Multiple Myeloma in Manitoba: A Population Based Study.

Background: We reviewed outcomes for all Manitoba myeloma patients 1993–2006 treated conventionally or with high dose therapy followed by stem cell transplantation.

Methods: A retrospective cohort study was undertaken where all individuals with a diagnosis of MM (ICD-O-3) were identified within the CancerCare Manitoba (CCMB) Registry and the Manitoba Blood and Bone Marrow Transplant (MBMT) Registry. Complete incidence, mortality and demographic data are available for all patients in the CCMB registry and complete staging, transplant characteristics and outcome data are available for individuals in the MBMT registry. A multivariate model was used to explore predictors of outcome for the entire cohort. Kaplan-Meier survival analysis was performed to compare those who have and who have not undergone transplantation, as well as to compare those who have undergone autologous (autoSCT) versus allogeneic stem cell transplantation (alloSCT).

Results: 771 pts were diagnosed with MM. Incidence rates of MM over the last decade have remained stable. Age and sex adjusted rates (per 10⁵) were 6.6 and 4.5 for males and females respectively. Median age of the cohort was 69, whereas the median age of those who have undergone transplantation is 54. 78 pts underwent autoSCT and 11 underwent alloSCT, with the majority of transplants performed after 2001. As a fraction of total transplants performed per year, MM transplant rates have remained stable since 2002 at 29%. Six pts have undergone sequential transplants for relapse or progression. Median overall survival for those undergoing transplantation is 5.2 years compared to 3 years for those not transplanted (p<0.01). On multivariate analysis, for the entire cohort, undergoing transplantation was associated with a hazard ratio for death of 0.39 (CI 0.25–0.6), while being 70 or above was associated with a hazard ratio for death of 1.45 (CI 1.12–1.87). For those who have undergone transplantation median overall survival was not affected by transplant type, age at transplant (< or ≥ 60), or disease status prior to transplantation (log-rank test p>0.05).

Conclusions: In this population based analysis, utilization of stem cell transplantation provides a survival benefit to patients with MM. For those eligible for autoSCT, disease status prior to transplantation does not affect outcome.