ANALYSIS OF T-CELL RECEPTOR GENE REARRANGEMENT IN LYMPH-NODES OF PATIENTS WITH MYCOSIS-FUNGOIDES - PROGNOSTIC IMPLICATIONS

Objective: To determine the prognostic value of analyzing lymph node ( LN) DNA from patients with mycosis fungoides for the presence of a mon oclonal T-cell population. Design: Inception cohort study. Setting: A tertiary care referral center in Seattle, Wash. Patients: Fifty-five u niformly staged patients with the diagnosis of mycosis fungoides and w ho had a lymph node biopsy, 21 with clinically abnormal nodes and 34 w ith normal nodes. Main Outcome Measures: Lymph nodes were evaluated by Southern blot analysis for T-cell receptor beta-chain (TCRB) gene rea rrangement and by histopathologic examination for the LN classificatio n using the National Cancer Institute system. Patients were observed c linically for a mean (+/- SD) of 4.7 +/- 3.4 years. Results: Patients with detectable TCRB gene rearrangement in lymph node DNA had an incre ased likelihood of a poor clinical outcome and a decreased probability of survival (P<.001 for both) compared with patients with the TCRB ge rmline. Although patients with clinically enlarged nodes were more lik ely to have the TCRB gene rearranged, those with normal nodes and the TCRB gene rearranged also had a poor clinical outcome and a decreased probability of survival. Similar to those with the TCRB gene rearrange d, most patients with advanced histopathologic changes (LN3 and LN4) h ad a poor prognosis. The presence of a rearranged TCRB gene, however, correctly predicted some patients with intermediate LN scores (LN2) wh o had a poor clinical outcome. Conclusions: Detection of a monoclonal T-cell population, as demonstrated by a rearranged TCRB gene on Southe rn blot analysis, in LNs of patients with mycosis fungoides is predict ive of a poor clinical outcome and a reduced probability of survival. Lymph node TCRB gene analysis provides additional prognostic informati on for patients with mycosis fungoides with intermediate LN histopatho logy.