[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.