There is no apparent “epidemic” of melanoma so much as there seems to be an epidemic of melanoma diagnoses.
As you read this section, keep in mind that the numbers of cases are per 100,000 people. When talking about incidence rates around 10 in 100,000, we are talking about a rate of 0.01% — i.e, very small.
The graph below from the National Cancer Institute shows that the incidence of diagnosed melanoma increased from about 8 cases per 100,000 people in 1975 to about 28 cases per 100,000 people in 2010.
While that graph appears alarming, the data on deaths from melanoma paint a different picture. The graph below, also from the National Cancer Institute, indicates that the death rate from melanoma has hardly increased at all, from about 2.2 deaths per 100,000 people to about 3.2 deaths per 100,000 people.
So while the rate of diagnoses increased by 20 people between 1975 and 2010, the mortality rate increased by only 1 death.
So it could very well be that the “epidemic” of melanoma is the phenomenon of over-detection and over-diagnoses — a failure to accurately differetiate between benign pigmented from malignant melanomas. As stated by the National Cancer Institute:
Studies show that distinguishing between benign pigmented lesions and early melanomas can be difficult, and even experienced dermatopathologists can have differing opinions.
A 2009 study in the British Journal of Dermatology concluded:
We therefore conclude that the large increase in reported incidence [of melanoma] is likley to be due to the diagnostic drift which classifies benign lesions as stage 1 melanoma.