nvestigation of Serum Folate-Receptor-1 in Patients with Non- Small Cell Lung Cancer

Abstract

Objective: Histopathological overexpression of folate receptor-1(FOLR1) involved in folate transport in cell growth has been reported in various cancers. Increased serum FOLR1 (sFOLR1) has also been reported in epithelial ovarian cancer. The aim was to investigate sFOLR1 levels in non-small cell lung cancer(NSCLC) patients and the response prediction of the standard chemotherapy targeting folic acid metabolism. Methods: In this prospective study, sFOLR1 levels were investigated in 30 healthy individuals and 60 patients with stage4 malign metastatic NSCLC before and after standard chemotherapy. The commercial immunoassay(ELISA) kit was used for the analysis of sFOLR1. Serum carcinoembryonic antigen(CEA), vitamin B12, and folate levels were also investigated. Results: In NSCLC patients sFOLR1 levels were significantly higher(p<0.001) than the healthy individuals. After 3 months of standard treatment, sFOLR1 was significantly lower than pre-treatment values in NSCLC patients(p<0.001). Diagnostic accuracy was strong in the differentiation of NSCLC patients from healthy individuals(AUC= 0.966). with the cut-off point of 82.45 pg/ml, the sFOLR1 level was performed with 95% sensitivity and 99% specificity. Pretreatment sFOLR1 levels were significantly lower in patients with-response to standard chemotherapy(p<0.01). The best predictive value was determined as 393.80 pg/ml. At the end of the 401 days, a significant difference was found in patients with high sFOLR1 predictive value. The median overall survival(OS) duration was 288 days for all patients (95% GA 198.13-377.87). Median progression-free survival(PFS) was 321 days(95% GA 211.90-430.10). Conclusions: For monitoring standard chemotherapy with drugs targeting folic acid metabolism, sFOLR-1 levels may be an important biomark