The incidence of melanoma has risen considerably over the past 30 years, and more than 96,000 new cases are estimated to be diagnosed in the United States in 2019, according to the recently published Cancer Facts & Figures 2019 report from the American Cancer Society.
According to the report, from 2006 to 2015, the incidence rate of melanoma increased by 3% each year among men and women age 50 years and older. Incidence rates among adults younger than age 50 years, however, have remained stable.
In total, the incidence rate of melanoma is higher in women than in men before age 50 years. By age 65 years, however, the incidence rate in men is double that of women; by age 80 years, the incidence rate in men is tripe that of women. Reasons underlying these trends are secondary to age and sex differences in occupational and recreational exposure to ultraviolet radiation (UV)—such as indoor tanning)—as well as detection practices and healthcare utilization, the report found.
The report also noted that while invasive melanoma makes up only about 1% of all skin cancer cases, it accounts for the majority of skin cancer deaths. In addition, most melanoma cases occur among non-Hispanic whites. Specifically, the annual incidence rate of melanoma in non-Hispanic whites is 27 per 100,000 compared with 5 per 100,000 in Hispanics and 1 in 100,000 in blacks and Asians/Pacific Islanders.
In an exclusive interview with Cancer Network, Ryan Fields, MD, a professor of surgery and chief of the Section of Surgical Oncology at Washington University School of Medicine's Siteman Cancer Center in St. Louis, hypothesized as to why melanoma incidence rates are on the rise in older adults. “First, we are more vigilant about detecting melanoma. Second, there is a decrease in the protective atmosphere that shields us from UV radiation, which is the leading risk factor for melanoma and all skin cancers. Third, people still use tanning beds that concentrate UV exposure, which is essentially a carcinogen that leads to increased risk of skin cancer,” he said.
The report predicts that an estimated 7,230 Americans will die of melanoma in 2019. Encouragingly, however, the death rate for melanoma has reportedly decreased by about 2% per year in US adults age 50 years and older. In adults younger than age 50 years, the death rate decreased by 4% per year.
The American Cancer Society stresses that although melanoma is very treatable when detected early, it is more likely than non-melanoma to metastasize to other parts of the body. Specifically, the 5-year relative survival rate for melanoma is 92%, with 84% of patients diagnosed at a localized stage. At a localized stage, the 5-year survival rate is 98%, according to the report.
“When caught early, meaning prior to spreading to lymph nodes or distant sites, melanoma is very curable with recurrence rates of less than 10%,” said Fields. “When melanoma has spread to lymph nodes or beyond, the rates of recurrence are higher, but the past 5 to 10 years have seen the tables turned on this once untreatable disease,” he said.
“With targeted/genetic therapy and immunotherapy, we have many options to treat advanced melanoma. We are seeing durable, long-term remission in patients with advanced disease. And there are many more immune-based therapies and vaccines being studied that will undoubtedly continue this trend towards improved outcomes in all stages of melanoma,” Fields noted.
Fields also stressed the importance of early detection. “We know from many studies that early detection leads to improved outcomes. Through improved education and advocacy, [such as] teaching patients about the A-B-C-Ds of skin lesions and when to be concerned about a mole that is new or changing, we can detect melanoma and other skin cancers at earlier stages, leading to improved outcomes,” he said.