There is no evaluation of axillary pathologic complete response rates (PCR) for all breast cancer subtypes. This includes patients with and without the pathologically proven node-positive disease. This study aims at providing a comprehensive analysis of all studies conducted on axillary PCR rates for various types of breast cancer subtypes in patients with the non-positive disease.
This study included a total of 33 unique studies and 57,531 unique patients. The included studies were conducted in the neoadjuvant therapy setting aimed at identifying axillary pCR for various subtypes. The primary outcome of the study was axillary pCR rates and residual axillary lymph node disease after neoadjuvant systematic therapy.
The findings identified axillary pCR rates for seven disease subtypes: 13% for luminal A breast cancer, 18% for HR-positive/ERBB2-negative, 35% for luminal B, 45% for HR-positive/ERBB2-positive, 48% for triple-negative, 59% for ERBB2-positive, and 60% for hormone receptor (HR)–negative/ERBB2-positive. Researchers did not find any significant differences in the axillary pCR rates across subtypes. The pCR rates by subtypes were studied with and without pathologically proven clinically node-positive breast cancer prior to neoadjuvant systematic therapy.
The research concluded that HR-positive/ERBB2-negative subtype was associated with the lowest pCR rate, whereas the HR-negative/ERBB2-positive subtype had the highest rate.
Ref: https://jamanetwork.com/journals/jamasurgery/article-abstract/2778930?resultClick=1
