Neopterin Is an Independent Prognostic Variable in Females with Breast Cancer

Abstract

Neopterin, produced by human monocytes/macrophages upon stimulation by interferon-gamma, is a sensitive marker for monitoring Th1-cell immune response in humans. In malignant diseases, the frequency of increases in neopterin in the serum and urine of patients depends on tumor stage and type. In a retrospective study comprising 129 females with breast cancer, urinary neopterin/creatinine ratios were measured at the time of diagnosis. Tumor characteristics were determined concomitantly. Urinary neopterin was increased in 18% of the patients. It did not correlate with tumor size or lymph node status, but it was influenced by the presence of distant metastases (P <0.05) and by tumor differentiation (P = 0.01). When product-limit estimates were calculated after follow-up for up to 13 years (median follow-up, 56 months), the presence of distant metastases (P <0.001), neopterin (P <0.001), tumor size (P = 0.001), and lymph node status (P <0.01) were significant predictors of survival. By multivariate analysis, a combination of the variables presence of distant metastases (P <0. 001), neopterin (P <0.01), and lymph node status (P <0.05) was found to jointly predict survival. In lymph node-negative patients without distant metastases, the relative risk of death associated with increased neopterin concentrations was 2.5 compared with patients with neopterin concentrations within the reference interval. Urinary neopterin provides additional prognostic information in patients with breast cancer.