Increased expression of caveolin-1 and microvessel density correlates with metastasis and poor prognosis in clear cell renal cell carcinoma.
OBJECTIVE
To investigate the relationship of caveolin-1 expression and microvessel density (MVD), a reflection of angiogenesis, with metastasis and prognosis in patients with clear cell renal cell carcinoma (RCC).


METHODS
Formalin-fixed, paraffin-embedded tissue sections of clear cell RCC from 67 patients who had undergone radical nephrectomy were stained immunohistochemically with specific antibodies against caveolin-1 and CD34. Caveolin-1 immunostaining was semi-quantitatively estimated based on the proportion (percentage of positive cells) and intensity. MVD was determined with CD34-stained slides. The expression pattern of caveolin-1 and MVD was compared with the clinicopathological variables.


RESULTS
Eighteen patients had either synchronous or metachronous metastases and 11 died during the follow-up. Caveolin-1 intensity was significantly correlated with tumour size (P = 0.005), TNM stage (P = 0.028), M stage (P = 0.012), grade (P = 0.015), and metastasis (synchronous or metachronous; P < 0.001). The caveolin-1 proportion (P = 0.037) and MVD (P = 0.011) were significantly correlated with metastasis. MVD was correlated with caveolin-1 intensity (r = 0.385, P = 0.001) and caveolin-1 proportion (r = 0.388, P = 0.001). There was no difference in the expression of caveolin-1 and MVD between primary and metastatic sites. The survival of patients with higher caveolin-1 intensity was significantly worse than that of patients with lower caveolin-1 intensity. Multivariate analyses indicated that only M-stage was an independent prognostic factor for cancer-specific survival and caveolin-1 expression was not an independent factor.


CONCLUSIONS
Increased expression of caveolin-1 and MVD is associated with metastasis and a worse prognosis in clear cell RCC. Caveolin-1 expression is correlated with MVD. These results suggest that caveolin-1 may be important in the progression of clear cell RCC and angiogenesis may be affected by caveolin-1 during the progression of RCC.
Joo
H J
HJ
Department of Pathology, Ajou University School of Medicine, Suwon, Korea.
Oh
D K
DK
Kim
Y S
YS
Lee
K B
KB
Kim
S J
SJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000098:blood supply / Q000378:metabolism* / Q000556:secondary; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000098:blood supply / Q000378:metabolism*; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D009389:Neovascularization, Pathologic / Q000473:pathology; D011379:Prognosis
C495540:CAV1 protein, human; D051242:Caveolin 1; D022461:Caveolins; D009363:Neoplasm Proteins