The association between extensive sun exposure and skin cancer has been recognized for some time. Malignant melanoma, squamous cell cancer, and basal cell cancer are skin cancers associated with ultraviolet (UV) radiation. Rates are much higher in places where there is a lot of sunshine year round. In our San Francisco Bay Area culture of swim team, soccer, golf, and tennis we have a very high rate of sun exposure and hence more skin cancers.
Skin cancers (skin neoplasms) are named after the type of skin cell from which they arise. Basal cell cancer originates from the lowest layer of the epidermis, and is the most common but least dangerous skin cancer. Squamous cell cancer originates from the middle layer, and is less common but more likely to spread and, if untreated, become fatal. Melanoma, which originates in the pigment-producing cells (melanocytes), is the least common, but most aggressive, most likely to spread and, if untreated, become fatal.
Melanoma is a highly aggressive skin cancer that often arises in a pigmented lesion or nevus, which accounts for about 1% of all skin cancers but it is responsible for majority of deaths from skin cancer. According to the American cancer society, about 76,380 Americans will be diagnosed with melanoma of skin in 2016 of which more than 8,500 are from California.
Melanoma has the potential to spread to the lymph nodes and to distant sites such as the brain, lung, and liver. The depth of melanoma determines the type and extent of treatment. Surgery for melanoma includes removal of the melanoma lesion from the skin along a margin with of normal surrounding tissue. Some patients may require more extensive surgery to evaluate the lymph nodes and determine the stage of disease. This procedure is called sentinel lymph node biopsy and may be indicated based on the thickness of melanoma and certain pathologic features.
Melanomas with deep invasion or spread to the lymph nodes may require additional treatment such as adjuvant chemotherapy or more extensive surgery. However, the majority of patients with melanoma are cured after the initial surgical excision.
Adjuvant therapy refers to the use of chemotherapy, targeted therapy, immunotherapy or radiotherapy in addition to surgical resection in the treatment of cancer. The goal of adjuvant therapy is to improve the survival and control the cancer in patients with stage III and IV disease. Targeted therapy and immunotherapy have shown to improve the outcomes for patients with advanced melanoma. These treatments take advantage of certain genetic differences in the tumor with the goal of destroying cancer cells while leaving normal cells intact or by activating the person’s immune system to destroy melanoma cells in the body.
Protection from UV radiation is important all year round, but risk is highest during the summer. The hours between 10 AM and 4 PM are the most hazardous for UV exposure. Minimizing exposure to UV radiation by wearing protective clothing, hats, and using sun screen are the main preventive measures. Protection of children from sun exposure is especially important as severe sunburns in childhood increase the risk of melanoma later in life. Sun damage to the skin is cumulative over your lifetime, so avoiding excess sun exposure, and using protective measures is extremely important.
Risk factors associated with higher rates of melanoma include personal or family history of melanoma, history of extensive UV radiation from sun light or indoor tanning, immunosuppression, and light skin features. Warning signs of melanoma include changes in the shape, size, color or character of an existing lesion or mole. Recognizing a new or changing skin lesion is essential in early detection and evaluation of melanoma. Consulting your primary care doctor or a dermatologist is essential when you notice a change in your skin.