THE IMPLICATION OF DNA CONTENT AND S-PHASE FRACTION IN ORAL CARCINOMAS WITH AND WITHOUT METASTASIS

Flow cytometry DNA analysis was performed on fresh tissue samples of 9 0 primary lesions and 32 metastatic lymph nodes of squamous cell carci nomas of the oral cavity and related regions to elucidate the characte ristics of tumors with metastatic potency: The incidence of aneuploidy for carcinomas with metastasis was 67%, which was significantly highe r than the 44% of carcinomas without metastasis, and aneuploid carcino mas (39%) had a higher tendency to metastasis than diploid carcinomas (20%). The incidence of aneuploidy and metastasis was related to the T classification, the degree of differentiation, and the histologic gra de of malignancy. The incidence of aneuploidy and mean DNA index of me tastatic lesions were 31% and 1.12, respectively, and the values were significantly lower than the 67% and 1.30 of the corresponding primary lesions. The results indicate that the chance of evolution of metasta tic cell lines is higher in aneuploid carcinomas than diploid carcinom as, possibly because the former is more heterogeneous than the latter, but most of the cell lines causing lymph-node metastasis are diploid cell lines. Metastatic lesions had a lower S-phase fraction than prima ry lesions, indicating that a high S-phase fraction does not always re flect the presence of metastatic cell lines.