A new meta-analysis of previously published studies has reported that breast cancer patients with pathological complete response as a result of neoadjuvant chemotherapy have favorable outcomes. Neoadjuvant chemotherapy is chemotherapy that takes place before surgery to remove a tumor, whereas adjuvant chemotherapy takes place after surgery. Neoadjuvant chemotherapy has become widely accepted in breast cancer treatment. It offers the opportunity to assess the cancer's response to chemotherapy by examining the breast tissue that was removed during surgery. While pathological complete response to chemotherapy (i.e., no microscopic evidence of viable cancer cells in the removed breast tissue) has been used to predict prognosis, published reports are inconsistent.

To conduct the study, the authors chose papers from the PubMed database based on specified inclusion and exclusion criteria. A total of 16 studies with 3,776 patients were selected for the meta-analysis.

Women who had a pathological complete response to chemotherapy were more than three times more likely to survive the follow-up period than those who had residual breast cancer. Similar findings were found for relapse-free survival. The authors conclude that pathologic response is a prognostic indicator for relapse-free survival, disease-free survival and overall survival, suggesting that patients with pathological complete response as a result of neoadjuvant chemotherapy have favorable outcomes.