indoor tanning and melanoma

Exposure to ultraviolet (UV) radiation is a major environmental factor for melanoma and non-melanoma skin cancer (NMSC) (1):

• evidence suggests that almost 90% of all melanomas, 85% of squamous cell carcinoma (SCC), and 82% of basal cell carcinoma (BCC) are attributable to excess UV radiation
• according to the monography from the International Agency for Research on Cancer (IARC), solar UV and the use of UV emitting tanning devices are classified as group 1 carcinogens, which are carcinogenic to humans based on the evidence from epidemiological research

A systematic review and meta-analysis examined the association between indoor tanning use and the risk of overall and early-onset (age < 50) melanoma and NMSC (1):

• showed significant association between skin cancer and indoor tanning
  • melanoma, RR= 1.27; NMSC, RR = 1.40; squamous cell carcinoma (SCC), RR = 1.58; basal cell carcinoma (BCC), RR = 1.24
  • risk was more pronounced in early-onset skin cancer
  • first exposure at an early age (age ≤ 20 years) and higher exposure (annual frequency ≥ 10 times) to indoor tanning showed increasing risk for melanoma and NMSC
• study authors concluded that:
  • meta-analysis suggests indoor tanning increases the risk of skin cancer, particularly early-onset melanoma and NMSC

A study compared the medical records of nearly 3000 tanning bed users and 3000 nonusers. Researchers also analyzed 182 melanoma skin biopsies from people who had used tanning beds versus those who had not (2):

• tanning bed users were more likely to have melanoma on body sites that are less often exposed to the sun—such as the lower back—and to have multiple melanomas
• melanomas in tanning bed users had a higher proportion of cells carrying pathogenic variations
• by increasing cellular variations and reaching a greater body area, tanning bed radiation may cause more skin damage than natural sunlight
  • melanocytes in skin from tanning bed users had higher mutation burdens and higher proportions of cells with pathogenic mutations—these differences were most prominent over body sites that experience comparatively less exposure to natural sunlight
• about 5% of tanning bed users were diagnosed with melanoma compared with 2% of nonusers
• after adjusting for age, sex, sunburn history, and family history, tanning bed use remained associated with a nearly 3-fold increased risk of melanoma compared to non-tanning bed users

Reference:

1. An S, Kim K, Moon S, Ko KP, Kim I, Lee JE, Park SK. Indoor Tanning and the Risk of Overall and Early-Onset Melanoma and Non-Melanoma Skin Cancer: Systematic Review and Meta-Analysis. Cancers (Basel). 2021 Nov 25;13(23):5940.
2. Pedram Gerami et al. Molecular effects of indoor tanning.Sci. 2025;11.