title: Plasma matrix metalloproteinase-9 level is better than serum matrix metalloproteinase-9 level to predict gastric cancer evolution.
abstract: OBJECTIVE
  Matrix metalloproteinase-9 (MMP-9) in blood is a promising new tumor marker. The aims of the present study are to compare the usefulness of plasma and serum MMP-9 levels for predicting gastric cancer development, invasion, and survival.
  
  
  METHODS
  In this nested case-control study, 114 gastric cancer patients and 87 healthy controls were enrolled. MMP-9 levels and activities were quantitatively measured by ELISA assay and zymography. The results were compared with the occurrence, clinicopathologic features, and outcomes of gastric cancer patients. The follow-up time for all patients was at least 5 years.
  
  
  RESULTS
  Serum MMP-9 levels were significantly higher than plasma MMP-9 levels. Both plasma and serum MMP-9 levels correlated significantly with active MMP-9 identified by zymography (P = 0.002 and P = 0.048, respectively). Plasma MMP-9 level was significantly elevated in gastric cancer patients when compared with control subjects (P < 0.001). Serum MMP-9 levels did not differ between the groups. Receiver-operator characteristics analysis showed the values of sensitivity (82.5%) and specificity (65.5%) at the maximum accuracy for plasma MMP-9 at >or=60 ng/mL (P < 0.001). Elevated plasma MMP-9 correlated significantly with lymph node metastasis [odds ratio (OR), 3.43; P = 0.019], lymphatic invasion (OR, 7.58; P = 0.009), and venous invasion (OR, 4.14; P = 0.033). Patients with elevated plasma MMP-9 levels had poorer survival rates than those with normal plasma MMP-9 levels (P = 0.038). Serum MMP-9 level did not correlate well with gastric cancer-invasive phenotypes or survival.
  
  
  CONCLUSIONS
  Our results suggest plasma MMP-9 level is a better marker than serum MMP-9 level for predicting gastric cancer development and progression.
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Chun-Ying
authors.initials: CY
authors.lastname: Wu
authors.forename: Ming-Shiang
authors.initials: MS
authors.lastname: Wu
authors.forename: En-Pei
authors.initials: EP
authors.lastname: Chiang
authors.forename: Yi-Ju
authors.initials: YJ
authors.lastname: Chen
authors.forename: Chien-Jen
authors.initials: CJ
authors.lastname: Chen
authors.forename: Nai-Hui
authors.initials: NH
authors.lastname: Chi
authors.forename: Ying-Ting
authors.initials: YT
authors.lastname: Shih
authors.forename: Gran-Hum
authors.initials: GH
authors.lastname: Chen
authors.forename: Jaw-Town
authors.initials: JT
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D008875:Middle Aged; D010949:Plasma / Q000737:chemistry*; D011379:Prognosis; D012372:ROC Curve; D044967:Serum / Q000737:chemistry*; D013274:Stomach Neoplasms / Q000097:blood* / Q000401:mortality / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D020780:Matrix Metalloproteinase 9