Native Renal Cysts and Dialysis Duration Are Risk Factors for Renal Cell Carcinoma in Renal Transplant Recipients

Abstract

Urinary tract cancers are the third most common cancers in renal transplant recipients (RTX). This study examined the impact of dialysis duration and native renal cyst(s) (NRC) on renal cell carcinoma (RCC) occurrence among 1036 RTX followed-up from 1995 to July 2007. Abdominal ultrasonography was planned within 1-month of transplant, then every 5 years, or 2 years if renal cysts developed. Based on presence and time of development of NRC, RTX were grouped into those with no (No-NRC), new (New-NRC), preexisting (Pre-NRC) and time-indeterminate NRC (TI-NRC). Ten asymptomatic RTX were diagnosed with RCC at a median of 5.8 years posttransplant and had 5-year graft and patient survivals of 90% and 100%, respectively, following appropriate therapy. RCC occurred only in Pre-NRC and TI-NRC who had significantly longer dialysis duration than No- or New-NRC (6.7 ± 3.9 and 3.3 ± 3.2 vs. 2.7 ± 3.1 and 2.6 ± 2.4 years, respectively). These results suggest that NRC and increased dialysis duration are risk factors for RCC posttransplant. Since early treatment of RCC gives excellent outcomes, regular ultrasonography performed within a month of transplantation, then every 5 years for those without cysts and every 2 years for those with cysts for early detection of RCC is recommended.