text: Exposure to ultraviolet radiation (UVR), whether from the sun or tanning devices is known to be a major cause of the three main types of skin cancer: non-melanoma skin cancer (basal cell carcinoma and squamous cell carcinoma) and melanoma. Overexposure to UVR induces at least two types of DNA damage: cyclobutane–pyrimidine dimers (CPDs) and 6–4 photoproducts (6–4PPs). While DNA repair enzymes can fix some mutations, if they are not sufficiently effective, a cell will acquire genetic mutations which may cause the cell to die or become cancerous. These mutations can result in cancer, aging, persistent mutation and cell death. For example, squamous cell carcinoma can be caused by a UVB-induced mutation in the p53 gene.
  Non-melanoma skin cancer includes squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), and is more common than melanoma. With early detection and treatment, it is typically not life-threatening. Prevalence increases with age, cumulative exposure to UV, and proximity to the equator. It is most prevalent in Australia, where the rate is 1,000 in 100,000 and where, as of 2000, it represented 75 percent of all cancers.
  Melanoma accounts for approximately one percent of skin cancer, and causes most of skin cancer-related deaths. The average age of diagnosis is 63, and it is the most common cancer in the 25–29 age group and the second most common in the 15-29 group, which may be due in part to the increased UV exposure and use of indoor tanning observed in this population. In the United States, the melanoma incidence rate was 22.3 per 100,000, based on 2010–2014 data from the National Institutes of Health Surveillance, Epidemiology and End Results (SEER) Program, and the death rate was 2.7 per 100,000. 9,730 people were estimated to die of melanoma in the United States in 2017, and these numbers are anticipated to continue rising. Although 91.7% of patients diagnosed with melanoma survive beyond 5-years, advanced melanoma is largely incurable, and only 19.9% percent of patients with metastatic disease survive beyond 5 years. An international meta-analysis performed in 2014 estimates that annually, 464,170 cases of skin cancer can be attributed to exposure to indoor tanning.
  A 2012 analysis of epidemiological studies found a 20% increase in the risk of melanoma (a relative risk of 1.20) among those who had ever used a tanning device compared to those who had not, and a 59% percent increase (a relative risk of 1.59) among those who had used one before age 35. Additionally, a 2014 systematic review and meta-analysis found that indoor tanners had a 16 percent increased risk of developing melanoma, which increased to 23 percent for North Americans. For those who started tanning indoors before age 25, their risk further increased to 35% compared to those who began after age 25.