Prognostic significance of MCM2high/Ki-67high in ameloblastoma

Objective

Minichromosome maintenance (MCM) protein 2 is critical for the beginning of DNA replication and is a notable marker for proliferating cells. The prognosis and management of ameloblastoma are based on histology and other factors. However, immunohistologic markers capable of detecting recurrence-prone ameloblastoma with a poor prognosis have not been adequately investigated. This study aimed to identify the association between MCM2 overexpression and recurrence prognosis and risk stratification.

Methods

Thirty-two patients who had been diagnosed with ameloblastoma at our department between January 1982 and December 2019 were included in this study. Thirty-two (fifteen follicular, ten plexiform, five unicystic, two desmoplastic) subtype cases were analyzed for immunohistochemical expressions of MCM2 and Ki-67.

Results

Disease-free survival (DFS) analysis revealed that patients with MCM2^high/Ki-67^high ameloblastoma had a significantly shorter median survival time (63 vs. 360 months) and lower DFS survival rate (50.0% vs. 90.0%) than those with MCM2^low/Ki-67^low (p = 0.003). Multivariate analysis revealed that a location (maxillary primary ameloblastoma) and MCM2^high/Ki-67^high were independent risk factors for DFS.

Conclusion

Our results identified MCM2^high/Ki-67^high ameloblastoma as a subgroup with poor recurrent prognosis and DFS. Ameloblastoma should be assessed using immunohistochemical staining. Our study revealed that tumors with a worse recurrent prognosis require appropriate clinical surveillance.