title: Bone and total alkaline phosphatase for screening skeletal metastasis in patients with solid tumours.
abstract: Alkaline phosphatase (AP) has several isoforms including bone alkaline phosphatase (BAP). We evaluated BAP and AP for screening for bone metastasis (BM) in patients with solid tumours. This is a prospective non-blinded study conducted at ABC Foundation School of Medicine Oncology clinics. A total of 40 subjects without a history of cancer and 62 patients with various solid tumours referred for a bone scan had serum drawn for BAP and AP determination. Bone alkaline phosphatase and AP levels in patients with cancer and BM, without BM and with no cancer, were 70.32 +/- 3.65 and 310.21 +/- 16.87 U/L; 41.40 +/- 2.80 and 113.23 +/- 12.95 U/L; 21.19 +/- 2.76 and 148.05 +/- 12.79 U/L respectively (P < 0.0001 for both AP and BAP). For BAP and AP sensitivity, specificity, positive and negative predictive values were 0.86 and 0.52; 0.69 and 1; 0.45 and 1; 0.94 and 0.87 respectively. ROC AUC value for BAP was 0.89 and for AP was 0.93. We conclude that BAP is more sensitive than AP, whereas AP had a remarkable specificity of 100%. In screening for BM in patients with solid tumours, obtaining initially BAP and then selecting for further investigation only patients with an abnormal AP may be a cost and resource saving strategy.
authors.affiliation: Federal University of São Paulo (UNIFESP), São Paulo, Brazil.
authors.forename: F
authors.initials: F
authors.lastname: Schindler
authors.forename: P P
authors.initials: PP
authors.lastname: Lajolo
authors.forename: H
authors.initials: H
authors.lastname: Pinczowski
authors.forename: F L A
authors.initials: FL
authors.lastname: Fonseca
authors.forename: A
authors.initials: A
authors.lastname: Barbieri
authors.forename: L H
authors.initials: LH
authors.lastname: Massonetto
authors.forename: F T
authors.initials: FT
authors.lastname: Katto
authors.forename: A
authors.initials: A
authors.lastname: Del Giglio
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood*; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000556:secondary; D001842:Bone and Bones / Q000201:enzymology*; D004796:Clinical Enzyme Tests; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D010146:Pain / Q000209:etiology; D012372:ROC Curve; D011877:Radionuclide Imaging
chemical_list: D000469:Alkaline Phosphatase