Gross genomic alterations differ between serous borderline tumors and serous adenocarcinomas--an image cytometric DNA ploidy analysis of 307 cases with histogenetic implications

Abstract

Our objective was to study the gross genomic alterations in serous borderline tumors and serous adenocarcinomas of the ovary. A retrospective analysis of 245 serous borderline tumors and 62 serous adenocarcinomas from 249 patients was performed using high-resolution image cytometric DNA ploidy analysis. DNA ploidy status, S-phase fraction, and DNA index were evaluated. The majority of serous borderline tumors were diploid (225/245 cases, 92%). The remaining 8% showed an aneuploid peak predominantly with DNA index of less than 1.4. Grades 2 and 3 serous adenocarcinomas were more often (80%) nondiploid, mostly with DNA index exceeding 1.4. Grade 1 serous adenocarcinomas were an intermediate group, more similar to serous borderline tumors. The S-phase fraction increased from serous borderline tumors (mean = 0.6%) through grade 1 serous adenocarcinomas (mean = 2.8%), being highest in grades 2 and 3 adenocarcinomas (mean = 6.8%). Our findings support the hypothesis that serous borderline tumors and grades 2 and 3 serous adenocarcinomas are genomically different lesions, with grade 1 serous adenocarcinomas being an intermediate group more close to borderline tumors.