Background: Cutaneous Squamous Cell Carcinoma is one of the most common malignancies worldwide and the majority arise in the head and neck region. Up to 5% can metastasize to regional lymph nodes which results in a poor prognosis. In patients with metastatic cutaneous squamous cell carcinoma there are conflicting reports on the predictors survival and recurrence.
Objective: To systematically review and perform meta-analysis of all published studies on the risk factors for overall survival, locorregional recurrence and disease specific survival of Metastatic cutaneous Squamous Cell Carcinoma in the Head and Neck (McSCCHN).
Data Sources: Pubmed, CINAHL and EMBASE were searched from from 1946 to April 2017.
Eligibility Criteria: Inclusion criteria were randomized controlled trials or observational studies reporting on at least 10 patients with McSCCHN, studies reporting one defined risk factor, studies reporting survival or locoregional control and clinical follow-up of 2 years of more. For the final analysis we included risk factors that were analyzed for the same outcome in at least three studies.
Study appraisal and Synthesis methods: Two reviewers independently abstracted the data. Risk of bias was estimated with the Newcastle-Ottawa Scale. Meta-Analysis was performed using the random-effects model.
Main outcomes and measures: The primary endpoint was overall survival. Secondary endpoints included locorregional recurrence and disease specific survival.
Results: A total of 13 observational studies were included, representing 1882 patients included in the analysis. Significant risk factors for overall survival were extracapsular spread (HR 1.90; 95% CI 1.12-3.23), immunosuppression (HR 2.67; 95% CI 2.42-2.95), and adjuvant radiotherapy (HR 0.42; 95% CI 0.25-0.69). Risk factors that were not significant predictors of overall survival were age, gender, nodal classification and lymph node ratio. Among these variables, significant heterogeneity was only observed for the presence of extracapsular spread (I2=68%, p < 0.05).
Implications: For McSCCHN, extracapsular spread, immunosuppression, and adjuvant radiotherapy represent the most important factors for overall survival. These risk factors may assist in better risk stratification of this patient population.