Resisting RECIST-Uniformity Versus Clinical Validity

The Response Evaluation Criteria in Solid Tumors (RECIST) International Working Group developed criteria for tumor response and progression to standardize radiological assessment in patients receiving chemotherapy in phase 2 trials. However, it is unclear whether the defined percentage change in tumor size and volume reflects true clinical benefit for the patient. The RECIST criteria were designed to improve objectivity in trials, but not to replace clinical decision making. The aim of this study was to understand clinicians' opinions about RECIST in current oncology practice.

Using Web-based questionnaires, we investigated attitudes to the use of RECIST at a large comprehensive cancer center and in an international group of gynecologic cancer specialists through the Gynecologic Cancer InterGroup. The results reported here relate to the survey focusing on gynecologic cancer.

Sixty medical professionals from 13 countries responded to the survey. The majority of respondents worked at a tertiary or specialist cancer center (51; 86%). Overall, 66% of respondents felt RECIST increased trial objectivity and was a good measure of response. The majority of respondents (81%) reported that they infrequently challenged RECIST evaluation. Overall, 60% felt more than 10% of patients came off trial for clinical rather than radiological progression. In the context of a new small lesion, only 35% felt that should always be considered disease progression. The importance of both clinician and radiologist input was highlighted with nontarget progression. Nontarget progression and target progression were recognized as equally important for clinical decision making (72%).

RECIST is a key criterion for endpoint assessment in clinical trials with its value recognized by clinicians. However, this survey also highlights the practical limitations of RECIST. Disconnect can be seen between the radiological result and the clinical picture-learning from these patients is critical. Continued efforts to improve metrics assessing patient benefit in trials remains a priority.