Class I histocompatibility antigen expression: a prognostic factor for aneuploid ovarian cancers

Epithelial ovarian cancers with aneuploid DNA content are associated with a poorer clinical course than diploid tumors. Flow cytometric analysis may further categorize aneuploid tumors based on the relative expression of cell surface histocompatibility (HLA) antigens. Surgical specimens from 20 patients with aneuploid tumors were stained using an indirect immunofluorescence method with primary murine monoclonal antibodies W36/22 (class I HLA surface antigens) and L5.1 (irrelevant antibody), counterstained with propidium iodide (DNA stain), and analyzed with the flow cytometer using a computer program to correct staining intensity for cell size. Patients with high or low class I expression were similar with respect to age, stage, histology, grade, and residual disease following surgical debulking; all patients were treated with cisplatin-based chemotherapy. Women with low class I HLA antigen expression had higher progression rates and death rates than patients with high class I HLA expression. Low class I HLA antigen expression is a poor prognostic factor among patients with aneuploid ovarian cancers.