['Extranodal natural killer/T-cell lymphoma, nasal type (ENKTL), is an aggressive type of lymphoma whose standard treatment and validated prognostic model have not yet been defined.', 'CD30 expression was detected using immunohistochemistry in 96 ENKTL patients, and the data were used to evaluate its relationship with clinical features, treatment response and prognosis.', 'Expression of CD30 was detected in 31.2% of ENKTL patients, which was significantly correlated with B symptoms and elevated serum lactate dehydrogenase. The complete remission rate was not significantly different between CD30-positive and negative groups. After a median follow-up time of 31 months, 5-year overall survival (OS) and 5-year progression-free survival (PFS) rates in the CD30-positive group were both significantly lower than those in the CD30-negative group (34.1% vs. 64.4%, P=0.002, for 5 year-OS; 26.0% vs. 66.7%, P<0.001, for 5 year-PFS). In patients with an International Prognostic Index (IPI) or Korean Prognostic Index (KPI) score of 0-1, CD30 positivity was associated with shorter 5-year OS and PFS (IPI: P=0.001 and 0.002, respectively; KPI: P=0.018 and 0.023, respectively). In a multivariate Cox regression model, CD30 expression and stage were independent prognostic factors for OS (p=0.004 and p=0.012, respectively) and PFS (p=0.001 and p=0.022, respectively).'] Is cD30 expression a novel prognostic indicator in extranodal natural killer/T-cell lymphoma , nasal type?