Cancer Antigen 125 Associated With Multiple Benign and Malignant Pathologies C. Miralles, MD, PhD, M. Orea, MD, P. España, MD, PhD, M. Provencio, MD, PhD, A. Sánchez, MD, B. Cantos, MD, R. Cubedo, MD, E. Carcereny, MD, F. Bonilla, MD, PhD, and T. Gea, MD, PhD Background: Cancer antigen (CA) 125 tumor-associated antigen is a high molecular glycopro- tein used for follow-up of epithelial ovarian cancer. The test is often requested as a differential diagnosis in patients with pleural or peritoneal fluid. This study analyzes the prevalence of CA-125 increases in a population of patients attending a general hospital and discusses the possible clinical implications of increased levels. Methods: On 4 different days, 380 CA-125 assays were performed in randomly selected patients attending our hospital. Serum CA-125 was measured with a commercial enzyme immunoassay, and clinical records were reviewed for assessment of clinical parameters. Results: Sixty-one patients (16%) had increased CA-125. The pathologies of these patients were heart failure in 9 (14.7%), lung disease 11 (18%), hepatic cirrhosis in 7 (11.4%), malignant tumors in 9 (14.7%), intra-abdominal nonhepatic disease in 6 (10%), previous surgery in 17 (27.8%), and miscellaneous in 2 (3%). Effusions were seen in 34 patients (55.7%). Conclusions: Our data confirm the variety of benign and malignant pathologies coursing with increased CA-125. Cardiovascular and chronic liver disease were the most frequent diagnoses in patients with increased CA-125; this supports the opinion that CA-125 lacks utility as a marker for malignancy. CA-125 could have a role in the follow-up of cardiovascular, hepatic, and tumoral diseases with serosal involvement. Key Words: CA-125—Serum markers—Mesothelial cells—Ovarian cancer—Serosal involve- ment. The cancer antigen (CA) 125 tumor-associated antigen is a high molecular glycoprotein produced by normal cells of different tissues derived from the celomic epi- thelium. Increased levels have been found in several pathologic situations, and this has demonstrated clinical utility for monitoring the course of epithelial ovarian cancer. Even though clinical utility other than the fol- low-up of ovarian carcinoma has not been accepted, many physicians still request the test in various clinical situations, especially as a potential marker of occult ovarian carcinoma when serosal structures are involved. When the level is high, multiple analyses and x-rays are required to confirm or refute the supposed occult malig- nancy. All these tests have important psychological and economic consequences for patients. The use of the CA-125 serum assay as a single diagnostic tool is re- stricted by the fact that the antigen CA-125 is produced by normal epithelia and not only by the ovarian cancer cell. We performed this study to evaluate the prevalence of CA-125 increases in a wide-ranging patient popula- tion attending a general hospital and to assess the possi- ble meaning of that increased level. PATIENTS AND METHODS A total of 380 CA-125 assays were performed on 4 different days in randomly selected patients attending Received May 10, 2002; accepted September 17, 2002. From the Servicio de Oncología Médica (CM, PE, MP, AS, BC, RC, EC, FB) and Servicio de Bioquímica (MO, TG), Clínica Puerta de Hierro, Hospital Universitario, Madrid, Spain. Address correspondence and reprint requests to: Pilar España, MD, PhD, Servicio de Oncología Médica, Hospital Universitario Clínica Puerta de Hierro, San Martín de Porres 4, 28035, Madrid, Spain; Fax: 34-91-3730535; E-mail: mpespanas@seom.org. Published by Lippincott Williams & Wilkins © 2003 The Society of Surgical Oncology, Inc. Annals of Surgical Oncology, 10(2):150–154 DOI: 10.1245/ASO.2003.05.015 150