Recist: Definition of Response
In clinical studies, formal response criteria have been developed and have gained wide acceptance. The National Cancer Institute (NCI) has proposed and implemented newer standard response criteria called Response Evaluation Criteria in Solid Tumors (RECIST). In contrast, the World Health Organization (WHO) has a different standard for assessing response. Major differences between these guidelines are outlined below.
Comparison of RECIST and WHO guidelines
Karnofsky performance index Performance Scales
The Karnofsky performance index and WHO (Zubrod) scale are commonly used as proxy measures for quality of life. Because they measure only one dimension of the construct, they would not be considered quality-of-life measures by today’s standards. However, given their historic relevance and current high frequency of usage as proxy measures, we have included them here.
WHO (Zubrod) scalea
This scale is used to measure performance of which the patient is capable. For example, a patient in the hospital for metabolic studies may be fully capable of performing normal activities but will remain in bed through his or her own choice. Such a patient should be coded 0, “normal.”
0 Normal activity
1 Symptoms but nearly fully ambulatory
2 Some bed time but needs to be in bed < 50% of normal daytime
3 Needs to be in bed > 50% of normal daytime
4 Unable to get out of bed
aZubrod CG, Schneiderman M, Frei E III, et al: Appraisal of methods for the study of chemotherapy of cancer in man: Comparative therapeutic trial of nitrogen mustard and triethylene thiophosphoramide. J Chron Dis 11:7–33, 1960.
