[Histoculture drug response assay on non-small cell lung cancer].

We examined the chemosensitivity of non-small cell lung cancer (NSCLC) tissues to CDDP, 5-FU, ADM, MMC, ETP and SN38 using histoculture drug response assay (HDRA). One-hundred and thirty surgical specimens from NSCLC patients who were not given preoperative chemotherapy were used. The inhibition indexes of CDDP, 5-FU, MMC, ADM, ETP and SN38 were 39.1 +/- 18.2%, 48.0 +/- 19.7%, 63.3 +/- 17.7%, 47.6 +/- 22.0%, 36.9 +/- 21.1%, and 37.9 +/- 25.2%, respectively. Inhibition indexes were above the cutoff level, i.e., 'judged sensitive,' in 40 cases (31.3%) for CDDP, 34 cases (27.4%) for 5-FU, 54 cases (44.3%) for MMC, 36 cases (33.0%) for ADM, 29 cases (29.8%) for ETP, and 34 cases (37.4%) for SN38, respectively. In almost one-third of patients, the inhibition indexes of all drugs were under cutoff levels. Correlations between in vitro chemosensitivity data and patient responses to chemotherapy were obtained from 16 evaluable patients, and a 44.4% true positive rate and a 100% true negative rate were observed. Our results with HDRA for NSCLC showed a high incidence of intrinsic multidrug resistance. HDRA may help doctors to avoid non-effective chemotherapy for NSCLC patients.