title: Oncological outcomes after partial vs radical nephrectomy in renal cell carcinomas of ≤7 cm with presumed renal sinus fat invasion on preoperative imaging.
abstract: OBJECTIVE
  To compare oncological outcomes of partial nephrectomy (PN) and radical nephrectomy (RN) for renal tumours of ≤7 cm in which preoperative imaging reveals potential renal sinus fat invasion (cT3a), as RN is preferred for these tumours due to concerns about high tumour stage.
  
  
  METHODS
  Among 1137 nephrectomies performed for renal tumours of ≤7 cm from January 2005 to August 2012, 401 solitary cT3a renal cell carcinomas (RCCs) without metastases were analysed. Classification as cT3a included only renal sinus fat invasion, as there were no tumours with suspected perinephric fat invasion. Multivariate models were used to evaluate predictors of recurrence-free survival (RFS) and cancer-specific survival (CSS).
  
  
  RESULTS
  There were 34 RCCs (8.5%) with unexpected perinephric fat invasion, but only 77 RCCs (19.2%) were staged as pT3a. During the median follow-up of 43.0 months, recurrence occurred in seven (6.7%) PN cases and 25 (8.4%) RN cases. Six recurred PN cases had positive surgical margins (PSMs). The two cohorts showed equal oncological outcomes for 5-year RFS and CSS. Multivariate analyses showed PSM, pathological T stage, sarcomatoid dedifferentiation, and type of surgery as significant predictors of recurrence. Older age, pathological T stage, and sarcomatoid dedifferentiation were significant predictors of cancer-specific mortality.
  
  
  CONCLUSIONS
  Renal tumours of ≤7 cm with presumed renal sinus fat invasion were mostly pT1. PN conferred equivalent oncological outcomes to RN. If clear surgical margins can be obtained, PN should be considered for these tumours, as patients may benefit from renal function preservation.
authors.affiliation: Departments of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyo Chul
authors.initials: KC
authors.lastname: Koo
authors.affiliation: Departments of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jong Chan
authors.initials: JC
authors.lastname: Kim
authors.affiliation: Departments of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kang Su
authors.initials: KS
authors.lastname: Cho
authors.affiliation: Departments of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Deuk
authors.initials: YD
authors.lastname: Choi
authors.affiliation: Departments of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sung Joon
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: Departments of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Choul
authors.initials: SC
authors.lastname: Yang
authors.affiliation: Departments of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Won Sik
authors.initials: WS
authors.lastname: Ham
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000453:epidemiology / Q000401:mortality / Q000473:pathology / Q000601:surgery; D003952:Diagnostic Imaging; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000453:epidemiology / Q000401:mortality / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: carcinoma; diagnostic imaging; nephrectomy; renal cell; treatment outcome