Molecular Subtypes of Clear-cell Renal Cell Carcinoma are Prognostic for Outcome After Complete Metastasectomy

Metastasectomy is routinely performed in selected patients with metastatic clear-cell renal cell carcinoma (ccRCC) as an alternative to systemic therapy. In the absence of randomized trials, the benefit and best way of patient selection remain unclear. Earlier, we described four molecular ccRCC-subtypes (ccrcc1-4) that have a prognostic and predictive value upon first-line sunitinib or pazopanib.

Assess the prognostic value of ccrcc1-4 subtypes after complete metastasectomy. (1) Compare outcomes of good-prognosis ccrccc2&3-tumors with intermediate/poor-prognosis ccrcc1&4-tumors. (2) Compare outcomes of the four subtypes separately.

Single-center retrospective study (1995-2017), assessing 43 ccRCC patients undergoing complete metastasectomy without systemic treatment.

Molecular subtype determined with established 35-gene expression classifier.

Median disease-free survival (DFS), time to systemic therapy, cancer-specific (CSS) and overall survival (OS) from metastasectomy, estimated with Kaplan-Meier method and tested against other predictors with multivariable Cox regression.

Median DFS was 23 mo for ccrcc2&3-tumors versus 9 mo for ccrcc1&4-tumors (p=0.011, hazard ratio [HR]=2.6). Median time to systemic therapy was 92 mo versus 28 mo (p=0.003, HR=3.3). Median CSS was 133 mo versus 50 mo (p<0.001, HR=2.7). Median OS was 127 mo versus 50 mo (p=0.011, HR=2.5). The classification remained independent upon multivariable analysis. Outcomes remained significantly different when comparing four subtypes separately. The intrinsic heterogeneity of expression profiles is a limitation of this approach.

Even after clinical patient selection, patients with a ccrcc1- or ccrcc4-tumor are at a higher risk of relapse after complete metastasectomy. Patients with a ccrcc2- or ccrcc3-tumor usually experience a long DFS. These results need validation in a larger cohort to establish the subtypes as prognostic marker.

Metastasectomy is recommended for some patients with metastatic clear-cell kidney cancer; however, we do not know who will benefit the most. We show that molecular subtypes increase the possibility to predict which patients are at risk for early relapse after metastasectomy and who may benefit more from other treatment options.

European urology. 2018 Feb 17 [Epub ahead of print]

Annelies Verbiest, Gabrielle Couchy, Sylvie Job, Laure Caruana, Evelyne Lerut, Raymond Oyen, Aurélien de Reyniès, Lorenzo Tosco, Steven Joniau, Hendrik Van Poppel, Dirk Van Raemdonck, Kathleen Van Den Eynde, Agnieszka Wozniak, Jessica Zucman-Rossi, Benoit Beuselinck

Laboratory of Experimental Oncology, Department of Oncology, KU Leuven, Leuven, Belgium., Inserm, UMR-1162, Génomique Fonctionnelle des Tumeurs Solides, IUH, Paris, France., Programme Cartes d'Identité des Tumeurs, Ligue Nationale Contre le Cancer, Paris, France., Department of Pathology, University Hospitals Leuven, Leuven, Belgium., Department of Radiology, University Hospitals Leuven, Leuven, Belgium., Department of Urology, University Hospitals Leuven, Leuven, Belgium; Department of Imaging and Pathology, KU Leuven, Leuven, Belgium., Department of Urology, University Hospitals Leuven, Leuven, Belgium., Department of Thoracic Surgery, University Hospitals Leuven, Leuven, Belgium., Laboratory of Experimental Oncology, Department of Oncology, KU Leuven, Leuven, Belgium; Inserm, UMR-1162, Génomique Fonctionnelle des Tumeurs Solides, IUH, Paris, France; Department of General Medical Oncology, University Hospitals Leuven, Leuven Cancer Institute, Leuven, Belgium. Electronic address: .