A retrospective clinical analysis of Japanese patients with peripheral T-cell lymphoma not otherwise specified: Hokkaido Hematology Study Group.

Peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) comprises a group of heterogeneous lymphomas that do not fit any other identified PTCL-subgroup and show poor prognosis. To clarify clinical aspects of Japanese PTCL-NOS patients, the Hokkaido Hematology Study Group conducted a multicenter retrospective analysis. The median age of the 107 patients (male 65.4 %) was 67 years. The majority (82.4 %) had stage III/IV disease. Following the international prognostic index, 65.7 % were categorized as high intermediate or high risk. Primary chemotherapy was selected in 96 (90 %) patients, 86 of whom received anthracycline regimens. Sixteen patients received high-dose chemotherapy with autologous stem cell transplantation. Forty-eight (52 %) of the 92 evaluable patients achieved complete remission (CR) or CR/unconfirmed after the primary treatment, in which 22 (46 %) relapsed. The estimated 5-year overall survival (OS) of all patients was 35 %. Three independent risk factors (RFs) associated with OS, bulky disease (hazard ratio HR = 5.324; p = 0.019), age >60 years (HR = 3.015; p = 0.025), and platelet count less than 10 × 10(4)/μL (HR = 3.999; p = 0.036), were identified in a multivariate analysis. Using these three RFs, the OS curves were significantly stratified into three risk groups (low risk, 0 RFs, 3-year-OS 72 %; intermediate risk, one RF, 30 %; high risk, two or three RFs, 0 %; p = 0.0005). These findings may provide valuable information for the management of Japanese PTCL-NOS patients.