Blood tests can detect several types of cancer by identifying specific substances, called tumor markers, that are released by cancer cells. These markers are measured in blood samples. Here's a breakdown of the cancers that can be detected through blood tests, based on the provided references:
Cancers Detectable Through Blood Tests
The following cancers can be detected using specific blood tests:
| Marker | Associated Cancers | Test Type |
|---|---|---|
| CA15-3/CA27.29 | Breast cancer | Blood |
| CA19-9 | Pancreatic cancer, gallbladder cancer, bile duct cancer, and gastric cancer | Blood |
| Calcitonin | Thyroid cancer | Blood |
| Carcinoembryonic antigen (CEA) | Colorectal cancer | Blood |
How These Blood Tests Work
These blood tests work by measuring the levels of specific tumor markers in the blood. These tumor markers are substances produced by cancer cells or by other cells in the body in response to cancer. Elevated levels of these markers can suggest the presence of certain cancers.
Important Notes
- Not Definitive: These blood tests are not definitive for cancer diagnosis. Elevated marker levels can sometimes be caused by non-cancerous conditions, and some cancers may not produce detectable levels of these markers.
- Part of a Diagnostic Process: These tests are usually used as a part of the diagnostic process, in conjunction with other tests like imaging and biopsies.
- Monitoring Response: Blood tests for tumor markers can also be used to monitor the treatment response and check for recurrence of cancer.
Specific Examples and Insights
- CEA and Colorectal Cancer: The Carcinoembryonic antigen (CEA) test is often used to monitor the progression and recurrence of colorectal cancer.
- CA19-9 for Pancreatic Cancer: The CA19-9 marker is commonly elevated in pancreatic, gallbladder, and bile duct cancers and is frequently used for monitoring these conditions.
- Calcitonin for Thyroid Cancer: Calcitonin is a useful marker, especially for medullary thyroid cancer.
- CA15-3/CA27.29 for Breast Cancer: These markers are helpful in the monitoring of breast cancer.
