Analyses of clinicopathologic factors affecting neck control after postoperative radiation as adjuvant treatment for lymph node metastasis in head and neck squamous cell carcinoma

Abstract

To investigate the clinicopathologic factors associated with neck control and distant metastasis in patients with neck metastases in head and neck squamous cell carcinoma (HNSCC) after postoperative radiation as adjuvant treatment. Clinicopathologic data of 208 pathologic N+ (pN+ ) patients with HNSCC initially treated with neck dissection and postoperative radiation in Bethune International Peace Hospital of China from January 2004 to December 2009 were reviewed. The clinicopathologic factors, includeding age, sex, primary tumor site, pathologic T and N stage, tumor growth pattern, histological grade, tumor resection margin, size and number of positive lymph node, number of levels with positive lymph node, and extracapsular nodal spread (ECS), were evaluated for their association with neck control and distant metastasis in patients with HNSCC after postoperative radiation. Univariate χ(2) test and multiple stepwise logistic regression model were used for the analysis. Overall 5-year neck control rate after postoperative radiotherapy was 72.6% (151/208), with 84.0% (63/75) for SND, 72.9% (78/107) for MRND, and 38.5% (10/26) for RND, respectively. Univariate analysis showed that neck control after postoperative radiation was related with following factors: primary tumor site, pathologic N stage, size of positive node, number of levels with positive node, number of positive node, and ECS. Pathologic N stage and number of levels with positive lymph node were associated with distant metastasis. Multivariate analysis indicated that ECS was the most significant risk factor for neck metastasis after surgery and postoperative radiotherapy and the number of levels with positive node was the most significant risk factor for distant metastasis. ECS is the most important pathologic factor in planning postoperative adjuvant treatment for pN+ patients with HNSCC, therefore ECS should be evaluated routinely after neck dissection. The value of postoperative radiotherapy in controlling the ECS-related recurrence after surgery is limited. Postoperative concurrent chemoradiotherapy and targeted therapy can be considered in HNSCC patients with ECS.