EVALUATION OF THE PATHOLOGIC COMPLETE RESPONSE IN PATIENTS WITH TRIPLE-NEGATIVE BREAST CANCER IN A PUBLIC HOSPITAL

Background: Triple-negative breast cancer (TNBC) accounts for about 15% to 20% of breast cancer diagnoses and has an aggressive natural history and poor prognosis. Patients who do not get a pathologic complete response (pCR) after neoadjuvant chemotherapy have a higher risk of relapse. Objectives: To evaluate the pCR in patients with TNBC who have undergone treatment at a single public hospital in the south of Brazil. The analysis of disease-free survival (DFS) and overall survival (OS) were the secondary objectives. Methods: A retrospective clinical study including patients with non-metastatic TNBC who underwent neoadjuvant chemotherapy between 2012 and 2016. The patients were alocated according to the chemotherapy protocol received: AC-T (doxorubicin 60mg/m2 q3w and cyclophosphamide 600mg/m2 q3w for 4 cycles followed by paclitaxel 80mg/m2 q1w for 12 weeks) and AC-TC (with the addition of carboplatin AUC 2 q1w concurrently with paclitaxel). Results: In total thirty-three patients (21 in the AC-T and 12 in the AC-CT group) were included in the study. There was no significant difference between the groups regarding the clinical staging T and N, subtype histological, grade and Ki-67. The pCR was obtained in 10 patients (47.6%) in the AC-T group and 7 (58.3%) in the AC-CT group, but without significant difference (OR 0.64, 95% CI 0.15 -2.72; = 0.721). In the univariate analysis there was no significant difference for pRC comparing clinical tumor size (T1-T2 versus T3-T4), clinical lymph node status (N0 versus N1-N2) and histological grade (G1-G2 versus G3). The rate of toxicity grade 3 or above was 75% in the AC-CT group and 19% in the AC-T group (OR 0.08; CI 0.01-0.43; p = 0.0028). The median values of SLD and SG were not reached in this study. Conclusion: Data from this retrospective study demonstrated that neoadjuvant chemotherapy with carboplatin in patients with TNBC did not significantly increase pCR rates but led to a significant increase in grade 3 toxicity compared to the non-carboplatin group.