Researchers looked at data of 2,880 Swedish people diagnosed with cutaneous melanoma aged between 20 and 60 and identified a 29 percent increased risk of overall cutaneous melanoma among tattooed individuals.
The tattoo size was found to be unrelated to CM risk. As such, larger tattoos were not observed to result in a higher risk of cutaneous melanoma.
“Coloured tattoos alone or in combination with black or grey in the tattoo seemed to be associated with a slightly higher risk of cutaneous melanoma,” the study authors wrote.
“We did not find that highly UV-exposed tattooed individuals had a higher risk of cutaneous melanoma than tattooed individuals with lower UV exposure. Thus, our data suggests that UV-accelerated pigment breakdown does not increase the risk of cutaneous melanoma beyond the risk associated with tattoo exposure per se.”
Individuals with tattoos for 10 to 15 years were found to have the highest risk of developing CM.
A review of case reports from 2012 concluded the link between tattoos and skin cancer was potentially coincidental. Case studies suffer from bias and cannot be used to evaluate associations between exposures and outcomes, researchers said.
“Thus, our results provide the first insight into a possible association between tattoos and skin cancer using an adequate methodological approach,” they wrote.
As for CM subtypes, tattooed individuals were found to have a roughly 40 percent higher risk of contracting two types of CM—invasive and in-situ cutaneous melanomas—than people without tattoos.
As such, the immune system is activated, with the ink pigments getting encapsulated by immune cells. These pigments then get transported to the lymph nodes.
“Azo pigments are the most common organic colourants in tattoo ink,” said Emelie Rietz Liljedahl, associate researcher in toxicology at Lund University.
“This could be a potential risk because we already know that these can break down into harmful chemicals that may cause cancer. This particularly applies for exposure to UV radiation from the sun, sun beds or laser treatments.”
The study was funded by Lund University, Swedish Research Council for Health, Magnus Bergvall Foundation, and the Crafoord Foundation. Two researchers declared competing interests, including receiving funds from government entities and private foundations. One of them also received money from pharma companies.
“Over the years, the FDA has received reports of people developing infections from contaminated tattoo inks, as well as allergic reactions to the inks themselves,” the agency stated at the time.
“And, scientists at the FDA and elsewhere have found that even unopened and sealed tattoo inks can harbor bacteria and other microorganisms that can cause infections.”
The FDA stated that about 30 percent of Americans and 40 percent of people aged between 18 and 34 years are estimated to have at least one tattoo.
