Incidence of metastasis to level V lymph nodes in clinically positive necks among Sri Lankan patients with oral squamous cell carcinoma

Abstract Introduction Oral squamous cell carcinoma (OSCC) remains the most common cancer among males in Sri Lanka. Metastasis to neck is a crucial prognostic factor. A modified radical/ radical neck dissection including levels I –V, is performed in patients with OSCC who has a clinically positive neck (cN+). Currently, evidence suggest sparing level V in a cN + may be justified due to less chance of metastasis in early stages of the disease. The incidence of metastasis to level V in patients with cN + s have not been previously investigated in a Sri Lankan context. Aims To determine level V lymph node metastasis and related clinico-pathological indicators in cN + s of OSCC patients. Materials and methods A multicentre retrospective study investigated post-operative biopsy reports of 187 patients for the period of 5- years. OSCC patients with cN + s who underwent neck dissections of levels I-V were included. Results Only 6.4% of patients had histopathologically positive level V lymph nodes. A total of 127 lymph nodes were harvested from level V of those who showed level V positivity and out of them 68 was positive with 1/3rd cases showing extra nodal extension (ENE). Buccal mucosa (n = 4) and lateral aspect of anterior 2/3 of the tongue (n = 4) were the common primary sites for level V metastasis. Patients who showed levels III and IV positivity, a considerably higher probability of level V nodes being positive was seen, which were statistically significant (p = 0.0001) Conclusion The need to routinely perform a modified radical/radical neck dissection for cN + s should be stopped as incidence of Level V positivity is significantly low. Assessing the cN + for N stage, status of levels III and IV, pattern of invasion, differentiation and the site may be used as predictors for level V positivity.