title: Multicenter evaluation of a new progastrin-releasing peptide (ProGRP) immunoassay across Europe and China.
abstract: BACKGROUND
  We performed a multicenter evaluation of the Elecsys® progastrin-releasing peptide (ProGRP) immunoassay in Europe and China.
  
  
  METHODS
  The assay was evaluated at three European and two Chinese sites by imprecision, stability, method comparison and differentiation potential in lung cancer.
  
  
  RESULTS
  Intermediate imprecision across five analyte concentrations ranged from 2.2% to 6.0% coefficient of variation. Good stability for plasma and serum samples was shown for various storage conditions. There was excellent correlation between the Elecsys® and ARCHITECT assays in plasma (slope 1.02, intercept -2.72pg/mL). The Elecsys® assay also showed good correlation between serum and plasma samples (slope 0.93, intercept 2.35pg/mL; correlation coefficient 0.97). ProGRP differentiated small-cell and non-small-cell lung cancer (NSCLC; area under the curve 0.90, 95% CI 0.87-0.93; 78.3% sensitivity, 95% specificity; at 84pg/mL), with no relevant effects of ethnicity, age, gender or smoking. Median ProGRP concentrations were low in benign diseases (38pg/mL), other malignancies (40pg/mL) or NSCLC (39pg/mL), except chronic kidney disease above stage 3 (>100pg/mL).
  
  
  CONCLUSIONS
  Increased stability of the Elecsys® ProGRP assay in serum and plasma offers clear benefits over existing assays. This first evaluation of a ProGRP assay in China demonstrated comparable differentiation potential among different ethnicities.
authors.affiliation: The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066CX, The Netherlands. Electronic address: t.korse@nki.nl.
authors.forename: Catharina M
authors.initials: CM
authors.lastname: Korse
authors.affiliation: University Hospital Bonn and Center of Integrative Oncology Cologne/Bonn, Sigmund-Freud-Strasse, Bonn 25-53127, Germany. Electronic address: stefan.holdenrieder@uni-bonn.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Holdenrieder
authors.affiliation: Xuanwu Hospital, Capital Medical University, No. 45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: xiuyizhi@aliyun.com.
authors.forename: Xiu-yi
authors.initials: XY
authors.lastname: Zhi
authors.affiliation: Peking Union Medical College Hospital (PUMCH), 1Shuaifuyuan, Dongcheng District, Beijing 100730, China. Electronic address: ajxt@public3.bta.net.cn.
authors.forename: Xiaotong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Peking Union Medical College Hospital (PUMCH), 1Shuaifuyuan, Dongcheng District, Beijing 100730, China. Electronic address: lingqiubj@aliyun.com.
authors.forename: Ling
authors.initials: L
authors.lastname: Qiu
authors.affiliation: Roche Diagnostics GmbH, Nonnenwald 2, Penzberg 82377, Germany. Electronic address: andrea.geistanger@roche.com.
authors.forename: Andrea
authors.initials: A
authors.lastname: Geistanger
authors.affiliation: Roche Diagnostics GmbH, Nonnenwald 2, Penzberg 82377, Germany. Electronic address: marcus-rene.lisy@roche.com.
authors.forename: Marcus-Rene
authors.initials: MR
authors.lastname: Lisy
authors.affiliation: Roche Diagnostics GmbH, Nonnenwald 2, Penzberg 82377, Germany. Electronic address: birgit.wehnl@roche.com.
authors.forename: Birgit
authors.initials: B
authors.lastname: Wehnl
authors.affiliation: The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066CX, The Netherlands. Electronic address: da.vd.broek@nki.nl.
authors.forename: Daan
authors.initials: D
authors.lastname: van den Broek
authors.affiliation: Hospital Clinic, University of Barcelona, Carrer Villarroel 170, Barcelona 08036, Spain. Electronic address: JMESCUDE@clinic.ub.es.
authors.forename: José M
authors.initials: JM
authors.lastname: Escudero
authors.affiliation: University Hospital Bonn and Center of Integrative Oncology Cologne/Bonn, Sigmund-Freud-Strasse, Bonn 25-53127, Germany. Electronic address: standop@uni-bonn.de.
authors.forename: Jens
authors.initials: J
authors.lastname: Standop
authors.affiliation: Xuanwu Hospital, Capital Medical University, No. 45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: hunthm1999@163.com.
authors.forename: Mu
authors.initials: M
authors.lastname: Hu
authors.affiliation: Hospital Clinic, University of Barcelona, Carrer Villarroel 170, Barcelona 08036, Spain. Electronic address: RMOLINA@clinic.ub.es.
authors.forename: Rafael
authors.initials: R
authors.lastname: Molina
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D044466:Asian People; D014408:Biomarkers, Tumor / Q000097:blood*; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood / Q000175:diagnosis* / Q000208:ethnology / Q000473:pathology; D018288:Carcinoma, Small Cell / Q000097:blood / Q000175:diagnosis* / Q000208:ethnology / Q000473:pathology; D002681:China; D003937:Diagnosis, Differential; D005060:Europe; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000592:standards*; D008175:Lung Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000208:ethnology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood*; D011994:Recombinant Proteins / Q000097:blood; D012680:Sensitivity and Specificity; D044465:White People
chemical_list: D014408:Biomarkers, Tumor; D010446:Peptide Fragments; D011994:Recombinant Proteins; C087079:pro-gastrin-releasing peptide (31-98)
keywords: Differential diagnosis; Immunoassay; ProGRP; Progastrin-releasing peptide; SCLC; Stability