Overall and disease-free survival base on the intrinsic molecular subtype of a cohort of 2,200 patients with breast cancer – experience at a Colombian comprehensive cancer center

Abstract

Introduction: the survival of patients with breast cancer varied depending on the timing of the diagnosis, the biological characteristics of the tumor, racial disparities and the therapies received. There are no Colombian reports on survival based on molecular subtypes. Objective: to describe the Overall Survival and Disease-Free Survival according to the immunohistochemistry subtypes and the clinical characteristics of the patients. Methodology: retrospective survival study. The cases were obtained from the institutional registry. including female breast cancer patients that underwent surgery between 2008 and 2012; the women were contacted by telephone to check on their vital condition and health status. The analysis was age-based, estimating survival up to the relapse of the disease, death or last control. Kaplan Meier curves were developed based on variables and subtypes. Results: 2,200 patients with an average age of 56.4 years (SD = 12.7) were treated; 66.5% were older than 49 years of age. 48.1% were early stages (I-IIA) and 38.7% were locally advanced disease (IIB-IIIC). The subtypes classification was as follows: Luminal A 37.7%, Luminal B/HER2- 33.1%, Luminal B/HER2+ 15.7%, HER2+ 4.7% and Triple negative 6.1%. The mean follow-up was 41 months, with an overall survival of 88.4% (CI95%: 86.8-89.8), and a disease-free survival of 86.5% (CI95%: 84.9 – 88.0). The overall survival based on subtypes was Luminal A 94.7%, Luminal B/ HER2- 84.7%, Luminal B/HER2+ 88.1%, HER2+ 77.8% and Triple negative 81.0%. Conclusions: high rates of overall survival and disease-free survival are found among our population, similar to those reported in the world literature. There were no differences in the biological behavior between the molecular subtypes in pre and post-menopausal women. Contrary to other trials reported, the results showed a high frequency of positive hormone tumors (85%) and a low frequency of triple negative tumors (8.9%), a finding that deserves further evaluation with prospective studies.