title: Natural history of renal cortical neoplasms during active surveillance with follow-up longer than 5 years.
abstract: OBJECTIVE
  To present our experience with patients who elected active surveillance for renal cortical neoplasms (RCNs) with ≥5 years of follow-up. Few data are available regarding the long-term natural history of RCNs during surveillance.
  
  
  METHODS
  We retrospectively reviewed our urologic oncology database and identified 44 patients with 51 RCNs who had received active surveillance for >5 years of follow-up. The patient and tumor characteristics and tumor growth rate and overall survival data were evaluated.
  
  
  RESULTS
  The median patient age was 71.7 years (range 55-92), with 32 patients (72.7%) having a Charlson comorbidity index of ≥2. The median tumor size was 2.67 cm (range 0.9-8.6) at diagnosis. Biopsy was performed in 17 patients (38.6%). Of these 17 patients, clear cell renal cell carcinoma was diagnosed in 15 and papillary renal cell carcinoma in 2 patients. The median follow-up was 77.1 months (range 60-137), and the median growth rate was 0.15 cm/y. Of these patients, 2 (4.5%) required delayed intervention. One underwent laparoscopic radical nephrectomy because of a high tumor growth rate, and one elected to withdraw from active surveillance because of personal anxiety, despite having a stable tumor size for 72 months. The latter patient underwent laparoscopic renal cryoablation. Histopathologic examination revealed clear cell renal cell carcinoma in both cases. No metastases or cancer-related deaths occurred in our cohort; 1 patient died of cardiovascular disease.
  
  
  CONCLUSIONS
  Most RCNs undergoing surveillance for >5 years grew slowly. The metastatic potential appeared minimal in patients who demonstrated low or absent tumor growth for a long period.
authors.affiliation: Department of Urology, Columbia University Medical Center, New York, NY 10032, USA. george.haramis@gmail.com
authors.forename: Georgios
authors.initials: G
authors.lastname: Haramis
authors.forename: Adam C
authors.initials: AC
authors.lastname: Mues
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Rosales
authors.forename: Zhamshid
authors.initials: Z
authors.lastname: Okhunov
authors.forename: Alberto Perez
authors.initials: AP
authors.lastname: Lanzac
authors.forename: Ketan
authors.initials: K
authors.lastname: Badani
authors.forename: Mantu
authors.initials: M
authors.lastname: Gupta
authors.forename: Mitchell C
authors.initials: MC
authors.lastname: Benson
authors.forename: James
authors.initials: J
authors.lastname: McKiernan
authors.forename: Jaime
authors.initials: J
authors.lastname: Landman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000628:therapy*; D003452:Cryosurgery; D005260:Female; D006801:Humans; D007672:Kidney Cortex; D007680:Kidney Neoplasms / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D057832:Watchful Waiting