Tattoos May Be risk factors forMalignant Lymphoma

Miriam Davis27 May 2024

TOPLINE:

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, triggers an immunologic response.

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METHODOLOGY:

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 (n = 11,905).
Tattoo exposure was assessed by a structured questionnaire in both cases and three random age- and sex-matched controls without lymphoma.
The primary outcome was the incidence rate ratio of malignant lymphoma in tattooed vs nontattooed individuals.

TAKEAWAY:

The prevalence of tattoos was 21% among cases and 18% among controls.
After adjustment for confounders, tattooed participants had a 21% higher risk for overall lymphoma than non-tattooed participants (incidence rate ratio = 1.21; 95% CI, 0.99-1.48).
In the subgroup analysis of lymphoma types, the highest risks of around 30% were found for diffuse large B-cell lymphoma (incidence rate ratio = 1.30; 95% CI, 0.99-1.71) and follicular lymphoma (incidence rate ratio = 1.29; 95% CI, 0.92-1.82) in tattooed vs non-tattooed individuals.
No evidence was found that the risk for lymphoma increased with a larger area of total tattooed body surface.

IN PRACTICE:

The authors reported that tattoo popularity has strikingly increased, with a current prevalence of ≥ 20% in European studies.

The authors concluded that "Our findings suggested that tattoo exposure was associated with an increased risk for malignant lymphoma. More epidemiologic research is urgently needed to establish causality." In the meantime, they also concluded, "The study underscores the importance of regulatory measures to control the chemical composition of tattoo ink."

SOURCE:

The lead and corresponding author is Christel Nielsen of Lund University, Lund, Sweden. The study appeared in eClinicalMedicine.

LIMITATIONS:

Limitations included the study's observational case-control design, one of the weakest types of study designs for establishing causality, and its low response rate to the questionnaire of 47%-54%.