Keratinocyte Cancer Mortality in Kidney Transplant Recipients.

ABSTRACT

BACKGROUND: Kidney transplant recipients are at increased risk of developing and dying from keratinocyte cancer. Risk factors for keratinocyte cancer death have not been previously described. METHODS: In a cohort of kidney transplant recipients transplanted in Queensland from 1995 to 2014, we identified keratinocyte cancer deaths by searching national transplant and state death registries to March 2020. Standardized keratinocyte cancer mortality rates and mortality ratios were calculated. We used a competing risks model to identify factors associated with keratinocyte cancer death and calculated relative risks (RRs) and 95% confidence intervals (CIs). RESULTS: There were 562 deaths in 1866 kidney transplant recipients (62% male individuals; 86% Caucasian) with 25 934 person-y of follow-up, of which 36 were due to squamous cell carcinoma and 1 to basal cell carcinoma with standardized mortality rates of 78 (95% CI, 53-111) and 2 (95% CI, 0.1-11) per 100 000 person-y, respectively. The standardized mortality ratio for keratinocyte cancer was 23 (95% CI, 23-24). Besides Caucasian ethnicity (associated with 100% of keratinocyte cancer deaths), male sex (RR, 3.24; 95% CI, 1.26-8.33), and older age at transplantation (≥50 versus <50 y; RR, 3.09; 95% CI, 1.38-6.89) were associated with increased risk of keratinocyte cancer death. CONCLUSIONS: Keratinocyte cancer mortality in kidney transplant recipients is over 20 times higher than in the general population. Most keratinocyte cancer deaths are due to cutaneous squamous cell carcinoma, however, basal cell carcinoma can be fatal. Education in skin cancer prevention is essential to avoid unnecessary deaths from keratinocyte cancer among kidney transplant recipients.