Peripheral T-cell lymphomas: Initial features, natural history, and prognostic factors in a series of 174 patients diagnosed according to the REAL Classification

Background: Peripheral T-cell lymphomas (PTCL) account for about 10% of all lymphomas in Western countries. The aim of the present study is to analyze the initial characteristics and prognostic factors in a large series of PTCL patients. Patients and methods: 174 patients (105 male/69 female; median age 61 years) were diagnosed with PTCL according to the R.E.A.L. Classification in nine Spanish institutions between 1985 and 1996. Cutaneous lymphomas and T-cell chronic lymphocytic/prolymphocytic leukemia were excluded from the study. Univariate and multivariate analyses were used to assess the prognostic value of the main initial variables. Results: The distribution according to histology subgroup was: PTCL unspecified, 95 cases (54.4%); anaplastic large-cell Ki-1-positive (ALCL), 30 cases (17%); angioimmunoblastic T cell, 22 cases (13%); angiocentric, 14 cases (8%); intestinal T cell, 12 cases (7%), and hepatosplenic gamma delta T cell, one case (0.6%). As compared to the other types, ALCL presented more frequently in ambulatory performance status, without extranodal involvement, in early stage, normal serum beta 2-microglobulin (B2M) level and low-risk international prognostic index (IPI). Most patients were treated with adriamycin-containing regimens. The overall CR rate was 49% (69% for ALCL vs. 45% for other PTCL; P < 0.02). The risk of relapse was 48% at four years. Median survival of the series was 22 months (65 months for ALCL vs. 20 months for other PTCL; P = 0.03), with a four-year probability of survival of 38% (95% confidence intervals (95% CI): 28-48). In the univariate analysis, in addition to the histology, older age, poor performance status, presence of B-symptoms, extranodal involvement, bone marrow infiltration, advanced Ann Arbor stage, high serum LDH, high serum B2M, and intermediate- or high-risk IPI were related to poor survival. In the multivariate analysis the histologic subgroup (ALCL vs. other PTCL) (P = 0.02; response rate (RR): 4.3), the presence of B-symptoms (P = 0.02, RR: 2.2), and the IPI (low vs. high) (P = 0.04, RR: 2) maintained independent predictive value. When the analysis was restricted to the unspecified subtype, only IPI had independent prognostic value (P = 0.003; RR: 3.5). Conclusions: PTCL have adverse prognostic features at diagnosis, respond poorly to therapy and have short survival, with no sustained remission. ALCL constitutes a subgroup which responds better to therapy and has a longer survival.