What can cause a false rise in Cancer Antigen 125 (CA125) levels?

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Last updated: June 3, 2025 • View editorial policy

From the Guidelines

CA125 levels can falsely rise due to several non-cancerous conditions, including endometriosis, uterine fibroids, pelvic inflammatory disease, ovarian cysts, pregnancy, and menstruation, as well as non-gynecological conditions like liver disease, pancreatitis, and inflammatory conditions 1. These false elevations occur because CA125 is produced not only by certain cancer cells but also by normal tissues like the peritoneum, pleura, and various epithelial tissues when they become inflamed or irritated. Some of the key conditions that can cause a false rise in CA125 levels include:

  • Benign gynecological conditions such as endometriosis, uterine fibroids, and ovarian cysts 2
  • Pregnancy and menstruation, which can cause temporary increases in CA125 levels 1
  • Non-gynecological conditions like liver disease (particularly cirrhosis), pancreatitis, peritonitis, pleural effusion, pericarditis, and various inflammatory conditions 1
  • Certain lung diseases, heart failure, and autoimmune disorders like lupus or rheumatoid arthritis can also contribute to elevated CA125 levels 2 It is essential to consider these potential causes of false elevation when interpreting CA125 levels, as they can lead to unnecessary anxiety and interventions if used in isolation 2. The use of multimodal screening, including serum CA125 measurement and ultrasound imaging, may be more effective in detecting ovarian cancer, but it is not yet considered the gold standard for early detection 2.

From the Research

Causes of False CA125 Rise

  • Benign gynecological conditions, such as pregnancy, pelvic inflammatory disease, tuberculosis, and cirrhosis of the liver, can cause a false rise in CA125 levels 3
  • Benign ovarian cysts, tubo-ovarian abscess, endometriosis, hyperstimulation syndrome, ectopic pregnancy, and fibroids can also lead to elevated CA125 levels 3
  • Other malignancies, benign ovarian disease, and benign gynecological conditions, particularly leiomyomas, can cause false positive results 4
  • Uterine fibroids can increase peripheral CA125 levels, and removal of the uterus or administration of GnRH analogue therapy can decrease these levels 5
  • Endometriosis, especially cystic ovarian endometriosis and deeply infiltrating endometriosis, can cause marked increases in CA125 levels 6
  • Acute pelvic inflammatory disease can also lead to elevated CA125 levels, which may decrease during treatment 7

Specific Conditions Associated with False CA125 Rise

  • Pregnancy: CA125 levels can be elevated during pregnancy 3
  • Pelvic inflammatory disease: CA125 levels can be elevated in patients with PID, especially those with adnexal masses or severe adnexal inflammation 7
  • Endometriosis: CA125 levels can be elevated in women with cystic ovarian endometriosis or deeply infiltrating endometriosis 6
  • Uterine fibroids: CA125 levels can be elevated in women with uterine fibroids, especially those with large fibroids 5

References

Guideline

acr appropriateness criteria<sup>®</sup> staging and follow-up of ovarian cancer.

Journal of the American College of Radiology, 2018

Research

CA 125 in benign gynecological conditions.

The International journal of biological markers, 1998

Research

The role of CA125 in clinical practice.

Journal of clinical pathology, 2005

Research

Peripheral CA 125 levels in patients with uterine fibroids.

Human reproduction (Oxford, England), 1992

Research

CA125 and endometriosis.

Human reproduction update, 1995

Research

Serum CA 125 in acute pelvic inflammatory disease.

British journal of obstetrics and gynaecology, 1989

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.