How to Decode Cancer Terminology • Jasper Health
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How to Decode Cancer Terminology

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Ablation, in situ, metastasis—when it comes to conversations about cancer, it can sometimes feel like speaking a whole different language. For most of us, medical terminology isn’t in our daily vocabulary, so encountering certain words during doctor’s appointments or when reading test results can feel confusing and even overwhelming. This guide breaks down some of the most common terminology used in cancer care.


Abnormal: A state or condition that is unusual, such as changes to the skin or a lump.

Benign: Non-cancerous.

Biopsy: A method for diagnosing cancer by using a needle, scalpel, or other tool to remove a small piece of tissue from the body for testing.

Chronic: A condition that lasts a long time and/or will require ongoing medical attention.

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

  • Grade 1: Tumor cells and the organization of the tumor tissue appear close to normal, indicating slow growth.
  • Grade 2: Cells are somewhat abnormal and will grow faster than normal cells.
  • Grade 3: Cells and tissue look abnormal and are disorganized, indicating they will grow rapidly.
  • Grade 4: The most abnormal-looking cells with a high level of disorganization, indicating they will grow and spread aggressively.

In situ: A cancer that is confined to its site of origin.

Malignant: The presence of cancer cells.

MetastasisA cancer that has spread from the place where it started.

Primary cancerThe original cancer in your body.

Prognosis: Your doctor’s prediction for the likely or expected development of the disease, including the chances of recovery.

Recurrence: The return of disease after treatment.

Remission: A decrease in or disappearance of the signs and symptoms of cancer, signaling the disease has been controlled. In a partial remission, some symptoms of cancer have disappeared; if there are no more signs or symptoms at all, it is described as a complete remission.

Stage: A classification system to describe how far along a cancer is. Staging describes not only where a cancer is located, but whether it is affecting other parts of the body. 

  • Stage 0: Cancer in situ (“in place”). Stage 0 cancers are still located in the place they started and have not spread to nearby tissues. Stage 0 may also indicate the presence of suspicious-looking cells that are not yet characterized as cancer.
  • Stage I: A small cancer or tumor that has not grown deeply into nearby tissues, spread to the lymph nodes, or metastasized to other parts of the body.
  • Stage II: The cancer or tumor is larger, but has not spread to the lymph nodes and/or surrounding tissues.
  • Stage III: The cancer or tumor is larger and may have spread to the lymph nodes and/or surrounding tissues.
  • Stage IV: The cancer has spread from where it started to at least one other body organ; this is also known as “secondary” or “metastatic” cancer. When a cancer metastasizes to a different part of the body, it is still defined by its original location. For example, if colon cancer metastasizes to the lungs, it is still referred to as colon cancer, not lung cancer.

Testing & Procedures

Ablation: The removal of a body part or tissue, usually through surgery. The removed material is often screened for abnormal cells.

ANC: Absolute neutrophil count. A measure of a certain type of white blood cells known as neutrophils, which can provide insight on a person’s risk for infection, inflammation, leukemia, and other conditions. The lower a person’s ANC, the higher the risk for infection.

Bence Jones protein: A small protein made by plasma cells. The presence of Bence-Jones proteins in urine can be a sign of multiple myeloma.

CBC: Complete blood count. A measure of the number of red blood cells, white blood cells, and platelets in the blood. A CBC is used to help diagnose and monitor many conditions and may be used to determine whether your body has the reserves to withstand a chemotherapy treatment. A CBC with differential also measures the number of each type of these white blood cells, which can help diagnose and monitor conditions like anemia and infection.

CT scan: Computerized Tomography scan. A CT scan allows doctors to see inside your body through a compilation of X-rays, which creates pictures of your organs, bones, and other tissues.

CytogeneticsA diagnostic test or tests that look for changes in chromosomes, including broken, missing, rearranged, or extra chromosomes, which can be a sign of a genetic disease or certain types of cancer.

DebulkingA type of surgery with the goal of removing as much cancerous tissue in a patient as possible.

FISH test: Fluorescence in situ hybridization test. A test that maps the genetic material in a person’s cells to visualize specific genes or portions of genes.

Flow CytometryAn evaluation of cells from blood, bone marrow, bodily fluids, or tumors to detect, identify, and count specific cells to study the development and progression of a person’s cancer.

Ki-67: A test performed on a sample of tissue taken from a tumor to help predict the tumor’s aggressiveness. This test is used as a way to measure how quickly a cancer’s cells are dividing and forming new cells.

Lymphocyte countA measurement of a type of white blood cells called lymphocytes, which can help your doctor diagnose an infection or possible lymphoma.

M SpikeMonoclonal spike. A blood or urine test that looks for the presence of M proteins of plasma cells, which are made in response to antibodies generated by the possible presence of myeloma.

MRI: Magnetic resonance imaging. A scan that uses radio waves and magnets to generate detailed images of your body. These scans can help doctors determine a tumor’s location, size, and whether it is cancerous or non-cancerous.

Next Generation SequencingA type of technology that allows for capturing and analyzing a large amount of genetic information. This allows doctors to see an individualized “picture” of a person’s cancer, which can guide treatment decisions.

PET: Positron Emission Tomography. PET scans use a mildly radioactive drug to light up areas of the body where cells are more active than normal, which can indicate the presence of cancer as well as whether it has spread to other areas of the body.

Platelet count: A blood test used to determine how many platelets are in the blood. It can help determine whether the body is making enough platelets, losing platelets, or seeing platelets destroyed. Certain cancers and cancer treatments can lower a person’s platelet counts, putting them at risk for uncontrolled bleeding.

RBC: Red blood count. A blood test used to evaluate the number of red blood cells in the blood, which may be used to look for conditions such as anemia, dehydration, malnutrition, and leukemia.

UltrasoundAn imaging technique that uses high-frequency sound pulses to create an image of internal body structures. Sometimes, a guided ultrasound is used to create an image of a tumor or guide a needle to the location for a biopsy.

WBC: White blood count. A blood test used to evaluate the number of white blood cells in the body. A higher number of white blood cells can indicate the presence of bacteria, viruses, cancer, or other foreign substances in the body.


Active Surveillance: Closely monitoring a low-grade, slow-growing cancer in its localized stage until a doctor feels that further treatment is needed to halt the disease at a curable stage. This term also may be used after you have received and finished treatment and are being closely monitored for a possible recurrence.

Ablation: The removal or destruction of body tissues through surgery, drugs, heat, cold, hormones, or high-energy radio waves. This can be both a testing and a treatment option.

Chemotherapy: Powerful drugs used to kill cancer cells or to stop them from growing. 

Immunosuppressive: Treatments that lower the body’s immune system. Immunosuppressive therapy may be used to keep a person from rejecting a bone marrow or organ transplant.

Immunotherapy: A form of cancer treatment using the body’s own immune system to fight cancer by boosting the action of the immune system to attack cancer cells. 

Radiotherapy: Also known as “radiation therapy,” a treatment that uses radiation (high energy electromagnetic waves) to kill cancer cells and shrink tumors.

Targeted therapy: Treatment that uses drugs or other substances to precisely identify and attack specific proteins on or signals from cancer cells in the body.

Looking for a term not on this list? The National Cancer Institute provides an extremely helpful searchable Dictionary of Cancer Terms. Your cancer care team is also a resource—if a doctor, nurse, or technician uses a word you don’t understand, don’t be afraid to speak up and ask for an explanation.

The content on this website is intended to provide the best possible information for you, but should not be considered—or used as a substitute for—medical advice. If you have questions about your diagnosis or treatment, please contact your health care provider(s). For questions or comments about this content, please email us at [email protected].