Allelic loss on chromosome 17 in human ovarian cancer

In order to identify a common region of deletion on chromosome 17 potentially containing a tumor‐suppressor gene, 27 ovarian carcinomas and 3 ovarian tumors of low malignant potential (LMP) were examined for loss of heterozygosity (LOH) at 6 p arm and 10 q arm loci. Ninety percent of all tumors had deletions at one or more loci. On the p arm, there was a single near‐common region of deletion on 17p 13.3 (D/7S30/ pYNZ22.1; 86% LOH), an intervening locus with a low LOH rate, and a more proximal locus on 17p11.2 (D/7S58/pEW301; 82% LOH) with a high LOH rate. In less aggressive tumors, LOH at Df 7S30 was not accompanied by LOH at p53 . The q arm had a common region of deletion for high‐stage carcinoma at D/7S579 (Mfd 188; 74% LOH) on q21, a locus tightly linked to the familial breast‐ovarian‐cancer syndrome (BRCAI) locus. D/7S579 was lost in all informative high‐stage carcinomas and retained in all low‐stage carcinomas and tumors of LMP. There may be at least 2 tumor‐suppressor genes, an early‐acting gene on the p arm and a gene on the q arm involved in tumor progression and metastasis.