Chromosome aberrations in nine patients with ovarian cancer.

Cytogenetic analysis was performed on 13 tumor specimens (six solid tissues and seven effusions) from nine patients with various types of ovarian cancer. Eight of these patients had not received cytotoxic therapy prior to the initial karyologic assessment. Extensive and complex numerical and structural alterations were seen in nearly all specimens. Consistent (clonal) abnormalities were found in each case, but karyotypic heterogeneity within a tumor was a consistent finding in this series. Aberrations of chromosomes 1, 3, 6, 7, 10, and 12 were each observed in five or more patients. Although no specific recurring translocations were observed, partial deletions of 3p, 6q, 8p, and 10q were each seen in three different cases. Breakpoints tended to recur at several chromosomal band regions, some of which appear to be near the known loci of certain protooncogenes. Double minute chromosomes were seen in one patient, and a homogeneously staining region was found in another. Karyotypic analysis was performed on one patient both before and after initiating chemotherapy, and the chromosome pattern became more complex after treatment. Overall, our findings indicate that karyotypes in newly diagnosed, untreated patients with ovarian cancer can be extremely complicated, and that the extent of chromosome change may increase with tumor progression. Furthermore, the recurrence of specific regional chromosome losses suggests that these sites contain genes whose loss plays a role in the formation of some ovarian tumors.