Results of a cohort study show a dose-response association between cumulative number of indoor tanning sessions and the risk of developing cutaneous squamous cell carcinoma (cSCC) among women. Importantly, the research found that women with any history of indoor tanning use were at increased risk for cSCC and that the dose-response association between cumulative number of sessions and cSCC risk was the same regardless of duration of use or age at indoor tanning initiation.
Simon Lergenmuller, M.Sc., is a Ph.D., student at the Oslo Centre for Biostatistics and Epidemiology, faculty of medicine, University of Oslo, Oslo, Norway, and lead author of the recently published paper [Lergenmuller S, et al. . 2019 Oct 2:1- 9. Epub ahead of print]. He said, “To our knowledge, this is the first study prospectively investigating the dose-response association between lifetime indoor tanning and risk for cSCC. Although we found that the risk is greater among women with a higher cumulative number of sessions, the main messages from our study are that there is no safe lower limit for using indoor tanning devices and that starting to use indoor tanning later in life seems to be as harmful as earlier initiation.”
“Furthermore, the results of our study provide support for developing policies to regulate indoor tanning. Avoiding indoor tanning may help to reduce cSCC, which is one of the most common type of cancer worldwide.”
The study was conducted in collaboration with researchers from the University of Tromsø, Norway, the Cancer Registry of Norway, and the QIMR Berghofer Medical Research Institute in Australia. It included data from women participating in the Norwegian Women and Cancer Study (NOWAC), which is a prospective population-based observational study initiated in 1991. Participants in NOWAC randomly selected women from the general population who were born between 1927 and 1963. They completed baseline questionnaires from 1991 to 2007 and follow-up questionnaires every 5 to 7 years thereafter.
The questionnaires collected information on pigmentation factors, sunburns, sunbathing vacations and indoor tanning (frequency, age at initiation and duration of use). Data for the study investigating indoor tanning and cSCC were obtained from questionnaires completed through Dec. 31, 2015, and a diagnosis of cSCC was identified through linkage to the Cancer Registry of Norway (CRN), with mandatory registration since 1952.