Hi, Thanks for writing in. It is always better to get a sore area in the breast clinically evaluated. Most are benign conditions but a recurrence must always be ruled out if you had previous breast cancer and took treatment for it. Radiation causes changes below the skin and this might manifest as a sore. It is not essential for an infection to be discharging in the early stages. Though it appears to be a post lumpectomy and radiation change that has taken place, it is suggested that you consult your doctor and get ultrasound scan done to screen for any suspicious activity in your breast. Also please feel your axilla for any lymph node swelling and bring it to the notice of your doctors. Please do not worry.