From the Guidelines
The pathologic complete response rate for triple-negative breast cancer after neoadjuvant chemotherapy is approximately 64.8% with the addition of pembrolizumab to chemotherapy, as demonstrated in the KEYNOTE 522 study. This is based on the most recent and highest quality evidence available, which suggests that the incorporation of immunotherapy in the pre-operative setting can significantly improve outcomes for patients with triple-negative breast cancer 1. The standard neoadjuvant regimens for TNBC, such as anthracycline and taxane-based combinations, typically result in pCR rates ranging from 30% to 40%. However, the addition of platinum agents or immune checkpoint inhibitors like pembrolizumab or atezolizumab can increase pCR rates to 50-65% in some studies 1. Some key points to consider when evaluating the effectiveness of neoadjuvant chemotherapy for TNBC include:
- The importance of achieving pCR, which strongly correlates with improved long-term outcomes, including disease-free and overall survival 1
- The potential benefits and risks of incorporating platinum agents or immune checkpoint inhibitors into standard chemotherapy regimens 1
- The need for careful consideration of individual patient factors, such as BRCA mutation status and potential risks of additional gonado-toxicity 1. Overall, the current evidence suggests that the addition of pembrolizumab to chemotherapy can significantly improve pCR rates for patients with triple-negative breast cancer, and this approach may be considered in clinical practice 1.
From the Research
Pathologic Complete Response Rate for Triple-Negative Breast Cancer
The pathologic complete response rate for triple-negative breast cancer after neoadjuvant chemotherapy varies across different studies.
- A study published in 2021 found that the pathological complete response rate in both breast and axilla was 48.1% for patients with triple-negative breast cancer treated with neoadjuvant cisplatin added to standard chemotherapy 2.
- Another study published in 2023 reported a pathological complete response rate of 32.5% for triple-negative breast cancer patients receiving neoadjuvant chemotherapy, with 57.7% of patients with BRCA1/2 pathogenic variants achieving complete pathological response 3.
- A 2018 study found that the pathological complete response rate was 55% for patients with triple-negative breast cancer treated with neoadjuvant carboplatin plus docetaxel 4.
- A 2010 study reported a pathological complete response rate of 54.6% for patients with triple-negative breast cancer receiving neoadjuvant docetaxel and carboplatin 5.
- A 2016 study found that BRCA1 carriers had a pathological complete response rate of 68% compared to 37% among non-carriers when treated with neo-adjuvant doxorubicin-cyclophosphamide followed by paclitaxel for triple-negative breast cancer 6.
Factors Associated with Pathologic Complete Response
Several factors have been associated with pathologic complete response in triple-negative breast cancer, including: