Prognostic factors of oral squamous cell carcinoma: the importance of recurrence and pTNM stage.

Background: Oral squamous cell carcinoma has a poor prognosis. Therefore, prognostic factors are important to increase the survival rate. This study assessed the survival rate and the prognostic factors for survival of patients with oral squamous cell carcinoma.

Method: This study included 168 patients who underwent surgery for oral squamous cell carcinoma between January 2006 and December 2021. The survival rate was analyzed with overall survival and disease-specific survival. The patient's age, sex, pTNM stage, primary sites (lip, tongue, mouth of floor, mandibular gingiva, maxillary gingiva, mandibular vestibule, maxillary vestibule, retromolar trigone, palate, buccal mucosa, primary intra-osseous site), smoking and alcohol drinking habits, depth of invasion, perineural and lymphovascular invasion, cell differentiation, and postoperative radiotherapy were evaluated to analyze risk factors. Kaplan-Meier methods were used to estimate the survival rates. Cox regression methods were used to investigate the main independent predictors of survival in univariable and multivariable analysis.

Results: Sixty-eight patients died of oral squamous cell carcinoma during follow-up periods. Their overall survival for 5 years was 51.2%, and the disease-specific survival was 59.2%. In univariable analysis, seven factors which are neck metastasis, depth of invasion, cell differentiation, lymphovascular invasion, postoperative radiotherapy, pTNM stage, and recurrence were significantly associated with survival. In multivariable analysis, pTNM stage and recurrence were significantly associated with survival.

Conclusion: In patients with oral squamous cell carcinoma, pTNM stage and recurrence were significant prognostic factors. Neck metastasis, depth of invasion, cell differentiation, lymphovascular invasion, and postoperative radiotherapy were also prognostic factors. These factors serve as markers for obtaining prognosis information in oral squamous cell carcinoma.