The overall incidence of cutaneous T-cell lymphoma (CTCL) increased in the United States from 2000 to 2018, according to a research letter published online Sept. 1 in JAMA Oncology.
Zhuo Ran Cai, M.D., from Stanford University in California, and colleagues describe recent trends in the incidence of histologically confirmed cases of first primary CTCL with malignant behavior and skin as the primary site of involvement using data from the Surveillance, Epidemiology, and End Results Program for 2000 to 2018.
From 2000 to 2018, the researchers identified 14,942 new cases of CTCL. The most common diagnosis was mycosis fungoides (MF), followed by primary CTCL (PCTCL) and primary cutaneous anaplastic large cell lymphoma. The overall incidence of CTCL was 8.55 per million, with an increase seen during the study period (annual percent change [APC], 0.61 percent). MF had the highest incidence among CTCL subtypes (5.42), while the highest increase was seen for Sézary syndrome (APC, 3.83 percent). The only subtype with decreasing incidence during the study period was PCTCL (APC, −1.39 percent). The highest incidence of CTCL was seen in men, non-Hispanic Black patients, individuals in the highest socioeconomic status quintiles, and those living in metropolitan counties (10.06, 11.68, 10.31, and 8.96, respectively). The overall incidence rate was six times higher for patients aged 40 years or older versus those aged younger than 40 years; however, patients aged younger than 40 years had significantly higher increases in overall CTCL and MF incidence rates (APC, 2.87 and 3.67 percent, respectively).
“One key new finding is the more rapid increase in incidence among young patients, possibly owing to earlier diagnosis,” the authors write.