Monday Medical: Melanoma: Know your enemy
June 8, 2014
Asymmetry: Half the lesion does not match the other half
Border irregularity: Edges are notched, blurred, etc.
Color variation: Pigment is not uniform; more than one color
Diameter: Greater than 6 mm
Ugly duckling: Lesion looks different from the rest
Editor’s note: A version of this article ran in the Steamboat Today on May 2, 2011.
More than 300 days of sunshine per year, a moderate or high ultraviolet index from March through October and elevation at more than 6,000 feet combine to give Northwest Colorado bragging rights for incidence rates for melanoma that are 30 percent higher than in the United States as a whole.
Although the rates of most other cancers in the U.S. have been declining, the incidence of melanoma is increasing — tripling in the white population during the past 20 years.
Melanoma is predicted to affect more than 70,000 people, causing about 8,000 deaths annually. The current lifetime risk is one case per 58 Americans. One person each hour dies from metastatic melanoma.
So where's the silver lining in this cloud spoiling our sunny days? Melanomas are almost always curable when diagnosed early. Prevention and early detection through education can change these gloomy statistics.
Melanoma is a cancer that begins in pigment-producing cells (melanocytes) predominantly found in the skin. The sequence of events that leads to melanoma formation is multifactorial but poorly understood.
Approximately 90 percent of melanomas are caused by exposure to sunlight. Sunlight can cause mutations in the DNA of skin cells. Accumulate enough mutations, and cancer will result. Melanomas may develop in pre-existing nevi (moles) or arise in unpigmented skin.
Risk factors include fair skin, multiple severe/blistering sunburns, increased number of common or dysplastic (atypical) moles, family history of melanoma, a changing mole and older age. Statistically, we can add living in Steamboat Springs or other high-altitude areas to that list.
Diagnosis of melanoma usually begins with history and physical exam and ends with pathologic confirmation of a tissue sample. A new or changing mole or blemish is the most common presentation.
The ABCDE(U) criteria listed in Table 1 are helpful in determining which moles may be melanomas or atypical moles. Lesions exhibiting these features should undergo a biopsy (tissue sampling).
Treatment for melanoma depends on the stage, which is determined by tumor thickness, tumor ulceration, lymph node status and spread to other organs. Surgery is the primary treatment for cutaneous (skin) melanoma.
The amount of tissue removed depends primarily on the thickness or depth of invasion of the cancer. Thicker melanomas may require sampling of lymph nodes to determine if the cancer cells have spread beyond the skin.
While thinner melanomas do not require an extensive "metastatic work-up," thicker melanomas require blood work and imaging studies. Follow-up care is critical, including frequent full-body skin exams and performance of monthly skin self-exams for early detection of a new melanoma.
Melanomas diagnosed early can be treated successfully with greater than a 90 percent five-year survival rate.
So, should you just move to Scotland, the least sunny spot on the planet? Absolutely not! The next article in this two-part series will teach you to defy the statistics of living in Northwest Colorado.
Maryann Wall, M.D., of Northwest Colorado Ear, Nose, Throat and Facial Plastic Surgery, PC, is board-certified in otolaryngology-head and neck surgery and facial plastic and reconstructive surgery.