Surgical Outcomes and Genomic Insights of Nonclear Cell Renal Cell Carcinoma With Synchronous and Metachronous Nodal Disease.

ABSTRACT

INTRODUCTION: Oncological outcomes in patients with nonclear cell renal cell carcinoma (non-ccRCC) treated with surgery for locoregional nodal disease (ND) remain incompletely characterized. The objective was to investigate the characteristics and outcomes of non-ccRCC patients treated with lymph node dissection (LND) and salvage-LND (S-LND). METHODS: A total of 1627 patients underwent nephrectomy for nonmetastatic non-ccRCC at Memorial Sloan Kettering Cancer Center between 2007 and 2023. Histology was grouped as papillary, chromophobe, unclassified, and rare subtypes. Retrospective evaluation identified 2.5% (n = 40) of patients with nodal disease at time of nephrectomy (synchronous-ND) and 1.1% (n = 18) with metachronous nodal disease limited to the retroperitoneum (metachronous-ND). Patients' demographics and tumor characteristics were recorded and evaluated by univariate and multivariate cox regression models. Recurrence-free survival (RFS) and overall survival (OS) were estimated by the Kaplan-Meier method. Patients who underwent tumor DNA sequencing during their clinical course were considered for genomic analysis. RESULTS: OS trended toward longer in metachronous-ND (51 vs 105 months; P = .2), though 23% of patients with synchronous-ND were recurrence-free at 45 months median follow-up. In multivariate analysis, rare histologies were associated with decreased OS (P = .030) and metachronous-ND with improved OS (P = .036). RFS and OS after S-LND was 15 and 96 months, respectively. Late onset of metachronous-ND/recurrence was associated with improved OS (P = .008). Genetic alterations in SETD2, TP53, B2M, and FGFR3 were exclusively seen in synchronous-ND, and tumor mutation burden (TMB) was also higher in patients with synchronous-ND (P = .016). CONCLUSIONS: Patients with metachronous-ND tend to have prolonged OS compared to synchronous-ND, but a substantial portion of patients with synchronous-ND still enter a durable disease-free state following LND. S-LND can likewise provide long-term survival, particularly in patients with longer time to metachronous nodal recurrence. Synchronous-ND was associated with SETD2, TP53, and NF2 alteration as well as higher TMB.