Retrospective analysis of 23 cases with peripheral T-cell lymphoma, unspecified: clinical characteristics and outcome

Peripheral T-cell lymphomas (PTCL) are a heterogeneous group of post-thymic malignancies relatively uncommon in the Western world and their prognosis and therapeutic approach are still not well defined. The aim of this study was to retrospectively analyze the clinical, hematological and histological features at diagnosis, the relevance of the International Prognostic Index and the outcome of a group of 23 patients affected by peripheral T-cell lymphoma, unspecified (PTCL-U), according to the Revised European-American Classification of Lymphoid Neoplasms (REAL), observed between September 1985 and April 1995 at our Institution.

Patients were separated into different prognostic groups according to Ann Arbor stage, cell size and International Prognostic Index. All patients had been treated with multiagent combination chemotherapy, mainly CHOP (9 cases) and F-MACHOP (9 cases), and were evaluable for response. The treatment was intensified with allogeneic bone marrow transplantation (BMT) in 1 patient and with autologous BMT in 4 patients.

Median age was 55 (range 18-77) years and 70% of the patients were males. Four patients were in stage II (17%), 5 in stage III (22%) and 14 in stage IV (61%). Patient risk was classified according to the International Prognostic Index as follows: 8 cases (35%) low risk, 2 cases (9%) low-intermediate, 8 cases (35%) high-intermediate, 5 cases (21%) high. Median follow-up time was 20 months (range 2-132). Median progression-free survival (PFS) and overall survival (OS) for all the patients studied were 10 and 34 months, respectively. Stage IV was associated with a poorer response rate and a shorter PFS (median 6 months) and OS (median 32 months). No statistical correlation was found between cell size and overall response (complete + partial remission), PFS (p = 0.38) or OS (p = 0.59), although a better trend was observed for the large cell group. A less favorable outcome was observed in patients in the high-intermediate + high risk groups, where median PFS and OS were 7 and 24 months, respectively, than in patients in the low + low-intermediate risk groups. No difference in response or outcome was detected between patients treated with the CHOP and the F-MACHOP regimens, while all 5 patients given high-dose chemotherapy and BMT are alive and in CR.

Our experience shows that PTCL-U are rare lymphomas frequently having an aggressive presentation. The response to conventional polychemotherapeutic regimens like CHOP or F-MACHOP is generally poor, especially in those cases with advanced stage and a high-intermediate or high International Prognostic Index. The observation that all five patients who were treated with bone marrow transplantation are alive and in complete remission suggests using this strategy, particularly in young patients with a poor International Prognostic Index.