title: Macrophage inhibitory cytokine 1 biomarker serum immunoassay in combination with PSA is a more specific diagnostic tool for detection of prostate cancer.
abstract: BACKGROUND
  Prostate cancer (PCa) is the most common malignancy among men in the United States. Though highly sensitive, the often-used prostate-specific antigen (PSA) test has low specificity which leads to overdiagnosis and overtreatment of PCa. This paper presents results of a retrospective study that indicates that testing for macrophage inhibitory cytokine 1 (MIC-1) concentration along with the PSA assay could provide much improved specificity to the assay.
  
  
  METHODS
  The MIC-1 serum level was determined by a novel p-Chip-based immunoassay run on 70 retrospective samples. The assay was configured on p-Chips, small integrated circuits (IC) capable of storing in their electronic memories a serial number to identify the molecular probe immobilized on its surface. The distribution of MIC-1 and pre-determined PSA concentrations were displayed in a 2D plot and the predictive power of the dual MIC-1/PSA assay was analyzed.
  
  
  RESULTS
  MIC-1 concentration in serum was elevated in PCa patients (1.44 ng/ml) compared to normal and biopsy-negative individuals (0.93 ng/ml and 0.88 ng/ml, respectively). In addition, the MIC-1 level was correlated with the progression of PCa. The area under the receiver operator curve (AUC-ROC) was 0.81 providing an assay sensitivity of 83.3% and specificity of 60.7% by using a cutoff of 0.494 for the logistic regression value of MIC-1 and PSA. Another approach, by defining high-frequency PCa zones in a two-dimensional plot, resulted in assay sensitivity of 78.6% and specificity of 89.3%.
  
  
  CONCLUSIONS
  The analysis based on correlation of MIC-1 and PSA concentrations in serum with the patient PCa status improved the specificity of PCa diagnosis without compromising the high sensitivity of the PSA test alone and has potential for PCa prognosis for patient therapy strategies.
authors: PharmaSeq, Inc., Monmouth Junction, New Jersey, United States of America.
authors: Ji
authors: J
authors: Li
authors: Johns Hopkins University School of Medicine (JHUSOM), Baltimore, Maryland, United States of America.
authors: Robert W
authors: RW
authors: Veltri
authors: PharmaSeq, Inc., Monmouth Junction, New Jersey, United States of America.
authors: Zhen
authors: Z
authors: Yuan
authors: Johns Hopkins University School of Medicine (JHUSOM), Baltimore, Maryland, United States of America.
authors: Christhunesa S
authors: CS
authors: Christudass
authors: PharmaSeq, Inc., Monmouth Junction, New Jersey, United States of America.
authors: Wlodek
authors: W
authors: Mandecki
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D001706:Biopsy; D018450:Disease Progression; D055436:Growth Differentiation Factor 15 / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor; C526140:GDF15 protein, human; D055436:Growth Differentiation Factor 15; D017430:Prostate-Specific Antigen