Objective: To evaluate whether serum human epididymis protein 4 (HE4) levels could be used as a marker to differentiate lung cancer from pulmonary tuberculosis (PTB) and as a prognostic indicator in patients with non-small-cell lung cancer (NSCLC).
Design: HE4 levels were measured in serum samples from 106 healthy controls, 190 lung cancer patients, 114 patients with PTB and 24 patients with pneumonia using enzyme-linked immunosorbent assay.
Results: Serum HE4 levels in lung cancer patients were significantly higher than those in patients with PTB and healthy controls (P < 0.001). Using the optimal cut-off value of 94.01 pmol/l, HE4 levels distinguished lung cancer from PTB with a sensitivity of 61.6% and a specificity of 93.0%. After adjusting for age and smoking status, a binary unconditional logistic regression model provided a sensitivity of 67.4% and a specificity of 86.0% for differentiating between these two diseases. In the NSCLC group, serum HE4 levels were significantly higher in patients at advanced stages (Stage I-II vs. Stage III-IV, P = 0.02). Higher levels of serum HE4 (≥ 83.90 pmol/l) were significantly correlated with a worse 3-year survival rate for patients with NSCLC (P < 0.05).
Conclusion: Serum HE4 may be used as a potential marker to differentiate lung cancer from PTB and healthy controls. In addition, higher levels of HE4 predict poor prognosis in NSCLC patients.