Mawaldi, Mohammad

ABSTRACT Background Post‐transplant malignancy is a major determinant of long‐term outcomes after solid organ transplantation. Whether simultaneous pancreas–kidney (SPK) transplantation confers a differential post‐transplant cancer risk compared With kidney transplantation alone (KA) remains uncertain. Methods We conducted a retrospective propensity score–matched cohort study of adult transplant recipients at three Mayo Clinic sites between 2001 and 2017. SPK recipients ( n = 484) were matched 1:1 with KA recipients using propensity scores. The primary outcome was post‐transplant cancer incidence analyzed using Fine–Gray competing risks regression with death as a competing event. Standardized incidence ratios (SIRs) were calculated relative to the US general population. Cox proportional hazards models with cancer modeled as a time‐varying covariate evaluated associations with mortality and death‐censored graft failure. Results Over a median follow‐up of 10 years, overall cancer incidence was similar between SPK and KA recipients (subdistribution hazard ratio [sHR] 0.80, 95% CI 0.63–1.02; p = 0.07). The observed trend toward lower cancer incidence in SPK recipients was driven by a lower incidence of non‐melanoma skin cancer (NMSC) (sHR 0.72, 95% CI 0.53–0.97; p = 0.03), which was attenuated after age adjustment (sHR 0.76, p = 0.07). Incidence of other malignancies did not differ between groups. Compared with the US general population, cancer risk excluding NMSC was approximately twofold higher in both cohorts (SIR 2.18 for SPK vs. 2.23 for KA). Incident malignancy was strongly associated with increased mortality (HR 3.40 in KA and 2.07 in SPK) but not with a statistically significant increase in graft failure. Conclusions In this propensity score–matched cohort study, overall post‐transplant malignancy incidence was comparable between SPK and KA recipients. Both groups experienced substantially elevated cancer risk relative to the general population, and incident malignancy was strongly associated with mortality. These findings suggest that malignancy risk is driven primarily by shared immunologic and demographic factors rather than transplant type.

Abstract Background Abdominal arterial calcification is a well-established predictor of cardiovascular events and mortality in kidney failure. Autosomal dominant polycystic kidney disease (ADPKD), a common genetic cause of kidney failure, presents with a distinct vascular profile. However, the burden of abdominal arterial calcification in ADPKD remains inadequately characterized. Clarifying these differences may improve cardiovascular risk stratification and transplant timing. Methods We conducted a retrospective cohort study of 4088 adult patients listed for kidney transplant at three Mayo Clinic sites (2005–2024). Patients were categorized by kidney failure cause: ADPKD vs. non-ADPKD. Abdominal arterial calcification was quantified on non-contrast computed tomography (CT) scans using a modified Agatston scoring method. Propensity score matching (1:1) adjusted for age, sex, race, lipid levels, left ventricular ejection fraction, dialysis exposure, coronary artery disease, neurovascular disease, and smoking history, was performed. Abdominal arterial calcification scores were compared between matched groups, and subgroup analyses evaluated abdominal arterial calcification severity across dialysis durations in ADPKD patients. Results After matching, 309 patients with ADPKD were compared with 309 non-ADPKD chronic kidney disease (CKD) controls. Abdominal arterial calcification scores were significantly lower in the ADPKD group (median: 425.3; IQR: 0.0–2033.5) than in the non-ADPKD group (median: 1256.8; IQR: 96.5–5033.8). Among ADPKD patients, abdominal arterial calcification scores increased with dialysis duration (P < .001). Conclusion ADPKD patients exhibit lower abdominal arterial calcification scores than their non-ADPKD counterparts after adjusting for clinical variables. Abdominal arterial calcification progression with dialysis highlights the importance of early transplant evaluation. This study introduces a novel adaptation of coronary calcium scoring software for quantifying abdominal calcification, offering a standardized approach to vascular risk assessment in kidney transplant candidates.