Dear LuckyOne: This is a question that might be best discussed with your breast surgeon, a plastic surgeon, and perhaps a breast cancer oncologist. As both diagnoses were DCIS, this means that there was no invasive cancer. A mastectomy may reduce the risk of local recurrence. However, depending on the proximity of the margin to the chest wall, it may be that radiation therapy will be recommended as well. Finally, radiation can sometimes affect plastic surgery results so it would be advisable to talk to all these experts who can make good recommendations as they pertain specifically to your situation.