title: The role of periodic serum CA19-9 test in surveillance after colorectal cancer surgery.
abstract: BACKGROUND
  The serum carcinoembryonic antigen (CEA) test is mainly used for postoperative surveillance of colorectal cancer patients in Western and Japanese guidelines, but evidence to support the use of CA19-9 is scarce.
  
  
  METHODS
  We analyzed the cohort data from 22 institutions of the Japanese Study Group for Postoperative Follow-up of Colorectal Cancer. Patients who had undergone curative surgery for primary colorectal cancer (pathological stage I-III) between 1997 and 2006 were eligible for analysis. Sensitivities of CEA and CA19-9 at the time of recurrence and the contribution of CA19-9 to detecting recurrences were assessed.
  
  
  RESULTS
  A total of 17,833 patients were eligible, and the overall recurrence rate was 18 %. The sensitivity of CA19-9 in detecting recurrence was lower than that of CEA (29 vs. 57 %). Among patients with recurrence, recurrences were first suspected in 96 % using standard surveillance modalities (CEA elevation, CT scan, clinic visit, and colonoscopy), whereas recurrences were suspected because of CA19-9 elevation in an estimated 1.3 % of patients. With regard to prognosis after recurrences, the sensitivity of CA19-9 was lower than that of CEA in the detection of surgically treatable recurrences (22 vs. 49 %). In terms of overall survival after recurrences, CA19-9 and CEA had almost comparable hazard ratios (1.66 and 1.48, respectively).
  
  
  CONCLUSIONS
  Our data suggested that the sensitivity of serum CA19-9 test is low, and that adding it to the current standard surveillance strategies is not beneficial.
authors: Department of Surgery, Kyoto University Hospital, 54 Shogoin-Kawahara-Cho, Sakyo-ku, Kyoto, Japan. rokamura@kuhp.kyoto-u.ac.jp.
authors: Ryosuke
authors: R
authors: Okamura
authors: Department of Surgery, Kyoto University Hospital, 54 Shogoin-Kawahara-Cho, Sakyo-ku, Kyoto, Japan.
authors: Suguru
authors: S
authors: Hasegawa
authors: Department of Surgery, Kyoto University Hospital, 54 Shogoin-Kawahara-Cho, Sakyo-ku, Kyoto, Japan.
authors: Koya
authors: K
authors: Hida
authors: Department of Surgery, Kyoto University Hospital, 54 Shogoin-Kawahara-Cho, Sakyo-ku, Kyoto, Japan.
authors: Nobuaki
authors: N
authors: Hoshino
authors: Department of Surgery, Kyoto University Hospital, 54 Shogoin-Kawahara-Cho, Sakyo-ku, Kyoto, Japan.
authors: Kenji
authors: K
authors: Kawada
authors: Tokyo Medical and Dental University, Tokyo, Japan.
authors: Kenichi
authors: K
authors: Sugihara
authors: Department of Surgery, Kyoto University Hospital, 54 Shogoin-Kawahara-Cho, Sakyo-ku, Kyoto, Japan.
authors: Yoshiharu
authors: Y
authors: Sakai
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000097:blood / Q000473:pathology* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000175:diagnosis; D011379:Prognosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen
keywords: CA19-9; Colorectal cancer; Recurrence; Surveillance