Central nervous system relapse in peripheral T-cell lymphomas: A Swedish lymphoma registry study.

Central Nervous System (CNS) relapse in non-Hodgkin lymphomas (NHL) carries a very poor prognosis. Risk factors and outcome have been studied in aggressive B-cell lymphomas but very little is known about the risk in peripheral T-cell lymphoma (PTCL). We aimed at analyzing risk factors for CNS involvement at first relapse or progression, and the outcome of these patients, in a large population-based cohort of PTCL patients. Twenty-eight out of 625 patients (4.5%) developed CNS disease over time. In multivariable analysis disease characteristics at diagnosis independently associated with an increased risk of later CNS involvement were involvement of >1 extranodal site (Hazard Ratio [HR] 2.60, 95% Confidence Interval [95% CI] 1.07-6.29, p=0.035), skin (HR 3.51, 95% CI 1.26-9.74, p=0.016) and gastrointestinal involvement (HR 3.06, 95% CI 1.30-7.18, p=0.010). The outcome of relapsed/refractory patients was very poor and CNS involvement was not associated with a significantly worse outcome compared to relapsed/refractory patients without CNS involvement in multivariable analysis (HR 1.6, 95% CI 0.96-2.6, p=0.074). The results from the present study indicate that CNS relapse in PTCL occurs at a frequency similar to what is seen in aggressive B-cell lymphomas, but the poor outcomes in relapse are largely driven by systemic rather than CNS disease.