The incidence of cutaneous T-cell lymphoma (CTCL) in the United States has increased in recent years, according to data published in JAMA Oncology. 

This finding contrasts previous findings showing plateaued rates of CTCL in the US, but it is similar to trends recently seen in Europe, the researchers noted. 

For this study, the researchers analyzed data from the SEER program from 2000 through 2018. They identified histologically confirmed cases of first primary CTCL with malignant behavior and the skin as the primary site of involvement. They used the 2000 US standard population to calculate age-adjusted annual incidence rates per million. 

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From 2000 to 2018, there were 14,942 new cases of CTCL. The overall incidence was 8.55 per million, and this increased during the study period, with an annual percent change of 0.61%.

When the researchers looked at CTCL subtypes, they found that mycosis fungoides had the highest incidence, at 5.42 per million. However, the largest increase was seen in Sezary syndrome, with an annual percent change of 3.83%.

The researchers examined trends by patient characteristics as well. The incidence of CTCL was highest in men (10.06 per million), non-Hispanic Black patients (11.68), individuals in the highest socioeconomic status quintiles (10.31), and patients living in metropolitan counties (8.96). 

The incidence of CTCL was 6-fold higher in patients 40 years of age or older, compared with patients younger than 40. However, the younger patients had significantly higher increases in overall CTCL incidence and in the incidence of mycosis fungoides. The annual percent change was 2.87% for CTCL overall and 3.67% for mycosis fungoides in this age group. 

The researchers noted that the trends seen in this study are likely multifactorial but may be driven by better diagnostic tools and increased awareness of CTCL.


Cai ZR, Chen ML, Weinstock MA, et al. Incidence trends of primary cutaneous t-cell lymphoma in the US from 2000 to 2018: A SEER population data analysis. JAMA Oncol. Published online September 1, 2022. doi:10.1001/jamaoncol.2022.3236