Stability of aneuploid clones during oral squamous cell carcinoma metastasis.

BACKGROUND

The development of aneuploid clones contributes to the expression 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 disseminate.

PATIENTS AND METHODS

DNA flow cytometry was performed on 73 primary oral squamous cell carcinomas and their synchronous lymph node metastases as well as on 20 other patients who experienced delayed manifestation of occult lymph node involvement.

RESULTS

Diploidy for both the primary and metastatic tumor was recognized in 6.5% of patients; 5.4% showed a shift from diploidy to aneuploidy while 3.2% had aneuploid tumors that associated with diploid metastases. Aneuploid clones in corresponding lesions were identified in 84.9% of cases. Despite the wide variation of individual DNA contents, 86.1% of the latter group expressed aneuploid clones with identical DNA indices in both the primary and metastatic tumors. The stability of initially established aneuploid clones was monitored even after 58 months of occult metastasis growth.

CONCLUSION

Lymph node metastases preferentially originate from pre-existing aneuploid tumor clones.