Allogeneic Stem Cell Transplantation for Non-Hodgkin Lymphoma: Data from National Czech Registry.

-Background: New chemotherapeutics protocols, included high dose therapy with hematopoietic stem cell transplantation (HSCT) and anti-CD20 therapy may be curative for many patients with non-Hodgkin’s lymphoma (NHL). However in some cases, standard approach, including autologous HSCT fails. Allogeneic HSCT (allo-SCT) may be effective, however is still associated with high treatment-related mortality (TRM). We report here a retrospective analysis of allogeneic SCT in pts with NHL reported to the Czech National Registry of SCT from four centers in years 1999–2005.

Methods: We analysed 57 patients with NHL (41 males, 16 females). Histological subtypes were: diffuse large cell lymphoma (DLBCL), n=16, follicular lymphoma (FL), n= 17, mantle cell lymphoma (MCL), n=8, peripheral T-cell lymphoma, n=7, Burkitt’s lymphoma, n=2 and 7 other unspecified lymphomas. Median age was 50 (19–64) years. Donors were identical siblings in 40 pts (70%) or unrelated volunteers in 17 (30%). Six (11%) pts received bone marrow and 51 (89%) received PBPC. Forty-three (75%) pts received reduce-intensity conditioning (RIC), fourteen (25%) were treated with conventional myeloablative regimen. Twenty-five (44%) patients had previous autologous HSCT. At time of allo-HSCT, thirty-eight (67%) pts had chemosensitive disease, thirteen (23%) were considered as chemoresistant (six were untested). Interval from diagnosis to SCT ranged from 9,5 to 198 months with median 21 months.

Results: All pts but one engrafted. Acute graft-versus-host disease (aGVHD) occurred in 18 (31%) pts (11× grade I–II, 7× grade III–IV). Of the 35 evaluable patients sixteen (46%) developed chronic GVHD (12× limited, 4× extensive). The 100-day, 1-year and 3-years TRM rates were 30%, 39% and 42% respectively. Relapse or progression was observed in 26%. With a median folow-up of 31 months (range, 4–108) of living patients, the actuarial overall survival (OS) rates at 3 years were 36%, progression free survival (PFS) 36% and relaps risk 41 %. The 3-years OS rates of patients with DLCL, FCL and MCL were 15%, 53% and 31% respectively. Patients after prior ASCT had significantly less outcome (3-year OS 16% vs 51%, p=0,04). There was not found the correlation between GVHD and relapse rate, the outcome of pts treated with myeloablative regimen and RIC was not significantly different (3-year OS 46% vs 36%, relaps risk 20% vs 47%, p=0,4). There was no diference in OS between related and unrelated transplants (3-year OS 40% vs 35%, p=0,16). We didn’t observe significant diference between pts transplanted in chemosensitive or chemoresistant disease (3-year OS resp PFS 43% vs 23%, p=0,09, resp 39% vs 31%, p=0,14) At time of last follow-up 32 patients were dead and 25 were alive (22 in complete remission).

Conclusion: Allogeneic HSCT represents an effective therapeutic option for patients with poor prognosis NHL, however TRM remains the problem as well as high relapse risk in some cases. RIC may be an option for erderly patients but it’s not clear if it offers the same effectivity as standard myeloablative regimen. Transplants from unrelated donors may be probably considered comparable to related.