Ki-67 Can Predict the Response to the Gemcitabine, Oxaliplatin And L-asparaginase Regimen (GELOX) and Prognosis in Patients with Nasal Natural Killer/T-cell Lymphoma

GELOX (gemcitabine, oxaliplatin and L-asparaginase) regimen showed an impressive result in our previous study, but the effect of this new regimen is still dissatisfying for some patients, so it is necessary to identify which patients will benefit from this regimen. A total of fifty-one cases with nasal natural killer/T-cell lymphoma receiving initial GELOX chemotherapy were enrolled in this study. The ki-67 expression detected by immunohistochemistry (IHC) in the specimens ranged from 10% to 90%, with a median value of 70%, so cases higher than the median value (${\geq}70%$) were defined as high ki-67 expression, and the others were designated as low ki-67 expression. The response rate had no statistical difference between low ki-67 expression group and high ki-67 expression group (P=0.291) though the value in the former group was relatively high. After a median follow-up of 18.03 months, the 3-year progression-free survival (PFS) for patients with low ki-67 expression was significantly higher than those with high ki-67 expression (83.8% vs. 47.9%, P=0.038). In the stage I/II subgroup, 3-year PFS and overall survival (OS) were statistically higher in the patients with low ki-67 expression than those with high ki-67 expression. Multivariate analysis revealed high ki-67 expression was an independent prognostic factor for PFS. These results suggest that low ki-67 expression can predict a good response of GELOX in these patients, and the combination of ki-67 expression and early stage is helpful to identify an excellent prognosis subgroup from patients receiving GELOX in this disease.