Histopathological predictors of response to treatment in patients with hormone receptor positive her2 negative breast cancer: A single center study

Abstract

Introduction: One in 18 women develops breast cancer throughout her life, this being the leading cause of death from cancer in women. The purpose of the present study was to establish the predictive value of the histopathological factors present in malignant breast tumors with positive hormone receptors Her2 negative in a group of patients in an oncology reference center.

Methodology: This longitudinal study was conducted at the "Dr. Juan Tanca Marengo" National Oncology Institute in Guayaquil - Ecuador. The inclusion period was from 2007 to 2009, with an observation period until December 2020. With a non-probabilistic sample, women with hormone-positive Her2 Neu negative breast cancer who had received adjuvant treatment during a follow-up period were included. Demographic, clinical, tumor-related, TNM classification and survival variables were measured. A descriptive univariate analysis of the sample is performed, a bivariate analysis comparing the group of deceased patients with the group of living patients; a correlation analysis between variables in scale; a survival analysis; and a COX regression is presented to predict survival based on the variables.

Results: 105 patients, 54.1 ± 11.4 years old, entered the study. 58.1% of cases are in the early stage, and 41.9% are in a locally advanced stage. Overall survival (OS) was 67.6% at 14 years, and progression-free survival (PFS) was 59.05%. Hormone blocking therapy was associated with PFS (R=0.544, P<0.01) and OS (R=0.399, P<0.05). Lymph node involvement in stage N0 had a PFS of 11.9 ± 0.4 years; stage N3 was 6.8 ± 1.6 years (P<0.01). The Cox regression model to predict progression-free or disease-free life was statistically significant with hormone blockade therapy (R2=0.607, P<0.001).

Conclusion: Hormone blockade therapy maintained for more than five years positively impacts the survival of patients with hormone-positive Her2 Neu negative breast cancer.