Immunosuppression Impact on Head and Neck Cutaneous Squamous Cell Carcinoma: A Systematic Review with Meta-analysis.
The primary objective was to define and quantify the relationship between immunosuppression and prognosis in patients with cutaneous squamous cell carcinoma of the head and neck. Ovid/Medline, PubMed, Embase, and Scopus were searched from inception through June 5, 2017, with cross-referenced subject headings of squamous cell carcinoma, skin neoplasms, head and neck neoplasms, and prognosis. Additional gray literature was queried. All prospective, retrospective, and cohort studies in the English literature investigating prognosis in patients with head and neck cutaneous squamous cell carcinoma were eligible for inclusion. Meta-analysis data were pooled using the fixed-effects model. The main outcome measures were hazard ratios detailing subgroup analysis between immunosuppressed and immunocompetent patients. Seventeen studies were eligible for inclusion; 317 of the 2886 patients were immunosuppressed. Meta-analysis with pooled hazard ratios was performed for all outcome variables with at least 3 reported hazard ratios. Immunosuppression portended a worse prognosis across all outcome variables of interest: locoregional recurrence (2.20; 95% confidence interval [CI], 1.45-3.36), disease-free survival (2.69; 95% CI, 1.60-4.51), disease-specific survival (3.61; 95% CI, 2.63-4.95), and overall survival (2.09; 95% CI, 1.64-2.67). This is the largest investigation into the impact of immunosuppression on head and neck cutaneous squamous cell carcinoma. Immunosuppressed patients experience worse recurrence and survival outcomes compared to immunocompetent counterparts. The data support formal inclusion of immunosuppression in head and neck cutaneous squamous cell carcinoma staging systems.