Survival Outcomes and Prognostic Factors in Oral Squamous Cell Carcinoma with Locoregional Recurrence: A Retrospective Analysis

Abstract

Introduction: Recurrence is known to occur in approximately 25% to 45% of patients treated for oral cancer. It is the most common cause of treatment failure in oral squamous cell carcinoma (OSCC), which adversely affects survival. Although recurrences in the oral cavity may be detected early, survival rates remain low. Aim: To identify the survival outcomes and prognostic factors in OSCC with locoregional recurrence. Materials and Methods: This retrospective study was conducted at the Malabar Cancer Centre between November 2020 to March 2021, analysing patients who were treated with curative intent between January 1997 and December 2017. It included 118 patients with OSCC who experienced recurrence-local, regional, or both-after curative treatment. Demographic variables, clinical variables, and follow-up details were analysed. Characteristics of the primary tumour, including nodal metastasis, stage, Extranodal Extension (ENE), Perineural Invasion (PNI), the extent of treatment, adjuvant therapy, and days to recurrence, were recorded. For the recurrent tumour, site, time to recurrence, and type of treatment received were noted additionally. Overall Survival (OS) was defined from the date of initial diagnosis, while the date of recurrence was determined by pathological confirmation. Statistical analysis was performed using SPSS software, version 20. All significant variables (p<0.05) were then tested in a multivariate analysis using Cox regression methods. Disease-specific survival (DSS) and OS were analysed using the Kaplan-Meier method. Results: A total of 146 patients with OSCC (15.01%) experienced a recurrence-local, regional, or both-upon analysis of 973 OSCC patients who underwent primary curative intent surgery. One hundred eighteen patients were included in the final analysis. Salvage surgery was performed on 65 (55.08%) patients. Thirtyeight patients (32.3%) who presented with early-stage disease initially developed a recurrence, whereas recurrences were more common among patients with advanced-stage disease, accounting for 80 (67.7%) cases. The median age of patients with recurrence was 60 years, with a median follow-up period of 46 months. The median OS time for patients with recurrence was 34 months ranging from 26.343 to 42.457 months. Univariate analysis revealed that nodal stage, salvage surgery, and time to recurrence were significant factors affecting OS. On multivariate analysis, salvage surgery and time to recurrence remained significant factors impacting survival. Conclusion: Salvage surgery and time to recurrence were identified as significant prognostic factors affecting survival outcomes in patients with OSCC experiencing locoregional recurrence. Salvage surgery significantly improves survival in oral cancer, where recurrence is usually detected more easily unlike other subsites. Patients with late recurrences demonstrated better survival outcomes. Tumours that recur early indicated poor oncological outcomes, suggesting an aggressive nature. Tumor biology is essential in guiding treatment options in recurrent settings.