The activated macrophage colony-stimulating factor (CSF-1) receptor as a predictor of poor outcome in advanced epithelial ovarian carcinoma

Objective. We have previously shown that the macrophage colony-stimulating factor receptor (CSF-1R) and its ligand, CSF-1, together predict poor prognosis in epithelial ovarian carcinoma. The activated or phosphorylated form of CSF-1R (CSF-1Rphos) has been associated with enhanced invasive and metastatic potential. Our goal is to correlate CSF-1Rphos with known prognostic factors and to determine its role in predicting outcome in advanced ovarian cancer. Methods. One hundred forty-two primary and forty-seven metastatic epithelial ovarian tumors from 98 patients were immunohistochemically stained using antibodies PY809 and PY723 against their respective tyrosine residues associated with local invasiveness and metastasis. X² analysis was used to correlate CSF-1Rphos staining and previously studied prognosticators within each group. Kaplan-Meier curves of survival were compared using the log-rank test with significance of P < 0.05. Results. Forty-seven and nine-tenths percent (68/142) of primary tumors and forty-eight and nine-tenths percent (23/47) of metastatic tumors stained positive for PY809 and PY723, respectively. The PY809+ group was strongly associated with CSF-1R (P = 0.015) as was the PY723+ group (P = 0.025) in its respective subset. CSF-1Rphos by itself was not a predictor of survival or disease-free interval (DFI) in either the primary or metastatic group. However, when combined with CSF-1R in the metastatic group, the two together predicted worse survival (P = 0.007) and decreased DFI (P = 0.011). Conclusions. Phosphorylated tyrosine kinase receptors are detectable in a significant number of ovarian tumors. Staining strongly correlates with CSF-1R. PY723+ metastases coexpressing CSF-1R portend a highly significant decrease in survival and increased risk of recurrence which may serve to identify high-risk ovarian cancer patients.