Outstanding problems with Response Evaluation Criteria in Solid Tumors (RECIST) in breast cancer

Abstract
In 1999 European Organization for Research and Treatment of Cancer, National Cancer Institute of the United States and National Cancer Institute of Canada published Response Evaluation Criteria in Solid Tumors (RECIST) as a revision of the WHO criteria to achieve a unified, objective set of criteria for assessing antitumor activity. The present paper discusses breast cancer assessment using RECIST and discusses various outstanding problems in breast cancer therapy.