Glossary
Plain-English definitions of the terms used on this site.
These are general educational definitions. They do not replace an explanation from your own clinical team.
A
- Adjuvant treatment
- Treatment given after the main treatment (usually surgery) to reduce the risk of the cancer returning, such as chemotherapy, endocrine therapy, HER2-directed treatment or radiotherapy.
- Autologous reconstruction
- Breast reconstruction that uses the patient's own tissue, most commonly from the lower abdomen, transferred to the chest.
- Axillary lymph-node dissection
- An operation that removes a larger group of lymph nodes from under the arm. It may be required in some circumstances, depending on the findings.
B
- Biomarker
- A measurable feature of the cancer, such as ER, PR or HER2 status, that helps determine which treatments may be effective.
- Breast-conserving surgery (BCS)
- Removal of the tumor and a surrounding margin while preserving the rest of the breast. Also called lumpectomy, wide local excision or partial mastectomy. It is usually followed by radiotherapy.
C
- Capsular contracture
- Tightening of the scar tissue that naturally forms around a breast implant, which can cause firmness, distortion or discomfort.
D
- DICOM
- The standard digital format for medical imaging. Original DICOM files allow a specialist to review the full images, unlike a screenshot or a photograph of a printed film.
- DIEP flap
- A deep inferior epigastric perforator flap: autologous reconstruction that uses skin and fat from the lower abdomen while attempting to preserve the abdominal muscle.
- Direct-to-implant reconstruction
- Placement of a permanent implant during the mastectomy operation, in appropriately selected patients, without a separate expansion stage.
- Ductal carcinoma in situ (DCIS)
- Abnormal cells confined to the milk ducts that have not spread into the surrounding breast tissue. It is non-invasive and is staged and treated differently from invasive cancer.
E
- Estrogen receptor (ER)
- A biomarker indicating whether the cancer may respond to endocrine (hormonal) therapy.
H
- HER2
- Human epidermal growth factor receptor 2, a biomarker that helps determine whether HER2-directed treatment may be effective.
I
- Invasive breast cancer
- Cancer that has grown beyond the ducts or lobules into the surrounding breast tissue, in contrast to carcinoma in situ.
K
- Ki-67
- A marker of how quickly cancer cells are dividing, sometimes reported to help describe the tumor.
L
- Lymphedema
- Swelling, usually of the arm, that can follow lymph-node surgery or radiotherapy. The risk is higher after more extensive lymph-node surgery.
- Lymphovascular invasion
- The presence of cancer cells within small blood or lymph vessels, sometimes noted in a pathology report.
M
- Mastectomy
- Removal of most or all of the breast tissue. The amount of skin removed and whether the nipple is preserved vary according to the cancer and the reconstructive plan.
- Microsurgery
- Surgery performed under a microscope to reconnect small blood vessels, used in autologous reconstruction such as a DIEP flap.
N
- Neoadjuvant treatment
- Systemic treatment, such as chemotherapy, given before surgery.
- Nipple-sparing mastectomy (NSM)
- A mastectomy that preserves the breast skin and the nipple–areola complex. It is available only for appropriately selected patients, and preserving the nipple does not preserve normal sensation.
O
- Oncoplastic surgery
- Breast-conserving surgery combined with techniques to reshape the remaining breast tissue.
P
- Post-mastectomy radiotherapy (PMRT)
- Radiotherapy given after mastectomy to reduce the risk of cancer returning in the chest wall or regional lymph nodes. It is based on cancer-related factors and can affect reconstruction.
- Progesterone receptor (PR)
- A biomarker reported alongside ER that relates to the likely benefit of endocrine therapy.
S
- Sentinel lymph-node biopsy
- Removal of a limited number of selected lymph nodes — the first to drain the breast — to check whether cancer has spread.
- Skin-sparing mastectomy
- A mastectomy that preserves much of the breast skin to support reconstruction.
T
- Tissue expander
- A temporary adjustable device placed after mastectomy and gradually filled to create space for a later permanent implant.
- Tumor grade
- A description of how abnormal the cancer cells look under the microscope, included in a pathology report.