Impact of Pathologic Complete Response on the Prognosis of Triple-Negative Breast Cancer Patients: A Cohort Study

Introduction Triple-negative breast cancer (TNBC) is a molecular subtype in which estrogen (ER)/progesterone receptor (PR) and human epidermal growth receptor 2 (HER2) expression does not occur. The objective of this study was to analyze the impact of pathologic complete response (pCR) after neoadjuvant chemotherapy on the prognosis of triple-negative breast cancer (TNBC) patients. Methods This cohort study was conducted in a private-sector oncology clinic located in the city of Teresina, Brazil. Medical charts of 532 breast cancer patients treated from 2007 to 2020 were analyzed. Of these patients, 83 women with TNBC were selected (10 patients were excluded from the study). Univariate and multivariate analyses (Cox regression) were performed to evaluate the impact on patient survival, comparing patients with or without pCR. A significance level of 5% was set. Overall survival (OS) and disease-free survival (DFS) curves were constructed according to the Kaplan-Meier model. Results Angiolymphatic invasion and positive sentinel lymph node were associated with a lower OS and/or DFS in TNBC (p<0.05). The 10-year OS was 78% and 49%, and the 10-year DFS was 97% and 32% in patients with or without pCR, respectively. Conclusion pCR after neoadjuvant chemotherapy was associated with improvement in OS and DFS in TNBC patients.