title: Impact of Microvascular Invasion and Tumor Necrosis on the Prognosis of Korean Patients with pT1b Renal Cell Carcinoma.
abstract: OBJECTIVE
  To evaluate prognostic factors in pT1b renal cell carcinoma (RCC) patients for which no specific studies have been conducted on.
  
  
  METHODS
  The data of 270 patients diagnosed with pT1bN0M0 RCC at 2 institutions between January 1998 and June 2010 were retrospectively analyzed. Univariate and multivariate analyses using Cox proportional hazard models were used to identify pathologic and clinical factors that influenced prognosis. Five-year recurrence-free survival and cancer-specific survival were analyzed using the Kaplan-Meier method.
  
  
  RESULTS
  The median follow-up period was 55.5 months, and the mean patient age was 55.2 years (range: 26-80). There were 12 cancer-related deaths, and tumor recurrence was noted in 22 patients between 8 and 120 months after surgery. Sites of metastases included the lung in 13 patients, bone in 5 patients, and other sites in 4 patients. Five-year recurrence-free survival and cancer-specific survival rates were 91.2 and 93.5%, respectively. Multivariate analyses revealed that the presence of microvascular invasion and tumor necrosis independently predicted prognosis.
  
  
  CONCLUSIONS
  Microvascular invasion and tumor necrosis were found to be independent prognostic factors in pT1b RCC. This result will help urologists to provide patients with more accurate prognoses, and patients with confirmed microvascular invasion and tumor necrosis will require closer follow-up.
authors.affiliation: Department of Urology, School of Medicine, Kyungpook National University, Daegu, Korea.
authors.forename: Se Yun
authors.initials: SY
authors.lastname: Kwon
authors.forename: Jun Nyung
authors.initials: JN
authors.lastname: Lee
authors.forename: Bum Soo
authors.initials: BS
authors.lastname: Kim
authors.forename: Young Hwii
authors.initials: YH
authors.lastname: Ko
authors.forename: Phil Hyun
authors.initials: PH
authors.lastname: Song
authors.forename: Hyun Tae
authors.initials: HT
authors.lastname: Kim
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Kim
authors.forename: Eun Sang
authors.initials: ES
authors.lastname: Yoo
authors.forename: Gyu-Seog
authors.initials: GS
authors.lastname: Choi
authors.forename: Bup Wan
authors.initials: BW
authors.lastname: Kim
authors.forename: Tae Gyun
authors.initials: TG
authors.lastname: Kwon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000098:blood supply / Q000175:diagnosis* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000098:blood supply / Q000175:diagnosis* / Q000601:surgery; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D015999:Multivariate Analysis; D009336:Necrosis; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000098:blood supply / Q000175:diagnosis / Q000208:ethnology; D009392:Nephrectomy; D011379:Prognosis; D016016:Proportional Hazards Models; D056910:Republic of Korea; D012189:Retrospective Studies; D055815:Young Adult