Evaluation of Pathological Complete Response Rate in Patients with HER2-Positive Breast Cancer Undergoing Neoadjuvant...

This study aimed to evaluate the pathological complete response rate (pCR) in HER2 breast cancer by comparing anthracycline-containing and anthracycline-free regimens.

A retrospective cohort study was performed to obtain data from women undergoing neoadjuvant chemotherapy associated with two groups: • AC-TH patients: treated with trastuzumab with confirmed HER2-positive breast cancer using an anthracycline-based therapy followed by taxane. • CTH patients: recieved trastuzumab concurrently during taxane use in an anthracycline-free regime (carboplatin plus a taxane). Clinical data, pCR, free-disease survival, and overall survival were compared using chi-square, log-rank Mantel-cox, multinomial logistic and Cox regression tests (p < 0.05, SPSS v20.0).

There are no differences between AC-TH and CTH in terms of: • pCR (p=0.745), •Disease- free survival (p=0.840), • Overall survival (p=0.642). The major prognostic factor for overall survival were: • Nodal metastasis (p=0.043, HR = 0.263 (CI95% = 0.072-0.959) and • Dose reduction (p=0.021, HR = 0.070 (CI95% = 0.007-0.667) and For disease-free survival: • Age (p=0.038, HR = 3.288, CI95% 1.068-10.123) and • pCR (p=0.028, HR = 0.354, CI95% = 0.140-0.895). AC-TH showed more cardiotoxicity (9.3% vs 3.4%).

Chemotherapy regimens with or without anthracycline, when combined with trastuzumab, demonstrate similar rates of pathological complete response and recurrence-free survival. Pathological complete response and age are independent variables associated with recurrence. However, the use of anthracycline leads to increased cardiotoxicity.