Evaluation of Cell Surface Expression of Phosphatidylserine in Ovarian Carcinoma Effusions Using the Annexin-V/7-AAD Assay

Phosphatidylserine cell surface exposure during apoptosis can be detected by its binding to the protein annexin-V. We investigated annexin-V expression in 76 ovarian carcinoma effusions using flow cytometry. Results were analyzed for association with clinicopathologic parameters and survival. Annexin-V expression was additionally compared with the previously studied apoptotic markers cleaved caspase-3, cleaved caspase-8, and deoxyuridine triphosphate (dUTP) incorporation into DNA fragments. Annexin-V was expressed in all specimens and was more frequently detected compared with cleaved caspases and dUTP incorporation (P < .001). Annexin-V expression was higher in grade 3 vs grades 1 and 2 tumors (P = .014). A higher percentage of annexin-V-expressing cells in postchemotherapy specimens was associated with poor overall (P = .005) and progression-free (P = .013) survival. We present the first evidence of annexin-V expression in ovarian carcinoma effusions. The higher annexin-V expression compared with other apoptosis parameters and its association with high-grade disease and poor survival in postchemotherapy patients suggest a role in cell survival rather than apoptosis in effusions.