Breast conservation surgery: An operation to remove the breast cancer but not the breast itself. Types of breast-conserving surgery include lumpectomy (removal of the lump), quadrantectomy (removal of one quarter of the breast), and segmental mastectomy (removal of the cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor).

Biopsy: Removal of a portion (sample) of tissue for pathological examination or diagnostic study.

Hormone Replacement Therapy (HRT):

Magnetic Resonance Imaging: A noninvasive diagnostic procedure using radio waves and magnetic fields to provide a highly detailed map of an interior structure of the body, such as the brain. MRI depicts detailed internal anatomy by exploiting the interaction of the magnetic properties of atoms with an external magnetic field.

Mammogram: An x-ray of the breast.

Carcinoma in situ: Cancer that is confined to the cells where it began, and has not spread into surrounding tissues.