Practical management of natural killer/T-cell lymphoma

Natural killer (NK)/T-cell lymphoma is a distinct clinic-pathological entity in the WHO classification of lymphoid neoplasms. It is uncommon among all lymphomas but is more prevalent in Asian countries. The pathogenesis remains unknown despite its strong association with Epstein-Barr virus (EBV) infection. Conventional chemotherapeutic regimens such as CHOP do not appear to be effective and the prognosis is dismal especially in advanced-stage disease. The major objective of this review will focus on the practical management of patients with NK/T-cell lymphoma especially on the treatment using L-asparaginase-based regimen. Data on gene and micro-RNA expression profiling studies are also discussed which may impact the development of new drugs targeting specific oncogenic pathways.

Gene expression profiling and other genetic studies have revealed distinct oncogenic signalling pathway activation and have identified potential targets for therapeutic intervention in NK/T-cell lymphoma. Quantitative measurement of EBV-DNA in cell-free plasma, rather than cellular EBV-DNA level predicts overall survival as shown by a recent prospective study. L-Asparaginase-based chemotherapeutic regimens such as SMILE and AspaMetDex have been demonstrated to be highly effective in the treatment of advanced-stage and relapsed/refractory disease.

An accurate histopathological diagnosis and precise staging using PET computed tomography (PET-CT) scan are essential in the management of patients with NK/T-cell lymphoma. Recent prospective trials have demonstrated that L-asparaginase-based chemotherapeutic regimen is highly effective and improves outcome of patients with locally advanced as well as disseminated disease. The impact of haematopoietic stem cell transplantation remains to be defined.