ABSTRACT
Background
Hematopoietic stem cell transplant (HSCT) is the preferred treatment for young patients with multiple myeloma (MM), but for older adults there is limited evidence on its effectiveness from clinical trials.
Methods
We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database to identify individuals age 66 years and older with multiple myeloma (MM) who were diagnosed between 2000 and 2007. We used traditional multivariable analysis, propensity score-based analysis, coarsened exact matching, and an instrumental variable analysis to compare survival for individuals who did or did not receive an hematopoietic stem cell transplant. Survival was measured by Cox proportional hazard models. All statistical tests were two-sided.
Results
Patients with MM receiving an HSCT were more likely to be white, married, younger, and have fewer comorbidities. Results from all analytic techniques consistently showed that HSCT statistically significantly improved survival, with hazard ratios (HRs) ranging from 0.531 to 0.608 (traditional multivariable analysis: HR = 0.582, 95% confidence interval [CI] = 0.49 to 0.69; propensity score analysis: HR = 0.572, 95% CI = 0.46 to 0.72; coarsened exact matching: HR = 0.608, 95% CI = 0.49 to 0.76; instrumental variable analysis: HR = 0.531, 95% CI = 0.36 to 0.78, all P values ≤ .001).
Conclusions
Overall survival has increased among patients with MM receiving HSCT. This finding was consistent across statistical methods, indicating robustness of our findings.