title: SERUM VALUES OF ALKALINE PHOSPHATASE AND LACTATE DEHYDROGENASE IN OSTEOSARCOMA.
abstract: OBJECTIVE
  To study the relationship between the pre and post chemotherapy (CT) serum levels of alkaline phosphatase (AP) and lactate dehydrogenase (LDH), and the percentage of tumor necrosis (TN) found in specimens after the pre surgical CT in patients with osteosarcoma.
  
  
  METHODS
  Series of cases with retrospective evaluation of patients diagnosed with osteosarcoma. Participants were divided into two groups according to serum values of both enzymes. The values of AP and LDH were obtained before and after preoperative CT. The percentage of tumor necrosis (TN) of surgical specimens of each patient was also included.
  
  
  RESULTS
  One hundred and thirty seven medical records were included from 1990 to 2013. Both the AP as LDH decreased in the patients studied, being the higher in pre CT than post CT. The average LHD decrease was 795.12U/L and AP decrease was 437.40 U/L. The average TN was 34.10 %. There was no statistically significant correlation between the serums values and the percentage of tumoral necrosis.
  
  
  CONCLUSIONS
  The serum levels values of AP and LDH are not good predictors for the chemotherapy-induced necrosis in patients with osteosarcoma. Level of Evidence IV, Case Series.
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, São Paulo, SP, Brazil.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Zumárraga
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, São Paulo, SP, Brazil.
authors.forename: André Mathias
authors.initials: AM
authors.lastname: Baptista
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, São Paulo, SP, Brazil.
authors.forename: Luis Pablo De La
authors.initials: LP
authors.lastname: Rosa
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, São Paulo, SP, Brazil.
authors.forename: Marcelo Tadeu
authors.initials: MT
authors.lastname: Caiero
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, São Paulo, SP, Brazil.
authors.forename: Olavo Pires De
authors.initials: OP
authors.lastname: Camargo
keywords: Alkaline phosphatase; Drug therapy; L-Lactate Dehydrogenase; Osteosarcoma; Prognosis.; Tumor necrosis factors