842P - Multicenter real-world study of newly diagnosed advanced-stage extranodal natural killer/T cell lymphoma (ENKTL): Proposal for intensive therapy

Background

Advanced-stage ENKTL is characterized by its low prevalence, poor prognosis, and inconclusive optimal therapy. This study investigated the treatment of newly diagnosed advanced-stage ENKTLs.

Methods

Newly diagnosed stage III/IV ENKTL patients from two large Chinese cancer centers in the last 10-15 years were retrospectively analyzed.

Results

With a median follow-up of 75.03 (range, 0.33-292.13) months, the median overall survival (OS) for the 195 newly diagnosed stage Ⅲ/Ⅳ ENKTL patients was 19.43 (range, 0.33-292.13) months, and estimated 1-, 2-, 3-, and 5-year OS were 59.5%, 46.3%, 41.8%, and 35.1%, respectively. First-line multi-modality therapy prolonged OS compared to single-modality therapy (P<0.001). Chemotherapy (CT)+radiotherapy (RT) compared to CT alone (P=0.007), and hematopoietic stem cell transplantation (HSCT) compared to non-HSCT (P<0.001) both significantly improved OS. For patients ≤60 years yet ineligible for HSCT, other therapies with complete remission led to comparable OS (P=0.141) with no significant differences in baseline features. Patients treated with chidamide maintenance therapy (MT) achieved a median progression-free survival (PFS) of 55.83 (range, 53.27-92.33) months and a median OS of 60.65 (range, 53.70-95.70) months. Non-anthracycline (ANT)- compared to ANT-, asparaginase (ASP)- compared to non-ASP-, and gemcitabine (GEM)- compared to non-GEM-based CT regimens, led to prolonged PFS (P=0.031; P=0.005; P=0.009) and OS (P=0.010; P=0.086; P=0.003), respectively. GEM+ASP combinations slightly improved PFS and OS compared to regimens containing GEM or ASP alone (P>0.05). GEM+ASP combinations led to significantly superior PFS (P=0.058[log-rank], P=0.036[Breslow]) and OS (P=0.008) compared to ANT+ASP regimens. First-line intensive therapy, including CT, RT, HSCT, and chidamide MT, was therefore proposed and could improve long-term survival for advanced-stage ENKTLs.

Conclusions

We propose the first-line intensive therapy for newly diagnosed advanced-stage ENKTLs, including CT, RT, HSCT, and chidamide MT. GEM+ASP combinations appear to yield the optimal efficacy and survival. RT, consolidative HSCT, or chidamide MT are recommended.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Chinese Geriatric Oncology Society Scientific Research Fund (CGOS-06-2014-1-1-01600).

Disclosure

All authors have declared no conflicts of interest.