Background: Histological and clinical criteria are generally used to differentiate second primary tumors (SPTs) from local recurrences. The purpose of the present study was to apply mitochondrial DNA (mtDNA) D-loop analysis to differentiate SPTs from local recurrences and to validate the clinical classification.
Methods: The study population consisted of 20 consecutive patients presenting multiple oral neoplastic lesions for a total of 25 paired lesions. The mtDNA D-loop analysis was performed by direct sequencing and phylogenetic clusterization.
Results: Agreement between mtDNA analysis and clinical classification was found in 19 cases. Discrepancies arose in 6 cases in which the clinical criteria based only on the spatial or temporal distance of the second lesion from the index tumor had led to a diagnosis of SPT (2 cases) or local recurrence (4 cases).
Conclusion: The present data highlight the value of mtDNA analysis in establishing the clonal relationship between the index tumor and the second neoplastic lesion.
Keywords: clonality; mitochondrial DNA D-loop; multiple tumors; oral cancer; second primary tumor.
Copyright © 2013 Wiley Periodicals, Inc.