Circulating levels of colony-stimulating factor 1 as a prognostic indicator in 82 patients with epithelial ovarian cancer

Serum samples from 82 patients with epithelial ovarian cancer, previously assayed for CA125, were assayed for circulating colony-stimulating factor 1 (CSF-1). An elevated CSF-1 concentration (> 450 U ml^-1 or > 5.42 ng ml^-1) was significantly associated with a worse survival (P = 0.02). The predictive value of raised CSF-1 levels was retained whether the first available sample for all patients (n = 82) or the first sample at the start of chemotherapy (n = 41) was considered. Mean CSF-1 levels (n = 14) dropped significantly during six courses of platinum-based chemotherapy (P = 0.02). Although an elevated CA125 concentration appeared to be a prognostic indicator in the total population (n = 82), it was not related to prognosis in the group of patients from whom samples had been drawn at the start of chemotherapy. In a Cox proportional hazards model, CSF-1, but not CA125, was significantly associated with outcome following adjustment for stage, grade and degree of surgical clearance.