DNA ploidy in oral cavity carcinomas, with special reference to prognosis.

Single-cell DNA cytofluorometry was performed on paraffin-embedded tissue of 140 patients with squamous cell carcinomas of the oral cavity. Half of the tumors (71 of 140) were DNA nondiploid. Well-differentiated carcinomas were more often DNA diploid than moderately well-differentiated ones (P less than 0.001; chi-square). The aneuploid tumors responded better to preoperative radiotherapy than did the DNA diploid (P less than 0.001) and polyploid tumors (P less than 0.05; chi-square). Using the multivariate Cox's regression analysis multiploid type tumor, age of the patients and presence of lymph node metastases were the only significant factors influencing survival. DNA diploid tumors in stages I and II had a better prognosis than DNA nondiploid (P less than 0.01; Kaplan-Meier). The reverse was true for stages III and IV, where DNA nondiploid tumors had a better prognosis (P less than 0.05; Kaplan-Meier). Tumor stages (P less than 0.001; Kaplan-Meier) and especially lymph node metastases (P less than 0.0005; Kaplan-Meier) were major prognostic factors. Tumor DNA ploidy may be a complement to clinical and morphologic parameters as a prognostic predictor in squamous cell carcinoma of the oral cavity.