The Response Evaluation Criteria In Solid Tumors (RECIST) was first published in 2000 and then updated in 2009. RECIST is a set of published rules that attempt to define when cancer tumors, including prostate cancer tumors, improve (“respond”), stay the same (“stabilize”), or worsen (“progress”) during treatment. This criteria has become very important as the majority of clinical trials evaluating cancer treatments for objective response in solid tumors use RECIST as an endpoint measure.

What is sometimes confusing is that RECIST is not intended to be used in a clinical setting. It is not meant to determine whether patients have improved or not, as RECIST is tumor-centric, not patient centric. In other words, RECIST is not intended to measure if a cancer survivor is declining, stable or improving, but it measures only the status of their tumors.

In current clinical practice many oncologists follow their patient’s disease by means of repeated imaging studies, evaluating biomarkers and the reported symptoms of their patients. They make their clinical decisions about continuing therapy on the basis of these objective and symptomatic criteria. The publishers of the RECIST criteria have made it clear that it is not intended that the RECIST guidelines play a role in that decision-making, except if determined appropriate by the treating oncologist.

Based on some new research exploring the association between RECIST 1.0 and 1.1 and changes and overall survival (OS) in men with metastatic castration-resistant prostate cancer (mCRPC) taking docetaxel (chemotherapy), oncologists can now begin to rely on RECIST as they evaluate the efficacy of docetaxel.

In the study, the researchers found an association between changes in objectively measurable tumors according to Response Evaluation Criteria in Solid Tumors (RECIST) and survival in men with metastatic prostate cancer receiving docetaxel chemotherapy.

Since bone scan and prostate-specific antigen changes (PSA serum tests) are unreliable and now that measurable tumors are more frequently detected because of better radiographic technology, a focus on the RECIST changes should be considered during drug development and treatment to provide an objective signal of drug efficacy, especially docetaxel.

European urology. 2015 Oct 20

[Epub ahead of print]; Guru Sonpavde, Gregory R Pond, Arnoud J Templeton, Abderrahim Fandi, Bertrand Tombal, Mark Rosenthal, Andrew J Armstrong, Daniel P Petrylak