Evaluation of prognostic factors for oral tongue squamous cell carcinoma: Significance of intratumoral tumor-infiltrating lymphocytes, lymph node ratio, and depth of invasion.

132 Background: Oral tongue squamous cell carcinoma (SCC) is an aggressive malignancy with a variable prognosis. Identifying reliable prognostic factors is crucial for developing personalized treatment strategies and improving patient outcomes. This study examined the prognostic significance of clinicopathological factors in oral tongue SCC. Methods: A retrospective cohort study was conducted on 192 patients who underwent surgical resection at Asan Medical Center between 2010 and 2017. Clinicopathological data, including age at diagnosis, American Joint Committee of Cancer (AJCC) 8 th edition stages, depth of invasion (DOI), extranodal extension (ENE), intratumoral and stromal (invasive front) tumor-infiltrating lymphocytes (TILs), lymphovascular invasion (LVI), margin status, metastatic-to-examined lymph nodes ratio (LNR), number of metastatic lymph nodes, perineural invasion (PNI), sex, size, tumor budding, tumor differentiation, tumor-to-stromal ratio (TSR), and worst pattern of invasion (WPOI) were analyzed. The total cohort, early-stage group, and late-stage group were analyzed separately. Results: Most variables showed significant associations with the survival rate. The multivariate Cox proportional hazard models for the total cohort showed significant results for intratumoral TILs, DOI grade, and LNR. However, other factors failed to show statistical significance. Intratumoral TIL was the only consistently potent factor for survival in all study groups. Conclusions: Our findings highlight the need for increased focus on the prognostic significance of intratumoral TILs. The DOI grade and LNR were also powerful prognostic factors, especially in late-stage tongue SCCs. Our data suggest that the prognostic significance of certain variables, such as the WPOI, may have been overestimated in the literature, thereby warranting a reassessment of the currently utilized prognostic markers in oral tongue SCC.