OBJECTIVETo investigate the clinical features and prognostic factors of primary mediastinal large B-cell lymphoma (PMLBCL).

METHODSThe clinical data of 82 patients with PMLBCL enrolled from January 2000 to January 2008 were retrospectively studied. All these patients were treated in four affiliated hospitals of Central South University,Hunan province. The prognostic factors were investigated.

RESULTSOf the 82 patients, 45 were men and 37 were women, the ratio was 1.22:1. The median age was 29.5 (ranged from 12 to 78) years old. There were 40 (48.78%) patients in stage I/II, 42 (51.22%) in stage III/IV. The complete response (CR) rate was 13.4% (11/82), and the overall response rate 76.83% (63/82). The 5-year overall survival was 58%. The univariate analysis indicated that the poor prognostic factors included stage III/IV(P=0.005), without rituximab (P=0.004), without radiotherapy (P=0.000), LDH ≥ ULN (upper limit of normal) (P=0.000), disease progression (P=0.000), international prognostic index (IPI)≥ 2 (P=0.000) and superior vena cava syndrome (P=0.015). Chemo-therapy alone (P=0.000) predicted poor outcome. Combination therapy (such as chemo-radiotherapy, chemotherapy combined with rituximab) had better prognosis. Compared to second-line treatment, rituximab as the first-line treatment can prolong PFS, but had no effect on the OS. In multivariate analysis, chemo-radiotherapy and IPI were independently related to prognosis.

CONCLUSIONPMLBCL mostly affects young adults, male patients were slightly more than female patients. It presents with a typical bulky mediastinal mass at diagnosis, which constricts surrounding organs. Patients treated with rituximab or radiation therapy had better prognosis. Rituximab is recommended to be used for the first-line treatment.