Which rises first, the Cancer Antigen 125 (CA 125) or the Erythrocyte Sedimentation Rate (ESR)?

From the Guidelines

Neither CA 125 nor ESR consistently rises first, as they measure different physiological processes and respond to different conditions. The timing of elevation depends entirely on the underlying disease process, with CA 125 increasing primarily in response to ovarian cancer and certain other malignancies, as well as some benign conditions like endometriosis or pelvic inflammatory disease 1. In ovarian cancer, CA 125 may rise early in disease progression, while ESR might increase later as the body mounts an inflammatory response to the growing tumor, as noted in studies on ovarian cancer diagnosis and follow-up 1. Some key points to consider include:

• CA 125 is a tumor marker that is elevated in about 50% of patients with stage I ovarian cancer and about 80% of patients with stage II or greater ovarian cancer 1.
• ESR is a non-specific inflammatory marker that rises in response to various inflammatory conditions, infections, and malignancies.
• The utility of CA 125 to detect early disease is questionable, and it is not specific for ovarian cancer, with raised levels also found in non-gynaecological malignancies and benign disease 1. In most scenarios, the direct comparison of the rise times of CA 125 and ESR is clinically irrelevant, as these tests are used for different purposes - CA 125 primarily for ovarian cancer monitoring and ESR for detecting and monitoring inflammatory conditions.

From the Research

Comparison of CA 125 and ESR

• The provided studies do not directly compare the timing of increases in CA 125 and ESR in patients with ovarian cancer or other conditions.
• However, one study 2 compared the clinical significance of CA 125 with conventional laboratory procedures, including ESR, as tumor markers in ovarian cancer.
• The study found that both CA 125 and ESR showed significant increases with progression of the disease, but CA 125 had higher specificity and sensitivity in monitoring tumor-free patients.
• The study also found that CA 125 exhibited the highest specificity and sensitivity when monitoring tumor-free patients, with a positive CA 125 titre indicating recurrent disease with great certainty.
• In contrast, ESR had a higher incidence of "false positive" marker courses, which may limit its usefulness in monitoring ovarian cancer patients.

Limitations of CA 125 and ESR

• CA 125 is not specific for ovarian cancer and can be elevated in patients with non-ovarian gynaecological and non-gynaecological tumours, as well as patients with benign diseases and even in apparently healthy persons 3, 4.
• ESR is a non-specific marker of inflammation and can be elevated in a variety of conditions, including infections, autoimmune disorders, and cancer 2.
• The provided studies suggest that CA 125 may be a more useful marker for monitoring ovarian cancer patients, but its limitations and lack of specificity must be taken into account when interpreting results 5, 6.

Clinical Utility of CA 125 and ESR

• The clinical utility of CA 125 monitoring in ovarian cancer patients has been questioned due to its limitations in terms of accuracy and lead-time potential 6.
• The study found that the different CA 125 assessment criteria provided similar results, and fine-tuning of the assessment criteria did not seem to improve the monitoring performance of CA 125.
• The results suggested that CA 125 used as a tumor marker for monitoring has inherent limitations, and supplementary markers and alternative assessment criteria are needed.