Clinical Utility of Serum BRAF and PTEN Proteins in the Diagnosis of Non-Small Cell Lung Cancer: A Pilot Study

INTRODUCTION: Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality worldwide. Early and accurate diagnosis is essential for improving clinical outcomes. BRAF, a key kinase in the MAPK pathway, and PTEN, a negative regulator of PI3K/Akt signaling, are both implicated in tumorigenesis. This pilot study aimed to evaluate the diagnostic potential of serum BRAF and PTEN protein levels in patients with NSCLC.
METHODS: In this cross-sectional pilot study, 60 histologically confirmed NSCLC patients and 20 age- and sex-matched healthy controls were recruited from Istanbul University Oncology Institution. Peripheral blood samples were collected prior to any systemic therapy. Serum BRAF and PTEN concentrations were measured using commercially available ELISA kits (CUSABIO). Statistical analyses included group comparisons, Pearson correlation, and receiver operating characteristic (ROC) curve analysis.
RESULTS: Median serum BRAF and PTEN levels were significantly higher in NSCLC patients compared with controls (p=0.001 for both). A strong positive correlation between BRAF and PTEN was observed (r=0.681, p<0.001). ROC analysis indicated that PTEN (AUC=0.830) demonstrated superior diagnostic accuracy compared with BRAF (AUC=0.765).
DISCUSSION AND CONCLUSION: This pilot study, the first to analyze serum BRAF and PTEN simultaneously in NSCLC, suggests that PTEN may serve as a promising noninvasive diagnostic biomarker. These preliminary results warrant validation in larger, multicenter studies to confirm diagnostic performance and explore integration into clinical workflows.

Keywords: Biomarker, BRAF, ELISA, non-small cell lung cancer (NSCLC), PTEN.