A new case-control study has uncovered a potential link between long-term tattoo exposure and increased risk of rare forms of non-Hodgkin lymphoma (NHL), particularly affecting those who have had tattoos for a decade or longer.
The Utah-based research, published in Cancer Medicine, analyzed data from 820 patients diagnosed with lymphoid or myeloid malignancies between 2019 and 2021, alongside more than 800 controls. The findings are particularly relevant given that nearly one-third of U.S. adults now have at least one tattoo.
Key Study Findings
Patients aged 20-60 who had received tattoos 10 or more years prior showed a significantly elevated risk of rare mature B-cell NHLs, with an odds ratio of 2.64 (95% CI, 1.23-5.68). These included specific subtypes such as marginal zone and mantle cell lymphomas, though some subtypes had sample sizes too small for individual analysis.
The study also identified potential associations with other hematologic conditions. Long-term tattoo exposure showed links to increased risk of myelodysplastic syndromes (MDS; OR, 1.48; 95% CI, 0.40-5.41) and chronic myeloid leukemia (CML; OR, 1.24; 95% CI, 0.45-3.43).
Mechanism and Latency Period
The researchers suggest that the increased cancer risk might be attributed to prolonged exposure to carcinogens combined with inflammatory and immune responses. The study's authors noted that this aligns with known risk factors for hematologic cancers, which often demonstrate a 10- to 20-year latency period.
Supporting Evidence
These findings are further supported by a larger case-control study published earlier this year, which found a 21% increased risk of lymphoma associated with having tattoos among 1,400 patients with the disease and 4,200 controls. That study noted particularly elevated risks within the first two years of getting a tattoo, followed by a pattern of risk fluctuation over time.
Study Limitations and Future Research
The researchers acknowledge several important limitations in their findings. Despite the substantial overall sample size, certain cancer subtypes and demographic groups had small representations, leading to imprecise estimates. Many of the risk estimates included 95% confidence intervals that overlapped with null results, suggesting some findings could be due to chance.
"As hematologic cancer subtypes are rare, we had small sample sizes for several groups, which led to imprecise estimates," the researchers noted, emphasizing the urgent need for additional research to better understand these under-studied cancers.
