Application of Pathological Complete Response in Tumor Clinical Trials

In recent years, neoadjuvant therapy has attracted much attention. It can not only reduce the stage of unresectable tumor and improve the breast conserving rate, but also has some potential advantages in the development of new drugs. Preoperative treatment provides an opportunity to assess biological effects, making it possible for new drugs to be tested in more sensitive, untreated populations. In addition, early therapeutic alternatives, such as pathological complete response （pCR） and residual tumor burden, can provide approximate indicators related to long-term prognosis, thus potentially shortening the time to find effective adjuvant therapy. At present, in order to promote the research and development of anti-tumor drugs, a series of guidelines have been issued in China to guide the end-point design of these clinical trials. However, the ability of pCR to accurately predict and long-term prognosis is still lacking of high-level evidence, which still needs to be repeatedly verified.