Quantitation of MCA, CA 19.9, CA 125 and TSA levels in lung cancer

Abstract

There is an accumulating body of evidence in the medical literature concerning the investigation of many biochemical markers for lung cancer [I]. The serum tumor markers which have been used in lung cancer have not shown a dmgnoshc ability h c h makes their routine clinical use recommeaded. Of these markers, carcinoembryonic antigen, the hest known, can only offer a sensitivity of 30 % with a specificity 90 YO [2]. Preliminary published data suggest that much-like carcinomaassociated antigen (MCA) is a rather specific and sensitive tumor marker in patients with breast carcinoma [3,4], but there is not yet cxmensus as to its posslble use in sera and in cytosol. Its utilw in lung cancer is still discussed 15). Carbohydrate antigen 19.9 (CA 19.9) is a carbohydrate antigenic determinant which has been identified as a sialylated lacto-Nfucopentaose 11, an oligosaccharide shanng structural f i r e s with L m i s blood group substances. It has been foynd on glycoproteins in the sera of cancer patients, more specifically in those with colorectal, gastric and pancreatic cancer [6,7]. Cancer a n t i p 125 (CA 125) is a high molecular mass glycoprotein expressed on the cell surface of some deriMtes of embryonic coelomic epithelium. This tumorassociated antigen widely used to monitor ovarian carcinomas has been suggested as a promising noninvasive test that could differentiate benign from malignant d t i o n s [8,9]. N-a&tybraminic acid or sialic acid is reMvely new marker which is under intensive evaluati00. Recent clinical andlaboratoryshuiieshaveshownthatavarietyoffancersare associated with elevated levels of sialic acid in serum and other biological fluids. Furthermore, it has been suggested that the measurement of sialic acid in the serum provides an additional test for dqnous and management of cancer [lo]. This investigation was effectuated to study and evaluate MCA, CA 19.9, CA 125 and TSA in different lung carcinoma cases and to m p a r e with normal cases. The experimental procedures were carried out in the Department of Biochemistry at Dokuz Eyllll Uniwmty Faculty of Medicine between September 1993 and August 1994. Th~s study was effectuated at two levels: tissue ( I ) and serum (2). (1) Study at the tissue level: Thirty-four tissues with histologically proven wn-snall cell lung cancer (NSCLC, n=27) and small cell lung cancer (SCLC, n=7) in comparison to normal lung cases(n=6) were investigated to quautitate the levels of MCA (much-like carcinomaassociated antigen), CA 19.9, and CA 125. Tissue samples were obtained from the patients undergoing fiberoptic bronchoscopy. MCA, CA 19.9, and CA 125 tissue levels were assayed in the supernatants of tissue homogenates by employing an enzyme-immunoassay (EIA). Using Kruskal Wallis and MaMBtwhrtney test, statistidy significant difference was found belween MCA levels in the group of overall lung cancer (0.49 f 1.0 Uhng protein) and the group of normal tissues (4.56 f 3.0 U/ mg protein), p< 0.01. No statistically significant hfference was detemuned . betweenthetotalmalignantandnormaltissue levels of CA 19.9 and CA 125. Also, significantly higher levels of MCA were obtained in the groups of NSCLC (0.6 f 1.1 Uhng protein) and SCLC (0.06 f 0.03 Uhng protein) than in n o d tissue samples @< 0.01), whereas CA 19.9 and CA 125 levels were observed not to be statistica!ly significant. In canclusion, MCA appears to be an additional tissue marker in the diagnosis of lung cancer. Table 1 represents tissue MCA, CA 19.9 and CA 125 levels. Tablel. Tissue MCA. CA 19.9 and CA 125 levels in lung carcinoma.