AUTHORS: B. Bjorkstrand1, T.W. Klausen2, K. Remes3, A. Gruber4, L.M. Knudsen2, O.J. Bergmann2, S. Lenhoff5 and H.E. Johnsen2,6
Departments of Hematology at 1Huddinge University Hospital, Sweden; 2Herlev University Hospital, Herlev, Denmark; 3Department of Medicine, University Central Hospital, Turku, Finland; 4Karolinska Hospital, Karolinska Institute, Stockholm, Sweden; 5Lund University Hospital, Lund, Sweden; 6Aalborg Hospital, University of Aarhus Denmark & for the Nordic Myeloma Study Group
Background. Autologous stem cell transplantation is now considered the standard of care in young patients with multiple myeloma (MM). This disease is the most common indication for high dose therapy supported by haematopoietic stem-cell transplantation, and more data support the benefit of this procedure in MM than in any other disease. The available results of randomized studies are in favor of tandem autologous transplantation; however the effect on long term survival is unclear. During 1994-2000 we have conducted sequential registration trials in the Nordic area, evaluating the treatment of multiple myeloma with high-dose chemotherapy. This has included a regional phase II registration study of double autologous stem-cell transplantations. Methods. During 1994-2000 we have registered a total of 485 previously untreated patients under the age of 60 years at diagnosis who on a regional basis were treated with single (Trial NMSG #5/94 and #7/98 (N=384)) or double (Trial HKTH (N=101)) high dose melphalan (200 mg/m2) therapy supported by autologous stem cell transplantation. Results. A complete or a very good partial response was achieved by 40 percent of patients in the single-transplant group and 60 percent of patients in the double-transplant group (P=0.0006). The probability of surviving event-free for 5 years after the diagnosis was 25 (18-32) percent in the single-transplant group and 44 (33-55) percent in the double-transplant group (P=0.0014). The estimated overall 5-year survival rate was 50 percent in the single-transplant group and 50 percent in the double-transplant group (P=0.9). In a multivariate analysis of variables including single versus double transplantation, beta-2 microglobulin level, age, sex and disease stage only beta-2 microglobulin came out significantly (p<0.0001) and (p=0.001) for overall and event free survival respectively. In accordance with these results a 1:1 case-control matched comparison between double and single transplantation did not identify significant differences in overall and event free survival. Conclusions. As compared with single autologous stem-cell transplantation double transplantation did not seem to improve the final outcome among patients with multiple myeloma in the Nordic area.