[Lani]

Ellie--not a silly question at all.

Bone marrow micrometastases are felt to be cancer stem cells, which are known to be quite dormant ie, they only "wake up" and reproduce very rarely.

They are felt to be the cause of recurrences--even 20 years later.

I have previously written about them comparing them to mildew in a shower stall. You may use a Tilex (main ingredient bleach) and think you have killed it, but actually it hides out as a spore and only reappears when the conditions are right ie, dampness and starts growing again.

Chemotherapy has been shown not to get rid of these tumor cells in the bone marrow if they were there before treatment, as chemotherapy works on dividing cells and they are just hiding out and not dividing.

What wakes them up? Depending on whom you are talking to you may get different answers. Dr. Judah Folkmann felt an angiogenic switch was involved. Dr. Wicha thinks inflammation is involved among other things.

Sampling the bone marrow before and after treatment and periodically thereafter may be a way to determine if the treatment was effective, ie, getting rid not only of the bulky tumor, but also of the tumor cells hiding and sleeping in the bone marrow.

To me this seems much better than just waiting for mets to be visible to conventional testing, by which time most oncologists proclaim the patient uncurable. If the treatment given is found not to have gotten rid of these cells, additional treatments could be undertaken and perhaps prevent them from ever becoming MACROmetastases.

Hope this helped explain why I feel serial bone marrow testing may really help revolutionize breast cancer followup and treatment