On this page, you’ll find an explanation of the most common terms in breast cancer.
If you have general questions that you don’t find the answer to, you can use our “Ask a Surgeon” section of our website to ask your question which can then be answered by a fellowship-trained board certified breast surgeon with authoritative and trustworthy information.
Dictionary of Breast Cancer Terminology
Hormone Therapy (Endocrine therapy)
Hormone therapy refers to a type of treatment that blocks or lowers hormones in the body to slow or stop the growth of breast cancer. It is also called hormonal therapy or endocrine therapy. Although it is called hormone therapy, the medication does not consist of hormones but actually lowers the level of hormones in the body.
There are several types of hormone therapy, including:
- Selective Estrogen Receptor Modulators (SERMs) such as:
- tamoxifen (Nolvadex – pill form, and Soltamox – liquid form)
- raloxifene (Evista)
- toremifene (Fareston)
- Aromatase inhibitors such as letrozole (Femara), anastrozole (Arimidex), and exemestane (Aromasin)
Hormone therapy is thought to decrease the risk of subsequent breast cancer approximately by half (i.e. 50%).
Patients who reach menopause while being on tamoxifen and still have their uterus in place (i.e. have not had uterus removed by hysterectomy) are commonly switched to an aromatase inhibitor due to the small risk of uterine cancer by tamoxifen in women of menopausal age.
Hormone therapy such as tamoxifen is also given to men with hormone-receptor positive breast cancer.
HER2-positive breast cancer
HER2-positive breast cancers are cancers with extra HER2 protein on the surface of the breast cancer cells, sometimes called “HER2-amplified”.
See also: HER2/neu
HER2/neu or HER2
HER2/neu is a protein involved in the growth of breast cancer cells. Breast cancer cells that have several copies of the HER2/neu protein on their cell surface than normal form a type of breast cancer that is called HER2 amplified. It is thought to be more aggressive than breast cancers that do not have more copies of HER2 protein than normal, but usually responds very well to medication that specifically homes in and targets the HER2 protein on the cancer cells, what is called “targeted therapy”. This medication includes trastuzumab (Herceptin) and pertuzumab (Perjeta). These medications are usually combined with other chemotherapy agents. This anti-HER2 medication is sometimes given prior to surgery to shrink the tumor, allowing a smaller surgery, in what is called “neoadjuvant chemotherapy”.
See also: What is breast cancer?
Gene expression profiling
Gene expression profiling refers to a test that looks at the genetic characteristics of the cancer cells to help plan treatment and to assess the risk of cancer coming back. This test is performed on patients already diagnosed with cancer and utilizes cancerous tissue obtained from the tumor rather than from the blood or saliva. This is in contrast to genetic testing, where a person’s entire genetic information is screened for possible mutations (genetic errors) to evaluate their risk of getting breast cancer.
There are two commonly used gene expression profiling tests on the market, Oncotype DX which analyzes 21 genes, and Mammaprint, which analyzes 80 genes.
A gene is the basic unit of a cell that contains genetic information that is passed on from parents to children. A gene may contain an error in the genetic information that is called a mutation. Mutations in some genes such as BRCA1, BRCA2, PALB2, CHEK2, ATM, and other are responsible for some inherited breast cancers that run in families. Patients who have a significant history of breast or other cancers in their family may consider genetic testing that analyzes their genetic information for mutations that may predispose them to get certain cancers and pass on this increased risk to their children.
Fatigue is a feeling of tiredness. This may be caused by some cancer treatments or by cancer in general.
Ductal carcinoma in situ (DCIS)
Ductal carcinoma in situ (DCIS) is breast cancer that is found in the milk duct of the breast and has not spread outside the duct. It is classified as Stage 0. Current recommendations include complete excision of the DCIS to a negative margin of at least 2 mm around the tumor. See also carcinoma in situ.
A breast duct is a small tube that carries milk from the breast lobules to the nipple. The breast has many ducts that ultimately converge onto the nipple. Refer to this article.
Diagnosis refers to the identification of a disease, such as breast cancer.
Clean margin (or clear or negative margin)
A clean or clear margin is when the pathology report states that there is a rim of normal, healthy tissue surrounding a cancer. It is also called a negative or clear margin. This improves the odds that a tumor has been completely resected. A positive margin may require a second operation to reexcise the margin(s) involved with tumor to obtain final clear margins. Current standards do not require a certain width of clear margin around an invasive tumor, i.e. one cell layer is enough according to published data. However, for noninvasive cancer (i.e. DCIS), current guidelines recommend a clear margin of at least 2 mm.
Chemotherapy is treatment with drugs that destroy or slow the growth of cancer cells. It can be taken prior to surgery to shrink down the tumor to allow a smaller surgery or for other reasons (neoadjuvant chemotherapy). Chemotherapy can be given after surgery to decrease the risk of tumor recurrence (adjuvant chemotherapy).
The case manager is a person who assists in the planning, coordination, monitoring, and evaluation of medical services for a patient.
Carcinoma in Situ
Carcinoma in situ is cancer that remains where it first began. It has not spread into nearby tissue.
In the context of breast cancer, ductal carcinoma in situ (DCIS) is Stage 0 breast cancer. The cancer cells remain within the breast duct and do not invade surrounding tissues within the breast or out of the breast. Presently, the recommendation for DCIS is complete excision to negative margins, ideally a rim of 2 mm of normal breast cells around the periphery of the tumor to decrease the chance of local recurrence.
On the other hand, lobular carcinoma in situ (LCIS) does not require excision since it has been reclassified as NOT CANCER. However, patients diagnosed with LCIS are possibly recommended to take antihormone medication such as tamoxifen or aromatase inhibitors to decrease their risk of breast cancer.
Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. In the context of breast cancer, a breast carcinoma is breast cancer that orginates in the lining of the breast duct or breast lobule, what is accurately termed, of “epithelial origin”.
Breast Cancer Stage
Breast cancer stage is rating system for describing the extent of a cancer, especially whether the disease has spread from the place where it began to other parts of the body.
Read more here.
Cancer Grade and Histologic Grade
Cancer grade refers to a rating system for describing how abnormal cancer cells look under a microscope. Grading provides information about how fast the cancer cells are likely to grow and divide. It specifically looks at how abnormal the nucleus of the cell looks, the ability of the tumor tissue to form glands resembling normal breast glands, and how fast the tumor cells are dividing.
Cancer Grade can be measured by the Nottingham Scoring System, or Nottingham histologic score which is simply a scoring system to assess the “grade” of breast cancers.
It is a total score based on 3 different sub-scores. The 3 sub-scores are assigned based on 3 components of how the breast cancer cells look under a microscope. (The details of these 3 components are not critical for you to understand). Each of the 3 components is assigned a sub-score of 1, 2, or 3, with 1 being best and 3 being worst. Once the 3 sub-scores are added, a Nottingham score is obtained: the minimum score possible is 3 (1+1+1) and the maximum possible is 9 (3+3+3).
A histologic grade of III is assigned to any patient with a Nottingham score of 8 or 9. Grade I refers to Nottingham scores of 3, 4, and 5, while Grade II refers to Nottingham scores of 6 and 7.
For further details about breast cancer grade, visit this link.
Read more about breast cancer here.
Cancer is a term for diseases in which abnormal cells grow and divide out of control. See: What is breast cancer?
Breast-conserving surgery is surgery that removes the cancer along with a small amount of normal tissue around it. Also called lumpectomy or partial mastectomy. The alternative to breast-conserving surgery is mastectomy.
Breast reconstruction involves surgery to recreate the shape of the breast after a mastectomy. Refer to the Breast Reconstruction category on this website.
A breast prosthesis is an external form that is worn under clothing to match the shape of a breast for patients who elect not to undergo breast reconstruction after mastectomy for breast cancer. It is usually worn at least one month after breast surgery to allow the incision and surgical site to heal before placing undue pressure on the skin flap by the prosthesis.
A breast implant is a saline- or silicone-filled sac that is surgically placed beneath the skin and chest muscle to recreate the shape of a breast after mastectomy, or to enhance the size of the breast in cosmetic surgery.
Brachytherapy involves radiation therapy that places radioactive material directly into or near the cancer. Also called internal radiation therapy. In the context of breast cancer, this usually involves placing a catheter inside the lumpectomy cavity after surgery for breast cancer through which radioactive material is inserted to irradiated the nearby tissues around the cavity.
Axillary lymph nodes
Axillary lymph nodes include lymph nodes in the underarm region. There are three levels of axillary lymph nodes (Level 1, Level 2, and Level 3). Only Levels 1 and 2 are removed during axillary lymph node dissection.
Axillary lymph node dissection (ALND)
Axillary lymph node dissection (ALND) is surgery to entirely remove lymph nodes from the underarm region. It is different than sentinel lymph node biopsy, which just aims to remove enough lymph nodes (usually three or more) to provide adequate sampling of the axillary lymph nodes to determine if the breast cancer has reached these lymph nodes. Axillary lymph node dissection used to be a routine surgery during breast cancer, but it is less used now, especially after the results of the ACOSOG Z0011 trial.
An aromatase inhibitor is a drug that lowers the amount of hormones in the body. It is prescribed as a type of hormone therapy for postmenopausal women who have hormone receptor-positive breast cancer. It is thought to decrease the risk of subsequent breast cancer by half (i.e. 50%). There are three commonly used aromatase inhibitors: letrozole (Femara), anastrozole (Arimidex), and exemestane (Aromasin).
An anesthesiologist is a medical doctor who specializes in giving drugs to keep patients from feeling pain during surgery.
Drugs given usually during a surgical procedure to keep patients from feeling pain during surgery. There are several types of anesthesia: local anesthesia (numbing medicine) is injected in the area of the surgical procedure; regional anesthesia usually numbs up a large region of the body such as the legs or lower abdomenl; and general anesthesia where the patient is usually completely asleep. Regional and general anesthesia is usually administered by an anesthesiologist. Local anesthesia is usually administered by the surgeon.
Treatment for breast cancer given after the primary treatment (usually surgery) to lower the risk of breast cancer coming back. It may include chemotherapy, radiation therapy, hormone therapy, and/or targeted therapy.
For example, if you had surgery upfront for breast cancer, your adjuvant therapy would consist possibly of chemotherapy, radiation therapy, or hormone therapy, or combination thereof.
The area of the body between the chest and the hips, also known as the tummy.