Level V Lymph Node Involvement in Oral Cavity Squamous Cell Carcinoma: Incidence and Implications for Surgical Management.

UNLABELLED: In India, oral cavity squamous cell carcinoma (OCSCC) is the most common cancer in men and the third most common in women, largely due to prevalent habits such as betel nut and tobacco chewing. Regional lymph node metastasis is the most significant prognostic factor in OCSCC, influencing both survival and recurrence. Among the cervical nodal levels, involvement of posterior-triangle (Level V) nodes is considered exceedingly rare in oral cavity cancers, raising concerns about the necessity of routine Level V dissection. Avoiding unnecessary dissection of this nodal level may help reduce postoperative morbidity, especially shoulder dysfunction, without compromising oncologic control. A prospective study was conducted on 128 patients with histologically confirmed OCSCC to evaluate the incidence of Level V lymph node metastasis and its correlation with adverse pathological features, including perineural invasion (PNI), extranodal extension (ENE), and depth of invasion (DOI). Statistical analyses were used to assess associations between these factors. Level V nodal metastasis was observed in only 1 of 128 cases (0.8%). Significant correlations were found between Level V involvement and both PNI and ENE, with a trend towards significance for DOI. These findings suggest that Level V metastasis is rare and typically associated with high-risk pathological features. Therefore, routine Level V dissection may not be warranted for all patients with OCSCC. A selective approach-reserving Level V clearance for patients with multilevel nodal involvement or high-risk features-may minimize surgical morbidity while maintaining oncologic safety. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13193-025-02492-5.