A Site-Based Analysis of Relationship Between Clinicopathological Factors and Their Influence on Locoregional Recurrence in Oral Squamous Cell Carcinoma

In India, oral cancers are the major cause of cancer-related death. Tongue and buccal mucosa being the major subsites in oral cancer have varying clinicopathological presentations. This study is intended to know the difference in clinicopathological behavior of these two subsites. This retrospective study included 474 patients of which 232 patients had tongue cancer and 242 patients had buccal alveolar complex (BAC) cancer. Comparison between the pathological characters including pattern of nodal involvement was analyzed. Disease-free survival (DFS) and factors influencing the DFS were analyzed and compared using Cox regression analysis. Mean age of the study population was 52.7 years. Tongue oral squamous cell carcinoma (OSCC) differed significantly from BAC OSCC in terms of age of presentation, tumor staging, and perineural invasion. Among neck nodal involvement, tongue OSCC commonly involved level IIa ( p < 0.001) whereas BAC involved level Ib ( p < 0.001). At a median follow-up of 27 months, 141 patients had disease recurrence, tongue OSCC commonly recurred in neck ( p = 0.008), and BAC OSCC relapsed at primary site ( p = 0.001). Patients older than 45 years with BAC cancer had lesser risk of recurrence (HR, 0.30; 95% CI, 0.2–0.5; p < 0.0001). Pathological tumor stage in tongue cancer (HR, 14.9; 95% CI, 2.6–84.8; p = 0.002) and grade of tumor differentiation in BAC OSCC (HR, 9.2; 95% CI, 1.9–43.3; p < 0.005) were the most significant factors that influenced tumor recurrence. There was a significant difference in factors influencing disease recurrence among tongue and BAC OSCC. Also, pattern of nodal metastasis and pattern of recurrence were different. Hence, further research on OSCC may be done site specific.