You can choose to have a double mastectomy; your surgeon should agree to it, given your age and the size of the tumor. Although you're probably no more likely to get cancer in the other breast than you were to get cancer in the first, if you're extremely worried about cancer in general, then a double mastectomy would help set your mind at ease: it would reduce your risk of recurrence in the affected breast, and would also lower the risk of a new cancer in the other breast considerably.

Do understand, though, that a double mastectomy wouldn't eliminate your risk entirely; there's always some breast tissue remaining. It's also very aggressive surgery, and you'd probably want to consider reconstruction, which is more difficult and aggressive surgery. I'd suggest you meet with your surgeon, and get all the facts before you opt for a double mastectomy. Also, you might find our post on single vs. double mastectomy helpful as you examine your options. Best of luck to you - PJH