Clones, dyes, nuclides, mouse kidneys, and ... virions: a new-clonogenic assay for tumor chemosensitivity

Chemotherapy of non-small cell lung carcinoma guided by an in vitro drug resistance assay measuring total tumour cell kill

Specimens from 45 patients with previously-untreated non-small cell lung cancer (NSCLC) were tested for in vitro chemosensitivity to ten drugs utilising the DiSC assay, which measures cell kill in the total (largely non-dividing) tumour cell population. Thirty-five assays were successful and 25 patients with advanced disease subsequently received chemotherapy with the 'best' three drugs selected by the assay. Six patients were Karnofsky performance status 60 or less and the median pretreatment weight loss was 8.5%. Nine patients had a partial response (response rate = 36%; 95% confidence interval = 17-55%) and the median survival of all patients was 202 days. Specimens from responding patients were significantly more sensitive in the assay to drugs in general (especially to etoposide and to 'natural product' drugs) and to the drugs used in treatment than were specimens from non-responding patients. In vitro drug resistance differences between responding and non-responding patients were of greater significance than were differences between other clinical and laboratory measurements. Assay results classified patients into two cohorts, having relatively high and low probabilities of responding to chemotherapy. Assay results also identified patient cohorts with above average and below average durations of survival. Five patients (20%) were found to have tumours with extreme drug resistance (EDR), defined as assay results for the average of all ten tested drugs falling greater than one standard deviation more resistant than the median for all tumours assayed, and none of these patients with EDR responded to chemotherapy.

Ovarian cancer: relationship between in vitro chemosensitivity and clinical response

Thirty-nine samples from 30 patients with epithelial ovarian cancer were collected. Using the method described by A. Hamburger (J. Natl. Cancer Inst. 66, 981 (1981] and P. Salmon et al. (N. Engl. J. Med. 308, 129 (1983], tumor cells were exposed to antineoplastic agents (Adriamycin and cis-platinum) and then cultured in double-layer agar. There were 23 evaluable patients. The percentage of complete and partial responses for patients whose cells were sensitive in vitro, whether or not treated with the same drugs, was 68, vs 44% compared to patients whose cells were resistant in vitro and treated in vivo with therapeutic regimens which may or may not have included drugs used in the test. More patients with residual tumor greater than 2 cm were resistant to chemotherapy.