Epithelial tumors of the ovary are the most common ovarian tumors of adult women. They exist in several different histological patterns and exhibit varying degrees of aggressiveness. Molecular genetic studies in epithelial ovarian cancer have shown that loss of heterozygosity (LOH) for regions of chromosome 17 is a common event, probably reflecting the inactivation of one or more tumor suppressor genes present on this chromosome. We examined 87 sporadic epithelial ovarian tumors of different grade and histological type at 16 loci on this chromosome and found that 35% of them showed LOH for chromosome 17. Of these, 84% showed LOH for all informative markers, suggesting that loss of the entire chromosome 17 homologue may have occurred. Interestingly, chromosome 17 loss was observed frequently in serous tumors (49%), was less common in endometrioid tumors (15%), and was rare in mucinous tumors (4%) (P = .01 and P = .0002, respectively). Our findings support the concept that the histological subtypes of epithelial ovarian cancer may be the result of different molecular genetic events.
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Molecular genetic studies of epithelial ovarian tumors have shown a significant role for chromosome 17 in ovarian cancer development. 6-1~ In particular, LOH and mutational studies have suggested the frequent involvement of four loci on chromosome 17. On the short arm of the chromosome, LOH and mutations at the p53 locus (at 17p13.1) as well as LOH at a more distal locus (at 17p13.3) have been observed in a high percentage of ovarian tumors. 14-\]6S imilarly, on the long arm of chromosome 17, frequent losses in the BRCA1 region (at 17q22-21) and at a more distally located locus (at 17q22-23) also have been reported\] 7'is In the majority of reported studies only a small number of chromo- From the Departments of Pathology and Obstetrics and Gynecology, Markey Cancer Center, and the Department of Microbiology and Immunology4 , University of Kentucky Medical Center, Lexington, KY. Accepted for publication July 29, 1994. Supported in part by National Cancer Institute Grant No. RO1 CA 606 47-01. Address correspondence and reprint requests to Manra Pieretti, PhD, Department of Pathology and Laboratory Medicine, Markey Cancer Center, University of Kentucky, 800 Rose St, Lexington, KY 40536-0093. Copyright © 1995 by W.B. Saunders Company 0046-8177/95/2604-000655.00/0
- chromosome 17
- loss of heterozygosity
- ovarian cancer