Nasal-type, extranodal natural killer/T-cell lymphoma is a heterogeneous disorder with poor prognosis, requiring risk stratification in this population. The combined value of baseline absolute lymphocyte count and absolute monocyte count provided prognostic information in some malignancies. However, the evidence requires validation in extranodal natural killer/T-cell lymphoma. Aiming to investigate the prognostic significance of absolute lymphocyte count/absolute monocyte count ratio and absolute lymphocyte count/absolute monocyte count prognostic score for extranodal natural killer/T-cell lymphoma, a retrospective research was carried out. A total of 264 patients with newly diagnosed extranodal natural killer/T-cell lymphoma were analyzed in this study. The patients' absolute lymphocyte count and absolute monocyte count tested at initial diagnosis were collected. Receiver operating curve analysis showed that the optimal cut-off values for absolute lymphocyte count and absolute monocyte count were 1.0 × 109 and 0.5 × 109L-1, respectively, and for absolute lymphocyte count/absolute monocyte count ratio was 2.85. After a median follow-up of 27 months (range 1-87 months), the 3-year overall survival and progression-free survival was 75.4% and 67.6%, respectively. Patients with absolute lymphocyte count/absolute monocyte count ratio ≥ 2.85 had better 3-year overall survival and progression-free survival than those with absolute lymphocyte count/absolute monocyte count ratio <2.85 (p < 0.001). According to absolute lymphocyte count/absolute monocyte count prognostic score, significant difference has been noticed in 3-year overall survival and progression-free survival (p < 0.001) and high absolute lymphocyte count/absolute monocyte count prognostic score was associated with poorer survival. The International Prognostic Index and Korean Prognostic Index were used for prognosis and showed no significant difference. When adding absolute lymphocyte count/absolute monocyte count ratio and absolute lymphocyte count/absolute monocyte count prognostic score to the International Prognostic Index and Korean Prognostic Index model, additional prognostic information was found. These results suggest that absolute lymphocyte count/absolute monocyte count ratio and absolute lymphocyte count/absolute monocyte count prognostic score might be useful prognostic factors in extranodal natural killer/T-cell lymphoma.
Keywords: Natural killer T cell; absolute lymphocyte count; absolute monocyte count; non-Hodgkin lymphoma.