Breast conserving therapy (BCT) involves breast conserving surgery followed by radiation therapy to eliminate residual cancer cells. BCT aims to provide equivalent survival to mastectomy with an acceptable cosmetic outcome and low recurrence rates. Patient selection involves evaluating tumor characteristics, breast imaging to determine extent of disease, and ruling out contraindications like multicentric tumors or prior radiation to the breast. The goal of surgery is a complete excision with negative margins followed by radiation therapy. Complications can include seroma, infection, and arm issues, though are less common than following mastectomy. BCT provides an alternative to mastectomy for many breast cancer patients when appropriate criteria are met.