The diagnostic and prognostic value of serum human kallikrein-related peptidases 11 in non-small cell lung cancer

The aim of this study was to explore the diagnostic and prognostic value of serum human kallikrein-related peptidases 11 (KLK11) level in non-small cell lung cancer (NSCLC). Serum specimens from 138 patients with NSCLC and 40 healthy controls were collected. The concentration of KLK11 was measured by enzyme-linked immunosorbent assay (ELISA). The concentration of KLK11 in NSCLC was significantly higher compared to that in the controls (P < 0.01). The serum KLK11 levels decreased with stage, presence of lymph node, and distant metastases, regardless of histology, age, and sex. With a cutoff point of 1.05 ng/ml, KLK11 showed a good diagnostic performance for NSCLC. Univariate analysis revealed that NSCLC patients with serum high KLK11 had a longer overall survival (OS) and progression-free survival (PFS) than those with low KLK11 (HR of 0.36, P = 0.002; HR of 0.46, P = 0.009). Cox multivariate analysis indicated that KLK11 was an independent prognostic indicator of PFS and OS (HR of 0.53, P = 0.042; HR of 0.48, P = 0.037). Kaplan-Meier survival curves further confirmed that patients with high KLK11 have longer PFS and OS (P = 0.003 and P = 0.018, respectively). In conclusion, the measurement of KLK11 might be a useful diagnostic and prognostic test for NSCLC patients.