Perspective : Melanoma diagnosis and monitoring : The sun is rising for melanoma therapy – but early detection remains in the shade

Melanoma is one of the most dangerous forms of cancer. The five-year survival rate is 98% if it is detected early. However, this rate plummets to 62% for regional disease and below 15% when tumors have spread to distant sites. Furthermore, the incidence of melanoma has been rising by about 3% per year, while the incidence of most common cancers is decreasing. A handful of targeted therapies have recently become available, though these drugs are expected to increase survival only by a few months in some patient groups before relapse. It may be possible to effectively treat patients, if early diagnosis can be made when the tumor burden is still low. Here, an overview of the current state-of-the-art is provided along with a case for technologies towards early point-of-care diagnosis. Melanoma facts and figures Skin tans when epidermal melanocytes, a specific type of cell that is genetically different from other cells in the skin, release a dark brown pigment called melanin in the top layer of the skin in response to ultraviolet (UV) light. Nature uses tanning as a protective mechanism against sun exposure to minimize UV light-induced damage to DNA. In addition, skin cells have evolved complex biochemical repair systems to fix potential damage to their genetic material. Unfortunately, excess damage can lead to incorporation of oncogenic mutations that result in neoplastic transformation of benign melanocytes into malignant melanoma. Most melanoma originates from the skin, but as melanocytes also reside in other tissues, it can occur in other places such as the eye (uveal melanoma). Indeed, melanoma is one of most dangerous forms of cancer in general, and skin cancer in particular. Even though melanoma represents less than 5% of total skin cancers, it is responsible for almost 75% of total skin cancer deaths. Major risk factors for melanoma such as unusually high numbers of normal or atypical moles, fair skin and/or red hair, family history of skin cancer and sun burns are generally well known. Unfortunately, these risk factors are often ignored as the popularity of tanning and recreational activities in sunny destinations without proper use of UV protection continue to rise. This has resulted in a disturbing trend where, in contrast to several other cancer types whose numbers are holding steady or are in decline (e.g., lung cancer), the incidence rate of melanoma has been increasing for over three decades, at about 2.8% per year. It is estimated that in 2014, in the US alone 76,100 new cases of melanoma will be diagnosed and 9,710 patients will die from this disease. Worldwide, there are an estimated