Cancer Terms Explained
When you or someone you love has been diagnosed with cancer, you’ll encounter new terms and phrases that make sorting out what’s going on confusing. We’ve got you covered.
Cancer is a familiar disease that comes with a distinctly unfamiliar vocabulary. What’s more, patients have often invented new terms to describe situations that the medical terminology has overlooked. The glossary below aims to make it easier for you to understand the medical terminology as well as the ever-growing lay vernacular surrounding cancer.
What Is Cancer?
Active Surveillance or Watchful Waiting An approach that doctors use to closely monitor a person’s condition without recommending treatment unless symptoms develop or change. Individuals with slow-growing cancers, like some prostate cancers, are good candidates for watchful waiting.
Adjuvant Therapy Given in addition to the primary therapy (usually surgery), adjuvant therapy, also known as adjunct or add-on therapy, maximizes treatment effectiveness and reduces relapse. Adjuvant therapy is given after the primary therapy. Conversely, neo-adjuvant therapy is given before the primary surgery, such as chemotherapy (with or without radiation) given before removing a tumor.
Androgen Deprivation Therapy (ADT) Also known as “hormone therapy,” this treatment is given to men with prostate cancer. ADT involves using drugs or surgery to lower the level of hormones, called androgens, in the body. It also works by stopping androgens from getting into prostate cancer cells. Androgens help trigger prostate cancer cells to grow.
Benign A word that, in the context of cancer, is used to describe tumors or imaging findings that are not cancerous or particularly suspicious.
Biologic Therapy (or Immunotherapy) A treatment made using living organisms, or artificially produced versions of substances made by living organisms, to treat cancer. The therapies usually stimulate the body’s immune system to attack cancer cells, or attack the cancer cells directly.
Biopsy A procedure in which a piece of tissue is removed from the body to be analyzed in a lab. A biopsy is often performed to determine if a tumor is cancerous. They are usually done with the aid of imaging to target the area of concern. Only a piece of the concerning tissue is removed with a needle.
Bone Marrow Soft, spongy tissue found inside bones where blood cells — white blood cells, red blood cells, and platelets — are formed.
Bone Marrow Transplant In this procedure, diseased bone marrow is eliminated via chemotherapy and possibly radiation, and is replaced by healthy marrow intravenously (IV).
BRCA1 and BRCA2 The names of two genes that, when mutated, increase the risk of breast and ovarian cancers, as well as others, such as prostate cancer, pancreatic cancer, and skin cancer. These can be passed down through families, and are more prevalent in certain ethnic communities.
Cancer A disease characterized by abnormal cell growth in an organ or organ system that may spread to other parts of the body. There are more than 100 types of cancer.
Cancer-Related Lymphedema Lymphedema is condition that causes swelling, mostly in the arms or legs but also in the face, neck, belly, and genitals. It happens when lymph fluid builds up under the skin, which can occur when the lymphatic system is disrupted or blocked. Cancer and certain cancer therapies, like surgery, radiation, and chemotherapy, can affect the flow of lymph fluid and lead to lymphedema. This is known as “cancer-related lymphedema.”
Cancer Pathologist A scientist who examines laboratory samples of tissue under a microscope in order to make a diagnosis of the type and stage of cancer in the sample.
Cancer Vaccine A term used for multiple types of therapies, all of which aim to train your body to recognize your cancer as foreign and kill it, or protect you from having the cancer coming back. Occasionally people also use this term to refer to the human papillomavirus (HPV) vaccine, which prevents infection by HPV, a virus associated with many types of cancer, such as cervical cancer, penis cancer, and head and neck cancers.
Carcinoma Carcinoma refers to cancers that develops from epithelial cells that line inner or outer surfaces of tissues and blood vessels. Types of cancer in this category include basal and squamous cell carcinoma (both skin cancers), renal cell carcinoma (the most common kidney cancer), and invasive and noninvasive breast cancers.
CAR T Therapy This stands for chimeric antigen receptor T cell, a therapy in which T cells are removed from the patient’s bloodstream, reprogrammed to attack the patient’s cancer, and then delivered back into the patient’s bloodstream.
Catheters These thin, flexible tubes allow doctors to deliver medication or other fluids into the body, or may be used to allow excess fluid to be drained from the body. Chemotherapy, blood transfusions, antibiotics, and intravenous (IV) fluids can all be given through a catheter, which is placed into a vein via a small needle.
Checkpoint Inhibitor Drugs that block proteins on cancer cells — like PD-1, PD-L1 and CTLA4 — that help cancer cells remain invisible to the immune system. Once the proteins are blocked by the drug, the immune system is able to “see” the cancer cells and attack them as it would foreign invaders. Checkpoint inhibitors are used to treat lung cancer, metastatic melanoma, and Hodgkin lymphoma, among other cancers.
Chemoprevention The use of drugs or other agents to reduce the risk of or prevent cancer. Chemoprevention may be prescribed to lower the incidence of cancer among those at high risk, including those with a family history of the disease.
Chemotherapy Anti-cancer drugs, usually used in combination, that treat cancer.
Chronic Myeloid Leukemia (CML) This cancer is characterized by unregulated growth of myeloid cells in bone marrow and their accumulation in the blood.
Clinical Trials Experiments or observations that evaluate a new medical treatment, drug, or device. Clinical trials in research find new and improved ways to treat, prevent, screen, and diagnose disease.
Cold Cap A hat that’s filled with a chilled gel coolant and worn to help prevent women from losing some of their hair during chemotherapy. It works by narrowing the blood vessels beneath the skin of the scalp, so less chemo reaches the hair follicles. The cold also lowers the activity of the hair follicles. The cap is worn before, during, and after chemo treatments.
Dysplasia Abnormal cells in tissue that precede the development of full-blown cancer. Usually this tissue is removed as a preventive measure.
Expanders These inflatable breast implants are used after a mastectomy is performed, and are designed to stretch the skin and muscle to make room for permanent implants. During a mastectomy, plastic surgeons insert tissue expanders beneath the skin and chest muscle. The expanders are gradually enlarged by filling them with periodic injections of a saltwater solution over several weeks or months. This helps stretch the area and prepare it for an implant.
First-Line Therapy The first chemotherapy or immunotherapy given for an advanced cancer. Also called induction therapy, primary therapy, and primary treatment.
First-Line, Second-Line, and Third-Line Therapy
Gleason Score A term that describes the “grade,” or degree of aggressiveness, of prostate cancer cells. The score is used to help plan treatment and determine a person’s prognosis. The Gleason score ranges from 6 to 10. The lower the score, the more normal the cells look, and the better a patient’s prognosis.
Hormone Therapy Also known as endocrine therapy, this form of treatment is used to treat cancers that rely on hormones to grow, such as breast and prostate cancer. It uses agents that block the body’s ability to produce hormones or interfere with how hormones function within the body.
HPV Human papillomavirus (HPV) is a virus acquired through skin-to-skin sexual contact. It can cause genital warts and some cancers, including cancer of the cervix, vulva, penis, anus, mouth, and throat. HPV is the most common sexually transmitted infection, with 14 million new cases each year. Vaccinations can now prevent HPV.
Immune-Related Adverse Events (irAEs) Side effects that can occur during or after treatment with immunotherapy. Some can be serious, even life-threatening, if they aren’t treated in a timely manner. IrAEs can affect any organ but often involve the gastrointestinal tract, endocrine glands, skin, and liver.
Immunotherapy Treatment that harnesses a patient’s own immune system to help fight the cancer. Immunotherapies attack cancer directly, or facilitate or stimulate the immune system’s ability to attack it. There are many forms of immunotherapies, including checkpoint inhibitors (PD-1 and PDL-1 inhibitors), CAR T therapy, and cancer vaccines.
In Vitro Fertilization (IVF) Cancer treatments can affect a woman’s ability to get pregnant. In vitro fertilization, or IVF, is an assisted reproductive technology that involves collecting mature eggs from a woman’s ovaries. The eggs are then fertilized by sperm in a lab, and the resulting embryo is implanted into a woman’s uterus. Some women choose to have their eggs collected, fertilized, and frozen before treatment to use after they finish cancer treatments.
Indolent Cancer A cancer that grows very slowly.
KRAS A gene that, when mutated, contributes to many cancers by allowing cancer cells to proliferate. Among the cancers it contributes to are colon and lung cancer.
Leukopenia Having a low number of white blood cells in your bloodstream.
Lumpectomy Surgery to remove cancer from a breast in which the tumor and a margin of some surrounding tissue is removed, but a large part of the breast is left intact.
Lymph Nodes Small ovoid-shaped structures located throughout the body, concentrated in the neck, underarm, chest, belly, and groin, that filter harmful substances out of the lymphatic system. Lymph nodes contain immune cells that assist in fighting infection. Swelling of a lymph node may indicate that the node is actively working to cope with an injury or infection. Lymph nodes located in the area of the primary cancer (regional lymph nodes) are also the first place cancer travels to if a patient’s cancer has spread.
Lymphatic System A system of veinlike vessels throughout the body that carry a watery fluid called lymph, which delivers oxygen and nutrients to cells, and carries away waste products.
Lymphoma This cancer of the lymphatic system, often characterized by enlarged lymph nodes, includes non-Hodgkin and Hodgkin subtypes. The type of lymphocyte, or white blood cell, distinguishes non-Hodgkin from Hodgkin. Non-Hodgkin lymphoma, the more common of the two, accounts for 4 percent of cancers.
Malignant This word, in conjunction with cancer, means that the diagnosis is not benign (noncancerous) but cancerous.
Maintenance Therapy A type of therapy given after cancer has disappeared following initial treatment. The goal of maintenance therapy is to prevent or delay the cancer from coming back. It may include drugs, vaccines, or other treatments that are given for a period of time.
Margin When a surgeon removes cancerous tissue from the body, they will remove a span of normal tissue surrounding the tumor — the margin — to make sure all cancerous tissue has been excised. If a margin is close (meaning a tumor is close to the edge of the tissue removed) or positive (cancer is seen at the edge of the tissue removed), it may be necessary to return to surgery to obtain what is called a “negative margin” (edges of tissue are free from cancerous cells).
Mastectomy Surgery to remove the entire breast. Doctors perform different types of mastectomies based on how much tissue and surrounding lymph nodes need to be removed.
Metastasis Metastasis has occurred when cancer cells have spread from the site of origin to a secondary or distant site in the body.
Monoclonal Antibodies (MAbs) A type of protein made in the lab from clones of an immune cell. The antibodies made by the cells are able to target and attack antigens on the surface of cancer cells. Monocolonal antibodies are sometimes combined with chemotherapy drugs or radioactive particles (conjugated monocolonal antibodies), delivering the therapy directly to the cancer cells.
Multiple Myeloma Cancer of plasma cells found in bone marrow. Overproliferation of these cancerous plasma cells overwhelms the bone marrow can lead to low blood counts, bone pain, infection, and anemia.
Mutation A permanent alteration to the DNA of a cell caused by changes in chromosome structure or DNA sequence. All cancers result from gene mutations, which can be inherited or acquired with age or exposure to substances known to cause mutations, such as cigarette smoke.
Neoplasm A word that may be used synonymously with tumor. A neoplasm is a mass of tissue as a result of excessive cell growth. The growth may be cancerous or noncancerous (benign).
Neutropenia A condition characterized by abnormally low levels of neutrophils, a type of white blood cells, or neutrophils. Neutrophils develop in the bone marrow and protect against infection. Chemotherapy causes neutropenia.
Nipple-Sparing Mastectomy With this type of mastectomy, all of the breast tissue is removed, but the nipple and majority of the skin of the breast are left in place.
Node Negative This means that the cancer has not spread to lymph nodes.
Non-Small-Cell Lung Cancer (NSCLC) NSCLC accounts for 85 percent of all epithelial lung cancers and includes adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.
Oncologist A doctor who is trained in diagnosing and treating people with cancer. Some oncologists specialize in particular types of cancer. These doctors are responsible for providing chemotherapy and other medications to treat or prevent new cancer.
PARP PARP stands for the enzyme poly ADP ribose polymerase, which are proteins involved in DNA repair. Drugs known as PARP inhibitors treat cancers that depend on PARP, such as platinum-sensitive ovarian cancer.
Pathology Report A report prepared by the pathologist who has examined samples of tissue in a laboratory, explaining what the tissue sample revealed. In the case of cancer, the report would include a diagnosis of the type of cancer, the type of tissue affected, and an indication of the severity of disease.
PICC Line PICC stands for “peripherally inserted central catheter.” It’s a type of catheter that’s inserted into a vein in the arm and runs up to a large vein in the chest. Doctors can deliver medicines, give fluids, or perform blood draws via a PICC line. It can stay in place for weeks or months.
Ports These are devices that are implanted in the body and used to deliver fluids or medicines and take blood samples. A port is placed under the skin, usually in the chest, during outpatient surgery. It’s attached to a catheter that leads into a large vein. A needle can be inserted through the port to transport or collect fluids. A port can stay in place for an extended amount of time, usually months or years.
Preimplantation Genetic Testing (PGT) A genetic test that’s used before transferring embryos created for IVF to the recipient. It involves screening the embryos for genetic diseases and chromosomal disorders. PGT can be used to identify inherited cancer syndromes, such as a BRCA1 or BRCA2 gene mutation.
Previvor Someone actively attempting to prevent cancer through surveillance or prophylactic surgery.
Prophylactic Preventive Bilateral Mastectomy (PBM) or Prophylactic Preventive Double Mastectomy (PDM) Surgery to remove one or both breasts to reduce the risk of developing cancer. Women who have a strong family history of breast cancer, those with a BRCA gene mutation, or those with other high-risk genetic mutations may opt to have this procedure as a preventive measure to prevent a breast cancer diagnosis in the future.
PSA (Prostate Specific Antigen) This is a protein made by the prostate gland. High PSA levels may indicate that a man has prostate cancer, a noncancerous enlargement of the prostate gland known as benign prostatic hyperplasia (BPH), an infection, or inflammation of the prostate. A simple blood test can measure PSA levels.
Radiation Therapy A form of cancer treatment that uses beams of intense energy to kill cancer cells. It is often used in combination with chemotherapy or surgery. Radiation therapy is considered a “local treatment” since it only treats the area that is specifically targeted.
Second-Line Therapy Treatment given when first-line therapy, the initial treatment, does not work or has stopped working.
Sarcoma Cancer that begin in bones and soft or connective tissues, such as muscle, tendons, fat, lymph, blood vessels, and nerves.
Small-Cell Lung Cancer (SCLC) Sometimes referred to as oat cell cancer, this type of lung cancer begins in the bronchia and accounts for 10 to 15 percent of lung cancers.
Stage When a cancer is diagnosed, doctors will stage it — meaning they will use tests to determine how advanced the cancer is. Most cancers are deemed stage 1, 2, 3, or 4. The lower the stage of a cancer, the more easily it is to cure. Stage 4 cancer is considered terminal and occurs when the cancer travels from its origin to another part of the body.
Survivor Someone who has finished and survived treatment.
Targeted Therapy Compounds known to interfere with cancer growth by precisely targeting specific molecules needed for a tumor’s growth.
Third-Line Therapy Treatment given when first line therapy and second line therapy don’t work or have stopped working.
Thriver Someone living with stage 4 cancer.
Treatment Plan This defined document describes a patient’s condition and includes information about diet, exercise, drug therapy, expected outcomes, and treatment duration. Common cancer treatment plans may include surgery, radiation, hormone therapy, stem cell transplantation, targeted therapies, chemotherapy, and immunotherapy.
Tumor Abnormal or excessive tissue growth. Tumors can be benign, precancerous, or cancerous.
Warrior Someone currently in treatment for cancer.