Analysis of Allelic Imbalance on Chromosome 17p13 in Stage I and Stage II Epithelial Ovarian Cancers

Abstract

Objectives.To determine whether there is evidence for allelic imbalance (AI) on chromosome 17p13 in early-stage epithelial ovarian tumors.Methods.Studies of allelic imbalance were performed on 29 stage I or stage II epithelial ovarian cancers using 5 short tandem repeat polymorphic markers (STRPs) on chromosome 17p13 by polymerase chain reaction (PCR) amplification.Results.Sixteen of 29 (55%) tumors showed AI at one or more loci, including 7 of 29 (24%) tumors that showed distinct regions of AI. AI at p53 was present in only 9 of 25 (36%) informative tumors. A region of AI, defined by marker D17S654, close to candidate genes OVCA1 and OVCA2, was identified distal to p53 and occurred in 11 of 23 (48%) informative tumors. This region of AI also extended more distal to this locus, and included marker D17S695 where AI occurred in 11 of 26 (42%) informative tumors. Microsatellite instability was observed in 2 of 29 tumors.Conclusions.This study supports the presence of at least one tumor suppressor gene on chromosome 17p13 distal to p53 that is involved in the early development of epithelial ovarian cancer. This study also suggests that the molecular analysis of early-stage epithelial ovarian cancers can provide important information on the genetic etiology of ovarian cancers.