Comprehensive analysis of clinicopathological features and outcomes of hormone positive breast cancer from a tertiary care centre in India.

e12581 Background: The composite data of clinicopathological features and outcomes in hormone receptor-positive (HR+) breast cancer from a low-middle income setting will provide valuable insight with respect to management of HR+ breast cancer. Methods: We conducted a retrospective analysis of individuals diagnosed with HR+ breast cancer at a tertiary care facility between May 2013 and April 2023. The primary outcome of the study was overall survival (OS) and secondary outcome was invasive disease free survival (iDFS) and factors affecting OS and iDFS. Results: The analysis included 2245 patients diagnosed with HR+ breast cancer. The median age at diagnosis was 48 (22-89) years and the median duration of symptoms were 5 months. A total of 1131 (50.37%) patients were post-menopausal at presentation and 24.5% of the patients are diagnosed with young onset breast cancer (age less than 40 years). Progesterone receptor (PR) negativity was seen in 15.45% of the cases. The clinical stage (American Joint Committee on Cancer 7 th edition) of disease at presentation was: stage I in 113 patients (5 %), II in 921 patients (41 %), III in 874 patients (38.9 %) and stage IV in 337 patients (15 %). A total of 977 patients (43.6%) were HR+/Her2 neu+ and 1268 patients (56.4%) were HR+/Her2neu negative. The median duration of follow up was 50.1 months (0.3-140.26 months). The 5-year iDFS was 87.5% (95% CI; 84.8-89.8) for early breast cancer (EBC) and 67.4% (95%CI; 63.2-71.2) for locally advanced breast cancer (LABC). Age less than 40 years [HR-2.31 95% CI(0.25 (0.10-0.57))], PR negativity [HR-0.50 95%CI(0.26-0.96) and higher lymph node ratio (>0.20) [HR-2.31 95% CI(1.14-4.68)] were significantly associated with iDFS in multivariate analysis. The 5-year OS for EBC was 96.1% (95% CI; 94.3-97.3) and 86.1% for LABC (95% CI; 82.3-88.8). Tumor size ≥5 cm was the only independent predictor of overall survival (HR: 8.11, p=0.003). Conclusions: This is the largest Indian study evaluating the clinicopathological features and outcomes of hormone positive breast cancer in a real world setting. Approximately half of the patients are diagnosed at an advanced stage (III/IV) which in turn have poor outcomes. Early initiation of screening mammography and use of adjuvant CDK4/6 inhibitors could be seen as potential option to improve outcomes in our cohort.