Karyotypic analysis of 32 malignant epithelial ovarian tumors.

The identification of recurrent specific cytogenetic findings in various malignancies has provided an improved means to diagnose and treat patients. To date, no characteristic markers have been found for epithelial ovarian cancer. This is due, in part, to several contributory factors, including the inability to identify optimal growth conditions for culture and the fact that most analyses of advanced-stage tumors are obtained from malignant effusions rather than from solid tissue. In addition, many reports include previously treated patients. In this study, 32 untreated solid epithelial ovarian tumors, including 8 tumors of low malignant potential (LMP), were obtained from primary and metastatic sites at initial surgical staging. Using a 2-culture plastic technique for tissue growth, we achieved a 96% short-term culture success rate. Only 4 normal 46,XX karyotypes were identified. Diploid or near-diploid genomes were associated with few cytogenetic alterations. Complex karyotypic morphologies were consistently associated with advanced or poorly differentiated tumors. Nonrandom cytogenetic aberrations most commonly involved chromosomes 1 and 6. A novel translocation, t(1;6)(p10;p10), was identified in both a metastatic LMP tumor and a poorly differentiated invasive tumor. This cytogenetic rearrangement can potentially be regarded as a clinically relevant early marker for tumorogenesis. Finally, karyotypes from both primary and metastatic sites were subject to a comparative analysis in 11 patients. In 4 cases, greater chromosomal complexity was associated with the primary site.