Sequential P‐GEMOX and radiotherapy for early‐stage extranodal natural killer/T‐cell lymphoma: A multicenter study

Extranodal natural killer/T‐cell lymphoma, nasal‐type (ENKTL) is a distinct subtype of non‐Hodgkin lymphoma and most of the patients presented localized disease. Combined modality therapy (CMT), namely chemotherapy combined with radiotherapy, has been recommended for patients with early‐stage ENKTL. However, the optimal CMT has not been fully clarified. This study reports the efficacy and toxicity of sequential P‐GEMOX (pegaspargase, gemcitabine and oxaliplatin) and radiotherapy in a large Chinese cohort comprising of 202 patients diagnosed with early‐stage ENKTL from six medical centers. The observed best overall response rate was 96.0% and 168 (83.2%) patients achieved complete remission. With a median follow‐up of 44.1 months, the 3‐year progression‐free survival (PFS) and overall survival (OS) were 74.6% and 85.2%, respectively. Multivariate analysis suggested that extensive primary tumor (PFS, hazard ratio [HR] 3.660, 95% CI 1.820–7.359, p < 0.001; OS, HR 3.825, 95% CI 1.442–10.148, p = 0.007) and Eastern Cooperative Oncology Group performance status ≥ 2 (PFS, 3.042, 95% CI 1.468–6.306, p = 0.003; OS, HR 3.983, 95% CI 1.678–9.457, p = 0.02) were independent prognostic factors for survival outcomes. Among the established prognostic models for ENKTL, the nomogram‐revised risk index model had optimal prognostic risk stratification ability (PFS, p < 0.001; OS, p < 0.001) and relatively balanced population distribution. The adverse events of this CMT were well‐tolerated and manageable. In conclusion, sequential P‐GEMOX and radiotherapy showed favorable efficacy with acceptable toxicity, and could be an effective treatment option for early‐stage ENKTL patients.