Track

Clinical Studies

Abstract

Cutaneous T-cell lymphoma (CTCL) has an annual incidence of 8.55 per million people¹.  Mycosis fungoides (MF) and Sezary syndrome (SS) are the two most common subtypes of CTCL² . Blood disease burden is a critical prognostic factor in the TNMB staging system for MF/SS ³. This study aimed to assess the relationship between cutaneous and blood disease burden in a cohort of 389 MF/SS patients at a tertiary academic CTCL clinic between 1/1/2012 and 12/31/2021 who had at least one clinic visit and at least one flow cytometry or peripheral blood morphology analysis. We assessed the relationship between affected body surface area (BSA) and blood stage per the 2022 ISCL/USCLC/EORTC criteria⁴. We also assessed correlations between BSA and several quantitative blood disease parameters including: absolute counts and percentages of CD4+/CD7- and CD4+/CD26- T-cells, CD4:CD8 ratio, and absolute convoluted lymphocyte counts. Last, we compared BSA to pathologists’ qualitative interpretations regarding the presence of discrete abnormal T-cell populations per flow cytometry and peripheral morphology. Due to patients’ heterogenous initial clinical presentations, we hypothesized that blood disease burden would not be associated with BSA. In contrast to our hypothesis, blood stage was associated with higher BSA. All continuous blood burden parameters except absolute CD4+/CD7- T-cell count and absolute convoluted lymphocyte count were associated with higher BSA. Additionally, qualitative interpretations of flow cytometry and peripheral morphology were associated with higher BSA. This study highlights the importance of using multiple flow cytometric parameters of blood burden to accurately and efficiently diagnose MF/SS of any stage.