In the first large study of its kind, tattoos were found to raise the risk for malignant lymphoma by about 20% compared with no tattoos. Tattoo ink often contains carcinogens and, when applied to the skin, can trigger an immunologic response.
This study was a population-based case-control study of all incident cases of malignant lymphoma in Swedish adults (aged 20-60 years) in the Swedish National Cancer Register between 2007 and 2017. The number of adults observed were about 11,000.
The primary outcome was the incidence rate ratio of malignant lymphoma in tattooed vs non-tattooed individuals. The outcome was that tattooed participants had a 21% higher risk for overall lymphoma than non-tattooed participants. No evidence was found that the risk for lymphoma increased with a larger area of total tattooed body surface.
This was an observational study which is one of the weakest types of study designs. Although findings suggested that tattoo exposure was associated with an increased risk for malignant lymphoma. More epidemiologic research is urgently needed to establish causality.
This study highlights the importance of regulatory measures to control the chemical composition of tattoo ink.