The Effect of Tumor Characteristics and Location on the Extent of Lymph Node Metastases of Head and Neck Cutaneous Squamous Cell Carcinoma

BACKGROUND: The extent of a neck dissection for patients with metastasis of cutaneous squamous cell carcinoma of the head and neck (HNcSCC) is still subject to debate and clear guidelines are lacking. Tumor characteristics like size, differentiation and tumor location are known risk factors for lymph node metastasis (LNM). There is some evidence that, depending on tumor location, LNM follows a specific pattern. This study aims to identify which tumor characteristics can predict the pattern and extent of LNM. METHOD: In this cohort study 80 patients were included, who underwent a primary neck dissection for LNM of HNcSCC between 2003 and 2018 at the University Medical Center Groningen, the Netherlands. Retrospective data was collected for primary tumor characteristics and LNM and included surgical and follow-up data. Influence of tumor characteristics on the extent of LNM was analyzed using non-parametric tests. Logistic regression analysis were used to identify a metastasis pattern based on the primary tumor location. RESULTS: Only primary tumor location was associated with the pattern of LNM. HNcSCC of the ear metastasized to level II (OR = 2.6) and the parotid gland (OR = 3.6). Cutaneous lip carcinoma metastasized to ipsilateral and contralateral level I (OR = 5.3). Posterior scalp tumors showed a metastasis pattern to level II (OR = 5.6); level III (OR = 11.2), level IV (OR = 4.7) and the parotid gland (OR = 10.8). Ear canal tumors showed a low risk of LNM for all levels. The extent of LNM was not related to age or any tumor characteristics i.e. tumor diameter, infiltration depth, differentiation grade, perineural growth and vascular invasion. CONCLUSION: Primary tumor location determines the LNM pattern. Whereas known unfavorable tumor characteristics did not relate to the extent of LNM. Location guided limited neck dissection combined with parotidectomy will treat most patients adequately.