Perhaps your body image is the major factor at this stage. A lumpectomy will leave you with your breast. But Sometimes the surgery leads to the need for the mastectomy when the surgeon actually sees the cancerous tissues. Personally I had no strong need to keep the breast and my surgeon was clearly in favor of a mastectomy. Turned out she was correct—more tumor than expected, more lymph nodes involved than expected. But yes, getting the cancer out is number one! Your surgeon will take care of that when the time comes. Good luck in your journey.