The role of radiotherapy and chemotherapy in the treatment of early stage extranodal natural killer T cell lymphoma, nasal type, in the era of multimodal treatment

Abstract

Purpose: To evaluate the role of radiotherapy (RT) and chemotherapy in the treatment of early stage extranodal natural killer/T-cell lymphoma (ENKTL).

Patients and Methods: Fifty-five patients with stage I or II ENKTL who were treated with RT between 1999 and 2013 were retrospectively analyzed. The median age was 54 years old (range, 24-81). Thirty-nine patients (71%) had Ann Arbor stage I diseases, and 16 patients (29%) had stage II diseases. Patients were grouped by treatment modalities: RT alone (n=19, 35%), upfront chemotherapy+RT (CT; n=16, 29%), and concurrent chemoradiotherapy (CCRT; n=20, 36%). Median RT dose was 48 Gy. Patient characteristics between each treatment group were well balanced. Patterns of failure and survival were analyzed.

Results: The overall response rate after RT was 94.6%. The most common failure was distant failure (10 patients), and 7 patients experienced local failure, comprising 5 in-field failures and 2 out-field failures. Equal frequency (16%) of both local and distant failure occurred in RT alone group and the most common failure sites were local failures (19%) in upfront CT+RT group, and distant failures (25%) in CCRT group. After 56 months of median follow-up (range, 1-178 months), the 5-year overall survival (OS) and progression free survival (PFS) rates were 66% and 54%, respectively. The 5-year OS rates for RT alone, upfront CT+RT, and CCRT groups were 76%, 69%, and 55%, respectively.

Conclusion: In the era of multimodal treatment for ENKTL, RT alone with advanced techniques deserves more attention for the local disease control. Maintenance treatment containing more effective chemotherapy should be considered for distant disease control.