# Cancer Antigen (CA) 15-3

> This test measures the amount of CA 15-3, a protein often released into the blood by breast cancer cells. It is primarily used to monitor how well treatment is working for invasive breast cancer or to check if the disease has returned.

- Labcorp code: 143404
- Category: [Cancer Detection](https://picardo.health/labs/tests/cancer-detection.md)
- Sample: blood
- Labcorp turnaround: within 1 day
- Collection: free at a Labcorp location, or $75.00 at home.
- Without a doctor: yes. People order it themselves, with no doctor's visit or referral.
- Price: shown on the review page its order link opens. Opening it orders nothing.
- Order link: https://app.picardo.health/labs/order?tests=143404&ref=assistant

## About ordering

People order for themselves, with no doctor's visit or referral, and results arrive in their Picardo account. Ordering is open to adults 18 and over in the US, except New York, New Jersey, Rhode Island, Pennsylvania, Maryland, Massachusetts, Hawaii and Maine. General health information, not medical advice.