Researchers at the Mayo Clinic compiled data for the incidence of melanoma in persons aged 18-39 between 1970 and 2009 in a single county in Minnesota. They found that the incidence of melanoma has increased steadily each decade since the 1970s: the incidences were 4.8 (cases per 100,000 person-years) in the 1970s, 11.8 in the 1980s, 16.8 in the 1990s, and 30.8 in the 2000s (from 2000 to 2009). That’s more than a 6-fold increase in just 30 years.
One likely explanation for at least part the increase in reported cases of melanoma is that increased awareness of the disease has led to more frequent and more accurate diagnosis. Another is that the criteria for calling a lesion a melanoma has changed over time. However, when the authors broke the data down by gender they found that the incidence of melanoma differed dramatically between men and women; the incidence rose 4-fold in men, but 8-fold in women. In theory, a gender difference would not be explained by changes in awareness or definition over time.
Why is the incidence of melanoma increasing more in women than in men? The study’s authors speculate (and yes, it’s speculation at this point) its because young women use tanning beds more frequently than men. And despite what the advocates of tanning beds say, the UV rays emanating from tanning beds DO damage the skin and CAN lead to an increased risk of skin cancer.