[tousled1]

Marejo,

The Serum HER2 test is a simple blood test that is similar to tumor marker tests. I've had it done every 12 weeks since I started Herceptin. A reading of 15 or below is considred "normal." When I was getting the test while on Herceptin my level kept dropping gradually. When it went up from 6.3 to 9.5 even though it was still within normal limit my oncologist ordered a scan and that's when we found the mets. It's been extremely reliable for me where as tumor marker tests have not. I know that it is approved for metastic breast cancer but not sure about early breast cancer.

The serum Her2/neu test is sometimes used to monitor cancer therapy. If the level is initially elevated then falls, it is likely that treatment is working; if it stays elevated, treatment is not working; and if the level falls then rises, the cancer may be recurring. It measures the amount of HER-2/neu protein released into the blood stream from the surface of HER-2/neu positive breast cancer cells

There is a lot of information on this site about the HER2 serum test. I think the initial one was an interview with Dr. Carney so if you search for Dr. Carney you should be able to get a lot of your questions answered. Also there's information about the test on the information page.

Since you are two years out since your diagnosis and having no problems I doubt that you would need the test. You can always print the information from this site and take it to your oncologist and see what he/she thinks.