Diagnostic value of human epididymis protein 4 in malignant pleural effusion in lung cancer

This study aimed to assess the diagnostic value of human epididymis protein 4 (HE4) in the pleural effusion of lung cancer patients.

HE4 protein in the pleural effusion of 60 lung cancer patients was measured by electrochemiluminescence, in parallel with those from 56 patients with benign lung disease, and the association with malignant pleural effusion was evaluated.

The level of HE4 in samples from lung cancer patients was significantly higher than the level for those with benign lung lesions (P= 0.001) and patients with lung adenocarcinoma showed significantly higher levels of HE4 than those with squamous cell carcinoma and small cell carcinoma (P= 0.002 and P= 0.034, respectively). Using an optimal threshold of 652.2 pmol/L, the HE4 level distinguished malignant lung cancer from benign lesions with a sensitivity of 78.3% and a specificity of 75.0%. Moreover, the HE4 level differentiated adenocarcinoma from benign lesions with a sensitivity of 75.9% and a specificity of 85.7% when a threshold of 744.05 pmol/L was used. However, there was no significant difference in the 2 year survival rates of lung cancer patients with high and low HE4 concentrations in pleural fluid (P= 0.882). In addition, there was no significant difference in HE4 levels between tuberculous and inflammatory pleural effusions (P= 0.309).

HE4 in the pleural fluid of lung cancer patients can be valuable in the diagnosis of malignant pleural effusion; however, it does not correlate with the prognosis of patients.