Ex Vivo Chemosensitivity of Head and Neck Carcinoma to Cytostatic Drug Combinations

Abstract

Previous studies focusing on response prediction to chemotherapy by chemosensitivity testing of tumor explants has focused on the response determination of single cytostatic drugs, in contrast to the common clinical application of cytostatic drug combinations. Therefore, the present study was aimed at determining the quantitative ex vivo chemoreactivity of epithelial cells from head and neck squamous cell carcinoma (HNSCC) specimens to cytostatic drug combinations. Specimens from 12 histologically-confirmed HNSCC were investigated. According to a previously established ex vivo colony formation assay, the individual cellular chemoreactivity was determined quantitatively for combinations of 4 cytostatic drugs: cis-platinum (cis-DDP), carboplatin (CBDCA), 5-Fluorouracil (5-FU) and docetaxel (DTX). The tests were performed using drug combinations according to recent clinical therapy regimens in the treatment of solid tumors: i) cis-DDP + 5FU, ii) CBDCA + 5FU, iii) cis-DDP + DTX and iv) CBDCA + DTX. The approach provides individual drug response patterns of epithelial as well as of stromal cells. Individual, selective sensitivities were found for each drug combination tested. The stromal and epithelial chemoreactivity profiles differed in most of the specimens. Moreover, stromal cell chemoresistance dominated selective epithelial chemosensitivities in the majority of cases. The determination of the epithelial ex vivo chemoreactivity identified individual chemosensitivities which were verified by the clinical history of the patient. Therefore, the described protocol to determine the ex vivo chemoresponse of HNSCC specimens to cytostatic drug combinations may help to provide clinicaly useful information concerning the individual chemoresponse of HNSCC with regard to individualization of oncological decision making.