Colony-stimulating factors detected in tumor cells and voided urine are potential prognostic markers for patients with muscle-invasive bladder cancer undergoing radical cystectomy.

Background: The clinical use of macrophage colony-stimulating factor, granulocyte colony-stimulating factor (G-CSF), and granulocyte macrophage colony-stimulating factor (GM-CSF) has improved the safety of cytotoxic chemotherapy. However, the overexpression of these CSFs in cancers has been reported to be associated with a poor prognosis in various malignancies. We evaluated the potential of CSF expression as a predictor of clinical outcome in patients with muscle-invasive bladder cancer (MIBC).

Methods: Consecutive patients (n=58) with MIBC who underwent radical cystectomy (RC) were included in this retrospective study. Treatment-naïve tumor specimens obtained by initial transurethral resection of bladder tumors prior to RC were immunostained with antibodies against macrophage colony-stimulating factor, G-CSF, and GM-CSF. We compared the clinicopathological variables and survival between these groups. Baseline levels of CSFs in the serum and voided urine were quantified using an enzyme-linked immunosorbent assay and compared with the expression of CSFs in the tumor lesions.

Results: Low expression of GM-CSF in the tumor cells was significantly correlated with a pathological T4 category (vs T2-3; P =0.02). In univariate survival analysis, high G-CSF and low GM-CSF expression in the tumor lesion were associated with poor outcomes. Furthermore, Cox proportional regression analysis revealed that high G-CSF and low GM-CSF expression in the tumor were independent predictors of shorter recurrence-free survival, cancer-specific survival, and overall survival. The levels of CSFs in voided urine were associated with the expression of CSFs in the tumor lesions.

Conclusion: GM-CSF and G-CSF expression in the tumor lesions obtained by initial transurethral resection are independent predictors of poor outcome in MIBC after RC. Levels of G-CSF and GM-CSF in urine before treatment could be useful in prognostication.