Cancer Terms & Definitions

A cancer diagnosis for your pet can be scary and confusing. Knowing the facts about cancer, diagnosis, treatment, and common terminology gives you the understanding necessary to plan your pet's care in partnership with your veterinarian and oncologist.

The content in the fact sheets below is based on information provided by the National Cancer Institute.

Understanding cancer

Cancer begins in cells, the building blocks that form tissues. Tissues make up the organs of the body. Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place. Sometimes, this orderly process goes wrong.

View the Understanding cancer fact sheet.

Understanding cancer prognosis

A prognosis is an estimate of the likely course and outcome of a disease. Many factors affect the prognosis of an animal with cancer, including the type, location, and stage of the cancer.

View the Understanding cancer prognosis fact sheet.

Cancer staging

Staging describes the extent or severity of an animal's cancer. Knowing the stage of disease helps the doctor plan treatment and estimate the animal's prognosis.

View the Cancer staging fact sheet.

Tumor grade

Tumor grade is a system used to classify cancer cells in terms of how abnormal they look under a microscope and how quickly the tumor is likely to grow and spread.

View the Tumor grade fact sheet.

Metastatic cancer

Metastatic cancer is cancer that has spread from the place where it first started to another place in the body.

View the Metastatic cancer fact sheet.

Targeted cancer therapies

Targeted cancer therapies are drugs or other substances that block the growth and spread of cancer by interfering with specific molecules involved in tumor growth and progression.

View the Targeted cancer therapies fact sheet.

Interpreting laboratory test results

A laboratory test is a medical procedure in which a sample of blood, urine, or other tissues or substances in the body is checked for certain features. Such tests are often used as part of a routine checkup to identify possible changes in an animal's health before any symptoms appear and they also play an important role in diagnosis when an animal has symptoms.

View the Interpreting laboratory test results.