T-cell receptor gene rearrangement clonality, flow cytometry status, and associated outcomes in early-stage CTCL.

Abstract

e20087 Background: Cutaneous T-Cell Lymphoma (CTCL) is a monoclonal lymphoproliferative disease. Studies hypothesize T-cell receptor gene (TCR) rearrangement and flow cytometry as means of predicting those at risk of aggressive disease. We aimed to assess outcomes in early-stage disease by TCR clonality and flow cytometry in peripheral blood. Methods: We performed a retrospective analysis of 328 pts with early-stage (1-2A) CTCL using our internal CTCL database with protocol approved by our institutional review board (IRB00045798). Early-stage CTCL pts included were those with TCR clonality and/or flow cytometry in the peripheral blood obtained within 6 months of diagnosis and/or at initial check. Overall survival (OS) and time to next treatment (TTNT) were examined. Missing data or OS/ TTNT values larger than 25 years were excluded. Univariate/multivariate models and Kaplan-Meier analyses were run for both OS and TTNT. Results: In the cohort (n = 328) the median age was 53.2 years (8.6-87.5), with equal sex predominance, and distribution among stages. 261 pts had TCR clonality assessed. 78.5% (n = 205) were non-clonal and 21.5% (n = 56) were clonal. 284 pts had flow assessed (n = 44/328 with missing data). 89.8% (255/284) were flow (-), initially. Of those without clonality, 95.29% (n = 182 p < 0.001) were flow (-). 76% (38/56 p < 0.001) with TCR clonality were flow (-). TCR clonality in the blood was not associated with a survival nor TTNT by univariate or multivariate analyses. Age at diagnosis was significant contributing to OS and TTNT in multivariate analyses (HR 1.04,CI 1.01-1.06,p < 0.01;HR 1.01, CI 1.00-1.02,p = 0.033, respectively). Flow cytometry status was not associated with TTNT. Flow cytometry in the blood was associated with survival but was limited to stage 2A pts (n = 98, p = 0.0171). Median survival of those with flow negative results was 20.8 yrs (CI 11.8,NA, p = 0.0171) with a 5-year survival of 95.8%(CI 87.4%-98.6%) compared to those with positive results of 12 yrs (CI 1.3, NA), p = 0.0171) with a 5-yr survival of 80.8%(CI 42.3%-94.9%). Conclusions: We found no difference in OS or TTNT by TCR status in blood for stage 1-2A disease. Flow cytometry status and OS differed in stage 2A pts. Significance of TCR clonality or flow cytometry in early-stage disease remains unclear. Findings raise questions of needing to risk-stratify in early-stage disease by TCR gene rearrangement or flow cytometry. Those with stage 2A disease, flow cytometry status may confer some benefit. Larger cohorts needed to further investigate these findings.