Serum biomarkers for predicting overall survival and early mortality in older patients with metastatic solid tumors

Objectives: We aimed to explore serum biomarkers for predicting survival of older patients with metastatic solid tumors who received first line palliative chemotherapy. Materials and Methods: Serum samples were prospectively collected before first-line chemotherapy at 11 academic centers in Korea. All patients were participants in a prospective cohort study of older patients with metastatic solid tumors. Serum levels of C-reactive protein (CRP), CXCL10, SIRT1, VEGF-A, activin A, C-terminal telopeptide of type I collagen (CTx), total 25-hydroxyvitamin D were measured by ELISA and interleukin-6 (IL-6), myostatin, irisin, FGF-19, FGF-21, FGF-23 by Luminex multiplex assay. Overall survival (OS) was determined. Results: Serum samples from 138 patients (median age: 75 years, range: 70-92 years) were collected from February 2014 to December 2016. During a median follow up time of 13.8 months, 73 (52.9%) patients died. Among 13 serum markers, CRP (log-rank, P = 0.009), activin A (P = 0.007), and myostatin (P = 0.047) were significantly correlated with OS in univariate analyses. Activin A (hazard ratio [HR] 2.22, 95% confidence interval [CI] 1.32-3.72; P = 0.003) and myostatin (HR 3.02, 95% CI 1.39-6.57; P = 0.005) were significantly associated with OS after adjustment for other clinical factors. In predicting early (6-month) mortality, two inflammatory markers, IL-6 and CRP, were included in the decision-tree model. Conclusion: In older patients with cancer, high serum concentrations of activin A and myostatin were predictive of poor OS. IL-6 and CRP might be useful to select older patients at risk of early mortality. These markers could be incorporated into predictive tools for clinical decision-making and warrant further investigation. (C) 2019 Elsevier Ltd. All rights reserved.