title: Clinical significance of CA19-9 in the follow-up of colorectal cancer patients with elevated preoperative serum CA19-9.
abstract: OBJECTIVE
  We hypothesized an advantage of using carbohydrate antigen 19-9 (CA19-9) over carcinoembryonic antigen (CEA) in postoperative surveillance of colorectal cancer (CRC) patients with elevated preoperative serum CA19-9 (PreCA19-9).
  
  
  METHODS
  We analyzed 197 CRC patients with elevated PreCA19-9 (>=37U/mL). Serum levels of CEA and CA19-9 were monitored postoperatively, according to standard protocol. IndexCEA and IndexCA19-9 were defined as the levels of CEA and CA19-9, respectively, recorded at recurrence confirmation or at the last follow-up of non-recurrence.
  
  
  RESULTS
  There were 56 recurrences during follow-up. IndexCA19-9 (cut-off, 38.6U/mL) had better sensitivity (0.80 vs. 0.68) and specificity (0.87 vs. 0.83) than did IndexCEA (cut-off. 2.8ng/mL). Area under the curve (AUC) analysis revealed that although IndexCA19-9 (0.90; 95% confidence interval [CI], 0.84-0.95) had better coverage than IndexCEA (0.84; 95% CI, 0.78-0.90), there was no significant difference (p=0.085). With the progressive rising of PreCA19-9 levels, we observed the trend of better AUC performance of IndexCA19-9 over IndexCEA. At a cut-off of 42U/mL for PreCA19-9, IndexCA19-9 began to have significantly better coverage than IndexCEA (p=0.027).
  
  
  CONCLUSIONS
  The surveillance advantage of CA19-9 over CEA was shown in the group of patients with preoperative CA19-9 levels >42U/mL.
authors: Shung-Haur
authors: SH
authors: Yang
authors: Jeng-Kai
authors: JK
authors: Jiang
authors: Shih-Ching
authors: SC
authors: Chang
authors: Chi-Jung
authors: CJ
authors: Juang
authors: Jen-Kou
authors: JK
authors: Lin
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D018395:CA-19-9 Antigen / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood; D015179:Colorectal Neoplasms / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen