Facing a Breast Cancer Diagnosis? This Glossary May Be Helpful
My name is Sarah Zimmerman, PA-C and I am a freelance writer and Physician Assistant. I recently started working in a breast center, and The SEAM editors have kindly asked me to write a regular column on all things breast cancer. I’m starting off with the basics but would also love to hear from readers. What would you like to know from ‘an insider?’ Leave a comment below.
I aim to provide medical knowledge in direct and accessible ways. The fact is, breast cancer is very complicated, and it’s easy to feel lost in the myriad diagnoses, tests, and treatment options. So often, when we’re given a cancer diagnosis, all we hear are alarm bells going off in our heads, and the specific and foreign medical jargon is too much. I’m here to try to make it all clearer.
Also, I will be a constant cheerleader, as I am privileged to witness so many patients thriving long after their cancer diagnosis, and I see many reasons for hope. Every day we get better at prevention, early identification, and treatment, and although living through cancer is a frightening and challenging experience, there is so much more life and health after breast cancer.
Here is the basic breast lump breakdown: once we find a lump/see a mass that looks suspicious, we need to learn if it’s cancerous, pre-cancerous, or non-cancerous; if it’s cancerous, we need to learn if it has traveled outside of the breast and if so, how far into the body, then we need to learn the very specific details of the cancer cells so we know how we can most effectively, quickly, and completely remove it and prevent it from coming back in the future.
Basic Breast Cancer Glossary of Terms
These are some of the most common, but there are a LOT. For a more comprehensive list.
Adjuvant Therapy- cancer treatment like chemotherapy, hormone therapy, and HER2-targeted therapies, provided by a medical oncologist, following surgery/radiation
Anesthesia- during surgery and other medical procedures, medications are injected, infused, or inhaled to ensure that no pain is experienced. During major surgery, they are used to put patients to sleep for the duration of the surgery. In preparation for surgery, patients talk to the hospital anesthesia team about their unique needs and concerns.
Areola- the darkly pigmented area around the nipple
Atypical Hyperplasia- pre-cancerous breast cells. If a biopsy of a breast lump comes back as an atypical overgrowth of breast cells originating in the ducts (ADH) or lobules (ALH) of the breast, it is considered premalignant (or pre-cancerous), and increases the likelihood of developing breast cancer in the future. These generally require removal by the breast surgeon and/or frequent imaging to monitor for active breast cancers.
Axilla/axillary- pertaining to the armpit/underarm area- the lymph nodes that come from the breasts are here, and we examine them with imaging and biopsies to determine if the breast cancer has spread outside of the breast. These lymph nodes can be surgically removed in an axillary lymph node dissection and the area can be radiated. The term sentinel lymph node means those nodes closest to (directly fed) from the tumor.
Benign- non-cancerous; some examples of benign breast conditions include cysts (fluid-filled sacs), fibroadenomas (fibrous benign tumor), galactocele (cyst containing milk), and most phyllodes tumors- although benign, some of these masses need to be surgically removed as they are highly likely to develop into malignant (cancerous) tumors in the future.
Biopsy- a small sample of cells, typically done with a thin needle (may see it referred to as “core needle biopsy” or “thin needle aspiration”) while a radiologist uses imaging to find the exact location of the breast lump or lymph node. Pathologists then do a microscopic review of the cells on slides.
BI-RADS (Breast Imaging Reporting and Data System)- a BIRAD score ranges from 0-6 and is given on mammograms and breast MRI’s. It is a standardized system used by the American College of Radiology to describe findings. A 0 means the imaging is incomplete and needs to be repeated, 1-3 is benign or most probably benign, 4-5 are suspicious/highly suggestive of malignant, and 6 is proven malignancy with a biopsy.
Breast Cancer Risk- using a survey of personal and family health history (Gail Model or Tyrer-Cuzick Model), we get an approximate estimate of an individual’s current and lifetime risk of developing breast cancer. If higher than average, genetic testing and additional breast cancer screening may be appropriate.
BRCA1 or BRCA2 (Breast Cancer gene 1 and 2)- everyone has inherited BRCA genes, but when we say that someone is “BRCA positive,” we mean that they have a BRCA gene mutation. Normal BRCA genes are protective against tumors, but for those with BRCA1 or 2 mutations, the BRCA genes don’t work properly, and the protection is absent. In those cases, the mutations significantly increase the likelihood of developing breast, ovarian, and other cancers. Therefore it’s important to take family and personal medical health surveys, to determine breast cancer risk, and genetic testing, if necessary. Genetic tests are simple, requiring a saliva or blood sample, and often covered by insurance. When someone learns that they have a genetic predisposition for cancer, they meet with a breast cancer care team to determine the best course of action to prevent breast cancer from developing. Organizations such as the Lynne Cohen Foundation Preventive Health Clinics may be helpful in determining your personal risk.
Bone Scan/Body scan- if an invasive breast cancer is discovered, it is typical to do an MRI of the breasts and then a PET scan or body CT scan to check for any additional areas of cancer. A DEXA scan may be used to evaluate the integrity of the bones during diagnosis and treatment, as well.
Breast Cancer Care team- the breast cancer care team typically includes a breast surgeon, a medical oncologist, a radiation oncologist, and possibly a plastic surgeon. Other providers might include a social worker, case manager, and nutritionist. Behind the scenes there will also be a pathologist and a radiologist who are helping to provide and interpret tests. When the team gathers to discuss how to best treat a breast cancer, it is at a tumor board.
Breast Reconstruction- following mastectomy (total removal of breast tissue), a plastic surgeon can offer reconstruction to restore the look and feel of the breast.
Carcinoma- abnormal (cancerous) cells that divide without control. This is the most common type of breast cancer, originating in the tissue of the organ, in the ducts and lobules. Carcinomas can be invasive, where the cells spread via lymph nodes to other parts of the body (like Invasive Ductal Carcinoma), or non-invasive (in situ) where they stay in the original tumor site (like Ductal Carcinoma In Situ).
Chemotherapy- or “chemo.” The use of specialized chemicals to kill fast growing cells in the body. In breast cancer, it is often used before surgery (called neoadjuvant therapy) to reduce the size of the tumor, or after surgery (called adjuvant therapy) to kill potentially hidden cancer cells. It can be administered with a pill, a shot, or with an infusion (IV) through a tube into a vein. Sometimes patients have a port, catheter, or pump placed to easily access a vein, to avoid having to be poked all the time for veinous access. Each type of chemotherapy has different uses and side effects (hair loss, nausea, etc), and the medical oncologist will review and manage those.
CT Scan (computerized tomography scan)- an imaging study that is a series of pictures created by a computer linked to an X-ray machine, providing us detailed internal images of the body
DCIS (Ductal Carcinoma in Situ)- breast cancer that is non-invasive, meaning it is confined to tumor in the ducts of the breast, also referred to as stage 0 breast cancer
DEXA Scan (bone scan) may be used to evaluate the integrity of the bones during breast cancer diagnosis and treatment. When an invasive breast cancer is discovered, other imaging that is used is an MRI of the breasts and a PET scan or body CT scan to check for any additional areas of cancer.
Duct- there are approximately ten ducts (tubes) in the breasts that carry milk from the lobules to the openings in the nipple during breastfeeding. They lead from the lobes/lobules where milk is made.
Excisional biopsy- surgical removal of abnormal tissue (tumor or lymph node, for example) with a small margin of normal tissue surrounding it to ensure no abnormal cells remain.
Genetic testing- our DNA is passed on to us from both biological parents, and approximately 10% of breast cancers are hereditary, or genetic. This means it is possible to prevent breast cancer from developing before it even starts if we know genetic risk. Breast cancer-specific gene mutations are BRCA1, BRCA2, CHEK2, PALB2, PTEN, ATM, TP53, CDH1, and STK11 and we are discovering more every day. These are genes that, when mutated, cause a significant increase in cancer risk. It’s important to know family history, and to take breast cancer risk surveys to determine if genetic testing is necessary. Genetic tests are simple, requiring a saliva or blood sample, and often, not always, covered by insurance. When someone learns that they have a genetic predisposition for cancer, they then have conversations with the breast cancer care team to determine their best course of action.
Hormone-Positive/Negative Breast Cancer: Estrogen and progesterone are female hormones produced in the body. Approximately 2/3 of breast cancers need estrogen and/or progesterone to grow and spread, so part of destroying tumors and preventing them from returning, we test the breast tumor cells (from a biopsy) to see if they have estrogen or progesterone receptors. If they do, they are considered Estrogen-Receptor positive (ER+) or Progesterone Receptor positive (PR+) and we can use hormone therapy as part of the treatment. When you hear the term ‘triple positive or ‘triple negative breast cancer, it refers to whether a tumor is ER+, PR+ or HER2+.
Hormone Therapy for Breast Cancer- this is not like hormone therapy for menopause symptoms where we’re adding estrogen to the body. Instead, this is therapy, effective on those tumors that are hormone-positive, that lowers or blocks estrogen altogether, to prevent the tumor from spreading and returning. Hormone therapy for breast cancer is given in a pill and is typically taken for 5+ years. Patients are on this long after the chemo/radiation/surgery portion of treatment is complete. Medical oncologists provide this therapy.
HER2 (human epidermal growth factor receptor 2)- when this cell growth protein is present in abnormally hight amounts, it can cause cancer cells to grow and spread more quickly. About 20% of breast cancers are HER2+ and we determine this via a biopsy of the tumor. These cancers tend to be more aggressive, BUT there are specific, effective, treatments that target HER2. When you hear the term ‘triple negative’ or ‘triple positive’ breast cancer, it is referring to estrogen-receptors (ER), progesterone-receptors (PR) and HER2 status. Provided by medical oncologist.
Immunotherapy- a type of biological cancer therapy (using substances made from living organisms) that helps the patient’s immune system fight cancer. Typically used for metastatic cancer or triple negative breast cancer. This therapy is provided by the medical oncologist.
Incision- surgical cut into the skin, generally closed with suture or staples, will heal into scar
In situ- a tumor residing exclusively in the primary tissue site, has not breached the walls of the cells or spread to lymph nodes or elsewhere (example: DCIS)
Invasive vs Non-invasive Breast Cancer- this refers to whether the cancer (malignancy) is isolated to the breast tumor (in situ) or if it has breached the walls and spread to other parts of the breast, lymph nodes, or elsewhere in the body. An examples of non-invasive breast cancer is DCIS (ductal carcinoma in situ) and an invasive cancer is IDC (invasive ductal carcinoma).
IDC (Invasive Ductal Carcinoma) – breast cancer that starts in the ducts and its cells spread out into other parts of the breast, lymph nodes, or other parts of the body. There are many types, included tubular, medullary, mucinous, cribriform, and papillary.
ILC (Invasive Lobular Carcinoma)- breast cancer that starts in the lobules of the breast. Types include Solid, Alveolar, Tubulolobular, Pleomorphic, and Signet ring cell.
LCIS (Lobular Carcinoma in Situ or lobular neoplasia)- cells in the lobules of the breasts that are borderline cancerous and mean high likelihood to develop cancer later in life. They are typically surgically removed or followed closely with imaging by the breast cancer care team
Lobes and lobules- inside the breasts, there are 15-20 lobes, or sacs that produce milk, that extend to 20-40 lobules. Milk is then delivered to the nipple via ducts.
Lump- any mass in the breast (or elsewhere in the body). Without imaging/biopsy it’s impossible to know if it is benign or malignant.
Lumpectomy- also known as breast-conserving surgery, this surgery removes only the tumor and a small rim of normal tissue around it (to have adequate margins, so none of the tumor is left behind). Most of the breast skin and tissue is left in place.
Lymph Node- tiny organs all over the body that are part of the lymphatic, or immune system, and transport immune cells and remove waste. This is what can carry cancer cells to the rest of the body, which is why we biopsy and surgically remove axillary lymph nodes.
Malignant- cancerous
Mammogram- specialized X-ray of the breast done annually for screening for women over 40 (or younger if a family history of breast cancer), or for diagnosis- 3D Digital Mammography or ‘breast tomosynthesis’ takes multiple 2-dimensional X-ray images and combines them into a 3-dimentional image using computer software, for a more precise diagnosis. Stereotactic mammography uses 3D mammogram guidance while a radiologist takes a needle biopsy of the mass.
Margin- when abnormal tissue is surgically removed (like in a lumpectomy or lymph node excision), a small rim of normal tissue around it is also removed to ensure that part of the mass is not left behind. A “clean” or “negative” margin means all of the tumor was removed and only normal cells are identified in the final pathology of that surrounding tissue ring.
Mastectomy- when a lumpectomy (breast-conserving surgery) is not adequate, this is surgical removal of the entire breast. This is generally done for large tumors and prophylactically (preventatively) for those with genetic predisposition to cancer. Depending on the diagnosis, this may include one or both breasts (bilateral mastectomy) and may or may not include removal of the nipple and some of the skin over the breasts, and the lymph nodes in the axilla. Often reconstruction is done by a plastic surgeon at the time of the mastectomy.
Metastasis- the spread of cancer cells outside of the original tumor location.
Metastatic Breast Cancer- Invasive breast cancer that has spread beyond the breast to other organs in the body (most often the bones, lungs, liver, or brain). The most advanced stage (stage IV) of breast cancer.
Medical Oncologist- the doctor in charge of chemotherapy and any other medicine- based treatment, like hormone therapy, HER2-target therapy, or immunotherapies.
MRI- An imaging technique that uses a magnet linked to a computer to make detailed pictures of organs or soft tissues in the body.
Neoadjuvant Therapy- chemotherapy or hormone therapy used as first treatment, before surgery/radiation. Often used to shrink tumors before surgery, these are managed by a medical oncologist. ‘Down-staging’ is when tumors have a good response to neoadjuvant therapy and the subsequent treatment plan can change to reflect the updated tumor stage.
Nipple- the small projection from the areola on the breast where ducts terminate and milk is delivered
Oncologist- Any physician in charge of planning and overseeing cancer treatment (for breast cancer, that includes medical oncologist, surgical oncologist, and radiation oncologists as the breast cancer care team)
Oncotype- for those patients whose cancer is estrogen-receptor positive and HER2 negative, testing the tumor for oncotype tells us how likely the breast cancer is to return and how much benefit there will be from chemotherapy in addition to hormone therapy.
PET Scan- diagnostic imaging that demonstrates which parts of the body are more rapidly metabolizing- a good way to find any other areas of cancer. A short-term radioactive sugar is given through an IV so a scanner can show which parts of the body are consuming more sugar. Cancer cells tend to consume more sugar than normal cells do.
Preoperative- before surgery
Postoperative- after surgery
Prophylactic- preventative, for example, a ‘bilateral prophylactic mastectomy’ for patients with a high genetic risk of developing breast cancer
Radiation Oncologist- the doctor in charge of radiation therapy
Radiation therapy- instead of using chemicals, this method of killing breast cancer cells uses intense beams of energy- typically X-rays or protons. Most common is external beam radiation, which involves high-energy beams sent from a specialized machine to a the precise point on the body to the site of the tumor. Another type of radiation is brachytherapy, where tiny radiation seeds/ribbons/capsules are placed inside the body at the tumor site. The specific method, schedule of treatments, and side effects are revied by the radiation oncologist.
SAVI SCOUT- this tiny, safe, surgical device is inserted by radiology in the weeks leading up to lumpectomy. It is a reflector, the size of a grain of rice, placed at the site of the tumor so that the breast surgeon can use nonradioactive surgical guidance (like GP) during surgery to pinpoint the exact location of the mass. It is removed during the procedure.
Sentinel Lymph Node- lymph nodes are tiny organs all over the body that are part of the lymphatic, or immune system, and transport immune cells and remove waste. This is what can carry cancer cells to the rest of the body, which is why we biopsy axillary lymph nodes and remove them surgically. Sentinel lymph nodes are the first axillary (underarm) lymph nodes that filter the lymph fluid from the breast tumor, and most likely to contain cancer cells if the cancer has started to spread.
Triple Positive/Negative breast cancer- this refers to the breast cancer’s estrogen, progesterone, and HER2 receptor status. In addition to surgery and radiation, if these are positive, hormone and HER2-targeted treatment can be used. If they are all negative, immunotherapy will likely be used.
Tumor- abnormal growth/mass of tissue that may be benign (non-cancerous) or malignant (cancerous). It’s impossible to know until imaging/biopsy is done. The primary tumor is the original cancer.
Tumor Grading- ranges from 1 to 3. Grade 1 are tumor cells that are slow-growing and appear almost normal. Grade 2 are more abnormal and fast-growing, and Grade 3 are fast-growing and appear the most abnormal.
Tumor Staging- a universal system used to determine the extent of cancer within the body that assesses Tumor size, Lymph Node status, and Metastases (spread through the body). Most commonly, breast cancer is staged 0-4 with the TNM System. This is somewhat confusing, because Stage 0 is still early breast cancer (carcinoma in situ). As a rule, the lower the number, the less the cancer has spread.
Tumor Board- when all the doctors on the breast cancer care team get together to discuss the best, most up-to-date treatment of a patient’s cancer. This typically includes the breast surgeon, medical oncologist, radiation oncologist, pathologist, radiologist, and anyone else involved.
Ultrasound- diagnostic test that uses sound waves to make images of tissues/organs. Often done in concordance with mammogram on the breast.
Usual Hyperplasia- benign (non-cancerous) rapid growth (proliferation) of breast cells that appear normal under the microscope. Although it is benign, it does increase risk of breast cancer in the future, so it’s important to follow closely with breast cancer care team.
Wire localization- immediately before a surgical excision, a very thin wire is inserted by radiology into the breast to pinpoint the location of the mass so it can be removed during a lumpectomy. The wire is then removed during the procedure. Alternatives, when appropriate, include surgical guidance systems, like the SAVI SCOUT Radar.
Where can we go for reliable information? It’s very normal to rush to the internet to find information, but as we all know, the credibility of info online varies. These sites have the most up-to-date and clinically sound recommendations.
Susan G. Komen offers articles and videos specifically made for people with breast cancer, pre-cancer, or inherited breast cancer risk. There are also financial, social, and emotional resources available.
Sarah Zimmerman is a freelance writer in Northern California and is working on her first novel. In past lives,, she has been a Physician Assistant in Women's Health and the owner of a vegan ice cream business. Sarah writes about marriage, sex, parenting, infertility, pregnancy loss, social justice, and women's mental and physical health, always with honesty and humor. She has written for Ravishly, Cafe Mom, Pregnant Chicken, and more and can be found at sarahzwriter.com and on Medium, Twitter, Facebook, Instagram and TikTok at @sarahzwriter.