32 NCCN Guidelines for Patients ® : Melanoma, 2018 3 Melanoma staging Stages of melanoma • M1b means the cancer has spread to the lungs with or without M1a areas of disease. • M1b(0) LDH not elevated • M1b(1) LDH elevated • M1c means the cancer has spread to internal organs with or without M1a or M1b areas of disease. • M1c(0) LDH not elevated • M1c(1) LDH elevated • M1d means the cancer has spread to the CNS ( c entral n ervous s ystem) with or without M1a, M1b, or M1c areas of disease. • M1d(0) LDH normal • M1d(1) LDH elevated Stages of melanoma The TNM scores are combined to assign the cancer a stage. Guide 1 shows the melanoma stage groupings. The stages are labeled by Roman numerals 0 to IV. The stage groupings are defined by the TNM scores according to the AJCC staging system. In general, melanomas of the same stage will have a similar outcome (prognosis) and thus are treated in a similar way. Most melanomas are found early, before they have spread beyond the primary tumor. Melanomas that are found and removed early may have a good prognosis and a low chance that they will come back (recur) after treatment. But, for melanomas that are thicker, are ulcerated, and/or have lymph node spread, the risk of recurrence after surgery goes up. The 5 stages of melanoma Stage 0 The melanoma is in situ—in its original place. The melanoma cells are only in the epidermis (the outer layer of skin) and have not invaded the dermis (the second layer of skin, under the epidermis). Stage I In stage IA, the tumor is thinner than 1.0 mm, the cells are dividing slowly, and there is no ulceration viewed under the microscope. Stage IB tumors are thinner than 1.0 mm and have ulceration, or 0.8 to 1.0 mm with or without ulceration, or they are a bit thicker (>1.0–2.0 mm) with no ulceration. In stage I, there is no cancer in the lymph vessels, lymph nodes, or distant organs. Stage II This stage is divided into 3 groups—A, B, and C— based on tumor thickness and ulceration status. In stage II, there is no cancer in the lymph vessels, lymph nodes, or distant organs. Stage III In stage III, melanoma has spread to nearby lymph vessels, lymph nodes, and/or nearby skin (satellites). The clinical stage includes tumors of any depth with metastases in lymph nodes and/or lymph vessels. Pathologic staging divides tumors of any size into 4 groups based on ulceration of the primary tumor and the extent of growth into the lymph vessels, lymph nodes, and nearby skin. Stage IV The melanoma has spread to one or more distant sites. The tumor may be of any thickness and with any range of spread in lymph vessels and lymph nodes.