Abstract
Objective
To determine the efficacy and prognosis of autologous hematopoietic stem cell transplantation (ASCT) as frontline treatment for peripheral T cell lymphoma (PTCL).
Methods
Clinical data from 46 PTCL patients who achieved complete (CR) or partial remission (PR) after ASCT from October 1996 to July 2014 were analysed retrospectively.
Results
Median patient age was 32 (range: 15–68) years. Disease types included PTCL, unspecified type, in 23 patients, anaplastic large cell lymphoma in eight, angioimmunoblastic lymphoma in eight, extranodal NK/T-cell lymphoma in five, and hepatosplenic T-cell lymphoma and enteropathy associated T-cell lymphoma in one each. Of these patients, 80% had Prognostic Index for Peripheral T-cell Lymphoma scores ≥1. Thirty-four patients had pre-transplantation CR and 12 had PR. Median follow up was 37 (6–176) months. The 5-year overall survival (OS) and progression-free survival (PFS) rates were 77.1% and 61.9%, respectively. Multivariate analysis showed that pre-transplantation CR was an independent risk factor for survival, and CR was more common than PR (OS 81% vs 59.3%; PFS 71.8% vs 17.8%).
Conclusion
Frontline consolidation treatment with ASCT was associated with favourable outcomes in patients with PTCL. Pre-transplantation CR was a prognostic factor for survival, suggesting that ASCT may be favoured as front-line consolidation therapy after first complete remission.
Keywords
Introduction
Peripheral T-cell lymphoma (PTCL) is a rare and highly heterogeneous tumour with a higher incidence in Asia compared with Europe and North America (30%–40% vs 15%). 1 PTCLs, apart from anaplastic lymphoma kinase (ALK)-positive anaplastic large T-cell lymphoma (ALCL), respond poorly to traditional chemotherapy. PTCL is more common than B-cell lymphoma, and has poorer long-term survival.1,2 The International T-Cell Lymphoma Study confirmed 10–15-year overall survival (OS) and progression-free survival (PFS) rates of only about 10%. 3 Despite the development of new oncological treatments, an effective treatment for T-cell lymphoma is still lacking, and the search for more effective treatments has become a primary focus for oncologists worldwide. Autologous hematopoietic stem cell transplantation (ASCT) is currently the chief consolidation treatment for T-cell lymphoma following conventional chemotherapy. 1 However, the heterogeneous nature of PTCL in terms of its presentation and response has led to a lack of randomized controlled clinical trials of ASCT for PTCL. In the current study, we retrospectively analysed the response rates and survival outcomes in patients with PTCL treated with ASCT.
Methods
Patients
Fifty-two patients diagnosed with PTCL who received first-line ASCT in our centre between January 1997 and December 2014 were included in this study. Our institutional criteria for proceeding to ASCT included age <70 years, Eastern Cooperative Oncology Group performance status ≤2 points, no active infection, no vital organ impairment (total bilirubin ≤1.5 mg/dl, left ventricular ejection fraction ≥50%, lung function and diffusion lung capacity ≥50% of expected value), and peripheral T-cell lymphoma diagnosis confirmed by immunohistochemistry according to the World Health Organization classification criteria. 4 We excluded six human immunodeficiency virus-positive cases, leaving 46 cases for subsequent analysis.
All histopathologic diagnoses were completed by trained pathologists. Rare or unusual pathologies were submitted to another clinical pathology department for further assessment. Data collected included the results of physical examinations, laboratory haematology, computed tomography (CT) or positron emission tomography/computed tomography (PET/CT) scans of the neck, chest, abdomen and pelvic cavities, and bone marrow aspiration and biopsy. Disease stage was determined using the Ann Arbor staging system. The International Prognostic Index (IPI) and Prognostic Index for T-cell lymphoma (PIT) 5 were also assessed for each patient.
Treatment programs
All patients received 6–8 weeks of pre-transplant induction chemotherapy. One patient received radiotherapy prior to chemotherapy to alleviate symptoms during the early stages of the disease related to severe bone pain. The initial chemotherapy prior to 2011 was CHOP (cyclophosphamide, epirubicin, vindesine, prednisone) or CHOP-like chemotherapy, and the initial treatment after 2011 was either HyperCVAD (course A: cyclophosphamide, vincristine, doxorubicin, and dexamethasone; course B: methotrexate and cytarabine) or GDP-ML (gemcitabine, dexamethasone, cisplatin, methotrexate, pegaspargase). After 2000, intensity-modulated chemotherapy (IMC) was also used routinely in all PTCL patients. IMC was defined as second-line treatment including MINE (ifosfamide, mesna, mitoxantrone, etoposide) or ESHAP (etoposide, cisplatin, methylprednisolone, cytarabine). Twenty patients received IMC after being in PR. The source of the stem cells was mobilized peripheral blood in all patients. Stem cells were mobilized with chemotherapy and granulocyte colony-stimulating factor (G-CSF) or granulocyte–macrophage colony-stimulating factor (GM-CSF) in 41 (89%) cases, and with G-CSF alone in five cases. The doses of G-CSF and GM-CSF were 5–10 µg/kg/day and 125–250 µg/day, respectively. The conditioning regimen was mainly BEAM (carmustine 300 mg/m2, day −7, etoposide 200 mg/m2, days −6 to −3, cytarabine 400 mg/m2, days −6 to −3, melphalan 140 mg/m2, day −2) 6 or CBVC (cyclophosphamide 1.8 g/m2, day −3 to −2, carmustine, 300 mg/m2, day −8, etoposide, 300 mg/m2, day −6 to −4, carboplatin 300 mg/m2, day −7 to −4). The second regimen, which was the routine conditioning regimen for ASCT in lymphoma patients in our institution, included the addition of carboplatin based on cyclophosphamide, carmustine, and etoposide (CBV).7,8
Clinical efficacy and follow-up criteria
The response to therapy was evaluated according to published standards prior to transplantation, 3 and 6 months after transplantation, and every 6 months thereafter. Assessments included a physical examination, complete blood count and biochemistry, bone marrow aspiration and biopsy, and imaging including CT or PET-CT. Complete remission (CR) or undetermined CR, partial remission (PR), stable disease (SD), and progressive disease (PD) were defined according to standard guidelines. 9 If PET-CT was performed, response was assessed according to the rules proposed by the International Harmonization Project in Lymphoma. 10 Post-transplant patients with suspected residual disease were followed up for 6 months or longer. If no changes were noted, this was considered as CR. Transplantation-related death was defined as death within 100 days after high-dosage pre-treatment chemotherapy unrelated to the disease itself, disease recurrence, or progression.
Statistical analysis
The primary endpoints were OS and PFS calculated using the Kaplan–Meier method. 11 OS was defined as the time from diagnosis to patient death or the last follow-up, and PFS was defined as the time from diagnosis to disease progression, death, or last follow-up. Factors affecting OS and PFS were analyzed using Cox’s proportional hazards regression analysis, and variables identified as statistically significant using univariate analysis were subsequently assessed by multivariate analysis. 12 Survival was compared using log-rank tests. 13 Statistical significance was set at a < 0.05 (two-tailed). SPSS 19.0 software (IBM, Chicago, IL, USA) was used for statistical analysis.
Results
Clinical characteristics of patients at diagnosis (In the seventh page, the second line).
PTCL-NOS: peripheral T cell lymphoma unspecified; ALK: anaplastic lymphoma kinase; ALCL: anaplastic large T-cell lymphoma; AITL: angioimmunoblastic T-cell lymphoma; EN-NKTCL: extranodal natural killer/T-cell lymphoma; HSTCL: hepatosplenic gamma/delta T-cell lymphoma; EATL: enteropathy-associated T-cell lymphoma; BM: bone marrow; LDH: lactate dehydrogenase; IPI: International Prognostic Index; PIT: Prognostic Index for Peripheral (Continued.) (Continued.) T-cell Lymphoma; CR: complete remission; PR: partial remission; CHOP: combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone; ECHOP: etoposide, cyclophosphamide, doxorubicin, vincristine, and prednisone. HyperCVAD: including courses A (cyclophosphamide, vindesine, epirubicin, and prednisone) and B (methotrexate and cytarabine); GDP-ML: gemcitabine, dexamethasone, cisplatin, methotrexate, and pegaspargase; MINE: mesna/ifosfamide, mitoxantrone, and etoposide; ESHAP: etoposide, methylprednisolone, cytarabine, and cisplatin.
Transplant-related factors.
BEAM: BCNU, etoposide, cytosine arabinoside and melphalan; CBVC: cyclophosphamide, bleomycin, etoposide, BCNU, and carboplatin; G-CSF: granulocyte colony-stimulating factor; GM-CSF: granulocyte–macrophage colony-stimulating factor.
The median time to neutrophil engraftment was 10 (range: 8–22) days and the median time to platelet engraftment was 10 (range: 7–24) days. The median duration of growth factor support after transplantation was 11 (range: 8–24) days. Thirty-two (69.6%) patients had neutropenic fever and 13 (28.3%) experienced infectious complications. All patients had non-tunnelled central venous catheters inserted into internal jugular or subclavian veins, and only one (2.2%) patient developed a catheter-related infection. All patients remained in hospital until successful neutrophil and platelet engraftment. The median hospital stay was 22 (range: 17–34) days.
Prognosis
As shown in Figure 1, the median follow-up period after diagnosis was 34 (range: 6–176) months, and 35 of 46 patients remained alive. The estimated 5-year OS rate was 71.1% (range: 63.8–%90.4%) and the PFS rate was 61.9% (range: 46.6%–77.2%). Overall, 11 patients died, of whom nine died of disease progression and two of salvage-treatment-related complications. Transplant-related mortality was zero, similar to prior reports in patients with diffuse large B-cell lymphoma.
6
Overall and progression-free survival from diagnosis in peripheral T cell lymphoma patients who achieved complete (CR) or partial remission (PR) after autologous stem cell transplantation (ASCT).
Prognostic risk factors
Univariate analysis of prognostic factors influencing outcome.
OS: overall survival; HR: hazard ratio; CI: confidence interval; PFS: progression-free survival; PR: partial remission; CR: complete remission; BM: bone marrow; IPI; International Prognostic Index; PIT: Prognostic Index for T-cell Lymphoma; LDH: lactate dehydrogenase; CBVC: cyclophosphamide, bleomycin, etoposide, BCNU, and carboplatin; BEAM: BCNU, etoposide, cytosine arabinoside, and melphalan. Note: Italics represent significant differences between the two groups were shown.
Multivariate analysis of potential prognostic factors for progression-free and overall survival.
OS: overall survival; HR: hazard ratio; PFS; progression-free survival; CI: confidence interval. Note: Italics represent significant differences between the two groups were shown.

Survival according to pre-transplant response for the 46 peripheral T cell lymphoma patients. Pre-transplant CR achievement was associated with significantly better OS and PFS than pre-transplant PR. CR: complete remission; PR: partial remission; OS: overall survival; PFS: progression free survival.
Discussion
Retrospective studies of HDT + ASCT as first-line treatment in patients with peripheral T cell lymphoma (PTCL).
Prospective studies on HDT + ASCT as first-line treatment in patients with peripheral T cell lymphoma (PTCL).
We also analysed the prognostic factors that might be associated with OS and PFS. Patients with pre-transplant CR had a better prognosis for ASCT than those who had not achieved CR. Similarly, a previous retrospective study 24 showed that frontline consolidation with ASCT in PTCL patients was associated with a 4-year OS of 76% and PFS of 56%, while the 4-year OS was as high as 84% and PFS was up to 61% in patients with pre-transplant CR. Corradini et al. 23 also reported strong correlations between CR before transplantation and 10-year OS and event-free survival (EFS), with 10-year EFS rates of 62% in patients who achieved pre-transplant CR, compared with only 10% in those who did not. PTCL patients who achieve CR after induction chemotherapy may thus be more suitable candidates for frontline ASCT.
IMC may be administered to improve survival and the CR rate of induction chemotherapy. Hodgkin’s lymphoma patients with advanced disease and positive PET assessment after two courses of chemotherapy who were given the bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine and prednisone (BEACOPP) regimen demonstrated better survival than those who received doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD). 25 In addition, intensified immunochemotherapy or rituximab, doxorubicin, cyclophosphamide, vindesine, bleomycin, and prednisone (RACVBP) has been used in low-risk 18–59-year-old patients with diffuse large B-cell lymphoma (according to IPI score), with survival rates exceeding those for the standard RCHOP program. 26 Although no previous studies have supported a similar approach for improving survival in PTCL patients, our results indicated that 60% of patients with PR after four courses of induction chemotherapy achieved CR after IMC, with a higher CR rate in the IMC compared with the non-IMC group (60% vs 33%, P = 0.365). However, the difference in survival between the groups was not significant, possibly because of the small number of cases involved.
New drug applications in China are generally slow to be approved, and improvements in existing pre-transplant therapies are therefore needed. Various aspects of PTCL remain incompletely understood, though a limited number of retrospective and prospective studies of ASCT in PTCL have indicated that disease progression occurs early during traditional chemotherapy, and about 30% of patients miss the opportunity for transplantation. In our centre, 231 patients younger than 70 years were diagnosed with PTCL, and although 173 of them received chemotherapy between January 1997 and December 2014, only 52 met the criteria for ASCT in our center. Moreover, ASCT was associated with limited improvements in survival of patients with PR, suggesting that new drug regimens with histone deacetylase inhibitors,27–30 new nucleotide analogues, 31 bortezomib,20,32 and anti-CD30 monoclonal antibody33–35 should be investigated in these patients. Genomics and proteomics are currently providing new therapeutic targets and biomarkers that may offer potential therapies for this type of lymphoma. PTCL classification is based not only on clinical and morphological features, but also on genetic and epigenetic factors. Different subclasses of PTCL may thus require specific treatments, and ALK inhibitors may be an appropriate option in ALK-positive anaplastic large cell lymphoma (ALCL) patients.36–38
This study had some limitations. Although we studied ASCT over an 18-year period, 96% of patients received their transplants after 2000. This was a retrospective study and was therefore subject to recall bias, and precise relapse data for some patients after transplantation could not be located. In addition, our subjects were younger than those in Western reports, possibly because of earlier onset of PTCL in China, which may be based on socioeconomic and ethnic differences.
In conclusion, frontline ASCT as consolidation therapy is associated with a good prognosis in patients with PTCL. Patients who achieve CR prior to ASCT may have a significantly better prognosis than those who achieve PR, but further randomized prospective studies are needed to confirm this conclusion.
Footnotes
Declaration of conflicting interests
The authors declare that there is no conflict of interest.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
