The main cause of the increased risk for both basal cell and squamous cell carcinomas is the cumulative damage by the sun and long-term exposure to weather and wind. The incidence therefore increases with age. Sun rays on the skin can, in addition to many beneficial effects such as vitamin D synthesis, tanning, and well-being, cause DNA damage in proliferating cells. Over time, this can lead to cancer. Skin types 1 and 2 are at a higher risk compared to other skin types.
Historically, there are Egyptian records from 500 BC possibly indicating that the sun can cause skin cancer.
In 1756, an English doctor named Pott showed that there was an increased risk of scrotal skin cancer among chimney sweepers due to carbon. Later, arsenic, X-rays, and chronic irritation were connected with an increase in skin cancer.
Certain hereditary dispositions such as Gorlins syndrome and xeroderma pigmentosum are at a higher risk for developing skin cancer at young ages.
Long-term immunosuppression after, for example, an organ transplant, appears to pose a higher risk for these skin cancers and represents a great and increasing challenge.