ERBB2 AND CHROMOSOME-17 CENTROMERE STUDIES OF OVARIAN-CANCER BY FLUORESCENCE IN-SITU HYBRIDIZATION

More than 26,000 new cases of ovarian cancer are identified each year in the United States, with almost 75% of these malignancies in advance d stages at the time of diagnosis. Early-stage disease has a cure rate of up to 90%, but the long-term survival rate of patients with advanc ed disease is 5-20%. At this time, there are no biomarkers that are ef fective indicators of early ovarian cancer. Recently, immunohistochemi cal and Southern blot studies have suggested that overexpression/ampli fication of the oncogene ERBB2 (HER2/neu) is associated with aggressiv e ovarian malignancies; however, some studies have not supported this conclusion. Because tumor cells are known to be highly heterogeneous, we used fluorescence in situ hybridization (FISH) to study individual ovarian cancer cells for HER2/neu amplification and chromosome 17 cent romere copy number. Simultaneous multicolor cohybridization of HER2/ne u and chromosome 17 centromere alpha-satellite probes were carried out on 43 ovarian cancer samples. Ten of the forty-three samples showed m oderate to high amplification of HER2/neu, with varying numbers of chr omosome 17 centromeres present. In some cells the amplified HER2/neu w as dispersed throughout the nucleus, whereas in other cells the amplif ied oncogenes were clustered together. Within a sample there was heter ogeneity in oncogene and centromere copy number. In this small study, we were unable to identify a specific clinical correlation. However, F ISH is a powerful method for the study of oncogene amplification in tu mor samples. (C) 1996 Wiley-Liss, Inc.