CA27.29 blood test

[Debbie L.]

>>I guess I was hoping for no trace of cancer in my system.

Cathy, there may well be no traces of cancer in your system, but (alas) we don't know how to check for that. The tumor markers (Ca27.29, CEA, CA 15-3) test for antigens that some tumors produce, but they are not testing specifically for cancer cells. The antigens are also produced (at lower levels) by normal cells, so I don't think anyone expects a level of zero on these tests. To help muddy the waters, some breast cancers don't cause a rise in tumor markers, and other non-cancerous things (mostly r/t inflammation) can cause a rise above normal.

I've never heard of a tumor marker of zero, has anyone else? A "normal" level means that this test has been validated to show no evidence of cancer when within normal range (with the above disclaimers).

Because these are such unreliable tests, most oncs don't use them after adjuvant treatment of early breast cancer. They are not recommended for that use in most treatment guidelines.

Tumor markers can be useful for those with advanced disease, once it has been established that the cancer does produce the antigens reliably. They can be used to monitor that a treatment is working (looking for declines) and also to signal that it's not (prompting scans to see what, if anything, is really going on).

It would be great if we had a reliable test to show "no cancer" (or the opposite), but right now, we do not. There is a lot of research into ways to assay circulating tumor cells, and/or DNA profiles in blood, but there is nothing ready for prime time at this point. Here's some info (maybe too much info!) from the NCI about tumor markers in general: http://www.cancer.gov/about-cancer/d...ers-fact-sheet .

Debbie Laxague

[Cath]

Thank you Debbie. You explained everything so well. That's exactly what I was looking for - that no one probably has a zero result and that it's not cancer floating around in my blood. The attached link was very informative. I appreciate you taking the time to explain this to me. Wish I wasn't such a worry wart but I am.

[Debbie L.]

Oh, Cathy -- I think cancer turns us ALL into worry warts, at least some of the time. It's normal, don't worry (smile). And thank you for the thank you, I'm glad the info helped.
Debbie