You have accessJournal of UrologyKidney Cancer: Epidemiology & Evaluation/Staging/Surveillance II (PD45)1 Apr 2020PD45-06 STAGE AT DIAGNOSIS AND CANCER-SPECIFIC MORTALITY FOR RARE VARIANT HISTOLOGY IN KIDNEY CANCER IN COMPARISON TO CLEAR CELL CARCINOMA: A POPULATION-BASED STUDY Marina Deuker*, Franziska Stolzenbach, Giuseppe Rosiello, Angela Pecoraro, Stefano Luzzago, Pierre Karakiewicz, and Felix Chun Marina Deuker*Marina Deuker* More articles by this author , Franziska StolzenbachFranziska Stolzenbach More articles by this author , Giuseppe RosielloGiuseppe Rosiello More articles by this author , Angela PecoraroAngela Pecoraro More articles by this author , Stefano LuzzagoStefano Luzzago More articles by this author , Pierre KarakiewiczPierre Karakiewicz More articles by this author , and Felix ChunFelix Chun More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000932.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: To evaluate stage at presentation and cancer specific mortality (CSM) according to rare variant histology relative to clear cell renal cell carcinoma (ccRCC). METHODS: Within the Surveillance, Epidemiology, and End Results registry (SEER, 2001–2016), we identified patients with rare histologic subtypes of kidney cancer. Kaplan-Meier-plots as well as multivariable adjustment was used to evaluate CSM after exact caliper matching for stage, grade and patient characteristics. Subgroup analyses consisted of surgically treated patients stratified according to partial (PN) vs. radical (RN) nephrectomy after inverse probability treatment weighting (IPTW). RESULTS: Analyses focused on sarcomatoid (1748), collecting duct (280), mesenchymal (190), neuroendocrine (94), renal medullary (72), mucinous tubular and spindle cell (62) and rhabdoid (49) tumors of all stages. All histologic variants except for mucinous tubular and spindle cell exhibited worse stage at diagnosis than ccRCC. After exact caliper matching with G4 ccRCC and multivariable adjustment, collecting duct tumors and sarcomatoid tumors remained with more unfavorable CSM (all p<0.01), while no significant differences in CSM were recorded for the other variants anymore. In subgroup analyses, sarcomatoid patients treated with PN showed worse CSM in multivariable Cox regression (HR=1.2, p=0.02) after IPTW, while collecting duct, mesenchymal and neuroendocrine tumors showed no worse CSM when PN was performed. CONCLUSIONS: Patients with rare variant histologies generally present in a more advanced stage at diagnosis. However, after equalizing stage at diagnosis, our observations partly refute the common belief that all variant histologies are considered far worse than high grade clear cell tumors, because only collecting duct and sarcomatoid tumors showed a significant survival disadvantage. In multivariable assessment. Subgroup analysis within PN vs. RN showed no survival disadvantage when PN was performed, except for patients with sarcomatoid tumors. Source of Funding: none © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e915-e915 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Marina Deuker* More articles by this author Franziska Stolzenbach More articles by this author Giuseppe Rosiello More articles by this author Angela Pecoraro More articles by this author Stefano Luzzago More articles by this author Pierre Karakiewicz More articles by this author Felix Chun More articles by this author Expand All Advertisement PDF downloadLoading ...