value less than 0.05 was considered significant. Results: Out of 700 women included in this study, 15.1% had used HRT at some point in their life. 0.7% of the women got diagnosed with the breast cancer newly after almost 5 years of follow up. The hazard ratio was 1.35 (95% CI 1.33, 1.40) of breast cancer risk in hormonal replacement therapy users in comparison to the non-users. The results show that the occurrence of breast cancer increases with the increase in the duration of HRT. The women who got HRT for less than 2 years had hazard ratio of 1.09 (95% CI 1.05, 1.23). The women who got HRT for 2 to 5 years had hazard ratio of 1.42 (95% CI 1.36, 1.50) and the one who got this therapy for more than 5 years had hazard ratio of 1.83(95% CI interval 1.74, 1.93). This pattern of increase in the breast cancer incidence with the increase in HRT duration was observed in both, the women who had invasive breast carcinoma and the women who had ductal carcinoma in situ. The breast cancer risk associated with HRT was also more in older women and the women with breasts of high density. Conclusion: As the results show, the risk of breast cancer do increase with the use of hormonal replacement therapy. As the duration of HRT increased, so did the risk of breast cancer. Risk factors like old age and higher breast density also increased the risk of breast cancer related to HRT.