title: Natural history of renal cell carcinoma: An immunohistochemical analysis of growth rate in patients with delayed treatment.
abstract: OBJECTIVE
  To investigate the natural history of renal cell carcinoma (RCC) with delayed treatment and to immunohistochemically analyze the correlation between some biomarkers and the growth rate of RCC.
  
  
  METHODS
  We reviewed our institutional databases to identify renal tumors which were confirmed to be RCC by delayed surgical treatment after at least 12 months of active surveillance (AS). Growth rate was defined as the average growth rate of the maximal diameter on computed tomography or magnetic resonance imaging. The clinicopathological characteristics and immunohistochemical biomarkers (Ki-67, p53, bcl-2, and vascular endothelial growth factor) were analyzed the correlation with the growth rate of RCC.
  
  
  RESULTS
  We identified 45 RCCs from 45 patients. The mean patient age was 54 years (range, 26-78 years). The mean tumor size increased from 2.39 cm (range, 0.10-6.70 cm) at presentation to 4.54 cm (range, 1.40-11.80 cm) after a mean time of 45.4 months (range, 12-155 months) of AS. The mean growth rate was 0.79 cm/y (range, 0.10-4.74 cm), and 36 (80.0%) tumors presented a growth rate ≤ 1.00 cm/y. Clear cell RCC had a trend of growing faster than other histological subtypes. Pathological grade was significantly correlated with the growth rate of RCC (p = 0.043). High positive ratio of Ki-67 (r = 0.351, p = 0.018) and being p53 positive (p = 0.019) were significantly correlated to the fast growth rate of RCC.
  
  
  CONCLUSIONS
  In general, RCCs under AS are slow growing with a wide variation of growth rate, with a portion of RCCs presenting rapid growth kinetics. RCC with rapid growth during AS is characterized by a high histological grade, high positive ratio of Ki-67, and being p53 positive.
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Center, Beijing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Center, Beijing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yao
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Center, Beijing, China. Electronic address: pineneedle@sina.com.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Li
authors.affiliation: Division of Urology and Department of Surgical Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Canada.
authors.forename: Michael A S
authors.initials: MA
authors.lastname: Jewett
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Center, Beijing, China.
authors.forename: Zhisong
authors.initials: Z
authors.lastname: He
authors.affiliation: Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Center, Beijing, China. Electronic address: zhouliqunmail@sina.com.
authors.forename: Liqun
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D002681:China; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D061665:Time-to-Treatment; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
chemical_list: D015415:Biomarkers; D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53
keywords: active surveillance; delayed intervention; growth rate; immunohistochemical analysis; renal cell carcinoma