title: Prognostic significance of perirenal infiltration in renal cell carcinoma (<7 cm).
abstract: OBJECTIVE
  Pathologic stage is the most accurate prognostic factor of renal cell carcinoma. We evaluated whether perirenal fat infiltration is a significant factor in tumors 7 cm or less in size.
  
  
  METHODS
  We retrospectively reviewed the record of 164 cases of tumors 7 cm or less in size. We divided the patients into two groups according to the presence of perirenal fat infiltration (group A, pT1; group B, pT3a). We evaluated relationships, recurrence-free survival and disease-specific survival according to clinicopathologic parameters. Statistical differences were calculated by log-rank test.
  
  
  RESULTS
  A total 131 patients were included in group A, with a mean age of 55.8 years, average tumor size was 4.2 cm, and a mean follow-up period of 43 months. Group B included 33 patients, with a mean age of 55.9 years, an average tumor size of 4.1 cm, and a mean follow-up period of 38 months. There was no significant difference in disease-specific survival; however, recurrence-free survival showed significantly different between two groups (group A: 95.5%, group B: 84.4%).
  
  
  CONCLUSIONS
  In this study, perirenal fat infiltration proved to be an independent prognostic factor for predicting disease-free survival in patients with tumors of 7 cm or less in size. Therefore, as this study showed, the presence of perirenal fat infiltration requires stricter follow-up planning, even in small renal cell carcinoma.
authors.affiliation: Department of Urology, Inje University Busan Paik Hospital, Busan 614-735, Korea.
authors.forename: Seongyub
authors.initials: S
authors.lastname: Oh
authors.forename: Jangho
authors.initials: J
authors.lastname: Yoon
authors.forename: Dongil
authors.initials: D
authors.lastname: Kang
authors.forename: Heung Lae
authors.initials: HL
authors.lastname: Cho
authors.forename: Jae-il
authors.initials: JI
authors.lastname: Chung
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies