Outcome of Patients with Primary Mediastinal Large B-Cell Non-Hodgkin’s Lymphomas: A Single Institution Analysis from 1996-2004.

Primary mediastinal large B-cell lymphoma represents a distinct subset of large B cell lymphoma, and it has been shown to occur preferentially in young females with a bulky mediastinal mass. Between 1996 and 2004, a total of 43 patients (pts) with primary mediastinal lymphoma were diagnosed and treated at our institution, 34 of them are evaluable for response and long-term follow-up. Twenty females and 14 males have been treated, the median age at diagnosis was 33 years (range: 18–56), 10 pts had stage I, 19 pts stage II and 5 pts stage III disease, respectively. Fifteen pts presented with B symptoms, LDH was increased in 68% of pts. First-line chemotherapy included CHOP (2 pts), R-CHOP (3 pts), CHOEP (8 pts), R-CHOEP (13 pts) or Mega-CHOEP (8 pts). 16 pts received Rituximab in combination with chemotherapy as front-line therapy. Complete response after first-line therapy has been observed in 71% and PR in 21% of pts. Later on, two pts in CR and 1 pt with PR relapsed after conventional chemotherapy. Radiotherapy was administered in 22 pts (65%) presenting with initial bulky disease. 19 pts have been autografted, 15 of them as part of up-front therapy. Indications for up-front autologous HCT were treatment within the Mega-CHOEP protocol (n=8), PR after first-line chemotherapy (n=3), IPI Score of 2 (n=2) and individual decision in 2 pts. Allogeneic HCT was performed as relapse therapy in 4 patients. Of the 15 pts who had up-front autologous HCT, 13 remained in CR. Overall, thirty pts were alive at the date of last contact with a median follow-up since diagnosis of 25 months (range 3–99). Three of 4 pts who had undergone allogeneic HCT in a advanced phase of disease died of transplant-related complications. In conclusion, in this patient group addition of Rituximab and/or dose-intensified first-line chemotherapy lead to a high rate of complete remissions as compared to historic controls. Whether up-front high-dose chemotherapy with autologous HCT or the administration of radiotherapy to the initial bulk improve PFS and OS remains an open question for this special lymphoma entity. The achievement of complete remission with primary treatment strategies seems to be essential to achieve long-term cure for this disease.