A Multicenter Retrospective Comparison of Sequential versus Sandwich Chemoradiotherapy for Stage IE-IIE Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type

Background: Chemotherapy and radiotherapy are critical for treating early-stage extranodal natural killer/T-cell lymphoma, nasal type (ENKTL); however, the optimal therapy sequence remains unclear. Therefore, we performed this study to compare the efficacy of L-asparaginase/pegaspargase-based sequential versus sandwich chemoradiotherapy for patients newly diagnosed with stage IE-IIE ENKTL. Methods: Patients were categorized into sequential (N = 111) and sandwich (N = 104) groups. Chemotherapy regimens included GELOX, SMILE, and VLP. The median radiotherapy dose was 55.0 Gy (range, 40.0-63.0 Gy). Adverse events, treatment responses, and survival outcomes were analyzed. Results: Patients' clinical characteristics were largely comparable between the 2 groups; however, the sandwich group comprised a larger number of Ann Arbor stage IIE patients. Local invasion was the most significant predictor of overall survival (OS); local invasion and Ann Arbor stage were significant predictors of progression-free survival (PFS). There were no significant differences in the complete response rate (85.6% vs. 89.4%, p = 0.396), 3-year OS (77.5% vs. 80.8%, p = 0.636), or 3-year PFS rates (74.8% vs. 76.9%, p = 0.806) in the sequential vs. sandwich groups, respectively. The incidence of grade 3/4 hematological toxicities was higher in the sandwich group than in the sequential group (27.9% vs. 15.3%, respectively, p = 0.025). The response rates and survival outcomes in stage IE and IIE patients did not differ between sequential and sandwich groups. Conclusions: In the era of L-asparaginase/pegaspargase, both sequential and sandwich chemoradiotherapy are safe and similarly effective in patients with newly diagnosed stage IE-IIE ENKTL.