A lumpectomy is the removal of a malignant lump in the breast, leaving the breast itself intact. A lumpectomy with node dissection is the removal of the malignant lump along with nearby lymph nodes. Patients with early, small, well-defined lesions less than 5 cm in size and staged as 0, I, or II are candidates for lumpectomy. Unfortunately, fewer than 20% of breast cancer patients have this type of lesion. Following lumpectomy, most patients will undergo radiation therapy.

Lumpectomy has 5- and 10-year survival and local recurrence rates at least equivalent to those of the modified radical mastectomy. In addition, the psychological benefits of avoiding breast removal are significant, making this an especially appealing option for many females with breast cancer.