Common Cancer Terms

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As a cancer patient, you may feel like you have to learn a new language. Medical terms can get confusing. But you need to understand what your cancer team says. Understanding some basic, common cancer terms can help.

This list doesn't cover everything. If you have further questions, visit the Learning Resource Center. There, you can talk to someone and find more answers. 

Common Cancer Terms About Tumors


A tumor forms when cells within your body start to grow out of control. Old cells don't die when they're supposed to. New cells form that your body doesn't need. These cells mass together. Tumors can be benign or malignant.


A tumor that doesn't spread is not cancer. We call this a benign tumor. People can have all kinds of benign tumors, lumps and fibroids. Many of these don't cause symptoms or problems.


We call a tumor that can spread to other parts of the body a malignant tumor. A malignant tumor is cancer. 


We use the term metastasis when cancer spreads from its original location to another part of the body. Cancer cells travel through the blood or lymphatic system to other organs and tissues. We call this stage IV cancer.

Stages of Cancer

Every cancer type gets a stage and a grade. For solid tumors, doctors figure out the stage of your cancer based on tumor size and if/where it has spread. The grade of a cancer reflects how fast and aggressive the tumor is behaving. Doctors use both grades and stages to determine the best treatment option. The criteria for blood cancers looks at other factors. 

See more info on solid tumor stages.

Treatment Terms


A prognosis describes your chance of recovery after treatment. Your doctor draws your prognosis from factors like your specific type of cancer and your overall health.

Adjuvant Therapy 

This type of therapy happens after your main cancer treatment. Adjuvant therapy aims to keep your cancer from coming back. In most cases, you'll have this kind of therapy after surgery. It can include chemotherapy, radiation therapy, immunotherapy, and hormone therapy.

Targeted Therapy 

This type of therapy focuses on certain genes, proteins, or other molecules inside cancer cells.

Learn more about cancer treatments.

Legal Terms

Healthcare Power of Attorney (POA) 

This legal document allows someone to make or communicate healthcare decisions for you if you can't.

Advance Directive

This form outlines what you want to happen to you in certain situations. It will empower the person you choose to make decisions about your healthcare.

Print and sign an advance directive.

Health Insurance Portability and Accountability Act (HIPAA) 

These federal rules protect your privacy as you undergo medical treatment. HIPAA laws govern the use and privacy of your personal information. They help you gain access to your medical records. HIPAA also lets people with specific medical conditions, like cancer, get health insurance for their family and themselves.

Read and sign a HIPAA form.

Family and Medical Leave Act (FMLA) 

This federal law provides specific protections for employees during their medical leave. This law also helps to protect employees when they take time off work to care for a sick loved one.