Objective: To evaluate the prognosis and determine the failure patterns after radiotherapy for low-risk early-stage patients with extranodal NK/T-cell lymphoma, nasal-type (ENKTCL). Methods: A total of 557 patients from 2000-2015 with low-risk early-stage ENKTCL who received radiotherapy (RT) with or without chemotherapy (CT) from China Lymphoma Collaborative Group were retrospectively reviewed. Among them, 427 patients received combined modality therapy, whereas 130 patients received RT alone. Survivals were calculated by Kaplan-Meier method and compared with Log-rank test. Overall survival (OS) was compared with age and sex-matched general Chinese population using expected survival and standardized mortality ratio (SMR). Cox stepwise regression model was used for multivariate analysis. Results: The 5-year OS and progression-free survival (PFS) were 87.2% and 77.2%. The SMR was 3.59 (P<0.001) at 1 year after treatment, whereas it was 1.50 at 4 years after treatment, without significant difference between ENKTCL group and country-matched general population (P=0.146). Compared with RT alone, CMT did not result in significantly superior 5-year OS (87.0% vs 87.4%, P=0.961) or PFS (76.1% vs 80.7%, P=0.129). Local failure (11.5%, 64/557) and distant failure (10.8%, 60/557) were the main failure modes, while regional failure was rare (2.9%, 16/557). The 5-year locoregional control rate (LRC) was 87.2% for the whole group, with 89.5% for ≥50 Gy versus 73.7% for <50 Gy (P<0.001). Radiotherapy dose was an independent factor affecting LRC(P<0.05). Conclusions: Radiotherapy achieves a favorable prognosis in patients with low-risk early-stage ENKTCL. The incidence of either locoregional or distant failure is low. Radiation dose still is an important prognostic factor for LRC.
目的： 探讨早期低危结外鼻型NK/T细胞淋巴瘤(ENKTCL)的放疗疗效和失败模式。 方法： 回顾性分析2000—2015年中国淋巴瘤协作组数据库中557例接受放疗的早期低危ENKTCL患者的放疗疗效。全组557例患者中，接受综合治疗427例，单纯放疗130例。采用Kaplan-Meier法计算生存率，Log rank检验分析组间差异，采用标准化死亡比(SMR)比较ENKTCL患者与年龄、性别相匹配的中国健康人群的预期生存，多因素分析采用Cox回归模型。 结果： 全组患者的5年总生存率和5年无进展生存率分别为87.2%和77.2%。患者治疗生存1年后SMR为匹配健康人群的3.59倍(P<0.001)，治疗生存4年后SMR为匹配健康人群的1.50倍(P＝0.146)。综合治疗与单纯放疗比较未能提高患者的5年总生存率(分别为87.0%和87.4%，P＝0.961)和5年无进展生存率(分别为76.1%和80.7%，P＝0.129)。全组患者的失败模式以局部失败(11.5%，64/557)和远处失败(10.8%，60/557)为主，区域失败罕见(2.9%，16/557)。全组患者5年局部区域控制率为87.2%，放疗剂量≥50 Gy和<50 Gy患者的5年局部区域控制率(LRC)分别为89.5%和73.7%(P<0.001)。放疗剂量为LRC的独立影响因素(P<0.05)。 结论： 早期低危ENKTCL患者放疗的预后较好，局部区域和远处失败均较低，放疗剂量为LRC的独立影响因素。.
Keywords: Extranodal nasal-type NK/T-cell lymphoma; Low risk early-stage; Prognosis; Radiotherapy.