Loading...
Since the mid-1980s, analysis of T-cell receptor (TCR) gene rearrangement has been applied to the study of mycosis fungoides (MF) and Sézary syndrome (SS). Higher skin stage is associated with lymph node (LN) involvement in MF, and LN involvement is known to be associated with a poor prognosis. These authors retrospectively evaluated the use of polymerase chain reaction/single-strand conformational polymorphism (PCR/SSCP) testing for TCR rearrangement to predict clinical outcome. LN specimens from 33 patients with MF and 27 patients with SS were analyzed by PCR/SSCP, and the results were correlated with clinical, skin, and histologic lymph node stages.
In the patients with MF, those with higher skin stage were more likely to have LN involvement (80% with stage T2 had no or limited involvement, and 64% with stage T3 had advanced involvement). T-cell clones were more frequently detected in patients with greater lymph node involvement (6 of 19 with no-to-limited involvement and 13 of 14 with advanced involvement had T-cell clones). Mean survival from time of biopsy ranged from 16 to 26 months in patients with clones and was 72 months in those without. Using proportional hazards regression analysis (PHRA), clinical stage and molecular LN stage were independent prognostic indicators after correcting for age and sex, and histologic LN stage approached significance. However, in multivariable regression analysis, no single variable provided independent prognostic information.
Among the patients with SS, 81% had T-cell clones. T-cell clones were more common in patients with higher LN stages, reaching 100% at stage T4. Median survival time was shorter in those who had clones (16.5 months) than those who did not (50.5 months). Only histologic LN stage was an independent predictor with PHRA, and, in regression analysis, no variable was a reliable independent predictor.
Fraser-Andrews EA et al. Molecular staging of lymph nodes from 60 patients with mycosis fungoides and Sézary syndrome: Correlation with histopathology and outcome suggests prognostic relevance in mycosis fungoides. Br J Dermatol 2006 Oct; 155:756-62.
Comment
T-cell clone status mirrors clinical status in patients with MF and SS. An earlier study (see Journal Watch Dermatology Oct 25 2005) found clinical stage to be the most important prognostic indicator in MF but also suggested, as do the current findings, that TCR analysis provides prognostic information in patients with early LN involvement. The statistical power in this study may have been insufficient to demonstrate TCR rearrangement’s worth as an independent prognostic factor, but the test can identify patients with poor prognosis who need more-aggressive therapy. In this era of cost containment, such data might suggest when TCR gene rearrangement testing should be part of LN staging.