title: Secondary malignancies after allogeneic hematopoietic stem cell transplantation using reduced-intensity conditioning and outpatient conduction.
abstract: BACKGROUND
  Patients given allogeneic hematopoietic stem cell transplants (HSCT) may develop secondary malignant neoplasms (SMN). Several variables have been identified but there are no data about the incidence of this complication in individuals given HSCT using reduced-intensity conditioning (RIC) methods.
  
  
  OBJECTIVE
  Define the incidence of SMN in patients given HSCT using a RIC preparative regimen conducted on an outpatient basis.
  
  
  METHODS
  Patients given HSCT in two institutions between October 1998 and 2012 were analyzed. To appraise the SMN appearance, those patients dead were also regarded as censored at that moment, as well as those lost to follow up and those alive at the closing of the study. 95% Confidence intervals (CI) for the survival or failure estimate were calculated with the Greenwood's method.
  
  
  RESULTS
  A total of 416 allografted patients with a Karnofsky performance index of 100% were included in the study. All patients received peripheral blood stem cells allografts. The conditioning regimen was delivered as an outpatient procedure in all individuals. No patient was given radiotherapy nor antithymocyte globulin during the conditioning. Three hundred and sixty five patients (88%) were never admitted to the hospital, whereas 12% were admitted because of grade III-IV acute graft versus host disease (aGVHD), fever, or mucositis. Median survival time was 15.7 months. Survival at 6 months (95% CI): 66.4% (61.5-70.8%), at 12 months: 53.3% (48.1-58.1%), at 60 months: 30.6% (30.5-41.5%). Eight patients with a SMN were identified in the group of 416 allografted patients, SMN rates (95% CI) were: one year post graft: 1.9% (0.7-4.9%), 5 years: 3.8% (1.6-9.2%), 10 years: 6.8% (2.6-17.7%) and 13 years post-graft: 20.2% (5.5-59.2%), the cumulative probability of SMN being 6.8 at 10 years. Since the number of expected cases in the general population is 0.62, the ratio of observed to expected cases is 12.9 (P < 0.001). This figure means that the risk of developing a malignant neoplasm in allografted individuals using our method is 12.9 times higher than that in the general population. There were three non-Hodgkin's lymphomas, two M2 acute myelogenous leukemias, one hairy cell leukemia, one tongue epidermoid carcinoma, and one breast carcinoma.
  
  
  CONCLUSIONS
  We have found a low incidence of SMN in this group of Mexican patients allografted with the Mexican RIC method. Possible explanations for this difference are discussed, focusing on the RIC preparative regimen.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Zamora-Ortiz
authors.forename: Sara
authors.initials: S
authors.lastname: Velázquez-Sánchez-de-Cima
authors.forename: Sergio
authors.initials: S
authors.lastname: Ponce-de-León
authors.forename: César Homero
authors.initials: CH
authors.lastname: Gutiérrez-Aguirre
authors.forename: Guillermo José
authors.initials: GJ
authors.lastname: Ruiz-Delgado
authors.forename: David
authors.initials: D
authors.lastname: Gomez-Almaguer
authors.forename: Guillermo José
authors.initials: GJ
authors.lastname: Ruiz-Argüelles
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D064591:Allografts; D002648:Child; D002675:Child, Preschool; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000209:etiology*; D019172:Transplantation Conditioning / Q000009:adverse effects* / Q000379:methods; D055815:Young Adult
keywords: Allograft; Secondary malignancy; Secondary neoplasm