A prognostic model based on pretreatment platelet lymphocyte ratio for stage IE/IIE upper aerodigestive tract extranodal NK/T cell lymphoma, nasal type.

Patients with stage IE/IIE natural killer T (NK/T) cell lymphomas have discrepant survival outcome. This study aims to establish a prognostic model based on the pretreatment platelet lymphocyte ratio (PLR) specifically for localized extranodal NK/T cell lymphoma to guide the therapy. We retrospectively analyzed the data of 252 patients with early-stage upper aerodigestive tract NK/T cell lymphoma. The 5-year overall survival rate in 252 patients was 67.1%. Prognostic factors for survival were female (P = 0.025; relative risk, 0.51; 95% CI 0.28-0.92), older age (P = 0.000; relative risk, 3.34; 95% CI 1.94-5.75), stage II(P = 0.020; relative risk, 1.79; 95% CI 1.10-2.91), lactate dehydrogenase (LDH) level (P = 0.009; relative risk, 2.00; 95% CI 1.19-3.35), and PLR (P = 0.020; relative risk, 1.77; 95% CI 1.10-2.87). Based on these five parameters, we identified three different risk groups: group 1(106 cases, 43.4%), no or one adverse factor; group 2(85 cases, 34.8%), two factors; group 3(53 cases, 21.7%), three to five factors. Five-year overall survival was 83.3% for group 1, 62.2% for group 2, and 43.1% for group 3 (P = 0.000). Compared with International Prognostic Index and Korean Prognostic Index, the new model has a better prognostic discrimination for the patients of stage IE/IIE upper aerodigestive tract NK/T cell lymphoma. The PLR-based prognosis model is useful to stratify patients with localized extranodal NK/T cell lymphoma into different risk groups and guide the treatment modalities selection.