Significance of clinical stage, extent of surgery and outcome in cutaneous head and neck squamous cell carcinoma Running heads short title: Novel staging system and outcome in CHNSCC

extent of surgery and outcome in cutaneous squamous cell carcinoma of the head and neck. Abstract The authors analyzed a new clinical staging system and its correlation with pathologic findings and patient survival. Patients were eligible for inclusion in this longitudinal retrospective cohort study if they had cutaneous squamous cell carcinoma on the head or neck, underwent surgery and had a minimum 3 year follow-up. The primary study variable was using a new clinical staging system. Secondary variables included the parotid as a predictor of metastatic spread to the lymphatic nodes in the neck and primary lesion histopathologic traits. The outcome variable was patient survival. Associations between variables were assessed using Fisher's exact test, Mann-Whitney test, Kaplan-Meier method and Mantel log-rank test. P<0.05 was considered significant. The sample was composed of 103 patients. Regional metastatic disease was found in 24 patients. Histopathological analysis showed a higher frequency of neck metastatic disease if the parotid was positive for metastases (p=0.022). An extended staging system showed significant correlation between survival rate and substages (p=0.0105). Perineural invasion was a negative prognostic factor (p=0.0151) The results of this study suggest that combining curative parotidectomy and elective neck dissection could be beneficial in high risk patients. Both neck and parotid metastases should be included in the clinical and histological N classification.