Incidence of occult metastasis in clinically N0 oral tongue squamous cell carcinoma and its association with tumor staging, thickness, and differentiation

Abstract

Introduction: Oral squamous cell carcinoma (SCC) is the most frequent head and neck cancer. The metastatic dissemination of these tumours usually occurs through the lymphatic system. The presence of occult lymph node metastasis is the most important prognostic factor. The high incidence of occult lymph nodal metastasis is a strong argument for the indication of elective neck dissection. However, there is a high percentage of patients who do not have metastasis in the pathological exam (pN0). Taking a homogenous group of patients all of whom received primary surgical treatment, at the same institution without prior radiotherapy or chemotherapy, applying stringent patient selection criteria, and standard pathological evaluation methods across the group, this study aims to establish predictors of cervical node metastasis in squamous carcinomas of the oral tongue. Result: During the study period, a total of 112 patients (98 males and 14 females; Mean age 49.7 years (range 15-70)) underwent resection of the primary tumor with SOND for N0 lymph node status of neck. A total of 1489 lymph nodes were analyzed in this study. Occult metastasis was found in 26 patients (23.2%). T-stage 4 was found to be a statistically significant predictor of occult lymph node metastasis in a cN0 neck. (95% CI, p-value 0.02). There was no correlation between gender, tumor thickness, and tumor differentiation and occurrence of occult metastasis. Discussion: Controversy exists over management of the neck in patients with cN0 oral SCC. As is evident there is no consistent statistically significant factor that can be attributed as a predictor of occult metastasis in head and neck cancer of the oral cavity. The search to identify reliable and accurate predictor(s) of occult metastases, or approaches to the management of patients with cN0 oral SCC, must continue. In absence of such predictors, keeping the high incidence of occult metastasis in mind, we recommend END in all cases of N0 OSCC.