Treatment of localized extranodal NK/T cell lymphoma, nasal type.

Extranodal NK/T cell lymphoma predominantly presents as a localized disease in the upper aerodigestive tract from the nasal cavity to the hypopharynx. Because radiotherapy has better outcomes than chemotherapy with reduced locoregional failure, it should be considered the preferred first-line therapy. However, the addition of chemotherapy is appropriate as part of the initial treatment because of the frequent systemic progression or relapse after radiotherapy. At present, the combination of radiotherapy and chemotherapy can be considered an effective treatment option, and the promising results of recent prospective studies with concurrent chemoradiotherapy support this treatment strategy. In contrast, intensive chemotherapy should be considered as initial treatment for patients with tumors in non-upper-aerodigestive-tract sites, such as skin or intestine because they usually progress to systemic disease. Likewise, for patients with poor prognostic factors, such as a high NK lymphoma prognostic index, autologous stem cell transplantation during remission and additional treatments with central nervous system prophylaxis may be beneficial. However, the precise role of these treatments needs to be clarified further by prospective clinical trials. Thus, a prospective study is warranted to explore a risk-adapted treatment strategy of applying initial chemoradiotherapy and additional consolidation treatments.