Oncology Glossary
Medical jargon can be overwhelming. We've translated complex terms into simple, comforting layperson's language to help you better understand your care.
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127 terms foundAdjuvant Therapy
Extra treatment given after the main treatment (like surgery) to lower the risk that the cancer will come back. Think of it as an extra safety measure to clear away any unseen, remaining cells.
Alopecia
The medical term for hair loss, which can be a temporary side effect of certain chemotherapy or radiation treatments. It is completely normal and hair usually grows back after treatment ends.
Anemia
A condition where your body has fewer red blood cells than normal, which can make you feel unusually tired, weak, or short of breath. It is a common, manageable side effect of cancer treatment.
Angiogenesis
The process by which a tumor creates its own new blood vessels to get the nutrients and oxygen it needs to grow.
Apoptosis
Also known as "programmed cell death," it is the body's normal way of getting rid of old or damaged cells. Cancer cells often figure out a way to avoid this process.
Benign
A tumor or growth that is not cancer. Benign tumors do not spread to other parts of the body and are usually not life-threatening.
Biomarker
A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease like cancer.
Biopsy
A small procedure where a tiny piece of tissue is safely removed and examined under a microscope. It is the most certain way for doctors to find out if a growth is cancer.
Brachytherapy
A highly targeted type of radiation therapy where a small radioactive source is placed gently inside or very close to the tumor. This helps protect healthy surrounding tissue from the radiation.
Cachexia
A physical wasting syndrome involving loss of weight and muscle mass that can happen in people with severe chronic illness, including cancer.
CAR T-Cell Therapy
A type of immunotherapy where a patient's own immune cells (T cells) are changed in a laboratory so they will bind to and kill cancer cells.
Carcinoma
The most common type of cancer that starts in the skin or the tissue lining internal organs (like the breast, colon, or lung).
Carcinoma in Situ
A group of abnormal cells that have not spread from the location where they first formed. Sometimes called stage 0 cancer.
Chemotherapy
The use of powerful medicines to treat cancer by stopping cancer cells from growing and dividing. It is often referred to simply as "chemo".
Clinical Trial
A carefully monitored medical research study that tests new and potentially better treatments or procedures to see if they are safe and effective for patients.
Complete Response
A very encouraging outcome where doctors can no longer find any signs of cancer in your body after treatment. Also called complete remission.
CT Scan
A painless imaging test that takes a series of X-ray pictures to create detailed, 3D images of the inside of your body. It helps doctors see the exact size and location of a tumor.
Cyst
A harmless sac or pouch filled with fluid or other material. Most cysts are not cancer.
Cytology
The study of individual cells under a microscope to detect abnormalities or cancer.
Cytotoxic
A substance that kills cells, including cancer cells. Many chemotherapy drugs are cytotoxic.
Dysplasia
The presence of abnormal cells within a tissue or organ. Dysplasia is not cancer, but it may sometimes become cancer.
Edema
Swelling caused by a buildup of fluid in the body's tissues. It can be a side effect of cancer or its treatment.
Endoscopy
A procedure that uses a thin, flexible tube with a light and camera to look inside the body's organs or cavities.
Epidermal Growth Factor Receptor (EGFR)
A protein found on the surface of some cells that helps them grow. Too much of this protein can cause cancer cells to grow faster.
Erythema
Redness of the skin. It can be a side effect of radiation therapy or certain chemotherapy drugs.
External Beam Radiation
The most common type of radiation therapy. A specialized machine (like a linear accelerator) carefully aims beams of radiation directly at the tumor from outside the body. It is completely painless, much like getting a regular X-ray.
Extravasation
The accidental leakage of intravenous (IV) drugs from the vein into the surrounding healthy tissue.
Fatigue
A deep, persistent feeling of physical or emotional tiredness that doesn't go away with rest. It is the most common side effect of cancer treatment, and there are many ways your care team can help you manage it.
Febrile Neutropenia
A condition where a patient has a fever and a dangerously low number of neutrophils (a type of white blood cell), indicating a high risk of infection.
Fibrosis
The thickening and scarring of connective tissue, usually as a result of injury. It can be a long-term side effect of radiation therapy.
Flow Cytometry
A laboratory method used to analyze the physical and chemical characteristics of cells or particles in a fluid as they pass through a laser.
Fractionation
The process of dividing the total dose of radiation into smaller, daily doses (called fractions). This gentle approach gives healthy cells time to recover between treatments.
Gene Expression Profiling
A test that looks at the pattern of many genes in a tissue sample to help doctors predict how a cancer will behave or respond to treatment.
Genome
The complete set of DNA (genetic material) in an organism.
Grade
A score doctors give cancer cells based on how they look under a microscope. It helps the care team understand how fast the cancer might grow and which treatments will work best.
Gray (Gy)
The standard medical unit used to measure the exact amount of radiation energy absorbed by the body during treatment.
Hematocrit
A blood test that measures the percentage of the volume of whole blood that is made up of red blood cells.
Hematologist
A medical doctor who specializes in diagnosing and treating diseases of the blood and blood-forming organs.
Histology
The study of the microscopic structure of tissues.
Hospice
A special type of compassionate care designed to provide comfort, peace, and dignity for someone nearing the end of life, focusing on quality of life rather than a cure.
Hypercalcemia
An abnormally high level of calcium in the blood, which can be a serious complication of certain types of cancer.
Hyperplasia
An increase in the number of cells in an organ or tissue that appear normal under a microscope. It is not cancer but may become cancer over time.
Hypoxia
A condition in which a region of the body is deprived of adequate oxygen supply. Tumors are often hypoxic, which can make them harder to treat.
Immunotherapy
A modern cancer treatment that helps boost or teach your body's own natural immune system to recognize and attack cancer cells.
In Situ
A Latin phrase meaning "in its original place." It refers to early-stage cancer cells that have not spread beyond the layer of tissue where they first developed.
Indolent
A type of cancer that grows and spreads slowly and often has few or no symptoms.
Infusion
A common way of gently delivering medicine, fluids, or nutrients slowly and continuously into a vein over a period of time.
Intraperitoneal
Meaning "within the peritoneal cavity" (the area that contains the abdominal organs). Some chemotherapy is given directly into this space.
Intravenous (IV)
Meaning "within a vein," this refers to giving medicines or fluids directly into the bloodstream through a tiny, soft tube.
Ischemia
An inadequate blood supply to an organ or part of the body.
Laparoscopy
A surgical procedure in which a fiber-optic instrument is inserted through the abdominal wall to view the organs in the abdomen or to permit a surgical procedure.
Lesion
A broad medical term for any area of tissue that has been damaged or changed due to injury or disease (such as a sore, wound, or tumor).
Linear Accelerator (LINAC)
The advanced machine used to deliver external beam radiation treatments. It is highly precise and shapes the radiation beams to exactly match the tumor.
Localized
Cancer that is confined entirely to the organ or tissue where it first started and has not spread to other parts of the body. This usually means it is easier to treat.
Lymph Nodes
Small, bean-shaped structures found throughout the body that act as filters for your immune system. Doctors often check them to see if cancer has started to spread.
Lymphedema
Swelling in an arm or leg caused by a lymphatic system blockage, often due to lymph node removal or damage during cancer treatment.
Macrophage
A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells.
Malignant
The medical term for cancerous. Malignant tumors can invade nearby tissues and spread to other parts of the body.
Margin
The border or edge of healthy tissue removed along with a tumor during surgery. A "clear" or "negative" margin means no cancer cells were found at the edges, which is great news.
Medical Oncologist
A specialized doctor who treats cancer using medicines such as chemotherapy, immunotherapy, or targeted therapy.
Melanoma
The most serious type of skin cancer that develops from the pigment-producing cells known as melanocytes.
Mesothelioma
A rare type of cancer that occurs in the thin layer of tissue that covers the majority of your internal organs, most often caused by asbestos exposure.
Metastasis
The process where cancer cells spread from where they first formed to a new part of the body. The new tumor is made of the same kind of cells as the original one.
Minimal Residual Disease (MRD)
Small numbers of cancer cells that remain in the body after treatment. These cells cannot be seen under a microscope and require highly sensitive tests to be detected.
Monoclonal Antibody
A laboratory-produced molecule that's carefully engineered to serve as a substitute antibody that can restore, enhance or mimic the immune system's attack on cancer cells.
Morbidity
The state of having a disease or the rate of disease in a population. In oncology, it often refers to complications from the cancer or its treatment.
Mortality
The number of deaths in a certain group of people in a certain period of time.
MRI (Magnetic Resonance Imaging)
A painless, radiation-free test that uses strong magnets and radio waves to create highly detailed pictures of the inside of your body.
Mucositis
Inflammation of the mucous membranes lining the digestive tract from the mouth to the anus. It is a common side effect of chemotherapy and radiation.
Mutation
A change in the DNA of a cell. Some mutations are normal, while others can cause cells to grow out of control and turn into cancer.
Myeloma
A cancer of the plasma cells, a type of white blood cell present in bone marrow.
Myelosuppression
A condition in which bone marrow activity is decreased, resulting in fewer red blood cells, white blood cells, and platelets. A common side effect of chemotherapy.
Necrosis
The death of living cells or tissues. In a tumor, rapid growth can lead to central necrosis due to a lack of blood supply.
Neoadjuvant Therapy
Treatment (like chemo or radiation) given before the main treatment (usually surgery) to shrink a tumor and make the surgery safer and more successful.
Neoplasm
An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. It can be benign or malignant.
Neuropathy (Peripheral)
Damage to the peripheral nerves, often causing weakness, numbness, and pain, usually in the hands and feet. Common side effect of certain chemotherapy drugs.
Neutropenia
A condition where your body has lower-than-normal levels of a certain type of white blood cell, making you more prone to catching infections. Your care team will monitor this closely during treatment.
Neutrophil
The most abundant type of white blood cell in the body. They act as the first responders to fight off bacterial infections.
Oncogene
A gene that is a mutated form of a gene involved in normal cell growth. Oncogenes can cause the growth of cancer cells.
Oncology
The specialized branch of medicine dedicated entirely to understanding, diagnosing, treating, and preventing cancer.
Osteosarcoma
The most common type of cancer that starts in the bones.
Palliative Care
Supportive care focused purely on relieving pain, stress, and symptoms of a serious illness like cancer, with the goal of keeping you as comfortable and happy as possible at any stage of treatment.
Pancytopenia
A medical condition in which there is a reduction in the number of red and white blood cells, as well as platelets.
Paraneoplastic Syndrome
A group of rare disorders that are triggered by an abnormal immune system response to a cancerous tumor.
Pathology
The study of disease by examining cells and tissues under a microscope. A pathology report helps your doctor know exactly what type of cancer is present.
PET Scan
A highly sensitive imaging test that looks at how cells in your body are functioning. It is very good at spotting active cancer cells.
Pharmacogenomics
The study of how a person's genes affect their response to drugs. This field helps tailor cancer treatments to individual patients.
Phlebotomy
The process of drawing blood from a vein for diagnostic tests.
Photodynamic Therapy (PDT)
A treatment that uses special drugs, called photosensitizing agents, along with light to kill cancer cells.
Placebo
An inactive substance (like a "sugar pill") that looks just like real medicine but contains no active drug. It is sometimes used in clinical trials for comparison.
Platelet
A tiny, disc-shaped piece of cell that is found in the blood and spleen. Platelets help form blood clots to slow or stop bleeding.
Polyp
A tissue growth on an internal mucous membrane, such as in the colon. While usually benign, some can develop into cancer.
Port (Port-a-cath)
A small, implantable device placed under the skin to make drawing blood or giving IV treatments much easier and more comfortable, saving you from repeated needle sticks.
Primary Site
The place in the body where cancer first starts growing.
Primary Tumor
The original location where the very first cancer cells started growing in the body.
Prognosis
A doctor's educated prediction about the likely course and outcome of a disease, including the chances of recovery.
Prophylactic
A medicine or course of action used to prevent disease (e.g., prophylactic surgery to remove tissue before cancer can develop).
Protocol
A carefully designed, step-by-step treatment plan that doctors follow to ensure you are getting the safest, most effective care for your specific situation.
Proton Therapy
A type of radiation therapy that uses protons rather than X-rays to treat cancer. It can more precisely target tumors while sparing healthy tissue.
Quality of Life
The overall enjoyment of life. In cancer care, this involves managing symptoms and side effects to keep the patient as comfortable and functional as possible.
Radiation Fibrosis
Scarring of tissue that can happen months or years after radiation therapy.
Radiation Oncologist
A highly specialized doctor (like Dr. Rathore) who expertly uses high-energy radiation to safely treat cancer and relieve symptoms.
Radiation Therapy
The careful use of high-energy rays or particles to destroy cancer cells and shrink tumors while doing the best to protect healthy tissue.
Radiosensitizer
A drug that makes tumor cells more sensitive to radiation therapy.
Radiosurgery (SRS/SBRT)
Despite the name, this is not actual surgery with a knife. It is a highly precise type of radiation therapy that delivers a large, powerful dose of radiation exactly to the tumor in just a few sessions.
Recurrence
The return of cancer after treatment and after a period of time when the cancer couldn't be detected.
Refractory
Cancer that does not respond to treatment. The cancer may be resistant at the beginning of treatment or it may become resistant during treatment.
Regression
A decrease in the size of a tumor or in the extent of cancer in the body.
Remission
A wonderful phase when the signs and symptoms of cancer are partly or entirely gone.
Resection
Surgical removal of all or part of an organ, tissue, or structure.
Sarcoma
A rarer type of cancer that begins in the bone, muscle, fat, blood vessels, or other connective tissues of the body.
Side Effect
Any reaction or problem caused by a treatment. The care team's priority is to help prevent and minimize side effects so you remain as comfortable as possible.
Stage
A way of describing exactly how much cancer is in the body and where it is located. It is essential for figuring out the best, most effective treatment plan.
Staging
The process of doing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from the original site to other parts of the body.
Stem Cell Transplant
A procedure that restores blood-forming stem cells in people who have had theirs destroyed by the very high doses of chemotherapy or radiation therapy that are used to treat certain cancers.
Subcutaneous
Meaning "under the skin." Some cancer medications are given as subcutaneous injections.
Survival Rate
The percentage of people in a study or treatment group who are still alive for a certain period of time after they were diagnosed with or started treatment for a disease, such as cancer.
Systemic Therapy
Treatments like chemotherapy or immunotherapy that travel through the entire bloodstream to reach cancer cells anywhere in the body.
T-Cell
A type of white blood cell that is at the core of adaptive immunity, the system that tailors the body's immune response to specific pathogens or cancer cells.
Targeted Therapy
A newer, smarter kind of cancer treatment that uses drugs to specifically identify and attack cancer cells while causing less damage to normal, healthy cells.
Thrombocytopenia
A condition in which there is a lower-than-normal number of platelets in the blood. It can be a side effect of chemotherapy and increases the risk of bleeding.
Toxicity
The degree to which a substance (such as a chemotherapy drug) is poisonous or harmful to the body.
Tumor
An abnormal lump or mass of tissue. Tumors can be either benign (not cancer) or malignant (cancer).
Tumor Burden
Also called tumor load; refers to the number of cancer cells, the size of a tumor, or the amount of cancer in the body.
Tumor Marker
Specific substances found in the blood or tissues that can go up when cancer is present. Doctors use simple tests for these markers to track how well treatment is working.
Tumor Microenvironment
The normal cells, molecules, and blood vessels that surround and feed a tumor cell. A tumor can change its microenvironment, and the microenvironment can affect how a tumor grows and spreads.
Vascular Endothelial Growth Factor (VEGF)
A substance made by cells that stimulates new blood vessel formation. Some cancer drugs block VEGF to starve the tumor of its blood supply.