Radiotherapy improves survival in early stage extranodal natural killer/T cell lymphoma patients receiving asparaginase-based chemotherapy.

// Yi-Yang Li 1, 2, 3, * , Ling-Ling Feng 2, 3, * , Shao-Qing Niu 4 , Han-Yu Wang 2, 3 , Lu-Lu Zhang 2, 3 , Liang Wang 2, 5 , Zhong-Jun Xia 2, 5 , Hui-Qiang Huang 2, 6 , Yun- FeiXia 2, 3 , Yu-Jing Zhang 2, 3 , Xi-Cheng Wang 1 1 Department of Oncology, the First affiliated Hospital of Guangdong Pharmaceutical University, Guangdong 510080, People’s Republicof China 2 State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong 510060, People’s Republicof China 3 Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong 510060, People’s Republicof China 4 Department of Radiation Oncology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510060, People’s Republicof China 5 Department of Hematologic Oncology, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong 5100600, People’s Republicof China 6 Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong 510060, People’s Republicof China * These authors have contributed equally to this work Correspondence to: Xi-Cheng Wang, email: 13902400598@126.com Yu-Jing Zhang, email: yujing_zhang1969@163.com Keywords: extranodal natural killer/T celllymphoma, non-Hodgkin lymphoma, asparaginase, radiotherapy, chemotherapy Received: September 18, 2016     Accepted: November 23, 2016     Published: December 17, 2016 ABSTRACT This study retrospectively investigated asparaginase-based chemotherapy treatment outcomes with or without radiotherapy in 143 patients with stage I E –II E extranodal natural killer/T celllymphoma (ENKTCL). All patients received a median of three cycles of asparaginase-based chemotherapy, while 121 patients received radiotherapy following the chemotherapy. The complete remission (CR) rate for all patients post-chemotherapy was 58.7%, and rose to 73.4% by the end of treatment. Patients who received radiotherapy achieved better survival outcomes than those who did not (89.7% vs. 49.0% for 2-year overall survival (OS), P <0.001; 86.8% vs. 37.4% for 2-year progression-free survival (PFS), P <0.001). Additionally, even patients who achieved CR post-chemotherapy exhibited differential survival rates with or without radiotherapy (90.8% vs. 60% for 2-year OS, P =0.006; 86.1% vs. 60% for 2-year PFS, P =0.044). Multivariate analysis revealed that radiotherapy was an independent factor favoring OS (HR=0.098, 95%CI=0.031–0.314, P =0.001) and PFS (HR=0.156, 95%CI=0.062–0.396, P =0.001). Thus, radiotherapy is recommended for stage I E– II E ENKTCL patients treated with asparaginase-based chemotherapy, even in cases of CR following chemotherapy.