[Study of the prognostic value of DNA ploidy and proliferation index (Ki-67) in renal cell carcinoma with venous thrombus].
BACKGROUND
Malignant tumours of the renal parenchyma are accompanied by extension to the inferior vena cava in 4% to 10% of cases. The objective of this study was to compare DNA ploidy and proliferation index of renal cell carcinoma (RCC) with renal vein (RV) thrombus and RCC with inferior vena cava (IVC) thrombus and to investigate a correlation between these markers and Fuhrman grade and patient survival.


METHODS
A retrospective study was conducted in 58 patients with RCC and venous thrombus (40 in the RV and 18 in the IVC). Flow cytometry (FCM) and MiBI antibody immunolabelling (Ki-67 index) were performed on the healthy parenchyma, the renal tumour and the venous thrombus. Eighteen tumours with inferior vena cava thrombus were compared to 40 tumours with renal vein thrombus. Fuhrman grade, the presence of capsular rupture, invasion of the perirenal fat, and the presence of sarcomatoid transformation were investigated for a possible correlation with survival.


RESULTS
No difference of expression of Ki-67 antigen expression was observed between the two populations of renal tumours with thrombus (RV/IVC), but a significant difference was observed for the two types of thrombus (RV/IVC). A difference in ploidy index was observed was also observed between tumours with RV and IVC thrombus (p<0.005). The tumours had less intense MiB1 immunolabelling and a lower DNA ploidy than their corresponding renal vein and inferior vena cava thrombi (Ki-67: 1.07% vs 5.12%, p<0.01: DNA index: 1.61 vs 1.87, p<0.01). A correlation between Fuhrman grade and tumour DNA index was demonstrated (1.149 for low grade tumours and 1.857 for high grade tumours, p<0.05). Sarcomatoid transformation, capsular effraction and capsular rupture were significantly correlated with Fuhrman grade (p<0.01) and patient survival (p<0.05).


CONCLUSIONS
The proliferation index is not a prognostic factor, but DNA ploidy appears to be more useful because of its correlation with Fuhrman grade and the level of extension of the thrombus (RV/IVC). The proliferation index and ploidy appear to be involved in the process of carcinogenesis and venous thrombus.
Rey
Denis
D
Service d'Urologie, Hôpital Robert Debré, CHU Reims, France. derey3@wanadoo.fr
Pfister
Christian
C
Gobet
Françoise
F
Martinez
Sophie
S
Staerman
Frédéric
F
Grise
Philippe
P
D000368:Aged; D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000276:immunology / Q000401:mortality / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D019394:Ki-67 Antigen; D007680:Kidney Neoplasms / Q000235:genetics* / Q000276:immunology / Q000401:mortality / Q000473:pathology*; D008297:Male; D009360:Neoplastic Cells, Circulating; D011003:Ploidies; D012082:Renal Veins; D012189:Retrospective Studies; D015996:Survival Rate; D014682:Vena Cava, Inferior
D019394:Ki-67 Antigen