Prophylactic Neck Dissection in Early Oral Tongue Squamous Cell Carcinoma 2.1 to 4.0 mm Depth

Abstract

Regional recurrence is common following surgery for T1/T2 oral tongue squamous cell carcinoma (SCC). Tumor depth >4.0 mm is commonly assigned as an indication for prophylactic neck dissection to improve regional control. Prophylactic neck dissection may detect extracapsular extension, a poor prognostic sign where adjuvant chemotherapy is indicated. The hypothesis in this study is that regional recurrence is a significant problem in 2.1- to 4.0-mm-depth tumors, and detection of extracapsular extension may be important in this group. Retrospective chart review. Australian tertiary referral center. Review of all patients with T1/T2 oral tongue SCC treated surgically between January 1991 and January 2009 (n = 81). Twenty-nine prophylactic and 5 therapeutic neck dissections followed for a median 34 months (range, 4-132 months). Tumor depths were 0 to 2.0 mm (n = 15), 2.1 to 4.0 mm (n = 18), 4.1 to 7.0 mm (n = 26), and >7.0 mm (n = 22). Tumors 2.1 to 4.0 mm depth had similar rates of occult nodes as 4.1 to 7.0 mm depth (25% vs 20%). Regional recurrence occurred in 31% overall, 44% in tumors 2.1 to 4.0 mm, and 27% in tumors 4.1 to 7.0 mm depth. Prophylactic neck dissection reduced regional recurrence (17% vs 43%, P = .02). Patients with pathologically negative necks had lower rates of regional recurrence than those with occult nodes (9% vs 50%, P < .01). Extracapsular extension increased regional recurrence (43% vs 7%, P = .02), including 25% of dissected necks with tumor depth 2.1 to 4.0 mm. Regional recurrence is a significant problem in 2.1- to 4.0-mm-depth T1/T2 tongue tumors. Prophylactic neck dissection may improve regional control in patients with adequate primary resection margins and determine need for adjuvant therapies in 2.1- to 4.0-mm-depth tumors.