Tumor–stroma ratio can predict lymph-node metastasis in cT1/2N0 oral tongue squamous cell carcinoma independent of tumor budding grade

Background cT1/2 oral tongue squamous cell carcinoma (OTSCC) often metastasizes to cervical lymph nodes. However, predicting neck lymph-node metastasis (NLM) remains challenging. Pathomorphological evaluation of tumor budding grade (TBG) and tumor–stroma ratio (TSR) reportedly can predict lymph-node metastases. Hence, this study aimed to evaluate TBG and TSR in OTSCC and investigate their relationship to occult NLM and cancer relapse. Methods Clinicopathological data of patients with cT1/2N0 OTSCC treated at the University of Tokyo Hospital between 2007 and 2017 were collected. TBG and TSR were evaluated using hematoxylin–eosin staining and cytokeratin AE1/AE3 immunostaining. Results Out of 70 patients, 16 underwent elective neck dissection in addition to primary-tumor resection, whereas 54 did not. During follow-up, NLM was found in 35 patients. NLM correlated with the pathological depth of invasion (pDOI) ( p 5 mm and stroma-rich tumors have a high risk for cancer relapse. TSR and pDOI may be promising NLM predictors in cT1/2N0 OTSCC.