title: [Retrospective study comparing low-dose versus standard dose of bortezomib in patients with multiple myeloma].
abstract: BACKGROUND
  Bortezomib is a selective inhibitor of the proteosoma that is used in multiple myeloma. In combination with other antineoplastic drugs, it has a well-documented impact in progression-free survival rates and overall survival rates with standard doses (1.3-1.5 mg/m(2)). However, up to 88% of patients on standard doses have unwanted side effects (neutropenia, neuropathy or anemia. Standard dose (1.3 mg/m(2)) is used in almost all patients and low dose (0.7-0.8 mg/m(2)) is reserved for patients with kidney disease and neuropathy.
  
  
  OBJECTIVE
  We aim to describe clinical, cytological, and cytometric outcomes, as well as overall survival and side effects of low dose versus standard dose of bortezomib in our institution.
  
  
  METHODS
  Retrospective, descriptive study based on data recovered from clinical charts of 48 multiple myeloma patients treated in our hospital between 2011 and 2013. We included data on age, gender, type of multiple myeloma, serum albumin, serum creatinine, beta 2 microglobulin, calcemia, imaging studies, disease stage, pre-and post-therapy bone marrow studies, adverse events and rate of progression. We also recorded events like date of death or of the last medical appointment.
  
  
  RESULTS
  Forty-eight multiple myeloma patients were treated with bortezomib-cyclophosphamide-dexamethasone. Twenty-one patients received low dose and 27 patients were treated with the standard dose. No statistical differences between the two groups were found for clinical response (p=0.6), cytological response (p=0.28), flow cytometric response (p= 0.3), rate of adverse effects and overall survival rates.
  
  
  CONCLUSIONS
  This retrospective analysis suggests that lower doses of bortezomib have similar effects in disease control measured by flow cytometry and cytology compared to standard doses in multiple myeloma patients.
authors.affiliation: Departamento de Hematología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile. Address: Avda. Libertador Bernardo O'Higgins 340, Santiago Centro, Chile . Email: mauriciosarmiento@hotmail.com.
authors.forename: Marcela
authors.initials: M
authors.lastname: Espinoza Zelada
authors.affiliation: Departamento de Hematología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Nicole
authors.initials: N
authors.lastname: Befferman Cordova
authors.affiliation: Departamento de Hematología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Ocqueteau Tachini
authors.affiliation: Departamento de Hematología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Ramírez Villanueva
authors.affiliation: Departamento de Hematología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Galleguillos M
authors.affiliation: Departamento de Hematología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Sarmiento Maldonado
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D000069286:Bortezomib / Q000008:administration & dosage*; D003520:Cyclophosphamide / Q000008:administration & dosage; D003907:Dexamethasone / Q000008:administration & dosage; D018572:Disease-Free Survival; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008875:Middle Aged; D009101:Multiple Myeloma / Q000188:drug therapy*; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D000069286:Bortezomib; D003907:Dexamethasone; D003520:Cyclophosphamide