RESUMEN
Objective: To assess the efficacy, safety, and related prognostic factors associated with the P-GemDOx regimen as a first-line treatment for patients with early-stage extranodal natural killer (NK) /T cell lymphoma (ENKTL) . Methods: A retrospective analysis was performed on sixty early-stage ENKTL patients treated with the P-GemDOx regimen who were admitted to the First Affiliated Hospital of Nanjing Medical University between August 2015 and May 2021. The Chi-square test or Fisher's exact test was used to compare group differences, and the Log-rank test was used to compare the differences in survival. Survival outcomes and prognostic factors were examined. Results: After completing 4 to 6 cycles of P-GemDOx chemotherapy, the overall response rate (ORR) was 88.3%, with forty-six patients (76.7% ) achieving complete response (CR). The 4-year progression-free survival (PFS) and overall survival (OS) rates were (66.3±7.1) % and (79.5±6.0) %, respectively. According to the PINK/PINK-E model, there was no significant difference in survival outcomes among risk groups. 23.3% of patients experienced progression of disease within 24 months (POD<24). OS estimates differed significantly (P<0.001) between the POD<24 group (n=14) and the POD≥24 group (n=46). Analysis showed that SUVmax > 12.8 at diagnosis, non-single nasal cavity infiltration, and response less than CR after 4-6 cycles all had a significant association with POD24. We used these data as the basis for predicting POD<24 international prognostic index (POD24-IPI). Patients were stratified into low-risk (no risk factors), intermediate-risk (one risk factor), or high risk (two or three risk factors). These groups were associated with 4-year OS rate of 100%, (85.6±9.7) %, and (65.0±10.2) %, respectively (P=0.014). The P-GemDOx regimen was well tolerated, with hematological toxicity being the main side effect. Conclusion: This study demonstrated that the P-GemDOx regimen is effective and safe in the first-line treatment of early-stage ENKTL, and POD24-IPI is a promising prognostic model.