title: Tumor markers in metastatic disease from cancer of unknown primary origin.
abstract: BACKGROUND
  About 5-10% of cancer patients suffer from cancer of unknown primary (CUP). Sophisticated diagnostic techniques have not improved diagnostic efficacy for these patients. The aim of our analysis was to evaluate serum levels of four tumor markers and to relate them to the histology, number, and sites of metastases, the response to chemotherapy, and survival.
  
  
  METHODS
  Blood samples from 46 patients with CUP were assayed for CEA, CA 19-9, CA 15-3 and CA 125. Specific IMx tumor marker assays (Abbott) were used to measure tumor marker quantities.
  
  
  RESULTS
  No significant differences were detected between the mean levels of all markers for the two histological types (adenocarcinoma vs. undifferentiated carcinoma). The comparison of tumor marker values in patients with one metastatic location to those with two or more showed no significant differences. We found no differences in marker values between patients with disease sites in the thorax vs. those with abdominal metastases. The comparison of marker negative, CEA positive and non-CEA positive patients failed to reveal significant differences in response rate. The comparison of CEA positive and marker negative patients showed significant differences in survival (log-rank, p=0.02).
  
  
  CONCLUSIONS
  Our results suggest that patients with CUP have a nonspecific overexpression of serum tumor markers and that routine use of these markers does not offer diagnostic assistance. Nevertheless, the pattern of expression of some biological markers, such as CEA, could have prognostic significance for survival.
authors.affiliation: Institute of Oncology and Radiology of Serbia, Pasterova 14, 11000 Belgrade, F. R. Yugoslavia.
authors.forename: Marijana
authors.initials: M
authors.lastname: Milović
authors.forename: Ivan
authors.initials: I
authors.lastname: Popov
authors.forename: Svietislav
authors.initials: S
authors.lastname: Jelić
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000097:blood / Q000175:diagnosis*
chemical_list: D014408:Biomarkers, Tumor