The likelihood of recurrence and death from melanoma is directly correlated with tumor thickness. Superficial spreading on the skin is not as important as the depth of invasion of the tumor into the skin layers. Ulceration is also a powerful adverse prognostic feature. The presence of lymphatic and lymph node involvement is associated with an increased risk of recurrence and metastatic spread of disease. Stage-for-stage, advanced age, and male sex are associated with a worse prognosis in melanoma.
When a cutaneous lesion is suspected to be a melanoma an excisional biopsy or punch biopsy will provide the examining pathologist the most information. In particular the ability to assess the thickness and depth of invasion. Ablative procedures such as cryotherapy should be avoided as these specific tumor characteristics along with the mitotic index will be prohibitive to evaluate. Once the diagnosis of melanoma is established, a wide local excision with healthy skin margins of 2cm is the treatment of choice. The procedure of sentinel lymph node mapping and selective lymphadenectomy is highly sensitive for the detection of microscopic metastatic disease. Definitive surgical excision remains the mainstay therapeutic modality for early stage localized melanoma. Radiation therapy, chemotherapy or immunotherapy should not be used as the sole therapeutic modality for early stage melanoma.
When surgical excision reveals the presence of lymph node metastasis treatment with high-dose interferon alfa-2b should be considered. Treatment with high-dose interferon in this setting has demonstrated a survival benefit by decreasing the risk of recurrence and the development of a distant metastatic disease. Isolated limb perfusion with melphalan and moderate hyperthermia are an effective treatment for recurrent or unresectable in-transit metastasis of an extremity. High concentrations of chemotherapy to the limb can be achieved without excessive systemic exposure by isolation of the circulation.
The prognosis for patients with Metastatic Melanoma
The prognosis for patients with metastatic melanoma is poor. Melanoma, a type of skin cancer, can spread to the liver, lungs, bones, and brain. However, melanomas are notorious for being tumors that can metastasize to the most unusual surfaces like the heart, intestines, urogenital tract, than any other tumor. Lastly, melanomas have a predictably unpredictable behavior meaning that they can remain indolent and quiescent for many years and have the recurrent disease even decades after the primary tumor had been diagnosed.
Among medical oncology, there is no other single solid tumor that has benefited from the development of new discoveries in the biology and treatment modalities than melanomas. The understanding of these tumors at a molecular level has permitted the development of targeted treatments that exploit certain tumor pathways that allow cancer to grow, proliferate, and metastasize. These novel therapeutic modalities have allowed cancer specialists to treat the patient’s tumor while sparing the remainder of the healthy organs.
For over two decades we have recognized the importance that the immune system plays in combating melanoma. Treatment with high-dose interleukin-2, an immune-mediated cytokine, was the only treatment that had demonstrated long-term disease survival in patients with metastatic disease. The discovery of the activity of cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and a second immune checkpoint programmed death 1/programmed death one ligand (PD-1/PD-L1) has emerged as a target for monoclonal antibodies against these tumor pathways. These novel agents have changed the landscape in the management of melanoma and have offered a more promising outlook for a patient who is afflicted with metastatic melanoma.