title: Tandem versus single autologous hematopoietic cell transplantation for the treatment of multiple myeloma: a systematic review and meta-analysis.
abstract: BACKGROUND
  Evidence bearing on the efficacy of tandem autologous hematopoietic transplant (AHCT) vs a single AHCT in patients with multiple myeloma (MM) is conflicting. We performed a systematic review and meta-analysis to synthesize the existing evidence related to the effectiveness of tandem vs single AHCT in patients with MM.
  
  
  METHODS
  We searched Medline, conference proceedings, and bibliographies of retrieved articles and contacted experts in the field to identify randomized controlled trials (RCTs) reported in any language that compared tandem with single AHCT in patients with MM through March 31, 2008. Endpoints were overall survival (OS), event-free survival (EFS), response rate, and treatment-related mortality (TRM). Data were pooled under a random-effects model.
  
  
  RESULTS
  Six RCTs enrolling 1803 patients met the inclusion criteria. Patients treated with tandem AHCT did not have better OS (hazard ratio [HR] for mortality for patients treated with tandem transplant vs single transplant = 0.94; 95% confidence interval [CI] = 0.77 to 1.14) or EFS (HR = 0.86; 95% CI = 0.70 to 1.05). Response rate was statistically significantly better with tandem AHCT (risk ratio = 0.79, 95% CI = 0.67 to 0.93), but with a statistically significant increase in TRM (risk ratio = 1.71, 95% CI = 1.05 to 2.79). There was statistically significant heterogeneity among RCTs for OS and EFS.
  
  
  CONCLUSIONS
  In previously untreated MM patients, use of tandem AHCT did not result in improved OS or EFS. We conclude that tandem AHCT is associated with improved response rates but at risk of clinically significant increase in TRM.
authors.affiliation: Department of Health Outcomes and Behavior, Moffitt Cancer Center, Tampa, FL, USA. ambuj.kumar@moffitt.org
authors.forename: Ambuj
authors.initials: A
authors.lastname: Kumar
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Kharfan-Dabaja
authors.forename: Axel
authors.initials: A
authors.lastname: Glasmacher
authors.forename: Benjamin
authors.initials: B
authors.lastname: Djulbegovic
mesh_terms: D018572:Disease-Free Survival; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D009101:Multiple Myeloma / Q000401:mortality* / Q000601:surgery*; D016017:Odds Ratio; D016032:Randomized Controlled Trials as Topic; D016019:Survival Analysis; D014182:Transplantation, Autologous; D016896:Treatment Outcome