A New Prognostic Model For Nasal-Type, Extranodal Natural Killer/T Cell Lymphoma.

e19042 Background: Nasal type, extranodal natural killer (NK)/T-cell lymphoma (ENKTL) is a heterogeneous disorder with poor prognosis, and there are no optimal therapy and risk-based prognostic model for this population. The objective of our study was to construct a new model for risk-based stratification. Methods: We retrospectively analyzed 145 patients who were newly diagnosed with ENKTCL and treated with the “sandwich” mode of the first-line therapy. Computed tomography (CT) or magnetic resonance (MR) of nasopharynx, neck, chest, and whole abdomen or positron emission tomography/computed tomography (PET/CT) of the entire body was used to evaluate disease. Of 145 patients, 134 patients who had complete information were included in the analysis. Results: With a median follow-up duration of 36 months, 3-year overall survival (OS) rate of all patients was 74.6%. Prognostic factors for survival were the Eastern Cooperative Oncology Group (ECOG) performance status(PS) (P <0.001; relative risk, 2.334; 95% CI, 1.666 to 3.270), lymphocyte/monocyte ratio (LMR) ≤ 2.85 (P = 0.015; relative risk, 2.149; 95% CI, 1. 159 to 3.986), decreased high density lipoprotein (HDL) (P=0.034; relative risk, 1.959; 95% CI, 1.051 to 3.652) and primary tumor invasion (PTI) (P=0.009; relative risk, 4.047; 95% CI, 1.421 to 11.529). Basing on the above four factors, a new prognostic model for 134 patients was constructed: group1 (12.0%), no adverse factor; group 2(50.7%), one factor; group3 (20.2%), two factors; and group 4(17.1%), three or four factors. The 3-year OS of these groups were 100%, 79.9%, 58.5% and 21.7%, respectively. The International Prognostic Index, Korean Prognostic Index and the Prognosis Index for Peripheral T cell lymphoma, Unspecified were used for predicting these patients’ prognosis, the result showed that the discrimination was not power. Conclusions: The newly proposed model could be a useful clinical tool to risk stratify patients with nasal type,extranodal natural killer (NK)/T-cell lymphoma in the future.