Introduction

According to the 2016 WHO classification, new entities were designated for characteristic patterns in renal cell carcinoma (RCC) in patients with end stage renal disease (ESRD), such as acquired cystic disease (ACD)-associated and clear cell papillary RCC. In this study, a central pathologist reanalyzed the pathological findings of RCC in patients with ESRD from multiple institutions, based on the new classification.

Methods

This study included 315 patients who underwent radical nephrectomy in 3 Japanese institutes from 1987 to 2015. A central pathologist reviewed sections from all patients according to the 2016 WHO classification.

Results

Based on the new classification, clear cell was diagnosed in 144 patients (46%), ACD-associated in 100 (31%), papillary in 41 (13%), chromophobe in 10 (3%), clear cell papillary in 3 (1%), MiT family translocation in 2 (1%), and unclassified in 15 (5%). We next compared clinicopathological findings of ACD-associated RCC with those of non-ACD-associated RCC. Multivariate analysis showed that independent prognostic clinical factors for occurrence of ACD-associated RCC were the presence of acquired cystic disease of the kidney (ACDK) (hazard ratio [HR]: 2×10⁹, p<0.01), age (HR: 0.97, p=0.03), and duration of dialysis (HR: 1.06, p<0.01). We further compared pathological features in ACD-associated and other RCCs. ACD-associated included more Furman grade 3/4 (90 vs. 47%, p<0.01). In contrast, other unfavorable findings was less frequent in ACD-associated RCC, including the presence of sarcomatoid features (2 vs. 7%, p=0.04), lymphovascular invasion (3 vs. 11%, p<0.01), and necrosis (7 vs. 13%, p=0.18).

Conclusions

ACD-associated RCC accounts for 31% of RCC in patients with ESRD, and prognostic clinical factors for occurrence include young age, long dialysis duration, and presence of ACDK. In addition, ACD-associated RCC showed higher Furman grade, but fewer cases with other unfavorable pathological features, suggesting the need for an independent nuclear grading system for ACD-associated RCC.

Funding

None