Targeted Agents for the Treatment of Melanoma: An Overview

Malignant melanoma is an important healthcare issue. The incidence of melanoma has in‐ creased dramatically during the last few decades and melanoma is now one of the most com‐ mon forms of cancer. This aggressive form of skin cancer is characterized by its high capacity for invasion and metastasis. Patients with advanced stages of the disease have universally poor prognoses with a median survival of 3–11 months, depending on various prognostic factors. Primary cutaneous melanomas are divided into four groups on the basis of histopathology: su‐ perficial spreading melanoma, nodular melanoma, lentigo maligna melanoma, and acral lenti‐ ginous melanoma. Superficial spreading melanoma is the most common form. In the early growth phase, tumor cells spread laterally into the epidermis, forming an irregular pattern with an uneven color on the skin. Nodular melanoma occurs most often on the chest or back where it has a tendency to grow vertically into the skin, penetrating deeply if not removed. Nodular melanoma lesions are often characterized by a darkly pigmented lump on the skin surface. Len‐ tigo maligna melanoma most commonly occurs on the facial areas of elderly people. It grows slowly and may take several years to develop. Acral lentiginous melanoma is usually found on the palms of the hands, the soles of the feet, or around the toenails. Melanoma is usually curable in its early stages; however, the disease may be fatal if it spreads to other parts of the body. Ma‐ lignant melanoma usually develops via the transformation and proliferation of melanocytes that reside in the basal cell layer of the epidermis. Melanoma can also develop when melano‐ cytes no longer respond to normal cellular growth control mechanisms, which allows the tumor cells to metastasize into nearby tissues or other organs, where they invade and compromise or‐ gan function. Thus, the development of alternative treatment for melanoma is critically impor‐ tant. Recent advances in oncology have led to novel therapeutics that is capable of targeting