Promising clinical outcomes of sequential and "Sandwich" chemotherapy and extended involved-field intensity-modulated radiotherapy in patients with stage I E /II E extranodal natural killer/T-cell lymphoma

The optimal treatment for the rare subtype of non-Hodgkin lymphoma, extranodal natural killer/T-cell lymphoma (ENKTL), nasal-type, has not been clearly defined. The purpose of the study was to investigate the efficacy of sequential and "Sandwich" chemotherapy and extended involved-field intensity-modulated radiotherapy (IMRT) in patients with stage I /II extranodal ENKTL, nasal-type. One hundred and fifty-five patients with stage I /II nasal-type ENKTL were enrolled in the study, including 99 patients treated with sequential chemotherapy and extended involved-field IMRT (SCRT) and 56 patients with "Sandwich" chemotherapy and extended involved-field IMRT and chemotherapy (SCRCT). All patients were treated with extended involved-field IMRT with median dose of 54.6 Gy to the primary tumor and positive lymph nodes. Ninety-four patients had Ann Arbor stage I disease, and 61 patients had stage II disease. The 5-year rates of loco-regional recurrence (LRR), progression-free survival (PFS), and overall survival (OS) were 17.0%, 78.5%, and 84.7%, respectively. Univariate analysis revealed that EBV DNA copy after treatment (normal vs elevated level) was significant prognostic factor for LRR, PFS, and OS (P