Hi Gretchen!
I've been on Metformin for the last year and it really has helped keep my glucose under control, although I've also done my best to limit carbs and to exercise as well.
I was reading elsewhere about the metformin studies regarding cancer and noted that they used breast cancer cells in their testing. As an 8yr survivor of BC and a Type 2 Diabetic on Metformin, I really hope that the studies prove that it does stop cancer cells from developing. From my point of view, it would make being diagnosed as a T2 as a blessing of sorts. I'd rather live with diabetes than die early from BC.
They've found that lactic acidosis is much less common than they thought. And the dosages for cancer treatment (with doxorubicin) are much lower than those used for BG control.