[Prognosis and treatment strategies of primary B-cell and NK/T-cell nasopharyngeal non-Hodgkin's lymphoma at early stage].

BACKGROUND & OBJECTIVE: Nasopharynx is a commonly involved site of non-Hodgkin's lymphoma (NHL), but the differences of clinical characteristics, prognosis, and treatment strategy between B-cell and NK/T-cell nasopharyngeal NHL have seldom been reported. This study was to investigate the clinical manifestations and treatment outcomes of primary B-cell and NK/T-cell nasopharyngeal NHL at early stage, and evaluate the prognostic differences, so as to provide evidences for treatment optimization.

METHODS: Clinical data of 80 patients with previously untreated nasopharyngeal NHL at early stage, admitted from May 1987 to Nov. 2003, were reviewed. Of the 80 cases, 48 were B-cell original (B group), 32 were NK/T-cell original (T group). Of the 80 patients, 42 received chemoradiotherapy, 31 received chemotherapy alone, and 7 received radiotherapy alone. Most chemotherapy-treated patients received CHOP regimen (cyclophosphamide, vincristine, adriamycin, and prednisone) for 1-10 cycles (median 5 cycles). Radiotherapy was given with high energy photon beams combined with high energy electron beams in conventional fractionation, with the total dose of 30-70 Gy (median 52 Gy). Treatment patterns of the 2 groups were similar, but B group received more chemotherapy cycles than T group did.

RESULTS: The 5-year overall survival rate and 5-year progression-free survival rate were significantly higher in B group than in T group (69.5% vs. 35.5%, P=0.003; 53.3% vs. 28.9%, P=0.032). Cox multivariate regression analysis suggested that B-cell phenotype, no B symptoms, and local control were independent favorable predictors of overall survival, while B-cell phenotype and good treatment response were independent favorable predictors of progression-free survival. Univariate stratified analysis with Kaplan-Meier method showed that, for B group, the cumulative 5-year overall survival rate was 68.1% in the 19 patients received chemotherapy alone, 61.7% in the 25 patients received chemoradiotherapy, and 100% in the 4 patients received radiotherapy alone (P=0.311); for T group, the cumulative 5-year overall survival rate was 0% in the 12 patients received chemotherapy alone, 44.1% in the 17 patients received chemoradiotherapy, and 33.3% in the 3 patients received radiotherapy alone (only 1 patient survived for 60 months)(P=0.020).

CONCLUSIONS: Among the patients with primary nasopharyngeal NHL at early stage, those with B-cell phenotype may have better prognosis as compared with those with NK/T-cell phenotype. The patients with NK/T-cell phenotype often suffered from B symptoms, with poor response to chemotherapy. Radiotherapy or chemoradiotherapy should be more emphasized in this group of patients.