Survival patterns and prognostic stratification based on distant metastasis characteristics in oral squamous cell...

Despite advances in the treatment of oral squamous cell carcinoma (OSCC), distant metastasis (DM) remains a major obstacle to improving its prognosis. This study aimed to predict survival based on DM characteristics and to detail related outcomes.

We conducted a multicenter retrospective cohort of patients diagnosed with OSCC and treated at two centers. Patients were assigned to discovery and validation cohorts. Data were extracted from medical records, with the presence and characterization of DM confirmed through clinical and radiological reports. Various thresholds for number of affected organs (metastatic sites) and number of metastatic foci were analyzed using subsequent Cox Regression to identify independent risk factors. Significant risk factors were incorporated into a 6-month prediction model, which stratified patients into high- and low-risk groups for worse disease-specific survival.

Among consecutive 1,725 patients, 105 (6 %) developed DM and were included in the analysis. Multivariate Cox Regression identified the absence of isolated pulmonary metastasis (Hazard Ratio, HR, 2.5; 95 % Confidence Interval, CI, 1.5-4.3) and the presence of more than three foci (HR, 2.6; 95 % CI, 1.4-4.5) as risk factors for worse disease-specific survival. In the validation cohort, the model (probability of death within 6 months) predicted a 46 % and 74 % risk for, respectively, low and high-risk patients (P > 0.999).

Metastatic OSCC patients exhibit distinct survival outcomes based on the characteristics of DM. This grouping system may improve clinical risk stratification and support more personalized treatment approaches.