Clinical characteristics and treatment of 69 patients with extranodal natural killer T-cell lymphoma

This study was conducted to retrospectively analyze the clinical characteristics and survival of patients with extranodal natural killer-T cell lymphoma (ENKL) and compare different treatment regimens. The univariate analysis demonstrated that survival was worse for patients with extranasal primary tumors, Eastern Cooperative Oncology Group performance status (ECOG PS) scores of ≥2, International Prognostic Index (IPI) scores of 3-5, Ann Arbor stage III and IV disease, B symptoms, lymph node involvement and absence of radiotherapy. The Cox analysis demonstrated that ECOG PS score, stage, IPI, presence of B symptoms and radiotherapy were independent prognostic factors for overall survival (OS). The effect of diverse therapies on survival was then analyzed, and it was found that the 5-year survival rate of patients receiving chemoradiotherapy differed significantly from that of patients who received chemotherapy alone [hazard ratio (HR)=0.347, P=0.0203], but did not differ significantly from the survival of patients treated with radiotherapy alone (HR=1.534, P=0.6371). A subgroup analysis revealed a difference between the radiotherapy and non-radiotherapy groups for patients with extranasal-type stage III/IV disease. It was concluded that ECOG score, stage, IPI, presence of B symptoms and radiotherapy were independent prognostic factors for OS in patients with ENKL. The addition of radiotherapy achieved better outcomes compared with chemotherapy alone, but no difference was observed between chemoradiotherapy and radiotherapy. Patients with advanced-stage disease may also benefit from radiotherapy.