Cohort and nested case-control study of cutaneous squamous cell carcinoma in solid organ transplant recipients, by medication.

Background: Knowledge is needed about the risk of cutaneous squamous cell carcinoma (cSCC) in solid organ transplant recipients (SOTRs) using contemporary immunosuppressive regimens.

Objective: Evaluate the risk of cSCC in relation to medications used by SOTRs.

Methods: The cohort and nest case-control study included 3308 SOTRs and 65,883 persons without transplantation during 2009-2019. Incident cSCC was identified from pathology data, and medications were identified from pharmacy data. Adjusted hazard ratios and 95% confidence intervals (CIs) were estimated using Cox proportional hazards analysis, with voriconazole examined as a time-dependent variable.

Results: The annual incidence of cSCC was 1.69% in SOTRs and 0.30% in persons without transplantation. The adjusted hazard ratio of cSCC associated with lung transplant was 14.83 (95% CI, 9.85-22.33) for lung and 6.53-10.69 for other organs. Risk in Latinx persons was higher than in other non-White groups. Among lung recipients, the hazard ratio was 1.14 for each month of voriconazole use (95% CI, 1.04-1.26). Azathioprine use for ≥7 months, relating to mycophenolate mofetil intolerance, was associated with a 4.22-fold increased risk of cSCC (95% CI, 1.90-9.40). Belatacept and other immunsuppressive medications were not associated with risk.

Limitation: The number of events was somewhat small.

Conclusions: The knowledge of risks and benefits in diverse patients can translate to improvements in care.