Primary mediastinal large B cell lymphoma with sclerosis: A clinical study of 92 patients treated at a single institution with macop-B and radiotherapy

Introduction: Primary mediastinal large B cell lymphoma (PMLBCL) represents a distinct clinicopathological entity of large B cell lymphoma occuring preferentially in young females with a bulky mediastinal mass. Methods: Between 1991 and April 2004, 92 consecutive untreated patients (pts) with PMLBCL were diagnosed and treated at our institution. The median age was 33 years (range 15–61), 68/92 (74%) were females,72 pts had stage II and 20 stage IIE, 43(47%) presented B symptoms, LDH was increased in 68(74%), 81(88%) had a bulky mass and 47(51%) had a superior vena cava syndrome. According to age-adjusted IPI score 52 pts had an IPI = 0–1 and 40 pts IPI = 2–3. All pts were treated with standard MACOP-B chemotherapy (CHT) and 86 pts underwent mediastinal radiation therapy (RT) at dose of 30–36 Gy. Six (7%) pts did not receive RT (refusal = 3, progression = 2, death = 1). The response was evaluated in all pts after CHT and at the end of RT. Results: After MACOP-B regimen the response rate was: CR/CRu = 72(78%), PR = 18 (20%), NR = 1(1%), toxic death = 1(1%). Six (6%) PR pts underwent to intensification therapy with high dose therapy and ASCT. After RT pts achieved CR/CRu = 78 (91%), PR = 3(3%), NR = 5(6%).After CHT 67 Gallium scan was positive in 51/60 (85%) while after RT was positive in 12/53(23%) P <0.0001.After a median follow-up of 58 months (1–165) relapse was observed in 9 pts. Five of the 9 relapsed pts are alive in CR after second line therapy with ASCT. Five not responding pts had progressive disease and died. To date 82 (90%) pts are currently in continuous CR. Projected 5-years OS and PFS are 88% and 84%, respectively. The 5 years OS was better for pts with IPI = 0–1 compared to IPI = 2–3 (96% vs 76% P = 0.006). Conclusions: Combined modality treatment using the MACOP-B regimen and mediastinal RT induces high response and survival rates. Radiation therapy plays an important role in the achievement of these results.