Common cancer terms defined

Much of the terminology associated with cancer is unfamiliar to you when you are diagnosed with a cancer. And when you’re new to a diagnosis and sitting in the doctor’s office, you might feel like you’re back in school trying to learn a foreign language. If you hear “oncology” and wonder what the definition is, know that it refers to the prevention, diagnosis and treatment of cancer.

Learning basic cancer medical terminology can help ease some of that anxiety and empower you to ask questions when you don’t understand something. We’ve broken down various cancer terms into easy categories for quick reference.

The basics of oncology

Let’s start with the foundational terms you’ll hear in any cancer clinic.

• Atypical: The cells don’t look quite normal under a microscope. An atypical description doesn’t automatically mean cancer, but it’s a sign that your doctor should take a closer look.
• Benign: This means a tumor isn’t cancerous. While it may still need to be removed or monitored, it hasn’t spread to other parts of your body.
• Biopsy: A doctor removes a tissue sample for examination under a microscope to determine whether cancer is present.
• Carcinoma: This cancer starts in the skin or tissue
• Malignant: This term refers to cancerous cells that have the potential to grow and spread if left untreated.
• Sarcoma: This rare cancer begins in connective tissues, like bones, muscles, cartilage, fat or blood vessels.

Understanding your diagnosis

Once your doctor reaches a diagnosis, your care team uses specific terminology to describe the cancer’s behavior. These universal terms help oncology specialists coordinate the appropriate plan for you.

• Grade: This describes how the cells look. Low-grade cells look fairly normal and grow slowly; high-grade cells look very different from normal cells and tend to grow faster.
• In situ: This Latin phrase, for in the original place, means the cancer hasn’t spread from where it started and moved into the surrounding tissue.
• Local: The cancer hasn’t spread to other organs and remains in the same spot where it started.
• Margin: When a surgeon removes a tumor, they also remove a tiny bit of healthy tissue around it. If your team tells you the margins are clear, it means they didn’t find any cancer cells at the edge of what they removed.
• Metastasis/metastisized: Cancer that has traveled from its origin to another part of the body has metastasized or spread.
• Prognosis: Your doctor’s best estimate of how the cancer will behave and how you’ll respond to treatment.
• Stage: A numbering system, usually 0–4, that describes the tumor’s size and whether it has spread to lymph nodes and/or other organs.
• Tumor: A mass of tissue formed by a collection or build-up of abnormal cells. Tumors can be benign (not cancerous) or malignant (cancerous).

Treatment and recovery terms

Like other diseases, a one-size-fits-all treatment plan doesn’t exist for cancer patients. When your team discusses your options for surgery or other therapies, you may hear some of this terminology.

• Adjuvant therapy: This treatment, like chemo or radiation, is given after the main treatment — like surgery — to eliminate any remaining cancer cells.
• Biomarker testing: A way for doctors to look at the genes or proteins in your cancer cells. These markers can help predict which treatments — like immunotherapy — might work best.
• Chemotherapy: Often shortened to chemo, this treatment involves using strong medicines, either in pill or IV form, to kill cancer cells or stop them from growing.
• Combined modality therapy: This means they’re using more than one type of treatment — like surgery and then chemo — to fight the cancer from different angles.
• Hormone therapy: Some cancers use hormones to grow. This therapy blocks those hormones or lowers their levels to slow the cancer.
• Immunotherapy: This newer treatment type trains your own immune system to recognize and attack cancer cells more effectively.
• Neoadjuvant therapy: Treatment given before the main treatment (often surgery) to help shrink a tumor and make it easier to remove.
• Palliative care: A specialized type of medical care focused on relieving symptoms and stress at any stage of a serious illness, not just end-of-life.
• Port: A small device placed under your skin and connected to a vein where you’ll receive chemo or have blood drawn.
• Radiation therapy: This treatment uses high-energy beams, like X-rays, to kill cancer cells and shrink tumors in a very specific area.
• Remission: This word often means success! You’ve reached your goal — the signs and symptoms of your cancer have been reduced or disappeared entirely.
• Stem cells: The body’s self-renewing material that can turn into different types of cells. In some treatments, doctors use these cells to help your bone marrow recover after high-dose chemo.