title: Study of serum antioxidant capacity and relation with CA 19-9 and PSA in patients with gastrointestinal tract and prostate tumors.
abstract: OBJECTIVE
  We undertook the present study to investigate the possible relation between total antioxidant capacity (TAC) and tumor marker (TM) values in serum samples of patients with and without gastrointestinal tract and prostate tumors.
  
  
  METHODS
  We measured the TAC using trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorption capacity (ORAC) assays in 80 serum samples: 20 presented elevated values of CA 19-9; 20 had elevated PSA levels and two groups of 20 samples had values within reference ranges respectively.
  
  
  RESULTS
  Total antioxidant capacity - measured using the two different analytical methods - was higher in serum samples from patients with elevated CA 19-9 and PSA levels. This antioxidant status, measured by ORAC assay, correlated significantly with CA 19-9 (r: 0.502, P<0.05) and PSA (r:0.792, P<0.001) when the values of these tumor markers were pathological.
  
  
  CONCLUSIONS
  We concluded that increased serum TAC of the patients with altered levels of CA 19-9 and PSA may be due to the response of increased reactive oxygen species and can be considered as a sign of oxidative stress of these patients. We know that tumor markers are a useful tool for follow-up care of oncologic patients, whereas their role in the diagnosis of a malignancy is controversial. Therefore, the evaluation of serum antioxidant capacity in these pathological processes could contribute to improve diagnosis of these patients.
authors: Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain. Electronic address: msvelez@ugr.es.
authors: M
authors: M
authors: López Vélez
authors: Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain. Electronic address: femartin@ugr.es.
authors: F
authors: F
authors: Martínez Martínez
mesh_terms: D000368:Aged; D000951:Antigens, Neoplasm / Q000097:blood*; D000975:Antioxidants / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000097:blood; D018395:CA-19-9 Antigen / Q000097:blood*; D016022:Case-Control Studies; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D017382:Reactive Oxygen Species
chemical_list: D000951:Antigens, Neoplasm; D000975:Antioxidants; D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D017382:Reactive Oxygen Species; D017430:Prostate-Specific Antigen