Histologic differentiation and chemosensitivity of human head and neck squamous cell carcinomas.

The chemosensitivities of 42 human head and neck squamous cell carcinomas were examined using the in vitro succinate dehydrogenase inhibition (SDI) test. The tumor tissues obtained at surgery or biopsy were exposed to five different antitumor drugs: adriamycin (ADM), cisplatin (CDDP), carboquone (CQ), 5-fluorouracil (5-FU), and 1-hexylcarbamoyl-5-fluorouracil (HCFU). The results were analyzed according to the histopathologic degree of differentiation of well, moderately, and poorly differentiated squamous cell carcinoma. The average decrease in succinate dehydrogenase activity was 43.2 +/- 24.9 for ADM, 29.0 +/- 14.2 for CDDP, 32.9 +/- 17.6 for CQ, 64.2 +/- 20.6 for 5-FU, and 26.8 +/- 16.9 for HCFU. There was a statistically significant difference in the decrease of succinate dehydrogenase activity between well and poorly differentiated squamous cell carcinomas. These data suggest that, for patients with a poorly differentiated squamous cell carcinoma, the response to anti-cancer drugs may be more satisfactory than in those with a well-differentiated squamous cell carcinoma.