Significance of serum sialoglycoproteins in patients with lung cancer.

Total sialic acid (TSA), lipid-bound sialic acid (LSA), hexoses (galactose and mannose) and mucoid proteins were analyzed by specific chemical methods from sera of 43 patients with lung cancer and 5 cases of benign lung diseases. The levels were compared with similar values obtained from 25 healthy individuals. The four biomarkers were significantly elevated in lung cancer patients as compared to controls as well as benign conditions (p less than 0.001). TSA, LSA and the hexoses levels were significantly higher in benign conditions as compared to controls (p less than 0.001, p less than 0.05, and p less than 0.001, respectively). Adenocarcinoma patients had lower mean values of all the four biomarkers than squamous-cell and small-cell carcinoma patients. Increased levels of LSA in squamous-cell carcinoma and TSA in small-cell carcinoma were statistically also significant as compared to adenocarcinoma (p less than 0.01 and p less than 0.05, respectively). LSA showed higher mean values in metastatic cancer than in primary lung cancer. The combination of these markers might be useful for differentiation between benign and malignant conditions and also for the diagnosis of metastatic lung cancer.