Evaluation of different staging systems and prognostic analysis of nasal-type extranodal NK/T-cell lymphoma based on consistent LVDP chemotherapy regimen

Nasal-type extranodal NK-T-cell lymphoma (ENKTL) is a rare non-Hodgkin lymphoma. The optimal staging system for it remains undefined. In this study, we evaluated different staging systems in 205 patients with nasal-type ENKTL based on a consistent LVDP (L-asparaginase, etoposide, dexamethasone, cisplatin) regimen. All patients were staged by Ann Arbor staging system (AASS) and CA staging system (CASS). Their characteristics, treatment responses, survival outcomes, prognostic factors, and prognostic values of AASS and CASS were analyzed. The median follow-up time was 78 months. All patients received a median 4 cycles of the LVDP chemotherapy. Based on CASS, patients with stages I through IV were more evenly distributed than with AASS, and numbered at 56 (27.3%), 70 (33.2%), 45 (21.9%), and 34 (17.6%), respectively. At the end of therapy, the objective response rate (ORR) was 81.2% for all patients. For all patients, the 5-year progression-free survival (PFS) and overall survival (OS) were 61.6% and 67.8%. According to AASS, the 5-year OS of patients with stages Ⅰ through Ⅳ were 77.9%, 61.2%, 60.0%, and 38.7%, respectively (χ²=20.578, p<0.001). Based on CASS, the 5-year OS of patients with stages Ⅰ to Ⅳ were 89.1%, 65.5%, 58.6%, and 45.4%, respectively (χ²=22.973, p<0.001). In ROC analysis of OS, the area under the curve (AUC) for CASS was 0.70 and 0.64 for AASS. CASS was better in discriminating survival than AASS (p = 0.018). In conclusion, the LVDP regimen is effective for nasal-type ENKTL and the CASS has a better prognostic value in survival analysis than the AASS.