Effectiveness and safety of neoadjuvant therapy in triple-negative breast cancer in a real-world population.

Objective: Triple-negative breast cancer is a subtype of aggressive breast cancer. Our aim is to evaluate the effectiveness and safety of neoadjuvant treatment in early-stage triple-negative breast cancer and to identify predictors of pathological complete response.

Methods: This is a single-center, retrospective study involving 79 patients with triple-negative breast cancer who initiated neoadjuvant treatment between January 2017 and October 2022. Descriptive analyses were performed as appropriate. Statistical analysis utilized bivariate logistic regression to explore the presence of factors related to pathological complete response, and the Kaplan-Meier method was employed for survival analysis.

Results: In the overall population, 27 patients (n=78; 34.6%) achieved pathological complete response in the breast and axillary lymph nodes, and 31 (n=73; 42.5%) achieved a grade 5 pathological complete response in the breast, according to the Miller and Payne classification. The addition of platinum to standard therapy improved both breast and axillary lymph node pathological complete response rates. Age less than 40 years was identified as a predictor of pathological complete response in our study population through bivariate analysis, while Ki67 levels lower than 70% were associated with a lower pathological complete response rate. Adverse events were reported in 72 patients (91.1%), with grade 3-5 adverse events observed in 33 (41.8%). There was a particularly notable increase in gastrointestinal and hematological adverse events when platinum was added.

Conclusions: In this population, we observed moderate rates of pathological complete response with acceptable chemotherapy tolerance. Platinum-based chemotherapy appears to enhance the likelihood of achieving pathological complete response, albeit with a less favorable safety profile. Therefore, evaluating the benefit-risk balance is crucial when selecting the optimal chemotherapy regimen for individual patients.