The real world effectiveness of hematopoietic transplant among elderly individuals with multiple myeloma

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.

Figure 1.

Consort Diagram. SEER = Surveillance, Epidemiology, and End Results.

Figure 2.

Kaplan-Meier survival curves between propensity score–matched patients who did and did not receive a hematopoietic stem cell transplant (HSCT). Solid line = No HSCT; dashed Line = HSCT. No. = 492; P < .01. All statistical tests were two-sided.