Genomic imbalances in 61 renal cancers from the proximal tubulus detected by comparative genomic hybridization

Comparative genomic hybridization (CGH) has been applied to characterize 61 primary renal cell carcinomas derived histogenetically from the proximal t ubulus. The tumor samples comprised 46 clear-cell renal cell carcinomas (cc RCCs) and 15 papillary renal cell carcinomas (pRCCs). Changes in the copy n umber of entire chromosomes or subregions were detected in 56 tumors (92%). In ccRCCs, losses of chromosome 3 or 3p (63%); 14q (30%); 9 (26%); and 6 o r 6q (17% each); 4 and 8 or 8p (15% each); 22 (11%); 2 or 2q and 19 (9% eac h); 7q, 10, 16, 17p, 18, and Y (7% each); and 5, 11, 13, 15, and 21 (4% eac h) were detected. Most frequent genomic gains in ccRCC were found on chromo some 5 (63%); 7 (35%); I or Iq (33%); 2q (24%); or 8q, 12, and 20 (20% each ); 3q (17%); 16 (15%); 19 (13%); 6 and 17 or 17q (11% each); and 4, 10, 11, 21, and Y (9% each). In pRCCs, gains in the copy number of chromosomes 7 a nd 17 (7/15, each) and 16 and 20 (6/15, each) were frequent. One pRCC showe d amplification of subchromosome regions 2q22 --> q33, 16q, 17q and the ent ire X chromosome. In pRCC, losses were less frequently seen than gains. Los ses of chromosomes 1, 14, 15, and Y (3/15 each) and 2, 4, 6, and 13 (2/15 e ach) were observed. In ccRCCs, statistical evaluation revealed significant correlations of chromosomal imbalances with tumor stage and grade, i.e., a gain in copy number of chromosome 5 correlated positively with low tumor gr ade, whereas a gain of chromosomes 10 and 17 correlated positively with hig h tumor grade. Furthermore, loss of chromosome 4 correlated positively with high tumor stage. Copyright (C) 2001 S. Karger AG, Basel.