Trisomy 8 in stage I and stage III ovarian cancer detected by fluorescence in situ hybridization.

Ovarian cancer is the leading cause of death from gynecologic maligancy among women in the United States. In 1997, there were nearly 27,000 ovarian cancer cases with over 14,000 deaths. Recent attempts at early detection of ovarian cancer have been aimed at the identification of biomarkers that would indicate an underlining malignant process or reflect the biological behavior of the tumor. Our previous studies revealed that chromosome 8 copy number abnormality, especially trisomy, is common in several cancers. Archival tissues from 24 cases of papillary serous ovarian carcinoma (10 stage I and 14 stage III) were analyzed by fluorescence in situ hybridization (FISH) with a chromosome 8-specific alpha-satellite probe (Oncor, Gaithersburg, MD). The analysis was done according to standard protocols of the Lifespan Academic Medical Center Cytogenetics Laboratory at Rhode Island Hospital. Twenty-one of 24 cases (87.5%) were found to be trisomic for chromosome 8, if a cutoff point of >/=15% cells with three signals is adopted. Overall, 80% of stage I and 93% of stage III tumors had trisomy 8. This study confirms the presence of a high frequency of trisomy 8 in both early and late stages of the disease and suggests that trisomy 8 may be an early event in the multistep process leading to ovarian cancer. It is of interest to note that a higher frequency of trisomy 8 was found in a higher stage of disease, consistent with our previous results on breast cancer. Thus, additional FISH studies of ovarian tumors for chromosome 8 copy number assessment may be warranted. Copyright 1999 Academic Press.