IN-VITRO DRUG-SENSITIVITY TESTING OF TUMOR-CELLS FROM PATIENTS WITH NON-HODGKINS-LYMPHOMA USING THE FLUOROMETRIC MICROCULTURE CYTOTOXICITY ASSAY

Background: Tumor cell drug sensitivity is an important determinant of chemotherapy response. Its measurement in vitro would aid in therapy individualization and new drug development Materials and methods: The fluorometric microculture cytotoxicity assay (FMCA), based on producti on by viable cells of fluorescent fluorescein after 3 days of culture, was used for cytotoxic drug sensitivity testing of 73 samples of tumo r cells from patients with non-Hodgkin's lymphoma (NHL). Results: The technical success rate was 92%, and FMCA data showed good correlation to the Disc assay. NHL samples from in vivo resistant tumors. There wa s no obvious samples were considerably more drug sensitive than were d ifference in drug sensitivity for high- vs. low-grade or untreated vs. previously treated low-grade NHL. For 26 patients, clinical outcome w as correlated to in vitro response giving a sensitivity and specificit y of 93 and 48%, respectively. Cross-resistance between standard drugs was frequent in vitro. Resistance modulators potentiated the effect o f vincristine and doxorubicin in 10-29% of the samples, most frequentl y from previously treated patients. Conclusions: The FMCA seems to rep ort clinically relevant drug sensitivity data for NHL, and thus it cou ld serve as a tool for optimization of chemotherapy in the future.