Review of the efficacy of individualized chemotherapy selected by in vitro drug sensitivity testing for patients with cancer.

The purpose of this study is to review the potential efficacy of individualized chemotherapy selected by in vitro drug sensitivity testing (DST) compared with empiric regimens for patients with cancer. MEDLINE and CANCERLIT were searched for articles published (in English) about prospective clinical trials in which patients were treated with chemotherapy that was selected with the use of in vitro DST. We identified 12 prospective studies that examined the benefit of chemotherapy selected by DST. Five hundred six patients (33%) were treated with chemotherapy that was selected with the use of in vitro DST. The mean response rate for patients treated with in vitro-selected therapy was 27% (range, 10% to 100%; n = 12 studies) compared with 18% (range, 0% to 100%; n = 7 studies) for patients treated with empiric therapy. Five studies (only one randomized) evaluated the impact of chemotherapy selected by in vitro DST on patient survival. Three studies showed that survival was 1 to 4 months longer for the 238 patients treated with empiric chemotherapy compared with that of the 65 patients treated with chemotherapy that was selected by in vitro testing. Two nonrandomized studies showed that survival was 4 or 19 months longer for 27 patients treated with chemotherapy selected by in vitro testing compared with that of 80 patients who were treated with empiric chemotherapy. Only one third of patients entered in prospective trials of in vitro DST were actually treated with an in vitro best regimen. The response rates seem to be better with in vitro selected chemotherapy regimens than with empiric regimens, but the impact on survival has not been adequately addressed.