Evaluating the Effectiveness of Neoadjuvant Therapy in Her2-Positive Invasive Breast Cancer: A Comprehensive Analysis of 167 Cases in Romania

TL;DR

This study analyzed 167 Romanian patients with Her2-positive breast cancer and found a 50.29% success rate for neoadjuvant therapy, with certain factors linked to better outcomes.

Contribution

The study is the largest of its kind in Romania and identifies pCR rates and predictors in Her2-positive breast cancer patients.

Findings

A 50.29% pathological complete response (pCR) rate was observed in Her2-positive invasive breast cancer patients.

Higher pCR rates were found in hormone-negative cases, Stage II cases, and cases with high Ki-67 values.

The study confirms that pCR is a strong predictor of improved survival outcomes in Her2-positive breast cancer.

Abstract

This study investigated treatment efficacy for 167 patients with invasive breast cancer. The treatment included chemotherapy and a targeted therapy for Her2-positive cancer. The overall success rate was 50.29%, meaning that in about half of patients the histopathological examination of resection specimens revealed a complete absence of invasive tumor cells in the breast tumor and the absence of tumor cell in the lymph nodes following therapy. The study identified some factors associated with a higher chance of therapy response. This study is the largest of its kind in Romania, and its results are similar to those of other studies on Her2-positive breast cancer.

Pathological complete response (pCR) following neoadjuvant therapy for IBC has shown a strong correlation with event-free survival and overall survival. Over the past three decades, the five-year net survival rate for breast cancer has generally increased; however, several Eastern European countries exhibit lower survival rates. Data from Romania, specifically regarding Her2-positive breast cancer response to therapy, are notably limited. Background/Objectives: The aim of our study was to evaluate the response to NAT using chemotherapy and Her2-targeted therapy in a cohort of 167 patients diagnosed with invasive breast cancer in our institution. Methods: We retrospectively analyzed 167 consecutive cases diagnosed with IBC in our institution between January 2020 and September 2024 with Stages II and III Her2-positive IBC. The overall pCR rates and several factors cited in the literature as predictors of pCR were analyzed. Results: Overall, the pCR rate was 50.29%, with higher values in 3+ cases (62.28%) compared to 2+ cases/ISH amplified (24.53%). Higher pCR rates were observed in hormone-negative cases, Stage II cases, estrogen receptor-negative cases, and high Ki-67 values. Patient age, ISH group, Her2 copy number, Her2:CEP17 ratio, and clinical lymph node involvement did not seem to influence pCR rates in our study. Conclusions: The data presented in our study represent, to the best of our knowledge, the largest cohort of patients diagnosed with Her2-positive IBC from Romania. The presented results and the pCR predictive factors were comparable to those cited in other studies on Her2-positive IBC cases.

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