Flow cytometric DNA ploidy and recurrence development in squamous cell carcinoma of the oral cavity.

This prospective study on 348 patients with oral squamous cell carcinoma who underwent radical surgery established a close association between the DNA ploidy status of the primary tumor and the risk of local recurrence development. Nine percent of patients with flow cytometrically diploid tumors developed a recurrence compared to 46% of those with aneuploid tumors. This correlation held true even if evaluated with respect to tumor stage or histological grade. Thirteen percent of the diploid and 59% of the aneuploid group showed lymph node metastasis. These results provide substantial evidence that cytogenetic events that underlie aneuploidy formation from initially diploid progenitor cells are functionally linked to the development of tumor cell populations that have the capability to establish independently growing colonies in foreign tissues.

Flow cytometric cellular DNA content and lymph-node metastasis in squamous-cell carcinoma of the oral cavity.

This prospective DNA flow cytometric study on 386 primary squamous cell carcinomas of the oral cavity showed that only 18% of the patients with diploid primary tumors had lymph node metastasis on admission compared to 52% of those with aneuploid carcinomas. The aneuploid group without evidence of lymph node involvement at the time of primary tumor treatment carried a 3-fold increased risk for developing late metastasis (23%) compared with the diploid group (8%). The clinical manifestation of occult metastasis in patients with diploid carcinomas was delayed by about two years compared to the aneuploid group. These ploidy-specific differences of the metastatic behaviour held true even if stratified with respect to tumor stage, histological grade and tumor localization. These results provide substantial evidence that cells with gross DNA content aberrations have a significantly higher probability of successfully producing a metastatic colony than flow cytometrically diploid tumor cells. An excellent 5-year survival rate of 90% in the diploid NO group in contrast to 52% in aneuploid NO cases and an even worse survival rate of 21% in patients with lymph node involvement at presentation underline the clinical importance of these findings.