He's Not Going to Talk About In Vitro Predictive Assays Again, Is He?

Abstract

It is difficult for anyone to determine why oncologists have not paid more attention to the use of in vitro predictive tests in the care of their patients. A review of already completed in vitro-in vivo othocorrelative trials in 2, 300 patients indicates percentages of 69 for true positives and 91 for true negatives from predictive assays. These percentages are as good as or better than those seen with already accepted tests, such as estrogen receptor assays or bacterial sensitivity testing systems. Results of a randomized trial of single-agent chemotherapy selections based on a capillary cloning assay versus a clinician's choice indicate the response rate is significantly higher when single-agent chemotherapy is selected by the cloning assay than when it is selected by a clinician (21%vs. 3%). An ongoing randomized trial in which investigators are attempting to corroborate these results in patients with previously untreated small cell lung cancer has been so slow to accrue patients that it is unlikely these trials and others will ever be completed. The usefulness, if any, of these assays and their potential to provide answers to important questions will never be determined unless attitudes are changed about participation in trials. A tool with potential for helping oncologists select patient therapy could be lost unless participation in these trials is obtained. [J Natl Cancer Inst 82: 96–101, 1990]