Double versus Single Autologous Stem-Cell Transplantation for Multiple Myeloma: a Region Based Study in 485 Patients from the Nordic Area
Multiple myeloma is commonly treated with stem cell transplantation in younger patients. A randomized study in 1996 found that double (or “tandem”) transplants resulted in an increase in overall survival, from 21% to 42% of patients. As a result, many institutions perform tandem transplants for these patients. This study aimed to assess the long term benefit of tandem transplant and was conducted in Sweden .
All 485 patients were under 60 years of age: 384 received a single transplant and 101 received tandem transplants. All patients received high-dose melphalan. Complete or very good partial response was achieved by 40% of patients in the single-transplant group, versus 60% of patients in double-transplant group (p=0.0006). Five-year event-free survival was 25% in single-transplant group and 44% in double-transplant group (P=0.0014). Despite this early advantage, the estimated 5-year overall survival rate was 50% in single-transplant group and 50% in double-transplant group (P=0.9).
In response to these results, further comparison was done, which found no long-term benefit to tandem transplant over single transplant. In a country like Sweden where socialized medicine prevails, performing tandem transplants for the treatment of all favorable myeloma patients without clear evidence of its long-term efficacy is not an affordable luxury. Although the five-year event-free survival was better with the double transplant arm, it is not considered to be a compelling enough endpoint to justify this approach universally, and thus single AuSCT remains the standard of care for this geographical region. In the future, a phase III trial in this population may be warranted, as randomization of patients would provide more confident data, as it is not clear in this phase II study how patients were selected to be in either the single or double transplant groups.