Gene Polymorphism at Codon 72 as a Response Predictor for Neoadjuvant Chemotherapy.

Introduction: Breast cancer is the most prevalent cancer in women worldwide, and neoadjuvant chemotherapy is a favored method for achieving pathologic complete response (pCR). The gene is involved in inducing the response to chemotherapy drugs.

Objectives: The present study sought to correlate polymorphism variants at codon 72 with pCR to neoadjuvant chemotherapy.

Casuistry And Methods: The study was conducted in the state of Sergipe, in northeastern Brazil. A total of 206 patients with a histopathological diagnosis of breast cancer who underwent neoadjuvant chemotherapy from 2019 to 2022 were included. DNA samples were collected for the evaluation of polymorphism at codon 72. A prospective evaluation of the cases was conducted to verify the surgical pathologic response after chemotherapy; the Response Evaluation Criteria in Solid Tumors (RECIST) were used. The study was approved by the University of São Paulo Ethics and Research Committee.

Results: Of the 168 patients, 44.6% were Arg72Arg, 17.3% were Pro72Pro, and 38.0% were Arg72Pro; pCR was achieved in 21.4% of the patients; 10.1% had progressive disease, 13.7% had stable disease, and 54.2% had a partial pathologic response. The only predictor of pCR in multivariate regression was immunohistochemistry ( < 0.001). In the multivariate analysis, Arg72Pro and Pro72Pro increased the odds of the patient evolving with stable disease. This study was innovative in demonstrating a predictor of stable disease in response to neoadjuvant chemotherapy.

Conclusion: polymorphism at codon 72 is not a predictor of pCR, but it can be a predictor of stable disease.