Clinical Characteristics and Prognostic Factors of Mature T-Cell Lymphomas. A Single Center Experience on 39 Cases.

Introduction: Mature T cell lymphomas are a rare and heterogeneous group of malignancies characterized by a poor prognosis. They usually present with advanced-stage disease and generally have a significantly worse outcome compared with aggressive B-cell lymphomas. The aim of the present study was the retrospective analysis of clinical and laboratory characteristics of patients with mature T cell lymphomas with the view to identify factors of prognostic significance.

Patients and Methods: 39 patients with mature T cell lymphoma, classified according to WHO classification, diagnosed in our institution within a 17 year period were analyzed. Cases with anaplastic and cutaneous lymphomas were excluded. There were 25 males and 14 females with a median age of 61 (26–80). 3 patients had stage I,. 7 stage II, 10 stage III and 19 stage IV disease. B symptoms were present in 28/39 cases and bulky disease in 6/39 cases. All cases were risk stratified according to the International Prognostic Index (IPI). 9 patients had IPI 0/1, 9 had IPI 2, 10 had IPI 3 and 8 IPI 4/5. In 3 cases the IPI could not be defined. 21 patients were treated with CHOP like therapy, 11 with COP and 7 with other treatment. The size and the immunophenotype of the neoplastic cell population in the diagnostic biopsy (Τ4, Τ8 or mixed), the patients’ clinical characteristics and their laboratory findings were analyzed to identify factors of prognostic significance.

Results. 17/39 patients (47.6%) achieved CR, 7/39 PR, while 6 had stable and 7 progressive disease. 2 patients died during induction treatment. 21/39 patients developed recurrent disease and the median disease free survival (DFS) was 78 months. Factors associated with significantly worse DFS were age above 60 (p=0.0005) and the presence of hepatomegaly at diagnosis (3 vs 78 months, p=0.0219), while the presence of extranodal disease was of borderline significance (p=0.0629). The patients’ median survival was 24 months. Factors associated with significantly shorter survival were female gender (14 vs 61 months, p=0.0396), the presence of supradiaphragmatic disease (p=0.0337) and eosinophilia at diagnosis (p=0.0467). Τhe IPI scoring system could distinguish between groups with a significant difference both in DFS and overall survival. DFS for IPI 4/5 was significantly shorter vs IPI 0-3 (p=0.0009). Patients with IPI 0/1 had a median survival 271 months, with IPI 2/3 24 months and with IPI 4/5 8 months (p=0.002). Histological characteristics like cell size or immunophenotype of the neoplastic cell were not important for prognosis.

Conclusions. Mature T cell lymphomas constitute an heterogenous group of aggressive lymphomas that can be prognostically evaluated using clinical parameters. The IPI scoring system can identify subgroups with significant differences both in terms of DFS and overall survival. The analysis of larger number of cases or of histological characteristics may be helpful in the identification of other clinical or laboratory parameters that will increase the discriminative capacity of the IPI scoring system in this group of aggressive lymphomas.