Sarcomatoid variant of squamous carcinoma in recurrent and second primary tumors of the oral cavity.

Background: Sarcomatoid variant of oral squamous cell carcinoma (OSCC) is aggressive tumors that frequently recur and metastasize. Our aim was to determine the survival outcomes and factors that predict its incidence in recurrent and second primary tumors (SPT).
Methods: We retrospectively analyzed the records of SPT and recurrent OSCC cases with sarcomatoid differentiation. The overall survival (OS) and disease-free survival (DFS) were determined by the Kaplan-Meier method. Logistic regression was used to identify the factors associated with SPT and recurrent sarcomatoid OSCC. Recursive partitioning was performed to classify the sample based on the clinicopathological factors of the index tumor.
Results: A total of 82 patients were included in the study with a median survival, calculated from the date of diagnosis of recurrence or SPT, of 6 months (recurrence-2 months, SPT-8 months). The 3-year OS for the recurrence group was 19.9% and for SPT group was 29%. Perineural invasion in the index tumor was significantly associated with sarcomatoid differentiation in the recurrent tumor. At one end of the spectrum of the recursive partitioning were the SPTs that had small index tumor sizes and DOI/thickness less than 14.5 cm (lowest risk), and at the other end were recurrent diseases that had index tumors of advanced T stage (highest risk).
Conclusion: Sarcomatoid variant in the recurrent/SPT OSCC infers a poor prognosis. Recurrent disease that had an index tumor with advanced T stage carries the worst outcomes. Perineural invasion in the index tumor can help predict the presence of sarcomatoid carcinoma in the recurrent or SPT.
(© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)