Cancer Terminology Glossary for Patients

• Abnormal Not normal; often refers to cells that look different from healthy cells. 
• Acute Symptoms or a condition that starts and progresses quickly.
• Benign A tumor that is not cancer (non-malignant). It may grow but does not spread to other parts of the body.
• Biomarker A biological molecule found in the blood, tissue, or other body fluids that is a sign of a normal or abnormal process, or a disease like cancer.
• Biopsy The removal of a small amount of tissue or cells for examination under a microscope. This is the only way to definitively diagnose cancer.
• Cancer A group of diseases characterized by the uncontrolled growth and spread of abnormal cells that can invade nearby tissues.
• Carcinogen Any substance or exposure that can cause cancer (e.g., tobacco smoke, radiation).
• Carcinoma The most common type of cancer, which starts in the epithelial cells (cells that line the internal organs and the outer surface of the body).
• Chronic Symptoms or a condition that persists for a long time.
• Diagnosis The process of identifying a disease (like cancer) based on symptoms, tests, and examination.
• Differentiation Describes how much the cancer cells look like normal cells. 
• Well-differentiated cells look similar to normal cells; poorly-differentiated or undifferentiated cells look very abnormal and tend to grow faster.
• Dysplasia An abnormal change in the size, shape, or organization of cells, which may or may not become cancerous.
• Grade A way to classify the cancer based on how abnormal the cancer cells look and how quickly they are likely to grow and spread. Usually graded 1 through 4.
• Non-invasive cancer Refers to cancer cells that are in their original location and have not spread into deeper tissue.
• Invasive Cancer Cancer that has spread beyond its original layer of tissue and is growing into surrounding tissues.
• Localized Cancer Cancer that is confined to the site where it started and has not spread to other parts of the body.
• Malignant A tumor that is cancer and has the ability to invade surrounding tissue and spread to distant organs.
• Metastasis The process by which cancer cells break away from the original (primary) tumor and spread to a different part of the body to form a new (secondary) tumor.
• Neoplasm An abnormal mass of tissue; another word for a tumor.
• Oncology The branch of medicine that specializes in the study and treatment of cancer.
• Pathologist A doctor who specializes in diagnosing disease by examining tissues, cells, and body fluids under a microscope.
• Polyp An abnormal growth of tissue that projects out from a mucous membrane, such as the lining of the colon. Can be benign or malignant.
• Prognosis The likely outcome or course of a disease; a prediction of the chance of recovery.
• Recurrence (or Relapse) The return of cancer after treatment, either in the original location or in a different part of the body.
• Refractory Cancer that is not responding to treatment.
• Remission A period when the signs and symptoms of cancer have disappeared or are significantly reduced. It can be partial or complete.
• Sarcoma A type of cancer that begins in bone or soft tissues like muscle, fat, or cartilage.
• Screening Testing for a disease, like cancer, in people who do not have any symptoms.
• Stage A way of describing the extent of the cancer, including the size of the tumor and whether it has spread. Often uses the TNM system (Tumor, Node, Metastasis).
• Tumor An abnormal mass of tissue formed by an accumulation of abnormal cells. It can be benign or malignant.
• Tumor Marker A substance in the blood or body tissue that may be a sign of cancer.
• Undifferentiated Cancer cells that are so abnormal that it's difficult to tell what kind of cell they originated from (often associated with more aggressive cancers).

⚕️ GENERAL CANCER TREATMENT TERMS

• Ablation A treatment that uses heat, cold, or chemicals to destroy abnormal tissue or tumors.
• Adjuvant Therapy Additional treatment (like chemotherapy or radiation) given after the primary treatment (usually surgery) to kill any remaining cancer cells and lower the risk of recurrence.
• Anastomosis The surgical procedure of connecting two organs or blood vessels after a section has been removed.
• Angiogenesis Inhibitor A drug that blocks the formation of new blood vessels that tumors need to grow.
• Antiemetic Medication given to prevent or reduce nausea and vomiting, often side effects of chemotherapy.
• Autologous Transplant A type of stem cell transplant using the patient's own healthy stem cells that were collected before treatment.
• Biological Therapy Treatment that uses the patient's own immune system to fight cancer; also called Immunotherapy.
• Brachytherapy A type of radiation therapy where a radioactive source (like seeds or wires) is placed directly into or near the tumor.
• Chemotherapy The use of powerful drugs to destroy cancer cells, often given in cycles to allow the body to recover.
• Clinical Trial A research study that involves volunteers to test new ways to prevent, detect, or treat diseases like cancer.
• Complementary Therapy Treatments used along with standard medical treatment to help manage symptoms and improve well-being (e.g., acupuncture, massage).
• CurativeTreatment aimed at curing the cancer (getting rid of it completely).
• Cytotoxic Anything that is toxic (poisonous) to cells; often used to describe chemotherapy drugs that kill cancer cells.
• External Beam Radiation The most common type of radiation therapy, where radiation is delivered from a machine outside the body.
• Fine Needle Aspiration (FNA) A procedure that uses a very thin needle to remove a small sample of fluid or cells from a tumor or mass.
• Hormone Therapy Treatment that uses drugs to block or add hormones to slow or stop the growth of cancers that are fueled by those hormones (e.g., breast or prostate cancer).
• Immunotherapy Treatment that uses your body’s own immune system to find and attack cancer cells; also called Biological Therapy.
• Intravenous (IV) Medication or fluid delivered directly into a vein.Local TherapyTreatment that only affects the tumor and the area around it (e.g., surgery and radiation).
• Mastectomy Surgery to remove the entire breast (or part of it, which is a partial mastectomy or lumpectomy).
• Medical Oncologist A doctor who specializes in treating cancer with medications, such as chemotherapy, hormone therapy, and targeted therapy.
• Neoadjuvant TherapyTreatment (like chemotherapy or radiation) given before the main treatment (usually surgery) to shrink the tumor.
• Palliative Care Specialized medical care that focuses on providing relief from the symptoms and stress of a serious illness, aiming to improve quality of life for both the patient and the family.
• Protocol A detailed plan for a course of medical treatment or a clinical trial.
• Radiation Oncologist  A doctor who specializes in treating cancer with radiation therapy.
• Radiation Therapy The use of high-energy radiation to kill cancer cells and shrink tumors.
• Resection The surgical removal of all or part of an organ or tissue (e.g., tumor resection).
• Systemic Therapy Treatment that uses drugs to travel through the bloodstream to reach cancer cells all over the body (e.g., chemotherapy, immunotherapy).
• Targeted Therapy Drugs designed to specifically target characteristics (like genes or proteins) that help cancer cells grow and survive, often sparing normal cells.

• Nausea and Vomiting A very common side effect, especially from chemotherapy and radiation to the abdomen. It can be immediate (acute) or delayed.
• Diarrhea Frequent, loose, or watery stools. It occurs when treatment damages the fast-dividing cells lining the 
• Gastrointestinal (GI) tract.Constipation Infrequent or difficult-to-pass stools. Often caused by certain chemotherapy drugs (like vinca alkaloids) or opioid pain medication.
• Mucositis Inflammation, soreness, or ulceration (sores) of the mucous membranes lining the mouth (called stomatitis), throat, and the rest of the GI tract. This makes eating and swallowing difficult.
• Dysgeusia / Taste Changes An alteration in the sense of taste, often described as a metallic, bitter, or chemical taste, even when eating familiar foods.
• Anorexia Loss of appetite or desire to eat, which can lead to weight loss and malnutrition.

•  Peripheral Neuropathy (PN) Nerve damage outside the brain and spinal cord, most commonly caused by certain chemotherapy drugs 
• (Chemotherapy-Induced Peripheral Neuropathy, or CIPN).Symptoms of PNTingling, numbness, burning, or sharp pain in the hands and feet (a "glove-and-sock" pattern), leading to difficulty with fine motor skills or balance.
• "Chemo Brain" (Cognitive Impairment) A common, non-medical term used to describe difficulty with memory, concentration, and focus that can occur during and long after treatment.
• Blood, Immune, & General Side Effects
• Term Description Fatigue (Cancer-Related Fatigue, or CRF) A persistent, debilitating sense of tiredness or exhaustion not relieved by rest. It is one of the most common and distressing side effects. 
• Neutropenia A lower-than-normal count of neutrophils (a type of white blood cell), which significantly increases the risk of serious infection. This is a potential medical emergency.
• Thrombocytopenia A lower-than-normal count of platelets (cells that help blood clot), leading to an increased risk of bruising and bleeding.Fever (Febrile Neutropenia)A high temperature (often defined as 100.4°F / 38°C or higher) that, when combined with neutropenia, is a critical sign of a severe infection.