Understanding cancer terminology is crucial for patients to navigate their diagnosis and treatment journey effectively.

We don’t expect you to remember all these words.

Use this tool to look up terms and engage confidently in discussions with your healthcare team to make informed decisions about your care.

Adjuvant Therapy

Typically therapy administered after surgical removal of the cancer to reduce the risk of cancer returning in the future.

Advance Care Planning

The process of planning for future medical care in case an individual becomes unable to make their own medical decisions.

Advance Directive

A legal document that indicates a patient’s wishes regarding their medical treatment in circumstances in which they are no longer able to express informed consent.

Advanced Care Planning

The process of planning for future medical care in case an individual becomes unable to make their own medical decisions.

Advanced Illness

Any chronic, progressive physical or mental condition that, in the absence of life-sustaining therapy or curative treatment, can lead to death.


A condition in which there is a shortage of red blood cells in the body, leading to fatigue and other symptoms.


A protein made by the immune system to fight infection.


A drug that helps prevent the clotting (coagulation) of blood.


A tumor that is not cancerous and does not spread to nearby tissues or other parts of the body.

Bereavement Care

Support and services provided to individuals after the death of a loved one.

Biological Therapy

Treatment that uses the patient’s immune system to fight cancer or to lessen the side effects caused by some cancer treatments.


A procedure to remove a piece of tissue or a sample of cells from the body so that it can be analyzed in a laboratory.

Blood Transfusion

The process of transferring blood or blood products into one’s circulation intravenously.


A material placed on the skin to increase the skin dose of radiation or to even out the dose delivered to the tumor.

Bone Marrow

The soft, sponge-like tissue inside bones that produces blood cells.

Bone Marrow Aspiration

A procedure in which a sample of liquid bone marrow is removed and tested.

Bone Marrow Biopsy

A procedure in which a small core sample of spongy bone marrow is removed and examined under a microscope.


An additional dose of radiation given to the tumor site.


A form of radiation therapy where a source of radiation is put inside or very near to the area needing treatment.


A term for diseases in which abnormal cells divide without control and can invade nearby tissues.


The process by which normal cells are transformed into cancer cells.


A type of cancer that begins in the skin or in tissues that line or cover internal organs.


Anyone who provides care for another person in need, such as a child, aging parent, or patient.

Case Management

A collaborative process that assesses, plans, implements, coordinates, monitors, and evaluates the options and services required to meet a patient’s health needs.


A type of cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing.


The process by which blood forms clots.

Comfort Care

Care that helps or soothes a person who is dying. The goals are to prevent or relieve suffering as much as possible and to improve quality of life while respecting the dying person’s wishes.

Complete Response

The disappearance of all signs of cancer in response to treatment; does not always mean the cancer has been cured.

Conformal Radiation Therapy

A type of radiation therapy that shapes the radiation beams to match the shape of the tumor.

Continuous Care

A type of care provided in the home for patients in a crisis situation during a period of pain or other medical symptoms that require continuous nursing availability.

Cultural Competence

The ability of healthcare providers to recognize the unique cultural and linguistic needs of a patient, and to adapt to meet them.

Curative Care

Care that treats or cures the disease.


The study of cells using a microscope.


A reduction in the number of blood cells.

Distant Recurrence

The return of cancer in a part of the body far from where it originally started.

Do Not Resuscitate (DNR)

A medical order written by a doctor instructing healthcare providers not to perform cardiopulmonary resuscitation (CPR) if a patient’s breathing stops or if the patient’s heart stops beating.

Durable Power of Attorney for Health Care

A legal document that designates someone to make medical decisions on an individual’s behalf if they are unable.


Abnormal cells that are not cancer but could become cancer over time.


Swelling caused by the buildup of fluid.

End-of-Life Care

Support and medical care given during the time surrounding death.


A procedure that uses a thin, flexible tube with a light and a lens to view organs or tissues inside the body.

Erythrocyte Sedimentation Rate (ESR)

A blood test that can reveal inflammatory activity in your body.


An increase in the number of red blood cells in the bloodstream.


The process by which red blood cells are produced.

Excisional Biopsy

A surgical procedure in which an entire lump or suspicious area is removed for diagnosis.

External Beam Radiation Therapy (EBRT)

A type of radiation therapy that delivers radiation from outside the body.

Family-Centered Care

An approach to healthcare that recognizes a patient functions within, and depends on, a family unit – whatever form that family takes. It also recognizes that family members also have a share in the patient’s illness burden, and have a valuable role to play in supporting and sustaining the patient.


A protein in the blood that is important for blood clotting.

Four-Dimensional Radiation Planning

A special type of radiation therapy planning scan that accounts for tumor motion induced by respirations.


The division of the total dose of radiation into smaller doses delivered over a number of days.


A technique in radiation therapy where the delivery of radiation is synchronized with the patient’s breathing.

Gene Therapy

Treatment that alters or replaces a person’s genes to help fight or prevent disease.

Goals of Care Conversation

Discussions between patients, their families, and healthcare providers to establish and align treatment plans with the patient’s values and preferences.


A description of a tumor based on how abnormal the cancer cells and tissue look under a microscope and how quickly the tumor is likely to grow and spread.

Graft-versus-host disease (GVHD)

A condition that can occur after a bone marrow transplant, where the donated bone marrow attacks the recipient’s body.


A type of white blood cell that has small granules containing proteins.

Gray (Gy)

The unit of measurement for a dose of radiation.

Grief Support

Services and support provided to individuals who are experiencing grief due to death or other loss.

HDR Brachytherapy

High-dose-rate brachytherapy, a type of brachytherapy where the radiation source is left in place for a short period of time.


The proportion of the blood that consists of red blood cells, expressed as a percentage.


A doctor who specializes in treating blood disorders.


The study of blood, blood-forming organs, and blood diseases.


The process of creating new blood cells in the body.


The presence of blood in the urine.


A protein in red blood cells that carries oxygen from the lungs to the rest of the body.


The breakdown of red blood cells.


An in inherited disorder in which blood doesn’t clot normally.


Excessive or uncontrolled bleeding.


The process that prevents and stops bleeding, or hemorrhage.

Home Health Care

Health care services provided in a patient’s home to promote, maintain, or restore health or lessen the effects of illness and disability.

Hormone Therapy

Treatment that adds, blocks, or removes hormones to slow or stop the growth of cancer cells that need hormones to grow.

Hospice Care

Specialized care designed to provide support to people in the final phase of a terminal illness.

Hospice Team

A group of professionals and volunteers that provide hospice services, including doctors, nurses, social workers, spiritual advisors, and more.

Image-Guided Radiation Therapy (IGRT)

The use of imaging during radiation therapy to improve the precision and accuracy of treatment delivery.


A type of cancer treatment that helps your immune system fight cancer.

In situ

Cancer that has not spread beyond the layer of cells where it began.

Inpatient Hospice

Hospice care that is provided in a hospital or other facility for patients who need more intensive care.

Intensity-Modulated Radiation Therapy (IMRT)

An advanced form of EBRT that modulates the radiation intensity to more precisely target the tumor while minimizing damage to surrounding tissues.

Intraoperative Radiation Therapy (IORT)

Radiation therapy delivered during surgery.

Invasive Cancer

Cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding, healthy tissues.

Iron-Deficiency Anemia

Anemia caused by a lack of iron in the body.

Isodose Lines

Lines on a radiation therapy plan that show areas receiving the same dose of radiation.


A surgical procedure to look at the organs inside the abdomen to check for signs of disease.

LDR Brachytherapy

Low-dose-rate brachytherapy, a type of brachytherapy where the radiation source is left in place for an extended period of time.


Cancer of the body’s blood-forming tissues, including the bone marrow and the lymphatic system.


An increased number of white blood cells in the blood.

Life-Sustaining Treatment

Any medical treatment, procedure, or medication that can potentially extend a person’s life.

Linear Accelerator

A machine that creates high-energy radiation to treat cancer.

Living Will

A legal document that outlines what medical treatments an individual would or would not like to receive if they can’t communicate their wishes.

Local Recurrence

The return of cancer to its original location.


Surgery to remove a tumor (lump) and a small amount of normal tissue around it.


Enlargement of lymph nodes.


Swelling (usually in the arms or legs) due to a build-up of lymph fluid.


A type of white blood cell that is part of the immune system.


A type of cancer that begins in cells of the lymph system (part of the immune system).


Cancerous; a tumor with cells that can invade and destroy nearby tissue and spread to other parts of the body.

Malignant Tumor

A tumor that is cancerous and capable of spreading.


Surgery to remove all or part of the breast.


The spread of cancer from the primary site (place where it started) to other places in the body.


A type of white blood cell that becomes a macrophage when it enters tissues.


A change in a gene’s DNA sequence.

Myelodysplastic Syndromes

Conditions caused by poorly formed or dysfunctional blood cells.


Cancer that occurs in plasma cells, a type of white blood cell, it can affect the bone marrow, kidneys and bones.

Neoadjuvant Therapy

Treatment given before the main treatment to shrink a tumor.


An abnormal mass of tissue that results when cells divide more than they should or do not die when they should.


A condition in which there is a low number of neutrophils (a type of white blood cell) in the blood.


A doctor who specializes in treating cancer.

Outpatient Hospice

Hospice care that is provided to patients in their own homes.

Pain Assessment

The process of identifying and evaluating pain, its location, intensity, and duration.

Pain Management

The process of providing medical care that alleviates or reduces pain.

Palliative Care

Care given to improve the quality of life of patients who have a serious or life-threatening disease, such as cancer.

Palliative Chemotherapy

Chemotherapy used to relieve symptoms, improve quality of life, or extend life for patients with incurable cancer.

Palliative Performance Scale (PPS)

A tool used to assess and score a patient’s functional status and determine their level of palliative care needs.

Palliative Sedation

The use of sedative medications to relieve extreme suffering by making the patient unaware and unconscious while dying.


A decrease in the number of red and white blood cells, as well as platelets.

Pap Test

A test where cells are scraped from the cervix and looked at under a microscope to see if there are any abnormal (or precancerous) cells.

Partial Response

A decrease in the size of a tumor, or in the extent of cancer in the body, in response to treatment.

Partial Thromboplastin Time (PTT)

A blood test that looks at how long it takes for blood to clot.


A doctor who identifies diseases by studying cells and tissues under a microscope.

Patient-Centered Care

A type of care that recognizes the patient’s preferences, values, and needs, and respects the patient and their family’s values and choices.


The liquid part of blood, in which blood cells are suspended.


Small blood cells that help form blood clots to stop bleeding.

Polycythemia Vera

A type of blood cancer that causes the bone marrow to make too many red blood cells.

Prothrombin Time (PT)

A test that measures how long it takes blood to clot.

Proton Therapy

A type of radiation therapy that uses positively charged particles called protons rather than x-rays to treat cancer.

Quality of Life

An individual’s overall appreciation of life, which can be negatively affected by illness, disability, or treatment.

Radiation Dermatitis

Skin irritation caused by radiation therapy. This commonly looks like a sunburn.

Radiation Dose

The amount of radiation administered during treatment.

Radiation Field

The area exposed to radiation during treatment.

Radiation Oncologist

Radiation oncologists treat cancer using radiation therapy.

Radiation Oncology

A medical specialty that uses high-energy rays, charged particles, or radioactive elements to treat cancer.

Radiation Physicist

A specialized physicist who helps plan radiation treatments, ensures the radiation machines deliver the correct dose, and makes sure patients are treated safely.

Radiation Therapist

A medical professional who administers radiation treatment.

Radiation Therapy

The use of high-energy rays (such as X-rays) or particles to kill or shrink cancer cells.

Red Blood Cells (Erythrocytes)

Cells that carry oxygen from the lungs to the rest of the body.


A decrease in or disappearance of signs and symptoms of cancer.

Respite Care

Short-term relief for primary caregivers. It can be arranged for just an afternoon or for several days or weeks.

Reticulocyte Count

A test that measures how fast red blood cells are being made by the bone marrow and released into the blood.


A type of cancer that begins in the bones and in the soft tissues of the body.

Sickle Cell Disease

A genetic disorder that causes abnormal hemoglobin, resulting in some red blood cells assuming an abnormal sickle shape.


A planning session before radiation therapy to determine the exact area to be treated.

Spiritual Support

Assistance provided by chaplains, pastoral counselors, or other spiritual guides in addressing the spiritual or religious needs of patients and their families.


The extent of a cancer in the body, including whether the disease has spread from the original site to other parts of the body.

Stem Cells

Cells in the bone marrow that have the ability to develop into different types of blood cells.

Stereotactic Radiosurgery (SRS)

A type of radiation therapy that delivers a high dose of radiation directly to the tumor in a single session.

Symptom Assessment

The evaluation of a patient’s symptoms to determine their cause and severity.

Symptom Burden

The cumulative impact of symptoms on a patient’s overall wellbeing.

Symptom Control

Management of the symptoms of a disease or condition.

Symptom Management

The practice of preventing or treating as early as possible the symptoms of a disease, side effects caused by treatment of a disease, and psychological, social, and spiritual problems related to a disease or its treatment.

Targeted Therapy

A type of cancer treatment that targets the changes in cancer cells that help them grow, divide, and spread.

Terminal Illness

A disease or condition that is likely to result in death.


A blood disorder involving less than normal amounts of an oxygen-carrying protein.


A condition in which there is an abnormally low number of platelets in the blood.


The formation or presence of a blood clot in a blood vessel.

TNM Staging System

A system used to describe the extent and spread of cancer, using three parameters: T (size of the primary tumor), N (number of nearby lymph nodes that have cancer), and M (whether the cancer has metastasized).

Total Body Irradiation (TBI)

Radiation therapy delivered to the entire body, often as preparation for a stem cell transplant.

Transition of Care

The coordination and continuity of healthcare during a movement from one healthcare setting to another (e.g. from home to a nursing facility), or from one mode of care to another (e.g. from active cancer treatment to hospice care).

Treatment Plan

The detailed plan for a patient’s radiation therapy, including the dose and schedule.

Tumor Bed

The area surrounding the tumor that may also be at risk for cancer cells.

Volunteer Services

Services provided by volunteers to support patients and families in hospice and palliative care settings, often consisting of household chores and therapeutic companionship.

White Blood Cells (Leukocytes)

Cells that help fight infection and disease.


A type of radiation used for imaging and treatment.