CA 125

DESCRIPTION: CA 125 – Sample Serum, plasma, cerebrospinal fluid Blood is taken in a vacuum tube (vacutube) with a red cap without additives or in a vacuum tube containing gel or in a vacuum tube (vacutube) with a green cap (Li-heparinate). or purple plug (EDTA). The stability of the sample (serum, plasma) is 3 months at -20°C, 5 days at 4-8°C and 3 days at 15-25°C. Carcinoma antigen 125 (CA 125) is structurally a glycoprotein with a molecular weight of about 200,000 daltons. It is produced by many cells, including ovarian cancer cells. It was found in fetal tissue and in the epithelium of bronchi and bronchioles of healthy individuals. Elevated values were found in the serum and cervical secretions of pregnant women, and it is a normal component of amniotic fluid. Carcinoma antigen 125 is present in 80% of non-mucinous (??) ovarian cancers. DETERMINATION: Recommended method of the Croatian Chamber of Medical Biochemists: Analyte/search: Carcinoma antigen 125 (CEA 125) Sample: Serum Measurement units: kIU/L The method of choice for determination is the immunometric method. RIA ELISA ECLIA CLINICAL SIGNIFICANCE: CA-125 is a serum marker for ovarian epithelial tumors. A normal serum CA-125 level is up to 35 U/ml. However, the increase in the level of CA-125 is not specific only to epithelial ovarian cancer, but its values are also elevated in other pathological conditions. CA 125 is primarily used for decisions about the treatment of ovarian cancer, monitoring of therapeutic success and control after completion of treatment. Its elevation in people with ovarian cancer often follows the clinical course of the disease. After surgical treatment or chemotherapy, its level coincides with the response to therapy. This is why it is superior to other tumor markers such as CEA. CA 125 is also elevated in other malignancies including endometrial, pancreatic, breast, lung and colon cancers and during menstruation, pregnancy, endometriosis and other benign gynecological and non-gynecological conditions. Considering the sensitivity and specificity, CA 125 is not suitable for screening in the early detection of ovarian cancer. In women under the age of 45, elevated CA-125 values in more than 95 percent of cases are the result of other pathological conditions and have no diagnostic significance in the detection of ovarian cancer. CA-125 is significantly elevated in all patients with advanced ovarian cancer. These values are of great importance in the monitoring of patients. If the CA-125 values drop to normal (below 35 U/ml) after the therapy, this does not mean a final cure. About 50 percent of ovarian cancer patients with normal CA-125 levels most likely have residual (remaining) disease. CA-125 values are generally not elevated if the residual tumor is smaller than 2 cm, but in about 30 percent of patients CA-125 has a normal value with a tumor larger than 2 cm. Despite everything, CA-125 still has significance in the prognosis of the disease. If, after correct surgery and three cycles of chemotherapy, CA-125 drops to a normal level, patients have a much greater chance of survival than those whose CA-125 values slowly decline. CA-125 is of great importance in the monitoring of patients treated for ovarian cancer. Determination of the CA 125 test should be requested before the start of therapy in order to obtain a baseline value that will later be compared with values obtained at certain intervals during therapy. Regular three-month follow-ups after treatment must include measurement of the CA-125 level (quarterly in the first and second year after surgery and twice a year thereafter) in order to detect any recurrence of the disease. A decrease in CA 125 concentrations during therapy is a sign that the cancer has responded to therapy. However, if the concentration of CA 125 remained elevated even after the end of the therapy, it is a sign that the disease has relapsed. 1) Physiological changes in the concentration of CA 125 in the serum (plasma) 2) Pathological changes in the concentration of CA 125 in the serum (plasma) A) Increased values of the concentration of CA 125 in the serum (plasma) in: Acute inflammation of the pancreas, acute pancreatitis, (false positive result) / Alcoholic cirrhosis / Biliary cirrhosis of the liver, unspecified / Benign neoplasm of the ovary / Other and unspecified ovarian cysts / Endometriosis, unspecified / Hepatocellular carcinoma; Hepatic cell carcinoma / Ectopic pregnancy, unspecified / Renal cell carcinoma / Uterine cancer, malignant neoplasm of the uterus / Chronic renal failure, chronic renal insufficiency (false positive result / Leiomyoma of the uterus, unspecified / Lymphoma / Malignant diseases / Female infertility, unspecified / Unspecified miscarriage / Non-Hodgkin’s lymphoma) / Gallbladder obstruction / Peritonitis; Abruptio placentae / Systemic lupus erythematosus (SLE) / Female pelvic inflammatory disease, unspecified / Malignant neoplasm of the cervix (cervix) / Malignant neoplasm of the pancreas, pancreatic cancer, pancreatic cancer / Malignant neoplasm of the liver, liver cancer, cancer of liver cells / Malignant neoplasm of other and insufficiently defined sites – Abdomen / Malignant neoplasm of the ovary (Ovarian cancer) / Malignant neoplasm of the lung, lung cancer / Malignant neoplasm of the body of the uterus (Endometrium) / Malignant neoplasm of the vagina / Malignant neoplasm of the stomach, gastric cancer, gastric cancer / Malignant neoplasm of the fallopian tube (Fallopian tube) B) Decreased CA concentration values 125 in serum (plasma) code: Condition after heart transplantation RISK FACTORS: Elevated values: Human anti-mouse antibodies Menstruation Menstrual cycle Operative procedure Childbirth Pregnancy Pregnancy – twins EFFECT OF DRUGS: Decreased values: Biologically decreased values: Danazol Chemotherapy RESULT: Reference range (depending on the method): Men and women: less than 35 kIU/L (less than 35 U/ml) Conversion factor: U/ml x 1 = kIU/L Conversion factor (SI – Conv): kIU/L x 1 = U/ml