1. Introduction
For many years, the incidence of skin cancer has been increasing
in western societies, not least northern Europe [1,2]. In Sweden, for
example, malignant melanoma (MM), the most lethal skin cancer
form, has become the most rapidly increasing malignancy during
recent decades and was in 2013 the fifth most common type of
cancer among women and the sixth most common type among
men. Additionally, non melanoma skin cancer (NMSC), included in
the cancer registry in Sweden, has become the second most