You have a source for this "rarity", statistics?
Ah statistics. All well and good to look at a large number. Generally speaking, taking statistics of all types of breast cancer, if you get breast cancer (statistics take into account early detection, which does not always happen with other forms of cancer...Paul Newman dies very rather rapidly after losing his battle with lung cancer, even though he was a smoker earlier in his life...Steve Reaves wife dies a mere ~7mo after he dies, yet she never smoked, was living/raised in relatively 'clean' air environment, and still she dies from lung cancer), statistics say you have an 85% chance of surviving the disease. Still leaves thousands of other women who die every year from breast cancer

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Yesterday's MacNN news story, which has not been linked to in this thread yet!?!
http://www.macnn.com/articles/09/01/16/cancer.recurring.in.jobs/
Was this quotation accurate? Another statistic?
Does it trump the other "physician" opinions being stated in this thread?
While it may not be a 'statistic', IMHO; cancer and the causes of each and every type are not well understood (except in a few instances)...as such, take 'statistics' in this regard with a large grain of salt. My mother had a stage 3A or maybe even 3B non-small cell carcinoma of her lung, she went through 4 mo. of chemo & radiation, then the whole lung was removed in surgery along with some nearby lymph nodes. She has had PET/CT scans yearly (sometimes the oncologist's office needs to be reminded of that) since then...and for what? Her initial non-small cell carcinoma (that which is identified by structure, and supposedly by the fact it's less aggressive, multiplies less rapidly) was *invisible* on her chest X-ray 7mo earlier when she had a mild heart attack, yet in just 7mo, that NSCC had grown to a tumor that encompassed more than 1/2 of her lung. 4yrs. later a lump under her tongue was diagnosed as a "mouth cancer". Well sort of, the tumor was removed, and after a week of tests, the specialist medical 'physicist' on staff at the med center, couldn't decide exactly what kind of cancer it supposedly was. Oh well, just zap her throat with high doses of computer guided radiation beams, which mostly killed any ability to taste food, throw in some milder chemo, et viola...cured? 4yrs later, she has been seen by the ENT that did the surgery to remove the tumor in her mouth. For what? An undetermined lump/infection that she was given antibiotics as a treatment for (which did nothing), is still there, right in that spot where she had the mouth 'cancer'.
Sometimes I don't think physicians/medical scientists have all the correct answers, even if they like to think they do.
So Tammy Faye Baker was in 'remission', twice? And still died? Eh, can't rely on wiki for absolute accuracy:
http://en.wikipedia.org/wiki/Tammy_Faye_Messner#Cancer
I know of a woman, who had breast cancer in her 60's, was treated for it, and "cancer free" (yet another fun terminology usage)...until she hit her 80's and got breast cancer again. If you live long enough, you'll likely get some type of terminal disease>>>damned statistics.