Breast cancer glossary
The words on a clinic letter or pathology report can be hard to follow. Here is what the most common ones mean, in plain English.
This glossary explains 36 terms you may see in breast clinic letters, scan results and pathology reports, such as DCIS, HER2-positive, grade and stage. Each definition links to a full guide and to the NHS, NICE or other source it is based on. Your care team can explain what your own results mean.
Screening and tests
- Breast screening
-
Checking women who have no symptoms for signs of breast cancer, usually with a mammogram. In England, women aged 50 up to their 71st birthday are invited every three years. Screening is not for new symptoms: a new breast change should be checked by a GP or doctor straight away.
Read our guide: Breast screening and mammograms Source: NHS: who breast screening is for
Quick reads: DCIS vs invasive breast cancerMammogram vs ultrasound vs MRI for breast cancerNHS vs private mammogram
- Mammogram
-
An X-ray of the breast. Each breast is pressed briefly between two flat plastic plates so clear images can be taken. Mammograms are used for routine screening and to investigate breast symptoms.
Read our guide: Breast screening and mammograms Source: NHS: what happens at your breast screening appointment
Quick reads: Mammogram vs ultrasound vs MRI for breast cancerBreast cyst vs fibroadenoma vs breast cancerNHS vs private mammogram
- Breast ultrasound
-
A scan that uses sound waves to make a picture of the inside of the breast or armpit. It can show whether a lump is solid or filled with fluid, and is often used for younger women, whose breast tissue can be harder to read on a mammogram.
Read our guide: How breast cancer is diagnosed Source: NHS: tests and next steps for breast cancer
Quick reads: Mammogram vs ultrasound vs MRI for breast cancerBreast cyst vs fibroadenoma vs breast cancer
- BiopsyAlso called Core needle biopsy
-
Removing a small sample of tissue, usually with a hollow needle under local anaesthetic, so it can be examined under a microscope. A biopsy is the only way to confirm whether a breast change is cancer.
Read our guide: How breast cancer is diagnosed Source: NHS: biopsy
Quick reads: Mammogram vs ultrasound vs MRI for breast cancerBreast cyst vs fibroadenoma vs breast cancer
- Triple assessment
-
The usual set of checks at a UK breast clinic: an examination by a specialist, imaging (a mammogram, an ultrasound or both) and, if needed, a biopsy. Many people have all three on the same day.
Read our guide: How breast cancer is diagnosed Source: NHS: tests and next steps for breast cancer
Quick reads: Mammogram vs ultrasound vs MRI for breast cancerBreast cyst vs fibroadenoma vs breast cancer
- Breast MRI
-
A scan that uses magnets and radio waves to make detailed pictures of the breast. It is offered for yearly checks to some women at higher risk, such as some carriers of BRCA gene variants, and in some situations after a diagnosis.
Read our guide: Breast MRI: when it is recommended Source: NICE CG164: surveillance for women at higher risk
Quick reads: Mammogram vs ultrasound vs MRI for breast cancer
- Dense breasts
-
Breasts with more glandular and fibrous tissue compared with fatty tissue. Density is seen on a mammogram, not felt. Dense tissue can make a mammogram harder to read and is linked to a somewhat higher risk of breast cancer.
Read our guide: Dense breasts and breast cancer Source: NHS: why breast screening is done
Quick reads: Mammogram vs ultrasound vs MRI for breast cancerDoes breast size affect breast cancer risk?
- TLC (Touch, Look, Check)Also called Breast awareness
-
A simple way to remember breast awareness: touch your breasts, look for changes, and check anything new with a GP or doctor. There is no special technique; the aim is to know what is normal for you.
Read our guide: How to check your breasts Source: Breast Cancer Now: Touch Look Check
Types of breast cancer
- DCIS (ductal carcinoma in situ)
-
Abnormal cells inside the milk ducts that have not spread into the surrounding breast tissue. DCIS is non-invasive (sometimes called stage 0). It is often found through screening and is usually treated to stop it becoming invasive.
Read our guide: DCIS explained Source: NHS inform: breast cancer in women
Quick reads: DCIS vs invasive breast cancer
- Invasive breast cancerAlso called Invasive ductal carcinoma, No special type (NST)
-
Cancer that has grown from the ducts or lobules into the surrounding breast tissue. The most common type is invasive breast cancer of no special type (NST), also called invasive ductal carcinoma.
Read our guide: Types of breast cancer Source: Breast Cancer Now: types of breast cancer
Quick reads: DCIS vs invasive breast cancer
- Invasive lobular breast cancer
-
Breast cancer that starts in the lobules, the glands that make milk. It is the second most common type, and can be harder to feel or see on a mammogram because it often grows in a line rather than as a lump.
Read our guide: Types of breast cancer Source: Breast Cancer Now: types of breast cancer
- Triple-negative breast cancer
-
Breast cancer whose cells have no oestrogen or progesterone receptors and do not make extra HER2 protein. Hormone and HER2-targeted treatments do not work on it, so chemotherapy is the main drug treatment, sometimes given with immunotherapy.
Read our guide: Triple-negative breast cancer Source: NICE NG101: triple-negative breast cancer
Quick reads: HER2-positive vs triple-negative breast cancer
- Inflammatory breast cancer
-
A rare, fast-growing type in which cancer cells block small lymph vessels in the skin. The breast may become red, swollen and warm, and the skin can look like orange peel. It often has no lump, so any of these changes needs urgent checking.
Read our guide: Inflammatory breast cancer Source: Breast Cancer Now: types of breast cancer
- Paget’s disease of the breast
-
An eczema-like change of the nipple and the darker skin around it, such as redness, scaling, itching or bleeding. It is usually linked to DCIS or an invasive cancer in the breast behind it.
Read our guide: Paget’s disease of the breast Source: NHS: Paget’s disease of the nipple
- Secondary (metastatic) breast cancerAlso called Stage 4 breast cancer, Advanced breast cancer
-
Breast cancer that has spread to other parts of the body, most often the bones, lungs or liver, and sometimes the brain. It can be treated, often for many years, but it cannot usually be cured.
Read our guide: Secondary breast cancer Source: NHS: treatment for breast cancer in women
Your pathology report
- Hormone receptor-positive (ER-positive, PR-positive)
-
The cancer cells have receptors for the hormones oestrogen (ER) or progesterone (PR), so these hormones can help the cancer grow. Most breast cancers are ER-positive, and hormone therapy can be used to treat them.
Read our guide: Types of breast cancer Source: NHS inform: breast cancer in women
Quick reads: HER2-positive vs triple-negative breast cancer
- HER2-positive
-
The cancer cells make a lot of a protein called HER2, which encourages them to grow. HER2-positive cancers can be treated with targeted drugs that block HER2, such as trastuzumab.
Read our guide: HER2-positive breast cancer Source: NICE NG101: HER2-positive breast cancer
Quick reads: HER2-positive vs triple-negative breast cancer
- Grade
-
How different the cancer cells look from normal cells under a microscope. Grade 1 cells look most like normal cells and tend to grow slowly; grade 3 cells look very different and tend to grow faster.
Read our guide: Understanding your pathology report Source: Macmillan: staging and grading of breast cancer
- Stage
-
How big the cancer is and how far it has spread, from stage 0 (non-invasive, such as DCIS) to stage 4 (spread to other parts of the body). Stage and grade are different things.
Read our guide: Stages of breast cancer Source: NHS inform: breast cancer in women
- TNM staging
-
A way of describing stage using three letters: T for the size of the tumour, N for whether cancer is in the lymph nodes, and M for whether it has spread (metastasised) to other parts of the body.
Read our guide: Stages of breast cancer Source: Macmillan: staging and grading of breast cancer
- Margins
-
The edge of healthy tissue around a cancer removed in surgery. A clear margin means no cancer cells were found at or very near the edge. If cancer cells are at or very close to the edge, more surgery may be offered.
Read our guide: Understanding your pathology report Source: NICE NG101: further surgery after breast-conserving surgery
Quick reads: DCIS vs invasive breast cancerLumpectomy vs mastectomy
- Lymph nodesAlso called Axillary lymph nodes
-
Small glands that are part of the immune system. The ones in the armpit (axilla) are usually the first place breast cancer spreads to, so they are checked with an ultrasound and, if needed, a biopsy or surgery.
Read our guide: Breast cancer surgery Source: NHS inform: breast cancer in women
Quick reads: Lumpectomy vs mastectomy
- Multidisciplinary team (MDT)
-
The group of specialists who meet to agree a treatment plan for each person, including surgeons, oncologists, radiologists, pathologists and breast care nurses.
Read our guide: Breast cancer treatment options Source: Macmillan: the MDT for breast cancer
Quick reads: HER2-positive vs triple-negative breast cancer
Treatment
- LumpectomyAlso called Breast-conserving surgery, Wide local excision
-
Surgery to remove the cancer with a border of healthy tissue, keeping most of the breast. It is usually followed by radiotherapy to the breast.
Read our guide: Breast cancer surgery Source: NHS inform: breast cancer in women
Quick reads: DCIS vs invasive breast cancerLumpectomy vs mastectomy
- Mastectomy
-
Surgery to remove the whole breast, often including the nipple and some of the skin. It may be recommended because of the size or position of the cancer, or chosen by the person. Reconstruction can often be done at the same time or later.
Read our guide: Breast cancer surgery Source: NHS: mastectomy
Quick reads: Lumpectomy vs mastectomy
- Sentinel lymph node biopsy
-
An operation to remove the first one or few lymph nodes in the armpit that a cancer would drain to, so they can be checked for cancer cells. If they are clear, the other nodes can usually be left.
Read our guide: Breast cancer surgery Source: NICE NG101: surgery to the breast and axilla
Quick reads: DCIS vs invasive breast cancerLumpectomy vs mastectomy
- Breast reconstruction
-
Surgery to recreate the shape of a breast after a mastectomy, using an implant, tissue from another part of the body, or both. It can happen at the same time as the mastectomy or later, and some people choose not to have it.
Read our guide: Breast reconstruction options Source: NICE NG101: breast reconstruction
Quick reads: Lumpectomy vs mastectomy
- Neoadjuvant treatment
-
Treatment given before surgery, usually chemotherapy and sometimes targeted or hormone therapy, to shrink the cancer and show how well it responds.
Read our guide: Breast cancer treatment options Source: NHS inform: breast cancer in women
Quick reads: Lumpectomy vs mastectomyHER2-positive vs triple-negative breast cancer
- Adjuvant treatment
-
Treatment given after surgery, such as radiotherapy, chemotherapy, hormone therapy or targeted therapy, to lower the chance of the cancer coming back.
Read our guide: Breast cancer treatment options Source: NHS: treatment for breast cancer in women
Quick reads: HER2-positive vs triple-negative breast cancer
- Chemotherapy
-
Medicines that destroy cancer cells, usually given into a vein in cycles over several months. Side effects depend on the drugs used and often include tiredness, hair loss and a higher risk of infection.
Read our guide: Chemotherapy side effects Source: NHS: chemotherapy
Quick reads: HER2-positive vs triple-negative breast cancerWhat should I bring to chemotherapy?
- Radiotherapy
-
Treatment with carefully aimed high-energy X-rays to destroy cancer cells. After breast cancer surgery it is often given to the breast or chest wall to lower the risk of the cancer coming back there.
Read our guide: Radiotherapy for breast cancer Source: NICE NG101: radiotherapy
Quick reads: Lumpectomy vs mastectomy
- Hormone therapyAlso called Endocrine therapy, Tamoxifen, Aromatase inhibitors
-
Treatment for hormone receptor-positive breast cancer that blocks oestrogen or lowers the amount the body makes. It includes tamoxifen and aromatase inhibitors such as anastrozole and letrozole, and is usually taken as a daily tablet for 5 years or longer.
Read our guide: Hormone therapy side effects Source: NICE NG101: endocrine therapy
- Targeted therapy
-
Drugs that act on a specific feature of cancer cells, such as the HER2 protein or proteins that control cell division. Examples include trastuzumab for HER2-positive cancer and CDK4/6 inhibitors for some hormone receptor-positive cancers.
Read our guide: CDK4/6 inhibitors Source: NICE NG101: HER2-positive breast cancer
Quick reads: HER2-positive vs triple-negative breast cancer
Risk, genes and life after treatment
- BRCA1 and BRCA2
-
Genes that normally help repair damaged DNA. People who inherit a harmful change (variant) in one of them have a much higher chance of breast and ovarian cancer. Genetic testing is offered when a person’s family history, or the features of their own cancer, suggest a higher chance of carrying a variant.
Read our guide: Genes and family history Source: NICE NG101: genetic testing
Quick reads: HER2-positive vs triple-negative breast cancer
- Recurrence
-
Breast cancer that comes back after treatment. It may return in the same breast or chest wall (local), in nearby lymph nodes (regional), or in another part of the body (secondary breast cancer).
Read our guide: Breast cancer recurrence Source: NICE NG101: local, regional and distant recurrence
- Lymphoedema
-
Long-term swelling, usually in the arm or hand, caused by a build-up of fluid when lymph nodes have been removed or damaged by treatment. It can be managed, especially when it is treated early.