Affiliation:
1. Indiana University School of Medicine, USA
2. Department of Urology, Indiana University, USA
3. Department of Biostatistics and Health Data, Indiana University, USA
4. Department of Pathology, Indiana University, USA
Abstract
Introduction: Papillary renal cell carcinoma (PRCC) is the second most common type of renal cell carcinoma. Although studies have explored the connection between PRCC subtype and disease prognosis, the evidence is conflicting. We compared oncologic outcomes of type 1 and 2 PRCCs following surgical management. Methods: A single-centre, retrospective review identified patients undergoing surgery for PRCC from 2000 to 2022. Demographic, imaging, staging pathology, and follow-up data were collected. Recurrence-free, cancer-specific, and overall survival (RFS, CSS, OS) were calculated using the Kaplan-Meier method and Cox proportional hazard ratio. Results: A total of 249 patients were identified. Of the total, 177 patients had type 1 PRCC, and 72 had type 2. The average age was 62 years and was similar between groups ( p = 0.66). The median RENAL score was 7 for both groups ( p = 0.12). Type 2 had a higher pathologic T-stage with fewer pT1 (58% vs 86%) and more pT3 masses (32% vs 7%) than type 1 ( p < 0.01). RFS, CSS, and OS were significantly worse in type 2 PRCC. However, this difference was not evident after adjusting for T-stage (Figure 1). Median follow-up duration was 16 months (interquartile range (IQR) 1–52). Conclusions: Type 2 PRCC is diagnosed at a higher stage than type 1. The difference between type 1 and 2 PRCC in RFS, OS, and CSS can be accounted for after correcting for staging. These findings suggest that surveillance and follow-up schedule for patients with papillary RCC should be based on pT-stage and not papillary subtype.