Long-term clinical and molecular remission after allogeneic stem cell transplantation (SCT) in patients with poor prognosis non-Hodgkin's lymphoma

From 1987 to 1999 35 patients with poor prognosis non-Hodgkin's lymphoma (N HL) underwent allogeneic stem cell transplantation (SCT) at the University Hospitals of Vienna and Graz. Initial biopsy specimens were reclassified ac cording to the Revised European-American Classification of Lymphoid Neoplas ms (REAL). All patients surviving 28 days engrafted. Twenty-eight of them ( 93%) attained clinical remission. At the last follow-up 14 patients were al ive and disease-free at a median of 5.0 (range, 2.3-12.9) years after allog eneic SCT. The actuarial overall survival is 35%. Five patients relapsed 1. 8 to 27.6 months after transplant, the probability of relapse is 23%, Of th e 21 deaths following SCT, seven were due to relapse/refractory disease and 14 due to transplant-related causes. The probability of treatment-related mortality is 48%. After SCT, minimal residual disease (MRD) was monitored b y polymerase chain reaction (PCR) in seven patients with a BCL-2/IgH transl ocation and in 13 with a clonal immunoglobulin heavy chain (IgH) rearrangem ent. All 20 patients attained clinical remission rapidly and converted to P CR negativity. In the follow-up nine of these patients are in long-term cli nical and molecular remission, six PCR-negative patients died of transplant -related causes and five patients relapsed. In summary, allogeneic stem cel l transplantation has a curative potential for patients with refractory and recurrent non-Hodgkin's lymphoma. In our series long-term disease-free sur vival was associated with molecular disease eradication after SCT. Treatmen t-related mortality rate was high, thus earlier referral of selected patien ts to allogeneic SCT should be considered.