CA 125 requesting in primary care

CA 125 measurement is part of the ovarian cancer diagnostic pathway.​

Ovarian cancer is the 5th most common malignancy in females.  It is usually diagnosed late with approximately 30% of cases having a palpable pelvic mass at presentation.  Symptoms are often non-specific abdominal symptoms but are characterised by their persistency and frequency.

Scottish Referral guidelines for suspected cancer recommend investigating patients who present with symptoms suspicious for ovarian cancer in:​

Women >50yrs with new symptoms of irritable bowel syndrome (IBS)​

Women >18 yrs with recurrent/persistent symptoms​

•  Bloating or abdominal distension​
•  Loss of appetite​
•  Feeling full quickly (early satiety) and /or loss of appetite​
•  Pelvic/abdominal pain​
•  Increased urinary frequency/urgency​
•  Change in bowel habit​

First-line investigations include: ​

•  Abdominal palpation​
•  Urgent Pelvic ultrasound scan AND serum CA 125 (DO NOT MEASURE DURING MENSTRUATION)​

CA125 may also be requested in the context of follow up/monitoring of patients with previously raised CA125 or monitoring of patients with known ovarian cancer (typically requested via secondary care)​

• CA 125 should not be measured in any of the following situations:​
• During early pregnancy​
• During menstruation​
• For the investigation of suspected endometriosis​
• As part of a tumour marker screen ​
  • CA 125 within the reference range does not exclude ovarian cancer​
  • CA 125 may be raised in other malignancies in addition to other non-malignant pathologies ​
• In a male patient ​

1. Scottish Referral Guidelines for Suspected Cancer [Internet]. NHSScotland; 2019. Gynaecological Cancers; 2019 Jan 01 [cited 2022 Oct 04]. Available from: https://www.cancerreferral.scot.nhs.uk/gynaecological-cancers/?alttemplate=guideline

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