LOH of chromosome 6q compared with LOH of 17q and 18q in ovarian cancers: relationship to p53 expression and clinicopathological findings

In 41 ovarian epithelial tumors (7 borderline and 34 invasive), loss of het erozygosity (LOH) of chromosomes 6q, 17q, and 18q was examined using 4 micr osatellite markers: ER (6q 25-1), BRCA1 (17q21), DCC (18q21), and D18S58 (1 8q23). The LOH was compared with clinicopathological findings, including p5 3 and ER expression. In borderline tumors, LOH and p53 expression were neve r found, while in invasive carcinomas LOH and p53 were found in 71% and 59% of cases, respectively. In particular, in invasive carcinomas 6q LOH repre sented a marker distinguishing two groups of tumors; those with 6q LOH were only of serous histotype and at advanced stages (III/IV). No significant d ifference was found for any of genes in 5-year survival of the patients. No correlation was found between ER expression and ER LOH, as well as between biological aggressiveness and 17q and/or 18q LOH. We conclude that p53 and LOH of the investigated loci distinguish borderlin e from invasive ovarian carcinomas; moreover, the comparison of these resul ts with clinicopathological parameters suggests that the presence of 6q LOH may be a factor accounting for greater biologic aggressiveness independent of the histologic subtype.