Patterns of Nodal Metastasis in Locally Advanced Oral Cancer Patients: Review of 268 Cases

Abstract

Statement of the Problem: Neck dissection is an integral part of surgical treatment of oral cavity carcinoma. Knowledge of patterns of nodal spread of tumor from various subsites in oral cavity is mandatory to avoid morbidity of radical neck dissections. Most of the existing literature about neck nodal metastasis pertains to head and neck cancer as a whole group. This study describes the neck nodal metastasis pattern of tumors from different subsites in oral cavity along with the factors affecting the regional relapse. Materials and Methods: A retrospective analysis of 268 patients with squamous cell carcinoma of oral cavity treated between 1999 and 2003 was performed. Patients were treated with upfront surgery (primary tumor resection and neck dissection) with or without adjuvant radiotherapy. Supraomohyoid and modified radical neck dissection were performed in clinically N0 and N patients respectively. Patterns of nodal metastasis to neck (levels I to V) and regional nodal relapse were evaluated. Method of Data Analysis: The collected database was analyzed using SPSS-10.Apart from descriptive analysis, factors associated with relapse were determined. All calculations were performed at the confidence interval of 95%. Significance was calculated using the ‘t test’. Results: A total of 322 neck dissections were performed for tumors located in buccal (27%), alveolobuccal (23%), alveolus (17%), tongue (17%), retromolar trigone (8%), lip (6%) and floor of mouth (2%). Mean tumor size was 3.1 cms. Pathological nodal involvement was present in 40.6% of the patients (of them 50% had more than one node positive). Most common involvements were at levels I, II and III. Level IV and V accounted for 3.8% only. For buccal, alveolus, lip and retromolar trigone tumors, 97% of the nodal metastasis was confined to levels I, II & III. Levels III, IV and V involvement was comparatively higher for tumors in tongue and alveolobuccal area. Skip metastasis was present in only 4.5% of the node positive patients. Extranodal spread was present in 18%. A total of 16 patients (6%) had regional nodal relapse. Mean number of positive nodes in patients with regional relapse was 3.06 (p 0.0001). Other factors associated with regional relapse were presence of pathological nodal metastasis and extranodal spread. Conclusion: Patterns of neck nodal metastasis from oral cavity carcinoma is different from other areas of head and neck with most of the spread being to levels I & II and rarely to levels IV & V. Skip metastasis is uncommon. Presence of nodal metastasis and extranodal spread are significant risk factors for regional relapse. In view of low incidence of level IV & V involvement and skip metastasis, more conservative neck dissections are justified in the management of advanced oral cancer.