Loss of heterozygosity on chromosome 17q in epithelial ovarian tumors: Association with carcinomas with serous differentiation

Loss of heterozygosity (LOH) on chromosome 17q is frequent in epithelial ov arian tumors, but its clinicopathologic significance remains to be elucidat ed. DNA of 50 patients with epithelial ovarian tumors was extracted from bl ood and fram fresh-frozen and paraffin-embedded tissue (14 benign, 7 border line, and 29 malignant). Six microsatellite loci were amplified by PCR (D17 S250, TRHA1, D17S800, D17S855, D17S579, D17S513). LOH was scored by the abs ence or reduction of the signal to less than 50% of one of the alleles in t umor DNA compared with normal DNA. LON: was identified on chromosome 17q in at least one locus in 12 tumors (24%), all of them carcinomas (12 of 29 tu mors, 41.3%). It occurred more frequently among high-grade serous carcinoma s (8 of 14 tumors, 57%) and mixed endometrioid-serous carcinomas (2 of 5, 4 0%). LOH was detected in all informative markers of 10 tumors, suggesting t he complete loss of an entire chromosome 17 homologue. Patients with LOH-po sitive carcinomas were older than those with LOH-negative malignant tumors (mean ages 67 and 49). The results support the hypothesis that LOH on chrom osome 17q may be associated with the development of ovarian cancers in elde rly patients, particularly with high-grade serous or mixed endometrioid-ser ous carcinomas.