Glossary of Terms

This glossary defines some of the medical and scientific terms commonly used by oncology physicians, nurses, researchers, therapists and technicians.

Adjuvant Treatment: Treatment that is added to increase the effectiveness of a primary therapy. In cancer, adjuvant treatment usually refers to chemotherapy or radiation therapy administered before or after surgery to increase the likelihood of cure.

Benign Tumor: A tumor that is not cancerous. It is the opposite of a malignant or cancerous tumor.

Biopsy: The surgical removal of a small piece of tissue for microscopic examination to determine if cancer cells are present. Biopsy is a very important procedure used to determine the type of cells of which the tumor is made. Different cancer treatments are prescribed depending on the tumor cell type.

Bone Marrow Transplant (BMT): A treatment of cancer that involves receiving high doses of chemotherapy and radiation (to kill all cancer cells in the body) and an infusion of healthy bone marrow (to help healthy new cells to grow). BMTs can be autologous, which is the infusion of the patient’s own bone marrow or allogenic, which is the infusion of someone else’s bone marrow that is genetically similar.

Brachytherapy: Treatment with radioactive sources placed into or very near the tumor or affected area. It includes surface application, body cavity application (intracavitary), and placement into the tissue (interstitial). Sometimes this term is used interchangeably with “internal radiation therapy” or “radiation implant”.

Bronchoscopy: A procedure that involves placing a flexible tube with a camera at the end (called a fibroscope) down the nose or throat to visualize, and often take tissue specimens, of the larynx, trachea, bronchus, and lungs.

CBC (Complete Blood Count): A test to measure blood cells including WBC (white blood cells) – cells that fight infection; RBC (red blood cells) – measured by the hemoglobin and hematocrit; these cells carry oxygen to the body’s tissues; and platelets – cells that help form clots and prevent bleeding.

CT Scan (Computer Tomography): A type of x-ray that yields a three-dimensional picture of the body that is about 100 times more sensitive than a standard x-ray. It can be given with or without contrast (medication given by drink or injection to enhance x-ray pictures).

Cancer: A general term for more than 100 diseases characterized by abnormal and uncontrolled growth of cells. The resulting mass, or tumor, can invade and destroy surrounding normal tissues. Cancer cells from the tumor can spread through the bloodstream or lymph system to start new cancers in other parts of the body.

Carcinoma: A form of cancer that develops in tissues covering or lining organs of the body, such as the skin, the uterus, the lung, or the breast.

Chemotherapy: The use of drugs or hormones to kill or arrest the growth of cancer cells. Chemotherapy drugs can be given orally (by pills), by intravenous injections (into the vein), by subcutaneous injection (under the skin), by intramuscular injection (into the muscle), by intra-arterial injection (into the arteries), or topically (with creams and/or gels).

Clinical Trials: In cancer research, a clinical trial is a study conducted with cancer patients, usually to evaluate a new drug or treatment. Studies are designed to find new and better ways to help patients. Generally, cancer clinical research evaluates surgery, chemotherapy, and/or radiation therapy techniques. Methods of prevention, detection or diagnosis also may be the subject of clinical trials. Patients are never placed in a clinical trial without their permission. (Please see Clinical Trials section.)

Colonoscopy: A procedure that allows inspection and tissue sampling of the rectum and large intestine by inserting a flexible tube with an attached camera through the rectum.

Combination Chemotherapy: Treatments using two or more chemotherapy drugs to achieve the most effective results.

Complementary: In the context of cancer treatment, it is a service used in addition to traditional care to add to the well being of the person being treated.

Cyst: A sac-like structure that contains liquid or semisolid material. A cyst may be benign (not harmful) or malignant (harmful).

Dosimetrist: Performs manual calculations and creates computer treatment plans for the accurate delivery of the radiation oncologist’s prescribed dose.

Gene: A hereditary unit that contains DNA and is found in every cell. DNA provides instructions that control biological development and function.

Grade: A scale of one to three indicating how much the tumor cells resemble normal cells (also referred to as differentiation). The lower the grade, the more the tumor cells resemble normal cells, which may mean a more favorable prognosis.

Hereditary Cancer: A mutation carried in the reproductive cells that can be passed on from one generation to another. Only five to ten percent of cancers are inherited.

Hormone Therapy: Hormones are secreted naturally by various organs of the body to help regulate growth, metabolism, and reproduction. Drugs which alter the function or secretion of hormones may be used alone to treat cancers or in combination with other chemotherapy drugs.

Hospice: A concept of psychosocial and support care to meet the special needs of patients and their families during the terminal stages of illness. Care is provided both in outpatient, inpatient and comfort home settings.

Immunology: Study of the body’s mechanisms for resisting disease and the invasion of foreign substances.

Immunotherapy: A treatment that stimulates the body’s own defense mechanisms to combat disease, such as cancer.

In Situ: In place, localized and confined to one area; a very early stage of cancer.

Invasive: Cancer that has spread from its place of origin to surrounding tissue.

Investigational: Treatments done under specific standards set up by the scientific community. These treatments typically have some basis for being tested in humans; for example, they work against some animal cancers.

Laryngectomy: The surgical removal of the larynx or voice box, resulting in the loss of normal speech.

Leukemia: Cancer of the blood-forming tissues such as bone marrow, lymph nodes, and spleen. Leukemia is characterized by the overproduction of abnormal, immature white blood cells.

Linear Accelerator: A machine that uses electrical energy to create a high-energy beam of x-rays or sub-atomic particles used to treat cancer.

Localized Cancer: A cancer still confined to its site of origin.

Lymph: A clear fluid that contains white blood cells and antibodies, and is circulated throughout the body by the lymphatic system.

Lymphedema: The swelling of an extremity or area of the body caused by the disruption or blockage of lymphatic channels by surgery and/or radiation.

Lymph Node: One of many round, oval, or bean-shaped bodies located along the course of lymphatic vessels; its function is to supply some white blood cells to the bloodstream and to remove bacteria and foreign particles from the lymph.

Lymphoma: Cancer that develops in the lymphatic system.

Magnetic Resonance Imaging (MRI): A type of diagnostic ray that uses magnets to obtain clear, detailed pictures of specific body sections. MRIs can create a greater contrast between some soft tissues (such as in the brain), which usually makes it a better tool than a CAT scan in such cases.

Malignant Tumor: A tumor that has been determined to be cancerous. It is the opposite of a benign/non-cancerous tumor.

Mammogram: The image produced by a low-dose x-ray of the breast.

Mammography: A screening and diagnostic technique that uses low-dose x-rays to find tumors in the breast. Mammography can reveal a tumor too small to be felt.

Margins: An area of tissue surrounding a tumor, which has been surgically removed. Clear margins, those without evidence of cancer, indicate that the surgeon has removed all of the microscopically visible cancer.

Medical Physicist: A person who makes sure that the radiation machine delivers the right amount of radiation to the correct site in the body. The physicist works with the radiation oncologist to choose the treatment schedule and dose that has the best chance of killing the most cancer cells.

Melanoma: A very aggressive type of skin cancer that can spread to other areas of the body if not detected and treated early.

Metastasis: The spread of cancer cells to other areas of the body. The term metastases refers to these new cancer sites, sometimes called mets.

Nadir: The period of time following chemotherapy, usually seven to ten days after chemotherapy, when blood counts drop, thereby increasing susceptibility to infection or bleeding.

Neoplasm: Any new abnormal growth. Neoplasms may be benign or malignant, but the term is generally used to describe a cancer.

Oncogenes: Certain stretches of cellular DNA that, when activated, contribute to the malignant transformation of cells.

Oncologist: A physician who specializes in cancer treatment. A medical oncologist specializes in delivering chemotherapy; a radiation oncologist specializes in delivering radiation for the treatment of neoplasms.

Oncology: The science dealing with the physical, chemical and biological properties and features of cancer, including the causes and progression of the disease.

Oncology Clinical Nurse Specialist: A nurse with advanced skills and knowledge about cancer care who assists patients and their families with treatment.

Oncology Nurse Practitioner: A registered nurse with advanced education in cancer care who provides nursing and medical services to cancer patients and their families.

Oncology Social Worker: A patient advocate who evaluates and helps to manage patients and their families with psychosocial issues throughout the course of cancer treatment. These issues include coping with illness, financial assistance, employment difficulties, and language and cultural barriers. The oncology social worker provides referrals to national and community resources for patients and families and facilitates support groups.

Palliative Treatment: Therapy that relieves symptoms, such as pain, but does not alter the course of the disease. Its primary purpose is to improve the quality of life.

Pathology: The study of disease through examination of body tissues and organs. This always includes a microscopic examination. Any tumor suspected of being cancerous must be diagnosed by pathologic examination.

Peripheral Blood Stem Cell Transplant (PBSC): A newer type of transplant similar to bone marrow transplant (BMT) that uses a patient’s own circulating peripheral cells as opposed to cells inside the bone marrow.

Physician’s Assistant: A specially trained individual certified to provide certain medical services under the supervision of a licensed physician.

Placebo: An inert substance, such as a sugar pill. A placebo may be used in clinical trials to compare the effects of a given treatment against no treatment.

Radioactive Implant: A source of radiation that is placed directly into and around a cancer to kill the cancer cells.

Radiation Therapist: A member of the cancer treatment team responsible for accurately recording, interpreting and administering the treatment prescribed by radiation oncologists.

Radiotherapy: Treatment of cancer with high-energy radiation. Radiation therapy may be the only treatment used, or it may be given before surgery to reduce the size of a cancer, after surgery to destroy any remaining cancer cells, in conjunction with chemotherapy, or to alleviate pain.

Recurrence: Reappearance of cancer at its original site after a period of remission is called a local recurrence. A distant recurrence occurs at a site away from the original and is also referred to as metastatic.

Remission: Complete or partial disappearance of the signs and symptoms of disease in response to treatment; the period during which a disease is under control.

Sarcoma: A cancer of muscle, connective tissue, bone or cartilage.

Side Effects: After-effects, or secondary effects, of treatment. For example, hair loss may be a side effect of chemotherapy; nausea may be a side effect of radiation therapy or chemotherapy. Most treatment-related side effects can be managed.

Simulation: A process involving special x-ray pictures that are used to plan radiation treatment so that the area to be treated is precisely located and marked for treatment.

Staging: An evaluation of the extent of disease, such as cancer. A classification based on stage at diagnosis helps determine appropriate treatment and prognosis.

Stereotactic Biopsy: A pinpoint biopsy, usually of the breast or brain, using specific equipment to determine the coordinates of the tumor to be biopsied.

Stereotactic Radiosurgery: A type of treatment that allows high doses of radiation to be given to small areas of the brain. This treatment uses a special frame to keep the patient’s head very still, and may require an overnight hospital stay for monitoring.

Surgery: The removal of a malignant tumor in an operation. Surgery is the oldest and most frequently used cancer treatment.

Tumor: An abnormal tissue swelling or mass; may be either benign or malignant.

Ultrasound Examination: The use of high frequency sound waves to locate a tumor inside the body. Also called ultrasonography.

Unproven: In cancer treatment, this term is meant to describe cancer treatment in which either the substance or the treatment method has not been shown scientifically to be effective in the treatment of the cancer disease process