Immunosuppression is a risk factor for worse survival and disease‐specific death in cutaneous squamous cell carcinoma

Abstract Background Previous literature on cutaneous squamous cell carcinoma (cSCC) suggests that the incidence, rate of metastasis, and tumour severity of cSCC are higher in immunosuppressed patients than in immunocompetent patients. However, current literature lacks an extensive comparison of cSCC clinical characteristics and outcomes in immunosuppressed patients. Objectives We compared cSCC tumour characteristics and disease‐related outcomes to help guide the clinical management of immunosuppressed patients. Methods We conducted a retrospective review of histopathologic and clinical data from 935 cSCC cases (19.5% immunosuppressed) from the Mayo Clinic. Results Immunosuppression was associated with younger age (69.3 vs. 74.8 years old, p < 0.0001), male gender (78.6% vs. 67.2%, p = 0.003), and higher grade cSCC tumour characterized by moderate or poor differentiation (25.7% vs. 15.8%, p = 0.009; 9.2% vs. 7.2%, p = 0.009, respectively). No significant differences were found in other tumour characteristics, including clinical tumour dimension, Brigham and Women's Hospital tumour staging or cumulative risk of metastasis and recurrence. Immunosuppressed patients had an increased risk of disease‐specific death on univariate analysis (hazard ratio [HR] [95% confidence interval, CI] 2.05 [1.13–3.74], p = 0.0128). Overall survival in the immunosuppressed population was worse (adjusted HR [95% CI] 1.83 [1.42–2.35], p < 0.001) and, notably, solid organ transplant recipients had the lowest overall survival when stratifying immunosuppressed patients by immunosuppression type (HR [95% CI] 1.62 [1.17–2.24], p < 0.0001). Conclusions In our study, immunosuppression status was predictive of poor differentiation of tumours and a reduction in overall and cSCC‐specific survival. Current staging systems for cSCC do not include immunosuppression as a risk factor and incorporating immune status may be beneficial for accurate risk stratification.