The Incidence of Cutaneous T-Cell Lymphoma Seems to Be Higher in Veterans

Stefan M. Schieke, MD, Assistant Professor of Dermatology at University of Wisconsin-Madison discusses cutaneous T-cell lymphoma (CTCL) in special populations such as African Americans and veterans of war.

According to a paper published in U.S. Medicine, “The Veterans Affairs (VA) classifies CTCL and other non-Hodgkin lymphomas as presumptively caused by Agent Orange exposure or service in the Vietnam theater, even without exposure to the problematic herbicide. Both arise at markedly elevated rates in veterans, but it had remained unknown just how much higher the rate of CTCL was.”

In a study published in the Journal of Investigative Dermatology, researchers noted that “an estimated 5-15% of all CTCL diagnosed each year occurs in veterans, a percentage far greater than the percentage of veterans in the total U.S. population.” The researchers hypothesized that as the Surveillance, Epidemiology, and End Results (SEER) Program, the main source of data for national disease incidence, excludes cases from VAMCs, the incidence of CTCL in the U.S. might be underreported.1

Researchers found a 6 to 8 times higher incidence of CTCL in veterans than in the general population. The demographics and trends in the number of CTCL patients per conflict era showed great variations. Our data changes the CTCL incidence trends in the US.

The findings suggest that specific military exposures, such as Agent Orange during the Vietnam War, may be potential pathogenic drivers and warrant further exploration of the causes behind increased incidence of CTCL in veterans.

Cutaneous T-cell lymphoma belongs to the non-Hodgkin lymphoma class of hematologic T-cell lymphoproliferative disorders. Cutaneous T-cell lymphoma is a rare group of malignancies, with an incidence of 6.4 cases per 1 million people. This form of T-cell lymphoma represents around 70% of primary cutaneous lymphomas.

Cutaneous T-cell lymphoma attacks the the body’s immune system, specifically, the lymphatic system, affecting the two types of white blood cells (lymphocytes): B-cells and T-cells. Whereas the B-lymphocytes act to neutralize the pathogens, the main job of the T-lymphocytes is to attach to these foreign cells, viruses, or cancerous growths, and directly destroy them.

Compared with other T-cell lymphomas, a distinguishing feature of CTCL is implied by the name: malignant T-cells migrating to, and collecting in, cutaneous tissue. Diagnosis can be challenging, because the initial signs and symptoms are largely skin-related and overlap with those of many other dermatologic disorders. Adding to the challenge, CTCL variants present with overlapping symptomatology, and correct identification of the CTCL subtype is key to both treatment and prognosis. Histopathologic features must be correlated with the clinical presentation to confirm the diagnosis.

Many forms of CTCL are relatively indolent compared with other T-cell lymphomas, but there are aggressive subtypes. This is illustrated by the two most common forms of CTCL: mycosis fungoides and Sézary syndrome. Although mycosis fungoides is considered a slow-growing variant, Sézary syndrome is aggressive and generally has a poor prognosis. Importantly, even the indolent subtypes can progress in some patients and become difficult to manage.


References
Boyle, A: CTCL 6-10 Times More Common in Veterans; Agent Orange a Factor New Therapies Raise Optimism about Treatment. US Medicine June 12, 2018.

Del Guzzo C, Levin A, Dana A, Vinnakota R, Park Y, Newman J, Langhoff E, Geskin L. 133: The incidence of cutaneous T-cell lymphoma in the veteran population. JID. 2016May;136(5):S24.

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  Cutaneous T-Cell Lymphoma