Stem Cell Transplantation for Multiple Myeloma Most Effective When Used Early-On in the Disease

NEW ORLEANS —Based on an analysis of prognostic factors in a large European registry study, it appears that autologous stem cell transplantation is most effective when applied early in the course of multiple myeloma in younger, responsive patients.

Bo T. Björkstrand, MD, of the Karolinska Institute, Stockholm, Sweden, on behalf of the European Group for Blood and Marrow Transplantation, reported the findings at the 41st annual meeting of the American Society of Hematology (ASH).

Autologous stem cell transplantation was used to treat 5,489 patients with multiple myeloma at 287 European centers from 1986 through 1998. Complete data were available for 1,905 patients, with a median age at transplantation of 52 years (range, 18 to 76).

A peripheral blood stem cell (PBSC) graft was used in 1,631 patients, a bone marrow graft in 201, and combined marrow plus PBSCs in 73. A double-transplant program was offered to 278 patients.

For all 5,489 patients, median time from diagnosis to transplant was 10 months (range, 1 to 211). Median overall survival from the time of transplant was 52 months, and median progression-free survival was 25 months, Dr. Björkstrand reported.

For the 1,905 patients for whom all data are available, the post-transplant complete remission rate was 52%. The achievement of complete remission gave a slight survival advantage over not achieving remission.

Transplant-Related Variables

Several transplant-related variables had an effect on survival. By univariate and multivariate analyses, a significantly longer overall survival and/or progression-free survival was associated with the following:

Response to prior chemotherapy.

• Transplant early in the disease course.
  
• Less advanced disease at diagnosis.
  
• Age less than 60.
  
• B2 microglobulin (B2M) less than 4.0 mg/L at diagnosis.
  
• Use of a conditioning regimen that did not include total body irradiation (TBI).
  
• Post-transplant interferon-alfa maintenance treatment. Long-term disease-free survival was noted for several such patients as long as 9 to 10 years post-transplant.

Factors not affecting survival were patient sex, source of graft, and graft purging, Dr. Björkstrand reported.

In an analysis of newly diagnosed, responsive patients transplanted after 1991, progression-free survival was significantly better in patients treated in a double transplant program than after single autografting, with a trend toward improved overall survival as well.

The conclusion, Dr. Björkstrand said, is that autografting in multiple myeloma is most effective when administered early to younger, responsive patients. A non-TBI conditioning regimen, the use of double transplants, and interferon-alfa maintenance treatment are procedural factors that seem to improve survival.