Cancer and Clinical Oncology; Vol. 2, No. 2; 2013 ISSN 1927-4858 E-ISSN 1927-4866 Published by Canadian Center of Science and Education 11 Plasma CA 19-9 in Advanced Non-Small Cell Lung Cancer Ahmed Abdallah 1 , Mohamed Wahba 1 , Ahmed El Bastawisy 2 , & Rabab Gaafar 2 1 Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt 2 National Cancer Institute, Cairo University, Medical Oncology, Cairo, Egypt Correspondence: Ahmed El Bastawisy, National Cancer Institute, Kasr El-Aini Street, Fom El-khalig Square, Cairo, Egypt. Tel: 20-100-110-4774. Fax: 20-022-270-7988. E-mail: a_s_basta@hotmail.com Received: May 31, 2013 Accepted: June 17, 2013 Online Published: July 22, 2013 doi:10.5539/cco.v2n2p11 URL: http://dx.doi.org/10.5539/cco.v2n2p11 Abstract Background: Lung cancer is the leading cause of cancer death worldwide however no serum marker is routinely recommended till now. Patients and Methods: This is a prospective case control study including two groups of adults, Group I: Includes healthy volunteers as controls. Group II: Includes patients with advanced non-small cell lung cancer (NSCLC). Plasma CA19-9 levels were measured at baseline by ELISA before first line chemotherapy. Primary end point was comparison between the levels of CA19-9 in patients and controls. Secondary endpoint was correlation between CA19-9 level and clinical response (CR), progression free survival (PFS) and overall survival (OS) in advanced NSCLC. Results: 34 healthy adults and 35 patients with advanced NSCLC were included and followed up during the period from October 2009 to February 2013 with median follow up of 10.5 months. The mean and median pre-treatment plasma CA 19-9 concentrations of NSCLC patients were 240.7 and 231U/ml respectively. There was statistically significant difference between the patient and control groups (p < 0.001). No significant correlations were found between CA19-9 levels and CR, PFS and OS p-values: 0.5, 0.3 and 0.6 respectively Conclusion: Plasma CA19-9 is a reliable marker for advanced NSCLC. Keywords: CA19-9 Non-small cell lung cancer 1. Introducation Among malignant tumors lung cancer is the leading cause of death worldwide (Jemal, 2008). Unfortunately, its prognosis is very poor; the disease is curable rarely with an estimated 5-year overall survival rate of 15% (Sun, 2007), therefore the development of novel diagnostic techniques to identify the disease in the early stages and to follow up its progression is important for more effective treatment and improved prognosis. Carbohydrate antigen 19-9 (CA 19-9) was originally isolated from a cell line of a human colorectal cancer as a mucin like product (Koprowski, 1979). The antigen is found in the several tissues, as the epithelial cells of the gall bladder, biliary ducts, pancreas and stomach (Magnai, 1983). CA 19-9 antigen in tissue exists primarily as an epitope present on a glycolipid, sialolacto- N fucopentose II ganglioside; in serum, the CA 199 antigen is associated with a mucin (Magnani, 1982). CA 19-9 was found to be elevated in both benign and malignant conditions, although the level in malignancy is significantly higher. CA 19-9 was found to be elevated in many types of malignancies as the pancreatic, colorectal, hepatic, lung, and ovarian cancers. Benign conditions associated with high levels of CA 19-9 including hepatobiliary system disease, pleural effusion, pneumonia, SLE, and renal failure (Pavai, 2003). The CA 19-9 is not a tumor specific, but it is a tumor associated antigen. CA 19-9 is synthesized normally by human pancreatic and biliary ductular cells, gastric, colonic, endometrial and salivary epithelia (Rhodes, 1990) and has been detected in the normal seminal fluid. This explains the high levels of CA 19-9 in many malignancies. Since its discovery by Koprowski and coworkers, CA 199 antigen has been used widely as a tool for the investigation and management of patients with pancreatic carcinoma. CA 19-9 has been studied in relation to gastrointestinal cancer and has been shown to have a good clinical value as a prognostic and monitoring tool for the follow up of therapy effectiveness of (Koprowski, 1981; Gupta, 1985). Multiple studies have shown that while high CA 19-9 serum levels appear to be useful in the diagnosis of