[Debbie L.]

Catherine, as far as I know, tumor markers have never been the "gold standard" for follow-up after treatment for primary breast cancer. The reasons for this are basically twofold:

1. They are unreliable: either not showing anything upon recurrence, or showing random false positives (leading to anxiety and invasive testing when there is no recurrence).

2. (probably the more-important bit) It has never been shown that picking up a recurrence with tumor markers (or imaging), before the recurrence is found because of symptoms improves the outcome (life is not prolonged nor improved).

It's a whole different discussion, about tumor markers for following disease (and/or response to treatment) for already-existing stage IV breast cancer. For some, tumor markers are useful in this regard. For others, the cancer doesn't elevate tumor markers even when it's widespread, so they are not useful for these women and men.

That said, it is true that many oncologists (and/or patients) do choose to draw tumor markers on some regular basis after treatment for primary breast cancer. I would guess (as others have mentioned) that your onc's change in his/her practice relates either to a buckling-under to the national (NCCN, in the US) guidelines, to insurance coverage (or more-accurately, the lack of it), or to their facility's move to standardize practice to be in line with "standard of care".

Everyone has different feelings about this. For me, I was relieved to learn that it was not ultra-vigilance that might make a difference to what would happen to me after treatment for primary breast cancer. That understanding allowed me to let go of the illusion of control and learn (sometimes kicking and screaming) to deal with the uncertainty. I learned (over time) to accept that it is essentially a crap shoot, and that if I had a recurrence -- how it was discovered would not affect the outcome.

The disclaimer here is that it is arguably of benefit to detect brain mets "early" (before symptoms) so that less-invasive treatment (targeted radiation vs. whole brain, for example) may be used. And we know that HER2+ breast cancer is more likely to result in brain mets. I think there's a strong argument for finding ways to monitor for brain mets of HER2+ breast cancer, both after primary breast cancer and stage IV diagnosis. But the best way to do that is probably with imaging, not tumor markers.