Posted this on another cancer website and they suggested I bring it up here
too:

My wife just got word after her very first mammogram that she needs to
come back for a biopsy due to "calcifications".  She's 39 years old,
no history of any breast cancer in her family, good health otherwise.
She does have a history of fibroids.  The nurse who scheduled the
biopsy for next week assured her that it is likely "nothing", but
that's also what they told her last week when she was called back to
"get more images".  We have no other details, and won't be able to
talk to the doctor until Tuesday, when she has the procedure.  Reading
information on the web, we get very mixed messages- most sources say
that the odds of malignancy even after a biopsy is ordered are fairly
small, and that's calcifications are usually benign.  Others, though,
suggest that a doctor would only request a biopsy if there are
significant troublesome patterns in the calcifications, and that the call
for a biopsy
suggests a significant chance of malignancy.

Anyone have
any thoughts or similar experiences to share?