[Chemotherapy testing for human ovarian cancer using in vitro colony assay]

The in vitro evaluation of anticancer drug efficacy was performed using the human tumor clonogenic assay developed by Hamburger and Salmon, and correlation between the in vitro and clinical efficacy was analyzed retrospectively. The in vitro colony assay method used in this study was a minor modification of the above method. Thirty-two out of forty-eight samples from patients with ovarian cancer formed more than five colonies per plate on in vitro colony assay. The median plating efficiency was 0.06% (range 0.02-1.3%) and the median colony count per plate was 279 (range: 8-4,000). With regard to colony formation of ovarian cancer according to the source of the specimen, the colony-forming rate of solid tumor was high (72%) as compared with 63% for ascites and 43% for pleural effusion. In vitro chemosensitivity was defined as more than a 50% decrease in colony formation and the rates for standard drugs on ovarian cancer were as follows: adriamycin (0.04 micrograms/ml) 29%, bleomycin (0.1 micrograms/ml) 24% cisplatin (0.2 micrograms/ml) 31%, 5-FU (1.0 micrograms/ml) 22%, hexamethylmelamine (1.0 micrograms/ml) 19%, L-PAM (0.4 micrograms/ml) 44%, mitomycin C (0.1 micrograms/ml) 38% and THP-adriamycin (0.5 micrograms/ml) 36%. A group of patients who had not been exposed to any anticancer drug showed higher sensitivity in vitro as compared with a group of patients who had received prior chemotherapy (35% vs 22%, p less than 0.05). Correlation between in vitro drug sensitivity and clinical responses in patients treated with the same drugs were analysed retrospectively. In all twenty cases, two were true positive cases (29%), while in ten cases, the results were true negative (77%), The overall predictive accuracy was 60%. In conclusion, ovarian cancer cells can form colonies well when the soft agar method is used and this assay method is suitable for the evaluation of various anticancer drugs in vitro.