The Clinicopathologic and Molecular Landscape of Clear Cell Papillary Renal Cell Carcinoma: Implications in Diagnosis and Management.

Clear cell papillary renal cell carcinoma (CCPRCC) is a recently described tumor entity. Several questions remain about its epidemiology, molecular features, and clinical behavior.

To comprehensively evaluate clinicopathologic and molecular features of CCPRCC, and compare it with more common kidney cancer subtypes.

We identified 89 CCPRCC patients and compared their clinicopathologic features with 1120 localized clear cell renal cell carcinoma (ccRCC) and 129 type 1 papillary renal cell carcinoma (pRCC) patients.

Nonparametric statistical testing was used to compare relevant features between tumor types. Overall, cancer-specific survival (CSS) and metastasis-free survival estimates were calculated from initial diagnosis using the Kaplan-Meier method. Patients with ipsilateral multifocal disease were explored further. A subset of CCPRCC tumors underwent genomic analysis and were compared with other RCC subtypes.

A higher proportion of female (45% vs 32%) and African-American (19% vs 3%) patients were observed in the CCPRCC cohort than in the ccRCC and pRCC cohorts. CCPRCC tumors also had increased odds of presenting with additional ipsilateral masses (odds ratio [OR]: 4.41 [confidence interval {CI}: 2.34, 8.15], p < 0.001) and bilateral disease (OR: 4.80 [CI: 2.40, 9.59], p < 0.001) compared with ccRCC tumors. On molecular analysis, CCPRCC tumors showed fewer somatic aberrations and a greater degree of mitochondrial DNA depletion. In multifocal CCPRCC tumors, histologic concordance among the different renal cell carcinoma masses was estimated at 44% (7/16), and none of the individuals presenting exclusively with CCPRCC tumors developed metastatic disease after 5 yr. In contrast, multifocal tumors with CCPRCC and other nonconcordant histologies were more likely to experience adverse outcomes (CSS, log rank p = 0.034).

CCPRCC is characterized by distinct molecular and epidemiologic features that could be used to refine current diagnostic approaches. Although their clinical course is generally indolent, multifocal CCPRCC tumors represent a unique diagnostic challenge. In this context, single-mass biopsies could miss concomitant aggressive disease, with a potential negative impact on patient outcomes. Furthermore, high discordance rates in multifocal CCPRCC tumors have important clinical implications in management.

We explored the molecular and clinical features of clear cell papillary renal cell carcinoma (CCPRCC) relative to other kidney cancer subtypes. While CCPRCC generally conveys a good prognosis, additional caution should be taken when it is diagnosed using biopsy if multiple kidney masses are present.

European urology. 2020 Oct 09 [Epub ahead of print]

Stanley Weng, Renzo G DiNatale, Andrew Silagy, Roy Mano, Kyrollis Attalla, Mahyar Kashani, Kate Weiss, Nicole E Benfante, Andrew G Winer, Jonathan A Coleman, Victor E Reuter, Paul Russo, Ed Reznik, Satish K Tickoo, A Ari Hakimi

Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Immunogenomics and Precision Oncology Platform, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Department of Urology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA., Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Immunogenomics and Precision Oncology Platform, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Computational Oncology, Department of Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Urology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA., Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Computational Oncology, Department of Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Center for Molecular Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA. Electronic address: ., Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Immunogenomics and Precision Oncology Platform, Memorial Sloan Kettering Cancer Center, New York, NY, USA. Electronic address: .