People with more than one tattoo session may have a decreased risk of developing melanoma—with one key caveat, according to research published by McCarty et al in the Journal of the National Cancer Institute.
A team led by Jennifer Doherty, PhD, Huntsman Cancer Institute investigator, Co-Leader of the Cancer Control and Population Sciences Program, and Professor of Population Health Sciences at the University of Utah, evaluated 7,000 Utahns and found that having two or more tattoo sessions decreased the risk of both invasive and in situ melanomas.
However, the researchers also found that participants with only one tattoo session were more likely to have melanoma, especially in situ. The reasons why that may be the case are speculative, and more research is needed to understand this disparate pattern.
“Tattoos are increasingly common, and it’s an understudied form of environmental exposure, especially in young people. We really need to understand how tattoos could impact risk for different types of cancer,” said Dr. Doherty. “For melanoma, the results seem to be mixed. But we see people with two, three, and four tattoo sessions having decreasing risk, and that’s a stronger pattern than the increased risk with just one session.”
According to Pew Research Center, one-third of American adults have tattoos. Around 41% of Americans younger than age 30 have at least one, as do 46% of people between the ages of 30 and 49.
Dr. Doherty explained that her research team originally hypothesized that having more tattoos would increase melanoma risk due to the carcinogens—like metals and other chemicals—found in tattoo ink. Additionally, the ink in a person’s skin can break down over time and create new carcinogens that weren’t originally in the tattoo. Tattoos can also cause inflammatory responses, and inflammation is often associated with cancer risk.
“The results that tattoos could decrease melanoma risk surprised us. But this isn’t a black and white case of ‘get more tattoos, and you could lower your risk of melanoma,’” added first study author Rachel McCarty, PhD, a former doctoral student at Huntsman Cancer Institute and a current postdoctoral scientist at the International Agency for Research on Cancer. “Instead, we need to do more research to understand what we are seeing and if this decreased risk is simply due to behavioral or physical factors, or if there could be beneficial immune responses associated with tattooing that lower melanoma risk.”
It may be that those with several tattoo sessions are more cautious with sun safety and take better care of their skin. Tattoos could also form a physical barrier that blocks ultraviolet radiation or cause an immune response against precancerous cells, the researchers theorized.
Dr. McCarty noted that those with tattoos should continue making informed decisions about skin protection. “Tattoo artists already advise their clients to wear sunscreen and sun protection to prevent tattoos from fading,” she said. “We know wearing sunscreen is an important safety step for everyone, even without tattoos. But it’s also important for those with tattoos to take extra precautions to prevent any additional harmful components from forming in the skin when pigments break down from UV exposure.”
Although this study revealed a decreased melanoma risk for those with tattoos, that may not be true for other types of cancer. An earlier project from Dr. Doherty’s team and a recent Swedish study both suggest that tattooing could be connected to an increased risk of certain blood cancers. Still, the new melanoma study is a step forward in understanding how tattoos may impact skin cancer risk.
Disclosure: For full disclosures of the study authors, visit academic.oup.com.
