title: Plasma diamine oxidase activity is a useful biomarker for evaluating gastrointestinal tract toxicities during chemotherapy with oral fluorouracil anti-cancer drugs in patients with gastric cancer.
abstract: OBJECTIVE
  Diamine oxidase (DAO) is an enzyme that catalyzes oxidation and is highly active in the mature upper villus cells of the intestinal mucosa. This study sought to evaluate plasma DAO activities during adjuvant chemotherapy in patients with gastric cancer.
  
  
  METHODS
  We investigated 20 patients with gastric cancer who were treated with oral fluorouracil anti-cancer drugs as adjuvant chemotherapy. Plasma DAO activity was measured in all patients before chemotherapy and at 2, 4 and 6 weeks after the start of chemotherapy, and quality of life was evaluated simultaneously.
  
  
  RESULTS
  The median DAO activity after 4 weeks of chemotherapy was significantly decreased compared to the pre-chemotherapy levels (6.6 vs. 7.5 U/l; p = 0.038). The changes in the rate of DAO activity at 2 and 6 weeks following the start of chemotherapy in patients with gastrointestinal tract toxicity were significantly lower than in those without toxicity (p =0.021 and 0.047, respectively). The patient cohort showed a slightly positive correlation between DAO activity and global health status and a negative correlation between DAO activity and appetite loss.
  
  
  CONCLUSIONS
  Plasma DAO activities may be useful for monitoring and evaluating gastrointestinal tract toxicities induced by adjuvant chemotherapy with oral fluorouracil in patients with gastric cancer.
authors.affiliation: Department of Surgery, Kochi Medical School, Nankoku, Japan. tsutomun@kochi-u.ac.jp
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Namikawa
authors.forename: Ian
authors.initials: I
authors.lastname: Fukudome
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kitagawa
authors.forename: Takehiro
authors.initials: T
authors.lastname: Okabayashi
authors.forename: Michiya
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hanazaki
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism*; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000009:adverse effects*; D014408:Biomarkers, Tumor / Q000097:blood; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects*; D041981:Gastrointestinal Tract / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011788:Quality of Life; D013274:Stomach Neoplasms / Q000097:blood* / Q000188:drug therapy* / Q000201:enzymology
chemical_list: D000964:Antimetabolites, Antineoplastic; D014408:Biomarkers, Tumor; D006631:Amine Oxidase (Copper-Containing); D005472:Fluorouracil