Stability of aneuploid clones during oral squamous cell carcinoma metastasis

Background: The development of aneuploid clones conributes to the expressio n of metastatic growth properties in head and neck squamous cell carcinomas . Controversy persists as to whether aneuploid clones acquire an autonomous metastatic potential or instead activate diploid tumor cells to disseminat e. Patients and Methods: DNA flow cytometry was performed on 73 primary ora l squamous cell carcinomas and their synchronous lymph node metastases as w ell as on 20 other patients who experienced delayed manifestation of occult lymph node involvement. Results: Diploidy for both the primary and metasta tic armor was recognized in 6.5% of patients; 5.4% showed a shift from dipl oidy to aneuploidy while 3.2% had aneuploid tumors that associated with dip loid metastases. Aneuploid clones in corresponding lesions were identified in 84.9% of cases. Despite the wide variation of individual DNA contents, 8 6.1% of the latter group expressed aneuploid clones with identical DNA indi ces in both the primary and metastatic tumors. The stability of initially e stablished aneuploid clones was monitored even after 58 months of occult me tastasis growth. Conclusion: Lymph node metastases preferentially originate from pre-existing aneuploid tumor clones.