Long-term outcome of patients with peripheral T-cell lymphoma treated with first-line intensive chemotherapy followed by autologous stem cell transplantation.

Background: Peripheral T-cell lymphomas (PTCL) are infrequent subtypes of non-Hodgkin's lymphomas. The clinical course is aggressive and the median survival is about 2-3 years. An optimal first-line chemotherapy protocol has not been established and the role of high-dose therapy with autologous stem cell transplantation (ASCT) is still unclear.

Aim: To analyze the long-term outcome of unselected PTCL patients treated with intensive first-line chemotherapy with high-dose therapy and ASCT.

Method: Here we report our experience with 29 patients with PTCL. The histological subtypes were as follows: peripheral T-cell lymphoma, not otherwise specified n=13; anaplastic large cell lymphoma (ALCL) ALK-negative n=5; ALCL ALK-positive n=3; ALCL with an unknown ALK status n=3; angioimmunoblastic lymphoma n=1; hepatosplenic lymphoma n=1; Sézary syndrome n=1; and enteropathy-associated T-cell lymphoma n=2. The median age at diagnosis was 48 years (29-64), most patients had advanced Ann Arbor stages (22 patients, 77%), IPI score ≥3 was found in 13 (45%) and PIT score ≥2 in 17 (59%) of the 29 patients. Eighteen patients received first-line high-dose therapy and autologous SCT consolidation; two patients were consolidaed with allogeneic SCT in the 1st complete remission and one patient in the 1st relapse. Ten patients with FDG-avid lymphoma were examined with integrated Positron emission tomography/ Computed tomography (PET/CT) at the time of diagnosis and after first-line therapy, two other patients were assessed with Positron emission tomography/ Computed tomography (PET/CT) only at time of restaging.

Results: Nineteen (66%) patients achieved complete remission, 3 (10%) partial remission and 7 (24%) patients failed the treatment. The overall response rate was 76%. PET negativity (complete metabolic response) after therapy was achieved in 8/12 (75%) individuals. After a median follow-up of 55.1 months, 14 (48.3%) patients relapsed or progressed and nine patients died (lymphoma progression). Eleven patients (50% of chemosensitive patients) survived more than 50 months. Three of the long-term survivors were treated with allogeneic SCT. The 2-year event-free survival (EFS) was 52% (95% confidence interval [CI], 0.33-0.71); the 2-year overall survival (OS) rate reached 65% (95%CI, 0.47-0.84). PET negativity was associated with a lower probability of relapse (chi-square p=0.09).

Conclusion: Our data show that intensive first-line therapy with etoposide-doxorubicine-based regimens and ASCT consolidation may lead to long-term disease control in about a half of patients with chemosensitive PTCL. Achievement PET negativity is probably an essential prerequisite for long-term complete remission.