140. Early Involvement of 6q in Surface Epithelial Ovarian Tumors

Cancer Research 56, 4493-4498,1996
( In Coll. con M.G.Tibiletti, B.Bernasconi, D.Furlan, C.Riva, M.Trubia, M.Franchi, P.Bolis, A.Mariani )
Summary: Complex karyotypes are often seen in primary surface epithelial ovarian cancer (SEOT ’s). Conventional cytogenetic as well as fluorescence in situ hybridization analyses coupled with loss of heterozygosity studies identified abnormalities of chromosome 6 as one of the most frequent lesions in these types of tumors. We performed cytogenetic analysis of direct preparations from 40 SEOT ’s, including borderline tumors and low or intermediate, and high-grade carcinomas to verify the frequency of chromosome 6 alterations. We also carried out fluorescence in situ hybridization analysis with a chromosome 6 library and yeast artificial chromosome clones from a region of the same chromosome
( 6q27). Chromosome 6 abnormalities were identified in 30 of 32 (93.7%) analyzable SEOT ’s. Twenty-five of 32 cases showed a deletion of 6q (78.12%) irespective of their histological grade. We wish to underline that this is the first report proving that del(6q) was the most frequent chromosome anomaly in near-diploid SEOT ’s and that it was the sole anomaly observed in four SEOT ’s with diploid complement. Our findings seggest that abnormalities of the telomeric region of chromosome 6 (6q27) may be considered one of the earliest lesions in the pathogenesis of ovarian carcinomas.