29 NCCN Guidelines for Patients ® : Melanoma, 2018 3 Melanoma staging Staging | TNM scores Cancer staging is how your doctors rate and describe the extent of cancer in your body. The rating—called the cancer stage—is based on the results of certain tests. The cancer treatments that doctors recommend highly depend on cancer staging. Part 3 describes the staging system used for melanoma. It also explains the different stages of melanoma. Contact your treatment team if you don’t know your cancer stage. This information will help you use the Treatment guide in Part 5. Staging Cancer staging is a way that doctors rate and describe the extent of cancer in your body. Cancer stages are defined by the growth of the first (primary) tumor and its spread to other sites in the body. Cancer staging is used by doctors to plan which treatment is best for you. Often, melanoma is staged twice. The first staging is the clinical stage. It is based on the physical exam and skin biopsy of the primary melanoma tumor. A skin biopsy is the removal of a sample of tissue from the concerning spot on your skin to test for cancer cells. The second staging is the pathologic stage. It is based on the clinical staging as well as results from biopsies of lymph nodes and other tissue removed during surgical treatment. Most of the time, the pathologic stage is the most important stage. This is because your lymph nodes can only be completely examined for cancer cells by viewing the biopsy sample with a microscope. Imaging tests might be used once pathologic staging is complete. Imaging tests take pictures of the inside of your body to look for signs of cancer. TNM scores The AJCC ( A merican J oint C ommittee on C ancer) staging system is used to stage melanoma skin cancer. In this system, each of the letters—T, N, and M—describes a different area of cancer growth. Your doctor will assign a score to each letter. TNM scores are based on the tests described in Part 2. These scores are used to assign the cancer a stage.