Grace, in my opinion, you're absolutely doing the right thing. Having a double mastectomy comes with all kinds of issues - do you want/need reconstruction? If not, a prosthesis? And how about that surgery - it's pretty serious. If you don't have to put yourself through all that - why do it?

The data shows that a woman who has a lumpectomy and radiaiton is no more likely to die of breast cancer than a woman who has a single mastectomy or even a double mastectomy. In other words - having a mastectomy does NOT reduce your risk of dying from cancer. Your risk of having a recurrence, yes. But your risk of dying - no. That's why I say, have the lumpectomy and radiation. Esp. since that treatment, for DCIS, is something like 99.8% effective at preventing a recurrence.

DCIS is an incredibly mild cancer; some doctors don't even call it cancer. So do what you feel you must for peace of mind, but I'd go with the lumpectomy and radiation. Good luck - PJH

Grace, as PJ says the effectiveness of lumpectomy and radiation compared to mastectomy is well established.  The only piece of information you haven't mentioned is whether you might have the BRCA gene.  If you are under 40 and have a family history of other breast cancers in young women, then you might want to talk to your doctor about genetic counseling.  Some women who have tested positive for either of the known BRCA genes do decide that double mastectomy will make them less likely to have breast cancer.  Even a double mastectomy cannot reduce the risk to zero because there is always a little bit of breast tissue that the surgeon can't remove.