[CA 19-9 in patients with benign pulmonary diseases]

Although serum CA 19-9 is considered to be a useful and specific tumor marker for pancreatic cancer, some patients with benign pulmonary diseases show elevated serum CA 19-9 levels. We measured serum CA 19-9 levels of 156 patients with benign pulmonary diseases (55 with asbestosis, 11 with bronchial asthma, 32 with bronchiectasis, 16 with idiopathic pulmonary fibrosis (IPF), 13 with healed pulmonary tuberculosis (HPT) and 29 other benign diseases). The percentage of patients with positive serum CA 19-9 was 42.3% (14.5% in asbestosis, 27.3% in bronchial asthma, 59.4% in bronchiectasis, 81.3% in IPF, 61.5% in HPT and 51.7% in others). In some patients, serum CA 19-9 levels were as high as those found in malignant gastrointestinal diseases. Serum CA 19-9 levels correlated well with disease activity. Immunohistochemically, CA 19-9 was expressed in mucous cells of the bronchial gland and surface of the bronchiolar surface epithelium cells in benign pulmonary disease. Gel filtration study suggested some difference in molecular weight between the serum CA 19-9 antigen of lung cancer and that of benign pulmonary diseases. It is suggested that serum CA 19-9 increases in the case of hyperplasia of the bronchiolar epithelium cells or the mucous cells of the bronchial gland. We conclude that benign pulmonary disease is one of the factors that affect serum CA 19-9 levels.