Relationship between proliferative activity of tumor cells and the enlargement pattern of metastatic lymph nodes in oral squamous cell carcinomas

Abstract

ObjectivesThis study was conducted to investigate the time-course changes in the size of metastatic lymph nodes and determine their relationship with the histological features of oral squamous cell carcinomas (OSCC). MethodsThirteen metastatic lymph nodes from 13 OSCC patients were examined in this study. The cervical lymph nodes were periodically followed up with ultrasonographic examination and diagnosed as metastatic when the minimum axis of the nodes (size) reached ≥8mm in three-dimensional measurements. Enlargement patterns of the metastatic nodes were compared with the histological features and proliferative activity of tumor cells by Ki-67 immunostaining of the primary tumors and nodes. ResultsThe enlargement patterns of the metastatic lymph nodes were classified into two types: rapid enlargement (RE), which involved rapid increase in node size, and slow enlargement (SE), which involved slow increase and fluctuation in size. No significant differences in histological findings between the RE and SE types were observed in the primary tumors or metastatic nodes. On the other hand, Ki-67 scores in primary tumors and metastatic foci were associated with the enlargement pattern of the metastatic nodes, wherein metastatic nodes of the RE type showed significantly higher Ki-67 scores than those of the SE type. ConclusionsThe proliferative activity of primary tumors can be a valuable marker for predicting the speed of enlargement of metastatic lymph nodes. In addition, it may aid in reaching a decision regarding follow-up duration in N0 neck cancer patients.