Genomic imbalances in human lung adenocarcinomas and squamous cell carcinomas

Comparative genomic hybridization analysis was performed on 67 non-small-ce ll lung cancers (NSCLCs), including 32 squamous cell carcinomas (SCCs) and 35 adenocarcinomas (ACs), to identify differences in the patterns of genomi c imbalance between these two histologic subtypes. Among the entire tumor s et. the chromosome arms most often overrepresented were 1q, 3q, 5p, and 8q, each detected in 50-55% of cases. The most frequently underrepresented arm s were 9q, 3p, 8p, and 17p. The number of imbalances was similar in SCCs an d ACs (median number/case: 12 and 11, respectively). Moreover, many imbalan ces, such as gains of 1q, 5p, and 8q, occurred at a high frequency in both histologic subgroups. Several statistically significant differences, howeve r, were found. The mon prominent difference was gain of 3q24-qter, seen in 81% of SCCs compared with 31% of ACs (P < 0.0001), with amplification at 3q 25-26 being detected in eight of 32 (25%) SCCs but in only two of 35 (6%) A Cs. Gain of 20p13 and loss of 4q also were seen at a significantly higher r ate in SCCs than in ACs, whereas overrepresentation of 6p was more common i n ACs. Gains of 7q and 8q each were associated with higher-stage tumors and either positive nodal involvement or higher tumor grade. These data sugges t that genes located in several chromosomal regions, particularly 3q25-26, may be associated with phenotypic properties that differentiate lung SCCs f rom ACs. Furthermore, certain imbalances, prominent among them gains of 7q and 8q, may be indicative of tumor aggressiveness in NSCLCs. (C) 2001 Wille y-Liss, Inc.