Difference in survival and prognosis between malignant tumors of odontogenic origin.

Introduction: The prognosis of metastatic ameloblastoma (METAM), now defined as a benign tumor, and malignant odontogenic tumors (MOT) is poorly studied in the literature. The aim of this study was to determine the prognosis and factors influencing the survival of these patients.

Material and methods: Using the SEER database, we retrieved clinical data of patients with malignant tumors of dental origin between 1975 and 2020. They include 3 histological groups: metastatic ameloblastoma (METAM), malignant odontogenic tumors (MOT, including odontogenic carcinoma, odontogenic sarcoma, primary intraosseous carcinoma, and ameloblastic carcinoma) and ameloblastic fibrosarcoma (AFS).

Results: On 251 patients, we observed no significant difference in disease-specific survival (DSS) between the three histological groups, with 5-year DSS of 77.4 % (59.9 - 100), 84.0 % (78.7 - 89.7) and 71.1 % (50.7 - 99.7) for METAM, MOT and AFS respectively (p = 0.460). In the MOT group, using a multivariate analysis, surgical treatment appeared to be a protective factor for DSS (HR = 0.483 [0.243 - 0.960], p = 0.038) after taking into account the potential confounding factors mentioned above. No variable significantly influenced DSS in the METAM and AFS group in univariate analysis.

Discussion: We found no difference in specific survival between the three histological groups. Although metastatic ameloblastoma was reclassified as a benign tumor by the WHO in 2017, the vital risk for patients remains consequent, and statistically similar to malignant odontogenic tumors.