Increase in melanoma incidence likely multifactorial

The increase in melanoma incidence has been caused by multiple factors, with overdiagnosis possibly playing a role, according to a review in the Journal of the American Academy of Dermatology.

“Since the 1970s, the incidence of melanoma has increased significantly while melanoma-specific mortality has remained stable,” Sonal Muzumdar, BS, of the department of dermatology at the University of Connecticut School of Medicine, and colleagues wrote. “This has raised concerns regarding the overdiagnosis of melanoma.”

The review article discussed factors that have contributed to the increase in diagnoses in the past few decades, including a greater understanding of the disease and its causes, an aging population, ultraviolet exposure, and an increase in biopsy rates and skin cancer screenings.

Ultraviolet exposure, especially with the popularity of indoor tanning since the 1970s, has been estimated to increase the risk for melanoma. The relative risk of melanoma attributed to all sun exposure is 1.34 (95% CI, 1.02-1.77), and the relative risks due to sunburns and chronic sun exposure are 2.03 (95% CI, 1.73-2.73) and 0.95 (95% CI, 0.87-1.04), respectively. The risk from indoor tanning is estimated to be between 2.6% and 9.4%.

Biopsies increased in the Medicare population by 154% between 1986 and 2001, according to the report, with melanoma diagnoses increasing by 140% in that time. In kind, skin cancer screenings have been provided for free from the American Academy of Dermatology since 1985, leading to an increase in diagnoses.

While the incidence of melanoma has increased, the mortality rate has stayed steady, raising concerns about overdiagnosis.

“While true disease prevalence may have risen, disease detection has also increased due to improved record keeping, increased screening efforts and enhanced understanding of the disease,” the authors wrote. “Given stable mortality in the setting of increased incidence, a component of melanoma overdiagnosis is likely present although other factors likely also contribute.”