ABSTRACT
Objective:To analyze the efficacy and prognostic factors of induced chemotherapy combined with radiotherapy in the treatment of early stage extranodal natural-killer/T cell lymphoma (ENKTCL).Methods:Two hundred and eighty-seven early stage NKTCL patients were treated in Affiliated Cancer Hospital of Guizhou Medical University from October 2003 to October 2021. All patients were aD ministrated with short courses of induced chemotherapy combined with radiotherapy. Clinical prognostic factors of early stage NKTCL were analyzed. The overall survival (OS) and progression-free survival (PFS) were calculated by Kaplan- Meier method, log-rank test was conducted for univariate analysis and Cox models were performed for multivariate analysis. Results:The 5-year OS and PFS were 72.8% and 68.9% in all patients. According to Nomogram risk index (NRI) prognostic model, 286 patients were divided into the low risk (NRI=0), intermediate low risk (NRI=1), intermediate high risk (NRI=2), high risk (NRI=3) and very high risk (NRI≥4) groups. In these 5 groups, the 5-year OS were 95.6%, 76.3%, 69.5%, 61.0% and 23.3%(all P<0.001), and the 5-year PFS were 93, 2%, 69.8%, 64.6%, 60.2% and 23.3%(all P<0.001), respectively. In the radiotherapy with a dose of ≥50 Gy and<50 Gy groups, the 5-year OS were 73.8% and 65.9%( P=0.123) and the 5-year PFS were 72.8% and 45.3%( P=0.001). According to the response to induced chemotherapy of complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD), the 5-year OS were 85.4%, 74.0%, 61.8% and 28.5%(all P<0.001), and the 5-year PFS were 83.7%, 66.8%, 65.7% and 27.4%(all P<0.001), respectively. Univariate analyses showed that stage Ⅱ, ECOG≥2, primary tumor invasion, radiotherapy dose<50 Gy and short-term efficacy of induced chemotherapy were poor prognostic factors for the 5-year OS and PFS (all P<0.05). Multivariate analyses demonstrated that primary tumor invasion, ECOG≥2 and stage Ⅱ were poor prognostic factors for OS (all P<0.05), and primary tumor invasion and ECOG≥2 were poor prognostic factors for PFS (all P<0.05). Conclusions:Early stage NKTCL patients can obtain high efficacy after induced chemotherapy combined with radiotherapy. Complete response to induced chemotherapy is associated with favorable prognosis.