Increased expression of colony stimulating factor-1 is a predictor of poor prognosis in patients with clear-cell renal cell carcinoma

Liu Yang, Qian Wu, Le Xu, Weijuan Zhang, Yu Zhu, Haiou Liu, Jiejie Xu, Jianxin Gu

This study aims to evaluate the impact of colony stimulating factor-1 (CSF-1) expression on recurrence and survival of patients with clear-cell renal cell carcinoma (ccRCC) following surgery. We retrospectively enrolled 267 patients (195 in the training cohort and 72 in the validation cohort) with ccRCC undergoing nephrectomy at a single institution. Clinicopathologic features, cancer-specific survival (CSS) and recurrence-free survival (RFS) were recorded. CSF-1 levels were assessed by immunohistochemistry in tumor tissues. Kaplan-Meier method was applied to compare survival curves. Cox regression models were used to analyze the impact of prognostic factors on CSS and RFS. Concordance index (C-index) was calculated to assess predictive accuracy. In both cohorts, CSF-1 expression positively correlated with advanced Fuhrman grade and necrosis. High CSF-1 expression indicated poor survival and early recurrence of ccRCC patients after surgery, especially those with advanced TNM stage disease. Multivariate Cox regression analysis showed CSF-1 expression was an independent unfavorable prognostic factor for recurrence and survival. The predictive accuracy of the University of California Los Angeles Integrated Staging System (UISS) was significantly improved when CSF-1 expression was incorporated. High CSF-1 expression is a potential adverse prognostic biomarker for recurrence and survival of ccRCC patients after nephrectomy.