Abstract:

Background and purpose: Extranodal natural killer/T-cell lymphoma (ENKTL) is a form of non-Hodgkin’s lymphoma. The ENKTL incidence in China is much higher than that in the Western countries. The disease is highly malignant, not sensitive to chemotherapy, has short survival period and poor prognosis. Epstein-Barr virus (EBV) infection has close relationship with the development of the disease. However, there are still a few patients without EBV infection. This study aimed to discuss the clinical features and prognosis of EBV-encoded small RNA (EBER) in situ hybridization negative ENKTL. Methods: From Aug. 2011 to Oct. 2015, 326 cases were diagnosed with ENKTL from the First Affiliated Hospital of Zhengzhou University. The expression of EBER was detected by in situ hybridization technique. The clinical pathological characteristics and prognosis of EBER-negative patients were analyzed. Results: In 326 patients with ENKTL, the negative rate of EBER was 2.45% (8/326). In 8 EBER-negative patients, the median survival time was 17 months. The log-rank test revealed that there was a significant difference between EBER-negative and EBER-positive curves (χ2=6.407, P=0.011). Multivariate Cox proportional hazards regression analysis showed that in EBER-negative ENKTL, only lactate dehydrogenase (LDH) predicted survival time (P=0.008). EBV-DNA copy number in plasma was not significantly correlated with survival time (P>0.05). Conclusion: The incidence of EBER-negative ENKTL is low. Patients with EBER-negative ENKTL have poorer prognosis than EBER-positive patients. Elevated LDH may be a factor indicating poor prognosis.

Key words: Extranodal NK/T-cell lymphoma, EB virus-encoded small RNA negative, Clinical features, Prognosis