Clinical features and survival of extranodal natural killer/T cell lymphoma with and without hemophagocytic syndrome.

Extranodal natural killer (NK)/T cell lymphoma-associated hemophagocytic syndrome (HPS) (NK/T-LAHS) is a heterogeneous and life-threatening disease, which warrants investigation of its risk factors and clinical features. We retrospectively analyzed the clinical records of 202 patients with extranodal NK/T cell lymphoma and compared the characteristics and survival of extranodal NK/T cell lymphoma patients with and without HPS. The cumulative incidence of NK/T-LAHS was 11.4 % (23/202). In a multivariate logistic regression model, younger age (p = 0.012), bone marrow involvement (p = 0.012), and reduced serum albumin (p < 0.001) were independent risk factors for developing HPS in patients with extranodal NK/T cell lymphoma. The survival of extranodal NK/T cell lymphoma patients was aggravated when complicated with HPS, with an overall 2-year survival of 72.1 and 30.4 %, respectively (p < 0.001). Six patients with HPS onset at lymphoma diagnosis tended to have a poor performance status (p = 0.040), while the rate of elevated bilirubin was significantly higher in 17 patients with HPS onset at lymphoma relapse (p = 0.045). After HPS onset, treatment response was poor (response rate, 17.4 %) and survival was dismal with a median of 26 days. Univariate analysis showed that patients with lactate dehydrogenase >1000 U/L (p = 0.048) and disseminated intravascular coagulation (p = 0.004) had shorter survival time. Extranodal NK/T cell lymphoma was frequently complicated with HPS, and survival was discouraging in this circumstance. Intensive chemotherapy regimens including L-asparaginase or pegaspargase and allogeneic stem cell transplantation should be investigated.