Stromal categorization of recurrent oral cancer after salvage surgery is associated with survival rates

Background: Recurrent oral cancer incurred grave outcome. Tumor microenvironment features, like tumorinfiltrating lymphocytes (TILs) or tumor stromal ratio (TSR) had prognostic significance in various cancers. We aimed to evaluate the impact of stromal categorization which incorporated the stromal TILs and TSR on survival outcomes in recurrent oral cancer. Methods: 162 patients who received surgery-based treatment between 2010 and 2020 were recruited. Outcomes were 5-year overall survival (OS) and disease-specific survival (DSS). The impact of stromal categorization of recurrent primary tumor or node on 5-year OS and DSS were assessed with the Kaplan-Meier method. Multivariate analysis was performed, incorporating variables at initial treatment and salvage surgery. Patients were further categorized using a survival decision tree. Results: Mean age was 56.1 (SD, 11.3) years; 153 patients (94.4%) were male; 51 patients (31.5%) had stromal category III. Local recurrence occurred in 94 patients (58%), regional recurrence in 55 (34%), and loco-regional recurrence in 13 (8%). Patients with stromal category III had poorer 5-year OS and DSS. Prior radiotherapy, advanced recurrent stage, positive surgical margin, and stromal category III were independent prognosticators for 5-year OS and DSS. In survival decision tree analysis, patients with prior radiotherapy and stromal category III had the worst outcomes. Conclusion: Stromal categorization is associated with outcomes in recurrent oral cancer. Patients with poor prognosticators, such as stromal categorization III, prior radiation, and advanced stage may require closer followup and intensive treatment.