Study on chemosensitivity of oral squamous cell carcinomas by histoculture drug response assay.

The aim of this study was to evaluate the reliability and utility of a histoculture drug response assay (HDRA) for treatment of squamous cell carcinoma in the oral cavity. Nineteen patients with squamous cell carcinoma of the oral cavity were assessed. Tumor tissue samples were histocultured on Gelfoam sponge gels in 24-well plates, followed by treatment with 5-fluorouracil (5-FU, 300 microg/ml), cisplatinum (CDDP, 20 microg/ml), 4-0-tetrahydropyranyl adriamycin (THP, 4.6 microg/ml), bleomycin (BLM, 20 microg/ml), adriamycin (ADM, 15 microg/ml) and docetaxel (TXT, 100 microg/ml). The controls were cultured without drug treatment. After completion of the culture, the relative cell survival in the tumors was determined using an MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide) assay. The inhibition rate was calculated, and sensitivity was defined as a tumor inhibition rate greater than 60% for 5-FU, 40% for TXT, and 50% for the other drugs. All cases were successfully evaluated by the HDRA, and no apparent relationships between the chemosensitivity test results and clinico-histopathological characteristics were seen. CDDP tended to be sensitive, whereas 5-FU, THP, and BLM tended to show resistance in many cases. A good correlation was obtained between the chemosensitivity test results and clinical response. In conclusion, HDRA is a useful method for selection of an anticancer agent for individual oral cancer patients, because of its ease of evaluation and high predictability.