Post-transplant diabetes mellitus and renal cell cancer after renal transplantation.

Abstract

Diabetes is a risk factor for cancer in the general population. However, few data are available on the association between post-transplant diabetes mellitus (PTDM) and cancer after transplantation. We analyzed this issue in a Spanish cohort of patients without diabetes before transplantation. PTDM was diagnosed with consensus criteria at 12 months after transplantation and 12 months before the diagnosis of cancer. The association between PTDM and cancer (overall and specific types) was evaluated with regression analysis. During a follow-up of 12 years (interquartile range 8-14), 85 cases of 603 developed cancer (829/100000/year) and 164 (27%) PTDM. The most frequent cancers were renal cell cancer (RCC) n=15, 146/cases/100000/year), lung (n=12, 117/cases/100000/year), colon (n=9, 88/cases/100000/year) and prostate (n=9, 88/cases/100000/year). In logistic regression, PTDM was not associated with cancer. Eight of the 164 patients with PTDM (4.9%) vs 7 of the 439 without PTDM developed RCC (1.6%) (P=.027). In multivariate analysis, PTDM was independently associated with RCC [odds ratio (OR) 2.92, confidence interval (CI) 1.03-8.27], adjusting for smoking (OR 4.020, 95% CI 1.34-12.02) and other covariates. PTDM was not associated with other types of cancer. Patients with PTDM must be considered a population at risk for RCC and accordingly, the subject of active surveillance.