Skin cancer is the most common form of cancer seen in the United States. About 1 million people are diagnosed every year. The most common form of skin cancer is basal cell carcinoma followed by squamous cell carcinoma and many other less common types. Skin cancers are most common in fair-skinned older patients however, with increasing UV exposure and ozone layer depletion; patients are being diagnosed at a much younger age.
Basal cell carcinoma (BCC) is slow growing but can be locally invasive if not removed early. These lesions usually appear as pearly, red bumps on sun-exposed areas. BCC is asymptomatic but bleeding with minimal trauma may be the first symptom. Previous therapy with x-rays (for facial acne) or arsenic exposure (even 30-40 years prior) increase the risk for BCC as well.
Squamous cell carcinoma (SCC) often arises from pre-cancerous lesions called actinic keratoses. These lesions usually appear as crusted or scaly patches with a red, inflamed base on sun-exposed parts of the skin. SCC is also seen more commonly in organ transplant patients and in previously traumatized skin. SCC can spread more easily to other parts of the body and should be treated as soon as possible after diagnosis.
Both BCC and SCC are diagnosed through skin biopsy and treated with Mohs micrographic surgery (when lesions appear on the head and neck) or surgical excision (when lesions are small and on the body). Mohs surgery allows the surgeon to take a sampling of skin and view it under the microscope to ensure all of the tumor has been removed. Newer topical treatments or photodynamic therapy can sometimes also be used in very superficial skin cancers.
Melanoma is the most serious type of skin cancer. It occurs when pigment cells in the skin called melanocytes are exposed to ultraviolet (UV) radiation. If the skin receives too much ultraviolet light, the melanocytes may begin to grow abnormally and become cancerous. Other risk factors include fair skin, family history of first-degree relatives with melanoma, history of one or more severe sunburns, a weak immune system and exposure to certain carcinogens. If melanoma has a chance to grow deep in the skin, it has a much higher chance of spreading to other parts of the body than other types of cancer. The first sign of melanoma is often a change in the size, shape, or color of a mole, but melanoma can also appear on the body as a new mole. Abnormal moles can appear anywhere on the skin. That’s why it is important to always examine your skin to check for new moles or changes in moles. In men, melanoma most often shows up on the back, head or neck. In women, melanoma often develops on the lower legs. Moles that change in color or in texture, take on an uneven shape, get larger, or become bigger than a pencil eraser should be evaluated immediately.
If a melanoma is diagnosed early, treatment consists of wide excision and/or Mohs surgery depending on the type of melanoma. Melanomas diagnosed later are harder to treat and require more invasive diagnostic techniques including sentinel lymph node biopsy. Beyond excision, treatments for deeper melanomas can include radiation therapy, chemotherapy, and immune therapies.