title: Comparative effectiveness analysis of different salvage therapy intensities used for diffuse large B-cell lymphoma in Northern or Southern Alberta: an instrumental variable analysis.
abstract: To date, no clinical trial has addressed salvage therapy intensity for relapsed/refractory diffuse large B-cell lymphoma (DLBCL). We sought to determine whether the more intensive salvage chemotherapy approach used in Southern Alberta (SAB) compared to the conventional dose salvage approach used in Northern Alberta (NAB) affects the rates of autologous stem cell transplant (ASCT) and survival in patients with relapsed DLBCL. Using instrumental variable analysis, we examined 147 consecutive patients with relapsed/refractory DLBCL from 2004 to 2010 who received salvage therapy in SAB (n = 70) or NAB (n = 77). Patients treated in SAB had higher rates of: salvage chemotherapy response (85.0% vs. 54.0%, p = 0.001), ASCT (61.4% vs. 41.6%, p = 0.016) and 4-year overall survival (41% vs. 20%, p = 0.002) than those in NAB, respectively. This study supports the hypothesis that selective use of intensive salvage chemotherapy leads to higher rates of ASCT and survival in this population.
authors.affiliation: Department of Oncology and Medicine, University of Calgary, Tom Baker Cancer Centre , Calgary, AB , Canada.
authors.forename: Danielle H
authors.initials: DH
authors.lastname: Oh
authors.forename: Sunita
authors.initials: S
authors.lastname: Ghosh
authors.forename: Neil
authors.initials: N
authors.lastname: Chua
authors.forename: Xanthoula
authors.initials: X
authors.lastname: Kostaras
authors.forename: Derek
authors.initials: D
authors.lastname: Tilley
authors.forename: Michael
authors.initials: M
authors.lastname: Chu
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Owen
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Stewart
mesh_terms: D000328:Adult; D000368:Aged; D000416:Alberta; D003131:Combined Modality Therapy; D004358:Drug Therapy / Q000379:methods; D005843:Geography; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology / Q000628:therapy*; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D017063:Outcome Assessment, Health Care / Q000379:methods*; D016879:Salvage Therapy / Q000379:methods*; D033581:Stem Cell Transplantation / Q000379:methods* / Q000706:statistics & numerical data; D016019:Survival Analysis; D014182:Transplantation, Autologous; D055815:Young Adult
keywords: Diffuse; comparative studies; hematopoietic; instrumental variable analysis; large B-cell; lymphoma; relapse; salvage; stem cell transplant; therapy