Demographic patterns of cutaneous T-cell lymphoma incidence in Texas based on two different cancer registries

Abstract

Cutaneous T-cell lymohomas (CTCLs) are rare, but potentially devastating malignancies, with Mycosis fungoides and Sézary Syndrome being the most common. In our previous study, we identified and described regions of geographic clustering of CTCL cases in Texas by analyzing ~1990 patients using two distinct cancer registries. In the current work, we describe in detail demographic patterns for this malignancy in our study population and apply logistic regression models to analyze the incidence of CTCL by sex, race, age, and clinical stage at the time of diagnosis. Furthermore, using Fisher's exact test, we analyze changes in incidence over time in the identified Houston communities with unusually high CTCL incidence. While CTCL primarily affects Caucasian individuals >55 years old, we confirm that it presents at a younger age and with more advanced disease stages in African-American and Hispanic individuals. Also, we demonstrate a significant increase in CTCL incidence over time in the identified communities. Spring, Katy, and Houston Memorial areas had high baseline rates. Furthermore, a statistically significant disease surge was observed in these areas after ~2005. This report supplements our initial study documenting the existence of geographic clustering of CTCL cases in Texas and in greater detail describes demographic trends for our patient population. The observed surge in CTCL incidence in the three identified communities further argues that this malignancy may be triggered by one or more external etiologic agents.

Keywords: Cutaneous T-cell lymphoma (CTCL); Sézary syndrome; demographic patterns; geographic clustering; mycosis fungoides.

Figure 1

Graphic representation of patient characteristics by race (MDACC database results). (A) Patient age of diagnosis distribution by race. (B) Clinical disease stage at the time of diagnosis by race.

Figure 2

Incidence rates of CTCL in the identified communities over time. (A) Graphical comparison of CTCL incidence rate for communities with high CTCL incidence during 2000–2005 versus 2006–2010 years (MDACC database results). (B) Fisher's exact test comparison of CTCL incidence in Houston communities to population rate of 6.4 cases per million per year.