Cell proliferation, apoptosis, angiogenesis and growth rate of incidentally found renal cell carcinoma.
BACKGROUND
Our previous study showed that the growth rate of incidentally found renal cell carcinoma (RCC) varied, and that the initial clinical and pathological features did not predict subsequent growth of the carcinoma. The objective of this study was to determine the relationships between cell proliferation, apoptosis, angiogenesis and the growth rates of these RCC.


METHODS
We examined cell proliferation, apoptosis, and angiogenesis in 16 incidentally found cases of RCC. Cell proliferation was assessed by immunohistochemical staining with a Ki-67 antibody. Apoptosis was assessed by the terminal deoxynucleotidyl transferase (TdT) mediated deoxy-UTP biotin nick end labeling (TUNEL) technique. The Ki-67 labeling index (KI) and the apoptotic index (AI) were determined as the ratio of immunohistochemically positive cells per 1000 cancer cells. The KI/AI ratio was also determined. Angiogenesis was evaluated by CD34 immunostaining. Finally, we investigated the correlation between these parameters and the growth rate of primary lesions of incidentally found RCC.


RESULTS
The KI ranged from 7 to 73 (median, 20), AI ranged from 6 to 171 (median, 26), and microvessel density (MVD) ranged from 21 to 673 (median, 265) for incidentally found RCC. Ki-67 labeling index, AI and MVD were not closely correlated to each other. Furthermore, these parameters were not associated with growth rates of incidentally found RCC. Only the KI/AI ratio was strongly correlated to the growth rate of incidentally found RCC (r = 0.709; P = 0.0083).


CONCLUSIONS
Our results suggest that the balance between cell proliferation and apoptosis partly determines the growth rate of primary lesions of incidentally found RCC.
Oda
Toshiro
T
Department of Urology, Division of Clinical Pathology, Sapporo Medical University School of Medicine, Japan.
Takahashi
Atsushi
A
Miyao
Noriomi
N
Yanase
Masahiro
M
Masumori
Naoya
N
Itoh
Naoki
N
Sato
Masa-Aki
MA
Kon
Shin-Ichiro
S
Tsukamoto
Taiji
T
D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000032:analysis*; D017209:Apoptosis; D002292:Carcinoma, Renal Cell / Q000098:blood supply / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D019394:Ki-67 Antigen / Q000032:analysis*; D007680:Kidney Neoplasms / Q000098:blood supply / Q000473:pathology*; D008875:Middle Aged; D009367:Neoplasm Staging; D009389:Neovascularization, Pathologic / Q000473:pathology
D018952:Antigens, CD34; D019394:Ki-67 Antigen