Melanoma staging is a standardized way for doctors to describe the severity of the disease. The cancer stage influences treatment choices and prognosis. With stage 3 melanoma, the cancer that originated in the skin has spread to one or more nearby lymph nodes. Stage 3 melanoma is further divided into substage A, B or C, based on qualities of the original tumor and the pattern of spread to the lymph nodes. On average, 62.6 percent of people live 5 years or longer after a diagnosis of stage 3 melanoma, according to the National Cancer Institute. However, the prognosis differs by substage.
Stage 3A melanoma has the best prognosis among the stage 3 melanomas. According to a 2009 report from the American Joint Committee on Cancer, or AJCC, 78 percent of people with stage 3A melanoma live 5 years or longer after their diagnosis. In stage 3A melanoma, only a microscopic amount of cancer has spread into 1 to 3 nearby lymph nodes. In many cases, stage 3A melanoma can be cured by surgical removal of the tumor and the nearby lymph nodes.
According to the 2009 AJCC report, the 5-year survival rate with stage 3B melanoma is 59 percent. The factors associated with the poorer prognosis for people with stage 3B melanoma are ulceration of the skin at the original tumor site and visually detectable spread of the cancer to up to 3 nearby lymph nodes. Surgical removal of the tumor and the nearby lymph nodes is typically the treatment of choice. According to National Cancer Institute treatment recommendations, supplemental chemotherapy might help lower the risk of recurrence after surgery in some cases.
With a predicted 5-year survival rate of 40 percent, stage 3C melanoma has the worst prognosis among stage 3 melanomas. The tumor characteristics that are related to the poorer prognosis include skin ulceration and spread of the cancer to 4 or more nearby lymph nodes. The U.S. Food and Drug Administration approved 6 new treatments for advanced melanomas between 2011 and 2014. Some people with stage 3C melanoma or another stage 3 melanoma that cannot be surgically removed may be candidates for these recently approved therapies or for clinical trials involving new treatments that are under evaluation.
Generally, melanomas without associated skin ulceration and melanomas of the limbs -- versus those of the head, neck or trunk -- are associated with better outcomes. Overall, women with melanoma have a better prognosis than men do. It is too soon to know how the prognosis for stage 3 melanoma will be affected by recently approved treatments. However, progress on many fronts, including genetic research, immune therapy and even health information technology, is making it possible for doctors and patients to aim for the best possible outcomes via customized treatment plans tailored to each case.