The role of periodic serum CA19-9 test in surveillance after colorectal cancer surgery

Abstract

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. 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. 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). 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.