CA 72-4
A tumour marker most associated with cancer of the stomach, and sometimes with ovarian and other cancers. It is not a screening test — its main use is to help monitor a known cancer's response to treatment and to watch for recurrence, alongside other markers and scans.
What it measures
CA 72-4 is a protein (also called TAG-72) that can be shed into the blood by certain cancers, most notably cancer of the stomach (gastric cancer), and also some ovarian, colorectal and other gastrointestinal cancers. Like other tumour markers, it is not a screening or diagnostic test on its own: many people with cancer have a normal level, and it can be mildly raised in benign conditions such as inflammation of the stomach or bowel, so it cannot confirm or rule out cancer by itself. Its real value comes once a relevant cancer is diagnosed. Then, if the level was raised at the start, tracking CA 72-4 over time helps show whether treatment is working (a falling level) and can give an early signal of recurrence (a rising level) before it shows up in other ways. It is often used together with CEA and CA 19-9 in gastric and gastrointestinal cancers, as a panel gives more reliable information than any single marker. Trends over time matter far more than a single value.
What a high value can mean
- A known gastric or gastrointestinal cancer — where it is used to monitor response and watch for recurrence.
- Some ovarian cancers — sometimes raised.
- A rising trend during follow-up — can signal recurrence, prompting imaging.
- Benign conditions — inflammation of the stomach, bowel, pancreas or ovary can mildly raise it, so a modest elevation is not specific.
What a low value can mean
- A normal or low level is the expected result — but does not exclude cancer, as many cancers do not raise it.
- A falling level during treatment — suggests the cancer is responding.
When to discuss with a doctor
CA 72-4 is a specialist test, used within the care of a known or suspected gastric (or, less often, ovarian or gastrointestinal) cancer rather than as a general screen — it is not recommended for finding cancer in people without symptoms. Its value is in trends: after a cancer is diagnosed and if the marker is raised, a fall with treatment or a rise during follow-up gives useful information, always interpreted with scans and the clinical picture. A mildly raised CA 72-4 on its own, especially without a known cancer, is often due to a benign cause and needs careful, unhurried interpretation rather than alarm. Mediora.AI shows CA 72-4 alongside CEA and CA 19-9 so the marker pattern is read together; interpreting it belongs with your oncology or specialist team.