title: Comparison of oncologic outcomes between sarcomatoid and clear cell renal cell carcinoma.
abstract: BACKGROUND
  Sarcomatoid renal cell carcinoma (sRCC) is a rare histological subtype that is associated with unfavorable prognosis. We sought to examine the effect of sRCC on cancer-specific mortality (CSM) relative to clear cell renal cell carcinoma (ccRCC), after adjusting for other variables, as well as other-cause mortality (OCM).
  
  
  METHODS
  We relied on the Surveillance, Epidemiology, and End Results-Medicare database from 2000 to 2009 to identify a cohort of 7916 patients with either sRCC (n = 234) or ccRCC (n = 7682) who received surgery as primary treatment. Patient, tumor, and treatment characteristics were evaluated. Then, 5-year smoothed Poisson regression CSM and OCM estimates were generated for stage-by-stage comparisons between sRCC and ccRCC. A multivariable competing-risks regression model predicting CSM and adjusting for several patient and tumor characteristics, as well as OCM, was finally fitted.
  
  
  RESULTS
  Compared to ccRCC patients, sRCC patients had more advanced and more aggressive disease at diagnosis. Specifically, 48 and 7 % of sRCC and ccRCC patients presented with stage IV disease, respectively (p < 0.001). Overall, 5-year CSM and OCM estimates were 67 and 17 % for sRCC patients and 14 and 19 % for ccRCC patients. In stage-by-stage analyses, sRCC was invariably associated with worse CSM. After adjusting for several characteristics as well as OCM, sRCC was associated with a 3.2 higher risk of CSM compared with ccRCC.
  
  
  CONCLUSIONS
  Patients with sRCC are present with more advanced disease. Moreover, sRCC is associated with a higher rate of CSM, even after adjusting for several characteristics and OCM.
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, 264 Blvd. Rene-Levesque E. Room 228, Montreal, QC, H2X 1P1, Canada. vincent.trudeau.1@umontreal.ca.|Department of Urology, University of Montreal Health Center, Montreal, Canada. vincent.trudeau.1@umontreal.ca.
authors.forename: Vincent
authors.initials: V
authors.lastname: Trudeau
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, 264 Blvd. Rene-Levesque E. Room 228, Montreal, QC, H2X 1P1, Canada.|Division of Oncology, Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Larcher
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, 264 Blvd. Rene-Levesque E. Room 228, Montreal, QC, H2X 1P1, Canada.
authors.forename: Maxine
authors.initials: M
authors.lastname: Sun
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, 264 Blvd. Rene-Levesque E. Room 228, Montreal, QC, H2X 1P1, Canada.|Martini-Clinic, Prostate Cancer Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Boehm
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, 264 Blvd. Rene-Levesque E. Room 228, Montreal, QC, H2X 1P1, Canada.|Division of Oncology, Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Dell'Oglio
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, 264 Blvd. Rene-Levesque E. Room 228, Montreal, QC, H2X 1P1, Canada.
authors.forename: José
authors.initials: J
authors.lastname: Sosa
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, 264 Blvd. Rene-Levesque E. Room 228, Montreal, QC, H2X 1P1, Canada.|Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Tian
authors.affiliation: Division of Oncology, Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Fossati
authors.affiliation: Division of Oncology, Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Briganti
authors.affiliation: Department of Urology, Medical University of Vienna, Vienna, Austria.
authors.forename: Shahrokh F
authors.initials: SF
authors.lastname: Shariat
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, 264 Blvd. Rene-Levesque E. Room 228, Montreal, QC, H2X 1P1, Canada.|Department of Urology, University of Montreal Health Center, Montreal, Canada.
authors.forename: Pierre I
authors.initials: PI
authors.lastname: Karakiewicz
mesh_terms: D000368:Aged; D002170:Canada / Q000453:epidemiology; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D002423:Cause of Death / Q000639:trends; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D008297:Male; D009392:Nephrectomy / Q000379:methods*; D011379:Prognosis; D018426:SEER Program; D012509:Sarcoma / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D015996:Survival Rate / Q000639:trends
keywords: Cancer-specific mortality; Histological subtype; Kidney cancer; Oncological outcomes; Sarcomatoid