The role of the NH2-terminal portion of pro-opiomelanocortin as a biomarker for human lung cancer.

In an epidemiological study, we evaluated the human amino-terminal portion (IR-hNT) of pro-opiomelanocortin (POMC) as a biomarker for lung cancer by measuring it by radioimmunoassay in the plasma of 180 patients with various histological types of pulmonary carcinoma. Seventy-seven patients with other cancers or benign lung disorders were our controls. An elevated IR-hNT level was measured in 12 percent of the lung neoplasm cases (22% in small-cell carcinoma) and in only 6 percent of the controls. The mean level in the lung cancer group was also higher than in the controls (p = 0.004), while it was higher in patients with small-cell carcinoma than in those with squamous-cell and adenocarcinoma (p = 0.013 and 0.002, respectively). Otherwise, we demonstrated a correlation between IR-hNT levels and altered liver function only in patients with a lung malignancy (p varying between 0.015 and less than 0.001). Finally, survival analysis failed to show that IR-hNT has a prognostic value when measured at the onset of lung cancer. These results allow us to conclude that IR-hNT, although not very sensitive in screening for carcinoma of the lung, may indicate the presence of liver metastases in this disease.