title: Do we really benefit from checking tumor markers in detecting recurrence in gastrointestinal cancer?
abstract: OBJECTIVE
  To evaluate the role of tumor markers carcinoembryonic antigen (CEA) and CA 19.9 in the early detection of local or systemic recurrence in gastrointestinal malignancies.
  
  
  METHODS
  Twenty-six patients with operable gastrointestinal cancer, who had elevated levels of either CEA or CA 19.9 or both during the postoperative follow-up period were evaluated. Serum estimation of tumor markers were carried out at 3-month intervals and the imaging and endoscopic procedures were performed at 6-month intervals or when a patient had an elevated tumor marker during follow-up.
  
  
  RESULTS
  The difference of mean serum levels of CA 19.9 but not of CEA was found to be statistically significant between the two groups of patients with or without radiographically / endoscopically evident recurrent disease (p < 0.05).
  
  
  CONCLUSIONS
  CA 19.9 was found to be a better, though not specific, indicator of recurrence. The relative small number of patients precludes reaching a firm conclusion. Further studies are needed to establish the role of these markers in determining early recurrence and their impact in overall survival.
authors.affiliation: Istanbul University, Cerrahpasa Medical Faculty, Department of Internal Medicine, Section of Medical Oncology, Istanbul, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Ozguroglu
authors.forename: H
authors.initials: H
authors.lastname: Turna