Central nervous system relapse in peripheral T-cell lymphomas: a Swedish Lymphoma Registry study.

Central nervous system (CNS) relapse in non-Hodgkin lymphoma (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, as well as the outcome of these patients, in a large population-based cohort of patients with PTCL. 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 for later CNS involvement were involvement of more than 1 extranodal site (hazard ratio [HR], 2.60; 95% confidence interval [CI], 1.07-6.29; P = .035) and skin (HR, 3.51; 95% CI, 1.26-9.74; P = .016) and gastrointestinal involvement (HR, 3.06; 95% CI, 1.30-7.18; P = .010). The outcome of relapsed/refractory patients was very poor, and CNS involvement was not associated with a significantly worse outcome compared with relapsed/refractory patients without CNS involvement in multivariable analysis (HR, 1.6; 95% CI, 0.96-2.6; P = .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.