How quickly can some bc's grow?

Hi-
I was dx. with bc on 9/15/03, stage IIA, 1/28 lymph nodes, mascetomy followed by 4 rounds of chemo - Adriamycin & Taxotere, Tamoxifen since 4/1/04.  Tumor specifics - 2.0 in size, elston -ellis grade 2/3 and surgical margins free of tumor (tumor 0.2 from deep margin).  Bone scand and CT scans in Oct. negative. Had bone scan and pelvis MRI on Thursday due to hip pain (they said it was probably from an earlier fall or arthritis) - doctor came in and said bone scan was questionable but MRI showed stage 4 - bone mets.  Is there a chance the MRI was misread?  How "easy" is it to distinguish btwn. arthritis, osteoporosis and bone mets on a MRI?  BTW, I'm 37 with no family history and am in reall good shape otherwise.

I'm just wondering if I should get a second opinion before moving forward.  My husband and I are just wondering if cancer can grow this quickly after negative scans and 4 rounds of chemo or if there is enough questions about how that could happen that it would seem like a good idea to get a second opinion.  Of course, if it is bone mets, I want to take care of it as quickly as possible.

Thanks!! :)
Debbie

[CCF-RN,MSN-rf]

Dear debman:  Unfortunately, it is possible for cancer to grow at any rate, although at stage IIA one would be hopeful that this would not be the case.  It is curious that the bone scan was negative.  An MRI is not always the best test to detect bone abnormalities but it is a good test, nonetheless.  You might consider having your scans re-read by a radiologist to confirm the findings.  It is never a bad idea to get a second opinion

[debman]

oops...should have mentioned tumor is ER+ - HER-2 slightly positive - FISH was done and was negative.  Not sure how much you need to know but trying to give you all the info that is floating around in my head!! :)

Thanks.