title: Gamma-glutamyl transpeptidase level is a novel adverse prognostic indicator in human metastatic colorectal cancer.
abstract: OBJECTIVE
  Biomarkers have been utilized for prognosis in colorectal cancer; however, relatively few have been identified. We compared the prognostic value of serum alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and gamma-glutamyl transpeptidase (GGT) with carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in patients with metastatic colorectal cancer (mCRC).
  
  
  METHODS
  Blood samples were collected from 239 patients with mCRC presenting between 2005 and 2010 in the Sun Yat-sen University Cancer Center.
  
  
  RESULTS
  CEA (P < 0.001), CA19-9 (P < 0.001), GGT (P < 0.001), ALP (P < 0.001) and LDH (P = 0.001) were statistically significant prognostic factors of overall survival (OS). CEA (P = 0.002) and GGT (P = 0.021) were validated as independent predictors. On univariate analysis, CEA (P = 0.003), CA19-9 (P = 0.006), GGT (P < 0.001) and ALP (P = 0.001) were statistically significant predictive factors of progression-free survival (PFS) in patients having first-line chemotherapy. CEA (P = 0.011) and GGT (P = 0.027) were independent predictors. GGT (P = 0.001), ALP (P = 0.016) and LDH (P = 0.039) levels were correlated with the tumour response rate assessed by CT, whilst CEA (P = 0.724) and CA19-9 (P = 0.822) were not. There was a statistically significant difference in OS (P < 0.001) and PFS (P < 0.001) among patients who had elevations of both CEA and GGT compared with those in whom only one or neither was elevated.
  
  
  CONCLUSIONS
  Among GGT, LDH and ALP, only GGT plays an independent role with CEA in predicting OS and PFS in mCRC. When coupled with CEA, GGT may lead to improved prognostic predictors.
authors.affiliation: Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
authors.forename: W-z
authors.initials: WZ
authors.lastname: He
authors.forename: G-f
authors.initials: GF
authors.lastname: Guo
authors.forename: C-x
authors.initials: CX
authors.lastname: Yin
authors.forename: C
authors.initials: C
authors.lastname: Jiang
authors.forename: F
authors.initials: F
authors.lastname: Wang
authors.forename: H-J
authors.initials: HJ
authors.lastname: Qiu
authors.forename: X-x
authors.initials: XX
authors.lastname: Chen
authors.forename: R-m
authors.initials: RM
authors.lastname: Rong
authors.forename: B
authors.initials: B
authors.lastname: Zhang
authors.forename: L-p
authors.initials: LP
authors.lastname: Xia
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000097:blood; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000401:mortality; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D007770:L-Lactate Dehydrogenase; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase
keywords: Gamma-glutamyl transpeptidase; biomarker; carcinoembryonic antigen; colorectal cancer; prognosis