Cutaneous Squamous Cell Carcinoma and Mortality in End-Stage Renal Disease

BACKGROUND: In the general population, cutaneous squamous cell carcinoma (cSCC) is associated with increased all-cause mortality. Transplant patients have been shown to have an increased risk of developing cSCC, and their cSCC is associated with an increased risk for mortality. In end-stage renal disease (ESRD) patients, there is extensive mortality and immune dysfunction. Because of this immune system dysfunction, we examined whether cSCC is associated with increased risk of all-cause mortality among ESRD patients, as well as the risk factors for cSCC.

METHODS: We analyzed ESRD patients in the United States Renal Data System from 2004-2014, excluding organ transplant recipients. We assessed mortality using a Cox Proportional Hazards (CPH) model to control for various demographic and clinical parameters, identified using international classification of diseases (ICD)-9 codes.

RESULTS: Of the 1,035,193 patients included, 624 (0.1%) were diagnosed with cSCC. The median survival time for those with cSCC was 3.91 years [95% confidence interval (CI)=3.67-4.15], versus 2.92 years [95%CI=2.92-2.93] for patients without cSCC. ESRD patients with cSCC were at lower risk of death [adjusted hazard ratio=0.75; 95%CI=0.69-0.82] compared to those without. Decreased risk of death was also associated with parameters such as black race, Hispanic ethnicity, tobacco dependence and actinic keratosis. Increased mortality risk was associated with increasing age, male sex, hemodialysis (versus peritoneal dialysis) and alcohol dependence.

CONCLUSIONS: Contrary to expectations, ESRD patients with a cSCC diagnosis showed reduced all-cause mortality risk relative to those without. The reason for this discrepancy remains unclear, suggesting the need for further study.