Peripheral T-cell lymphoma (PTCL) represents a heterogeneous group of nodal and extranodal mature T-cell lymphomas, which constitute about 5 - 10% of all non-Hodgkin lymphomas (NHLs) in Western countries compared to 20 - 30% of all lymphomas in the East Asia. The most common histologies include PTCL, not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), and anaplastic large cell lymphoma (ALCL) [3]. Most of these subtypes include a high percentage of patients with advanced disease stage, widespread dissemination and aggressive behavior. As a result, the prognosis of PTCL remains dismal, with the 5-year overall survival (OS) rate for many of these subtypes ranging between 25 and 45%, except for ALCL (ALK ), which demonstrates a better 5-year OS (70%) [4 - 6]. Thus, new therapeutic strategies are needed to improve the survival of patients with PTCL.
Current multiagent chemotherapeutic regimens for patients with PTCL are extrapolated mainly from therapeutic paradigms of B-cell lymphomas, with the cornerstone treatment being an anthracycline-containing regimen. Although some patients with PTCL can be cured with these approaches, relapsed and chemorefractory disease constitutes a significant clinical dilemma in the care of these patients [7]. At present, high dose chemotherapy with autologous stem cell support seems to offer potential curative treatment for those patients with relapsed PTCL who are responsive to salvage chemotherapy [8]. However, the majority of elderly patients with relapsed or refractory PTCL cannot benefit from high dose chemotherapy as a result of advanced age, significant comorbidities, poor functional status, toxicities from previous treatments and inherent chemoresistance [9]. Conventional salvage regimens have been mostly designed for younger or fitter populations, and can hardly be delivered to these elderly patients due to marked hematologic and non-hematologic toxicities, mainly involving renal and neurological functions [10]. Therefore, it is imperative that innovative salvage regimens based on drug combinations with increased efficacy and reduced toxicity be explored for the management of elderly patients with relapsed or refractory PTCLs.
BCD chemotherapy regimen is proposed as the salvage treatment for relapsed or refractory PTCLs in this study protocol, which would be expected to show more promising clinical outcomes than that of bendamustine single therapy. Platinum combination with bendamustine is a theoretically ideal salvage regimen for the patients of PTCLs because these both agents are highly effective drugs in lymphoma treatment and have rare cross-resistance. Carboplatin was selected as a platinum agent for combination with bendamustine, which is a second generation platinum agent and has a less neurotoxicity than that of cisplatin, considering use for previously treated patients with vinc alkaloid agents.