Melanoma, a type of skin cancer that forms from melanocytes (pigment-producing cells), is a complex disease that is mostly curable in the early states but considerably more difficult to treat in the later stages.1,2
In the year 2011, melanomas were rated as the seventh-most common type of cancer, occurring at a rate of 19.7 cases per 100,000 individuals, according to recent data from the Centers for Disease Control and Prevention.3
Although melanomas account for fewer than 2% of skin cancers, melanoma causes the vast majority of skin cancer–related deaths.4
In 2011, a total of 65,647 patients developed new cases of melanoma (38,415 men and 27,232 women), and a total of 9128 deaths were reported (6001 men and 3127 women).5
The American Cancer Society projects that 73,870 new cases of melanoma will be diagnosed in 2015, with the majority occurring in men (42,670 cases) and a smaller proportion occurring in women (31,200 cases).4
In 2015, a total of 9940 deaths are expected to occur, approximately two-thirds of which will occur in men.4
Melanoma rates have been rising for at least the past 3 decades. Between 2002 and 2006, the incidence of melanoma grew 33% in men and 23% in women—faster than any other cancer with the exception of lung cancer.6
Between the intervals of 2002-2006 and 2007-2011, the number of adults in the United States receiving treatment for skin cancer grew from 3.4 million to 4.9 million.7
Furthermore, the average annual cost of treatment between 2002-2006 and 2007-2011 more than doubled, from $3.6 billion per year to $8.1 billion per year.7,8
Although the mean age at diagnosis is 62 years (median 59 years), melanoma is one of the most common cancers in individuals under the age of 30 years, and it is particularly likely to occur at a younger age in patients with a family history of disease.4,6
The lifetime risk of developing melanoma varies among different ethnic populations: it is 2.4% for Caucasians, 0.1% for people of African descent, and 0.5% for Hispanics. Some risk factors for melanoma are modifiable while others are not. Non-modifiable risk factors include age (the risk of developing melanoma rises with age, although many cases occur before the age of 30 years); family history (approximately 10% of cases of melanoma occur in patients with a family history of the disease, suggesting that genetic factors have an important role in treatment); a history of prior melanoma; multiple clinically atypical moles or dysplastic nevi; and immunosuppression or use of immunosuppressive medications, as patients with weakened immune systems, including those taking immunosuppressive medications and patients with the human immunodeficiency virus, are more likely than other individuals to develop melanoma.
Modifiable risk factors include ultraviolet light exposure and frequent sunburns (particularly during childhood). A person with a history of melanoma has an increased risk of developing recurrent melanoma, and approximately 5% of those who have had melanoma will develop it again.4
As a result, continual monitoring is required for anyone who has had a case of melanoma.
It is reported that 2% to 5% of patients have metastatic melanoma at diagnosis. Approximately 82% to 85% of new diagnoses of melanoma are detected when the disease is localized, and another 10% to 13% of patients present with regional disease at first diagnosis.6
A number of predictive factors have been used to determine survival. For example, factors that are predictive of poor survival include advanced age (>70 years) and high levels of lactate dehydrogenase.4
Melanoma may initially present as a suspicious pigmented lesion, with the presence or absence of melanoma confirmed by biopsy. Following the biopsy, a pathology report may be ordered to evaluate and record the thickness of the lesion, whether or not the lesion is ulcerated, the mitotic rate, the status of tumor margins, the presence or absence of microsatellitosis, and other clinical factors. Following this report, patients may be evaluated through a skin exam and assessed for melanomarelated risk factors (eg, family history, history of melanoma or other skin lesions), whether or not the tumor is draining to lymph nodes; additional tests may also be performed as indicated.6
Stage III legions may be treated differently depending on whether or not melanoma has spread to sentinel nodes, or if metastases are in transit.6
Figure 1. Survival Curves Comparing Different Nodal Categories of Stage III Melanoma1
Reprinted with permission from Balch CM, Gershenwald JE, Soong SJ, et al. Final version of 2009 AJCC melanoma staging and classification. J Clin Oncol. 2009;27(36):6199-6206. © 2009 American Society of Clinical Oncology. All rights reserved.