Cancer Risk After Simultaneous Pancreas-Kidney Transplantation Compared With Kidney Transplant Alone: A...

Area of Science:

• Transplantation immunology
• Oncology
• Epidemiology

Background:

• Post-transplant malignancy significantly impacts long-term outcomes in solid organ transplantation.
• Uncertainty exists regarding differential cancer risk between simultaneous pancreas-kidney (SPK) and kidney-alone (KA) transplantation.

Purpose of the Study:

• To compare post-transplant cancer incidence in SPK versus KA recipients.
• To assess the association of cancer with mortality and graft failure in these cohorts.

Main Methods:

• Retrospective propensity score-matched cohort study of 484 SPK and 484 KA recipients (2001-2017).
• Fine-Gray competing risks regression and Cox proportional hazards models were utilized.
• Standardized incidence ratios (SIRs) compared cancer risk to the US general population.

Main Results:

• Overall cancer incidence was similar between SPK and KA recipients (sHR 0.80, p=0.07).
• A trend towards lower non-melanoma skin cancer (NMSC) in SPK was observed (sHR 0.72, p=0.03), attenuated after age adjustment.
• Both SPK and KA cohorts had approximately twofold higher cancer risk than the general population (SIRs ~2.2).
• Incident malignancy was strongly associated with increased mortality (HRs 3.40 for KA, 2.07 for SPK) but not graft failure.

Conclusions:

• SPK and KA transplantation demonstrate comparable overall post-transplant malignancy incidence.
• Both transplant types are associated with substantially elevated cancer risk compared to the general population.
• Shared immunologic and demographic factors, rather than transplant type, likely drive malignancy risk.