Which factors can determine the prognosis in melanoma?

This study evaluated which factors can help determine the prognosis of melanoma patients with skin metastases.

Melanoma is a type of skin cancer that originates in the pigmented cells of the skin called melanocytes. The 5-year survival rates of patients with melanoma can vary widely, and the prognosis of the disease depends on factors such as whether the cancer is localized to a single region of the skin, with or without a breakdown of the skin over the melanoma (ulceration), or has spread to the nearby lymph nodes or other parts of the body (metastasized). While it is known that lymph node involvement and ulceration are associated with a poorer prognosis in melanoma patients, there is not sufficient data regarding patients with melanoma that has spread to the nearby skin (loco-regional skin metastases). This study aimed to evaluate the outcomes of these patients and which factors predict their prognosis.

This study included 380 patients with melanoma and loco-regional skin metastases. 50.5% of the participants developed loco-regional skin metastases after the surgical removal of the initial melanoma, while 34.5% of patients had skin metastases at the time of the diagnosis and in 15% of patients the place of the initial melanoma could not be determined. Factors such as age, tumor size, tumor location, ulceration and the number of lymph nodes involved were measured to determine their effects on 5-year survival rates (the percentage of patients surviving melanoma 5 years after the diagnosis).

Overall, the 5-year survival rates were 60.1% for patients with skin metastases only (no lymph nodes invaded) and 36.3% for patients with skin and lymph node metastases. The most important prognostic factors were tumor size and thickness and the number of lymph nodes involved. As the number of involved lymph nodes increased, the negative impact on survival also increased. Also, tumors larger than 3 mm were associated with a more negative prognosis. No association was found between the time skin metastases were diagnosed durin the disease and survival. 

This study showed that not only lymph node involvement counts as a prognostic factor in melanoma patients. The number of lymph nodes involved and the size and thickness of the tumor are the most important factors which can determine the prognosis of patients with melanoma and loco-regional skin metastases.