Treatment Outcome for Primary Mediastinal Large B-Cell Lymphoma: A Retrospective Analysis of 72 Cases

ABSTRACT Background Primary mediastinal B-cell lymphoma (PMBCL) believed to arise from a small population of thymic medullary B-cells. There is still inconsistency in the literature with regard to the survival outcomes, also to the treatment strategy and prognosis. We hypothesized that R-CHOP in combination with infiltrated field radiation therapy are tolerable and effective and, retrospectively analyze the data from our institute the toxicity of, response rate for, and outcome of treatment. Methods Seventy-two consecutively observed Chinese patients were treated with R-CHOP or R-CHOP like regiments every 21 days, which consisted of intravenously rituximab at 375 mg/m2 on day 1, cyclophosphamide at 750 mg/m2 on day 1, Doxorubicin at 50 mg/m2 on day 1, vincristin at 1.4 mg/m2 on day 1 and oral Prednisone at -100 mg/day on days 1–5. Among them, six patients received additional bleomycin therapy. Patients received at least four courses of treatment. Sixty-three responders received irradiation at sites of bulky masses after 3–4 weeks of completion of chemotherapy. The dose ranged from 30.6 to 39.6 Gy (mean dose 36 Gy in 20 fractions). Autologous stem cell transplantation was carried out in seven patients with high International Prognostic Index Results Sixty-eight patients received R-CHOP, 73% patients reached CR or CRu and 2% had SD. Four patients received CHOP along. Three of the four reached CR or CRu and one had SD. Of 43 patients, 29 had completed the standard planned treatment with IFRT; 8 of 43 patients had BMT; Among 20 patients in PR after chemotherapy, 18 (92%) obtained a CR after IFRT, and 2 remained in PR and subsequently died of progressive disease. In chemo + BMT group of patients, CR 3 (41.86%); 3 patients who had received both IR and BMT successively all CR. The overall 5-year PFS and OS rates were 41% and 56.6%, respectively. Conclusions In our opinion, the superiority of R-CHOP chemotherapy regimen in combination with radiotherapy in the first-line treatment of PMBL is not enough. First-line PBSCT is better than R-CHOP plus irradiation. Further prospective randomized clinical trials are awaited.