Deep remission from induction chemotherapy predicts favorable long-term survivals in early stage extranodal nasal NK/T-cell lymphoma receiving sequential chemotherapy and radiation

Objective: We aimed to assess the association between induction chemotherapy (CT) response and survivals and to explore an induction CT response-adapted treatment strategy for localized extranodal NK/T-cell lymphoma (NKTCL) receiving first-line sequential CT and radiation (RT). Methods: We retrospectively reviewed the data of patients with localized NKTCL receiving first-line CT+RT from 2010 to 2020 at two independent institutes (primary cohort, n = 203; validation cohort, n = 67). Responses after induction CT (initial response), RT (final response) and survivals were analyzed. Results: Patients with initial complete remission (CR) had higher final CR rate than the others (99.1% vs. 78.7%, P < 0.001). Initial CR was associated with superior 5-year progression-free survival (PFS, 90.0% vs. 61.4% vs. 30.8%, P < 0.001) and overall survival (OS, 93.5% vs. 70.7% vs. 60.6%, P < 0.001), as compared to initial partial remission or non-response. Though majority of cases with initial non-CR achieved final CR after RT, they still had a tendency of shortened OS compared with initial CRs (86.9% vs. 90.6%, P = 0.063). Multivariate analysis demonstrated patients with initial non-CR had higher relapse (HR = 4.748, 95% CI, 2.396-9.407, P < 0.001) and death hazard (HR = 4.296, 95% CI, 1.802-10.24, P = 0.001). Furthermore, more intensive therapy of & GE;6 total cycles of CT yielded significantly superior 5-year OS for patients with initial non-CR (76.7% vs. 54.7%, P = 0.026) rather than patients with initial CR. Conclusion: Deep remission from induction CT was associated with favorable survivals in localized NKTCL receiving CT+RT, and an induction CT response-adapted individualized treatment strategy might be recommended in clinical practice.

Automated summary

This study aimed to assess the association between induction chemotherapy response and survival in localized extranodal NK/T-cell lymphoma (NKTCL) patients and explore a response-adapted treatment strategy. The results showed that deep remission was associated with favorable survival, and intensified chemotherapy could improve the survival of patients who did not achieve complete remission after induction chemotherapy.