Related Experiment Videos
What do we know about the origin of CA 125?
1Department of Obstetrics and Gynecology, University of Geneva, Switzerland.
Summary
Cancer Antigen 125 (CA 125) is found in normal tissues like the endometrium and peritoneum. Elevated CA 125 levels can result from normal physiological processes, not solely from ovarian cancer.
Area of Science:
- Gynecologic Oncology
- Immunology
- Biochemistry
Background:
- The murine monoclonal antibody OC 125 targets Cancer Antigen 125 (CA 125).
- CA 125 is expressed in fetal derivatives of coelomic epithelia and adult tissues, including Müllerian epithelia, peritoneum, pleura, pericardium, fallopian tubes, and endometrium.
- Normal tissues like the endometrium and peritoneum produce CA 125.
Purpose of the Study:
- To investigate the expression and sources of Cancer Antigen 125 (CA 125).
- To understand the contribution of normal tissue production to circulating CA 125 levels.
- To assess the diagnostic limitations of CA 125 serum assays.
Main Methods:
- Utilized the murine monoclonal antibody OC 125 to identify the CA 125 antigen.
- Analyzed CA 125 expression in fetal and adult tissues.
- Examined CA 125 levels during menstruation and peritoneal irritation.
Main Results:
- CA 125 is present in normal adult tissues such as the endometrium, fallopian tubes, pleura, and peritoneum.
- Normal endometrial production significantly contributes to circulating CA 125 during menstruation.
- Peritoneal irritation (e.g., hyperstimulation, salpingitis, ectopic pregnancy, laparotomy) leads to elevated CA 125 due to peritoneally derived antigen.
Conclusions:
- The CA 125 antigen is produced by normal epithelia, including those of the peritoneum, endometrium, and benign ovarian cysts.
- Elevated CA 125 serum levels can occur due to physiological conditions and peritoneal irritation, not exclusively in ovarian cancer.
- The diagnostic utility of CA 125 as a sole marker for ovarian cancer is limited by its expression in normal tissues.