Risk-adapted therapy for early-stage extranodal nasal-type NK/T-cell lymphoma: analysis from a multicenter study.

The optimal combination and sequence of radiotherapy (RT) and chemotherapy (CT) for extranodal nasal-type natural killer/T-cell lymphoma (NKTCL) are not well-defined. The aim of this study was to create a risk-adapted therapeutic strategy for early-stage NKTCL. A total of 1273 early-stage patients from 10 institutions were reviewed. Patients received CT alone (n = 170), RT alone (n = 253), RT followed by CT (n = 209), or CT followed by RT (n = 641). A comprehensive comparative study was performed using multivariable and propensity score-matched analyses. Early-stage NKTCL was classified as low risk or high risk based on 5 independent prognostic factors (stage, age, performance status, lactate dehydrogenase, primary tumor invasion). RT alone and RT with or without CT were more effective than CT alone (5-year overall survival [OS], 69.6% and 67.7% vs 33.9%, P < .001). For low-risk patients, RT alone achieved a favorable OS (88.8%); incorporation of induction or consolidation CT did not provide additional benefit (86.9% and 86.3%). For high-risk patients, RT followed by CT resulted in superior OS (72.2%) compared with induction CT and RT (58.3%, P = .004) or RT alone (59.6%, P = .017). After adjustment, similar significant differences in OS were still observed between treatment groups. New CT regimens provided limited benefit in early-stage NKTCL. Risk-adapted therapy involving RT alone for low-risk patients and RT consolidated by CT for high-risk patients is a viable, effective strategy for early-stage NKTCL.