DNA content, malignancy grading and prognosis in T1 and T2 oral cavity carcinomas.

Microscopic malignancy grading using the 8-factor system proposed by Jakobsson et al. (1973), the 4-factor system set up by Glanz and Eichhorn (1985), and DNA cytofluorometry were applied to thirteen T1 and thirty-seven T2 squamous cell carcinomas of the oral cavity, 9 with and 41 without metastases. There was a significant correlation between the presence of lymph node metastases (N1) and the malignancy scores (P less than 0.05) and tumour DNA ploidy (P less than 0.01, chi-square). The total number of patients with initial and late lymph node metastases correlated significantly with polyploid nuclei (P less than 0.05) and with malignancy scores (P less than 0.001), which also correlated with regional recurrences (P less than 0.01, chi-square). No remaining tumour after preoperative radiotherapy indicated less risk for local recurrence than if tumour persisted (P less than 0.01, chi-square). The cumulative survival (Kaplan-Meier) was worse for patients with nodal involvement (N1) than for those without (N0) (P less than 0.01), and for patients with poorly differentiated tumours compared with moderately well differentiated (P less than 0.05) and to well differentiated (P less than 0.001). The prognosis was worse for patients with high malignancy scores than those with low (P less than 0.001). DNA diploid tumours had a better prognosis than DNA non-diploid, but the difference was not significant.