A multi-institutional comparison of outcomes of immunosuppressed and immunocompetent patients treated with surgery and radiation therapy for cutaneous squamous cell carcinoma of the head and neck.

BACKGROUND: Patients who are chronically immunosuppressed have higher rates of cutaneous squamous cell carcinoma of the head and neck (cSCC-HN). This is the largest multi-institutional study to date investigating the effect of immune status on disease outcomes in patients with cSCC-HN who underwent surgery and received postoperative radiation therapy (RT).

METHODS: Patients from 3 institutions who underwent surgery and also received postoperative RT for primary or recurrent, stage I through IV cSCC-HN between 1995 and 2015 were included in this institutional review board-approved study. Patients categorized as immunosuppressed had chronic hematologic malignancy, human immunodeficiency/acquired immunodeficiency syndrome, or had received immunosuppressive therapy for organ transplantation ≥6 months before diagnosis. Overall survival, locoregional recurrence-free survival, and progression-free survival were calculated using the Kaplan-Meier method. Univariate and multivariate analyses were performed using Cox proportional-hazards regression.

RESULTS: Of 205 patients, 138 (67.3%) were immunocompetent, and 67 (32.7%) were immunosuppressed. Locoregional recurrence-free survival (47.3% vs 86.1%; P < .0001) and progression-free survival (38.7% vs 71.6%; P = .002) were significantly lower in immunosuppressed patients at 2 years. The 2-year OS rate in immunosuppressed patients demonstrated a similar trend (60.9% vs 78.1%; P = .135) but did not meet significance. On multivariate analysis, immunosuppressed status (hazard ratio [HR], 3.79; P < .0001), recurrent disease (HR, 2.67; P = .001), poor differentiation (HR, 2.08; P = .006), and perineural invasion (HR, 2.05; P = .009) were significantly associated with locoregional recurrence.

CONCLUSIONS: Immunosuppressed patients with cSCC-HN had dramatically lower outcomes compared with immunocompetent patients, despite receiving bimodality therapy. Immune status is a strong prognostic factor that should be accounted for in prognostic systems, treatment algorithms, and clinical trial design. Cancer 2017;123:2054-2060. © 2017 American Cancer Society.