Comparative Study of Chromosomal Imbalances, Histological and Clinical Features in a Series of 86 Clear Cell Renal Cell Carcinomas
Julien Dagher, Frederic Dugay, Gregory Verhoest, Florian Cabillic, Sylvie Jaillard, Catherine Henry, Yannick Arlot-Bonnemains, Karim Bensalah, Cecile Vigneau, Nathalie Rioux-Leclercq, Marc-Antoine Belaud-Rotureau. CHU Pontchaillou, Rennes, France; Faculty of Medicine, Rennes, France
Background: Clear cell renal cell carcinoma (ccRCC) is the most common type of renal cancer. The aim of this study was to define specific chromosomal imbalances in ccRCC which could be related to clinical or histological criteria of malignancy.
Design: Tumors and karyotypes of 86 patients who underwent nephrectomy for ccRCC were analyzed from April 2009 till July 2012. Cytogenetic results were correlated with clinical and histological data.
Results: The mean number of chromosomal aberrations per case was 3.7. This number was significantly higher (5.5, p<0.05) in Fuhrman grade 4 cases (F4) than in the other grades although there was a trend but not significant variation between F2 (2.3) and F3 (3.3) cases. The results were similar considering separately the mean number of chromosomal losses (F4: 4.7; F3: 2.1; F2: 1.8) and the mean number of chromosomal gains (F4: 2.5; F3: 1.4; F2: 1.0). The mean number of genomic losses was always more frequent than gains (p<0.05). The most frequently observed abnormalities were chromosomal losses in 3p (50%), and Y (36%). Compared to the F2 group, the F4 cases had a distinct pattern with more frequent losses of chromosomes 4, 7, 9, 13, 14, 18, 20, 21, 22, Y and more frequent gains of chromosomes 12, 16 and 20 (p<0.05). Only a loss of the chromosome Y was more frequent in the F3 than the F2 cases. A loss of chromosomes 9 or Y was associated with a higher Fuhrman grade (F3 or F4, p<0.05). Sarcomatoid and necrosis features were both associated with losses of chromosomes 4, 7, 9, and 22. Separately, sarcomatoid features were related to losses of chromosome 14 and gains of 16 and 20 (p<0.05). Necrosis was also associated with a loss of chromosome 18. T stage varied with losses of chromosomes 4, 18, and Y; N stage with losses of chromosomes 4, 7 and 22, and gains of 16 (p<0.05). Renal fat invasion and microscopic vascular invasion were respectively associated with a chromosome 13 loss and a chromosome 12 gain (p<0.05). The number of chromosomal imbalances showed a relation with higher Fuhrman grades starting 4 imbalances, and with sarcomatoid features for more than 5 imbalances.
Conclusions: A significant relation exists in ccRCC between cytogenetic specific chromosomal imbalances and specific histological prognostic factors. Further studies considering the relation with patients' survival would crystallize these observations.
Category: Genitourinary (including renal tumors)
Monday, March 4, 2013 1:00 PM
Poster Session II # 172, Monday Afternoon