Progastrin-releasing peptide as a diagnostic and therapeutic biomarker of small cell lung cancer

Lung cancer is the most common fatal cancer and its prevalence is increasing in Korea (1-3). Tumor markers have been studied in patients with lung cancer as tools to differentiate lung cancer subtypes and improve diagnosis and treatment selection (4,5). Neuron-specific enolase (NSE) and progastrin-releasing peptide (proGRP) are the most beneficial tumor markers in neuroendocrine tumors, such as small cell lung cancer (SCLC) (6,7). Although NSE was a historically recommended tumor marker for SCLC (8). NSE also stains up to 80% of non-small cell lung cancer (NSCLC) in tissue examinations and is elevated in the serum of 20–30% patients with NSCLC (9)