Association Between Immunosuppression and Outcomes in Oral Cavity Squamous Cell Carcinoma.

Objective: To assess the effect of immunosuppression on recurrence and mortality outcomes in oral cavity squamous cell carcinoma (SCC) after initial surgical treatment.

Study Design: Retrospective cohort study.

Setting: A single academic tertiary referral center.

Methods: Patients with oral cavity SCC treated with initial surgery were included. Immunosuppressed versus nonimmunosuppressed groups were compared. Primary end points were 5-year overall recurrence and all-cause mortality. Secondary end points were recurrence subtypes (local, regional, and distant) and disease-specific mortality.

Results: Of 803 patients with oral cavity SCC, 71 (9%) were immunosuppressed from therapeutic drug use (n = 48) or systemic disease (n = 23). The immunosuppressed group consisted of patients with a history of transplant (21%), autoimmune or pulmonary disorder (45%), hematologic malignancy or myeloproliferative disorder (30%), and HIV infection (3%). After adjusting for baseline variables of age, sex, comorbidities, pathologic tumor characteristics, and adjuvant treatment, all recurrence and mortality outcomes were worse in the immunosuppressed group. The multivariate-adjusted hazard ratio for overall recurrence was 2.16 (95% CI, 1.50-3.12; < .01), and all-cause mortality was 1.79 (95% CI, 1.15-2.78; < .01) in Cox regression analysis. The 2 groups were then matched in a 1:5 ratio according to the same baseline variables. All end points apart from disease-specific mortality were significantly worse in the immunosuppressed group after matching.

Conclusion: This study demonstrates that immunosuppression is associated with poor outcomes in oral cavity SCC, with an approximate 2-fold increase in rates of recurrence and mortality. Future studies are needed to assess the risks and benefits of adjusting therapeutic immunosuppression in this population.