My doctor told me to do a breast biopsy, what are the chances that i will have cancer if i was told this?

100% or 0%: You either have breast cancer and it will destroy you if you neglect it, or your mass is benign and your adventure will end with relief and a reminder to keep up lifetime surveillance. I'm not going to tell you what percentage of breast biospies turn out to be malignant, as your mass may be more or less suspicious. One woman in two will have a breast biopsy during her lifetime. Be brave.

Are you referring: to a needle biopsy? It depends on the specific imaging or clinical features, but in general, across the board, about 80% turn out benign.

No way to know.: Until the biopsy comes back, there is no way to determine the chance of cancer. The truth is that there is a chance of cancer, and no matter how small that chance, your doctor thinks something is suspicious enough to require a biopsy. My advice: If a biopsy is advised, then follow through on it. Of course you're scared. But you can deal with whatever the biopsy shows! We're here for you.

@20%: Only @ 20% of the biopsies are positive for cancer. Best wishes for a good result.