Upfront Autologous Stem Cell Transplantation in First Complete Remission for Advanced‐Stage Extra‐Nodal NK /T‐Cell Lymphoma: A Multicenter Retrospective Study

The aim of this study was to evaluate the effect of upfront autologous stem cell transplantation (ASCT) on the prognosis in patients with advanced-stage extra-nodal NK/T-cell lymphoma (NKTCL) achieving first complete remission (CR1) after frontline therapy. To this end, we retrospectively reviewed data from patients diagnosed with stage III or IV NKTCL who achieved CR1 after frontline treatment between 2006 and 2023 at 14 medical centers in China. A total of 107 patients were included in this study. The majority of patients (87%) received non-anthracycline-based first-line chemotherapy, and 38 (36%) received upfront ASCT consolidation at the time of CR1. With a median follow-up time of 39.8 months, progression-free survival (PFS) and overall survival (OS) rates were significantly better in the ASCT group than in the non-ASCT group (3-year PFS: 78.2% vs. 54.6%, p = 0.005; 3-year OS: 86.0% vs. 68.9%, p = 0.04). However, in the subgroup of patients receiving non-anthracycline-based chemotherapy (N = 93), ASCT was significantly associated with better PFS (3-year PFS: 77.6% vs. 59.3%, p = 0.025) but not with OS (3-year OS: 85.6% vs. 74.8%, p = 0.164). In multivariate analyzes, upfront ASCT was an independent predictor of better PFS (hazard ratio [HR] = 0.37, 95% confidence interval [CI]: 0.15-0.88, p = 0.025) but not OS after adjusting for baseline prognostic index of NK-cell lymphoma (PINK), types of first-line chemotherapy, and local radiotherapy. After propensity score matched analyzes, upfront ASCT remained significantly associated with better PFS but not with OS. These real-world data suggest upfront ASCT prolongs PFS in patients with advanced-stage NKTCL in CR1, yet its impact on OS remains unclear.