CA125

Immunology

---

Description

The main application of all tumour markers is monitoring for relapse or progression. Use as a diagnostic aid requires care and knowledge of the test limitations. Opportunistic screening is discouraged. Current guidelines suggest that CA125 is the best tumour marker available for epithelial ovarian cancer. It is not sensitive or specific enough to be used for diagnosis or screening, but can be used for staging, prognosis, detecting reoccurance and monitoring therapy [1,4]. CA125 belongs to the family of hybridoma-defined tumor markers. The major fraction of CA125 is located on a high-molecular weight glycoprotein (200-1000 kD), but smaller subcomponents can also be detected [2]. Although the highest CA125 values occur in patients suffering from stage IV ovarian carcinoma, elevated values can also be observed in malignancies of the endometrium, breast, gastrointestinal tract and various other malignancies [2]. CA125 can be used to help distingush a malignant pelvic mass from a benign mass [3]. Elevated values are sometimes found in various benign gynecological diseases such as ovarian cysts, ovarian metaplasia, endometriosis, uterus myomatosus and cervicitis [2]. Slight elevations of this marker may also occur in early pregnancy and in various benign diseases (e.g. acute and chronic pancreatitis, benign gastrointestinal diseases, renal insufficiency, autoimmune diseases and others). Markedly elevated levels have been found in benign liver diseases such as cirrhosis and hepatitis. Extreme elevations can occur in any kind of ascites due to malignant disease [2,3].

---

Indications

Monitoring of epithelial ovarian carcinoma.

---

Sample Type

2mL Serum (Gel 5mL Yellow tube), or 2mL Heparin (Lithium or Sodium) or 2mL EDTA Plasma.
Requests from outside Sheffield: transport at ambient temperature via Royal Mail or Courier.

---

Reference Range

Normal range: 0-35 kU/L.

Reference range established by manufacturer and verified in house.

---

Turnaround Time

Within 2 days

---

Testing Frequency

Daily

---

References

Sturgeon CM and Diamandis EP. Use of tumour markers in clinical practice: Quality requirements. The National Acadamy of Clinical Biochemistry. Laboratory medicine practice guidelines. 2009. [Ref 1]
Sturgeon CM, et al. Serum Tumour Markers: How to order and interpret them. British Medical Journal. 2009. 339; 852-858.
PRU handbook of clinical immunochemistry. 9th Edition. 2007. [Ref 2]
Blast RC, et al. New Tumour markers: CA 125 and beyond. Int J Gynocol cancer. 2005. 15 (3):274-281. [Ref 4]
Sturgeon C. Practice guidelines for tumour marker use in the clinic. Clin Chem. 2002. 48(8):1151-1159. [Ref 3]
Duffy M.J. Tumour Markers in Clinical Practice: A review focusing on common solid cancers. Med Princ Pract. 2013. 22: 4-11.

---

Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.