A novel pathological finding, "BABA", for a prognostic factor in oral tongue carcinoma.

92 Background: Oral tongue carcinoma is one of the cancers with poor prognosis. The UICC staging classification is commonly used to predict outcomes and to select the treatments, although there are cases where cancer relapse early despite being at the same Stages, indicating a need for additional prognostic factors to predict patient outcomes accurately. Recent advances in RNA sequencing of tumor and immune cells, as well as elucidation of the tumor microenvironment, have enabled the identification of many genes associated with recurrence risk and immunosuppressive environment around the tumor, which essential for precision treatment of the patients with high risks of recurrence. However pathological findings remain the first step in selecting samples with a high risk of recurrence for further analysis of RNA sequencing or the tumor microenvironment. In this study, we identified a novel pathological feature named as “BABA” (Broadening Amoeboid Behavior of Advanced tumor cells) that appears around the invasive front of tumors. It describes the way in which cancer cells progress like amoeba between muscle fibers and affect the prognosis of oral tongue carcinoma, making it a potential factor for the future analysis of next-generation sequencing or tumor microenvironment. Methods: Patients with oral tongue squamous cell carcinoma who underwent surgery were recruited, excluding those who had received salvage treatment for recurrence, those with simultaneous occurrence of carcinoma, those who had undergone palliative therapy, postoperative therapy, or those who lacked any pathological findings. Survival analyses for existing pathological findings, such as pT (pathological primary stage), pN (pathological nodal stage), ENE (extra nodal extension) status, lymphatic invasion, venous invasion, perineural extension, margin status, WPOI (worst pattern of invasion) and BABA were conducted. Results: A total number of 211 patients were analyzed in this study. Patients with positive for BABA had a two-year overall survival rate and recurrence-free survival rate of 0.78(p=0.02) and 0.39 (p<0.001), respectively, according to Kaplan-Meier analysis. In the multivariate analysis for overall survival using Cox regression model, venous invasion and pN ≥1 were significant prognostic factors, with HR (95%CI) of 3.0 (1.5-6.3) and 2.4 (1.2-4.5), respectively. In the multivariate analysis for recurrence free survival using Cox regression model, positive for lymphatic invasion, venous invasion, BABA, pN ≥1 were significant factors, with HR (95%CI) of 2.1 (1.2-3.6), 2.0 (1.1-3.4), 2.2 (1.3-3.7) and 2.0 (1.2-3.6), respectively. Conclusions: BABA is the novel risk factor for recurrence in oral tongue carcinoma. Identifying BABA could help clinicians better predict recurrence and develop more personalized treatment strategies.