Significance of Level V Lymph Node Dissection in Clinically Node Positive Oral Cavity Squamous Cell Carcinoma and Evaluation of Potential Risk Factors for Level V Lymph Node Metastasis

Level V lymph node (LN) dissection has been significantly associated with postoperative shoulder dysfunction as a sequel of spinal accessory nerve (SAN) dysfunction. The aim of study was to determine the role of level V LN dissection in clinically node positive (cN+) oral cavity cancer. We have prospectively evaluated 210 patients of oral cavity squamous cell carcinoma (SCC). During neck dissection, the contents of the level V LN were dissected, labelled, and processed separately from the neck dissection specimen. We studied the prevalence of histopathologic metastasis to level V nodes in clinically node negative (cN0), cN1 and cN2 groups. Potential risk factors for the involvement of level V LN were also analysed. Of 210 cases, 48 were cN0. Out of them 77 % were pN0 and none of cNo (48) patients had level V metastases. Out of 162 cN+ cases, 112 were cN1 and 49 cN2. Amongst cN1 (112) cases, cN1 with palpable level lb LN (99), 60 % had pN0 and none of them had level V LN involvement but cN1 with palpable ll/lll LN (13), 85 % had pN+ and 1 patient had level V LN involvement (8 %). 8 patients from cN2 (49) group had level V LN involvement (16 %). Over all level V LN involvement was 4.3 %. Tongue was the most common site to give rise to level V LN metastases and extra capsular spread (ECS) was present in 100 % patient with level V LN metastases. Thus, we concluded that, apart from cN0, patients with cN1 oral cavity cancer with level lb as only site, carefully selected cases could safely undergo SND. Potential risk factors for level V LN metastases are clinically evident ECS, multiple LN involvement and cN1 with deep jugular chain of LN involvement.