ECC 2013 Abstract#2151 - Intensified Follow-up in Colorectal Cancer Patients Using Frequent Carcino-Embryonic Antigen (CEA) Measurements and CEA-Triggered Imaging

Abstract #2151:  Intensified Follow-up in Colorectal Cancer Patients Using Frequent Carcino-Embryonic Antigen (CEA) Measurements and CEA-Triggered Imaging C. Verberne, P.M. Doornbos, I. Grossmann, G.H. De Bock, T. Wiggers

Background: The ultimate goal of post surgical follow-up is to identify relapsing patients as early as possible and to offer appropriate individuals the potential for curative salvage procedures.  Advances in local therapy is leading to a change in the pattern of recurrences and the options for subsequent treatment.  While guidelines exist to assist clinicians, the optimal strategy is unknown. CEA is an inexpensive, sensitive, valid and readily available test.  The CEA Watch Trial describes an intensive follow-up protocol with the hypothesis that identification of the trend of rise rather than the absolute value of CEA may lead to earlier detection of relapsing patients.

Methods: Eleven hospitals in the Netherlands participated in this randmomized controlled multicenter prospective study using a stepped wedge cluster design.  At prespecified time-points, hospitals changed from their usual follow-up care to an intensified schedule of CEA measurements every two months with a repeat at four weeks if the CEA value increased by 20%.  Imaging was obtained if there was a further rise.

Results: 3223 patients were included in the analysis.  There was a total of 243 recurrences detected during the study; 139 (57%) in the intensive follow-up group and 104 (43%) in the usual care group.  Of these, 90 patients were able to be treated with curative intent.  While the time to diagnosis did not differ between the groups, a significantly higher proportion in the intensive follow-up group were able to be offerred a potentially curative procedure (42 vs. 30%, p = 0.04).

Conclusions: The CEA watch protocol was more likely than standard care follow-up to detect recurrent disease at a stage treatable with curative intent.

This trial used an interesting trial design in which the randomization occurred at the hospital rather than the individual level. The results suggest that monitoring CEA trends more frequently with decisions to evaluate radiographically based on a specified rise over time rather than an absolute CEA value has the potential to both identify more patients with recurrences as well as offer them subsequent therapy with curative intent. It is still too early to identify whether this will, in fact, result in a difference in cure rates between the groups or whether there will be an influence of lead-time bias and so longer follow-up is needed. Also, given that CEA values may begin to rise many months before abnormalities are detectable by traditional imaging modalities, it is not clear whether assessments are required every two months, or if a three month schedule might be sufficient with confirmatory assessments four weeks later as performed in this study. A key element is to ensure that these patients are discussed with experienced individuals at multidisciplinary cancer conferences. In addition, in Canada’s public payer healthcare system, it will be necessary to evaluate the cost-effectiveness of this strategy.
— CARE Gastrointestinal Cancer Faculty