Preoperative irradiation in oral cavity carcinoma. A study with special reference to DNA pattern, histological response and prognosis.

The relation between DNA pattern and response to preoperative radiotherapy was studied in 51 patients with oral squamous cell carcinomas operated 4 weeks after irradiation. Small tumors (T1 and T2) showed more pronounced response to radiotherapy than larger ones (T3 and T4), as did DNA aneuploid tumors. Eight of 11 DNA aneuploid tumors showed no remaining tumor in the operation specimen, compared to 6 of 21 DNA polyploid and 2 of 19 DNA diploid tumors. None of 16 patients without demonstrable remaining cancer in the operation specimen had local recurrence. The presence of lymph node metastases was the most important prognostic factor.