Prognostic factors of Chinese patients with T/NK-cell lymphoma: a single institution study of 170 patients

T/natural killer-cell lymphoma (T/NKCL) is a heterogeneous group of lymphoma and has a higher incidence in Asia than in Western countries. T/NKCL is presented with various clinicopathologic features, and in general, associated with a poor clinical outcome. This study aims to analyze the clinical prognostic factors in patients with T/NKCL. From January 1999 to December 2009, a total of 170 patients with T/NKCL, except mycosis fungoides, were included in this retrospective study. The diagnosis was established according to World Health Organization classification. The clinical characteristics and prognostic factors were evaluated. Of the 170 patients, mainly peripheral T-cell lymphoma-unspecified (65 cases), precursor T-lymphoblastic lymphoma/leukemia (31 cases) and nasal NK/T-cell lymphoma (NKTCL, 19 cases), advanced disease (Ann Arbor stages III-IV) was presented in 68.8% and extranodal involvement was in 71.2% of the patients. According to the international prognostic index (IPI), 77 cases were categorized as high/intermediate or high-risk group. Using the prognostic index for peripheral T-cell lymphoma-unspecified (PIT), 87 cases were classified as group 3 or 4. Most of the initial regimens were CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone)-based chemotherapy (87.6%). Cumulative probability of overall survival at 5 years was 43%, and the median survival time was 44.5 months. Univariate analysis revealed that factors associated with a poor outcome were poor performance status (ECOG > 1) (P = 0.001), advanced disease (P = 0.009), the presence of B symptom (P = 0.001), multiple extranodal involvement (P = 0.005), bone marrow involvement (P = 0.003), elevated lactic dehydrogenase level (P = 0.019), IPI (P < 0.001), PIT (P < 0.001), abnormal white blood cell count (P = 0.016), decreased platelet count (P = 0.005) and serum Epstein-Barr virus (EBV) IgA positivity (P = 0.016). In the multivariate analysis, PIT (P < 0.001; relative risk, 3.221; 95% CI = 2.115-4.907) and EBV serum IgA (P = 0.049; relative risk, 1.901; 95% CI = 1.002-3.606) remained independent factors predictive for overall survival. The PIT may therefore be a useful index for risk stratification in patients with T/NKCL. The serum EBV antibody test could be a simple and quick marker to predict the outcome of the patients.