Follow-Up Tests Improve Colorectal Cancer Recurrence Detection
Image: ADVIA Centaur XP Immunoassay System (Photo courtesy of Siemens).
The effect of scheduled blood measurement of carcinoembryonic antigen and tomographic scan as follow-up to detect recurrent colorectal cancer treatable with curative intent has been evaluated.
Among patients who had undergone curative surgery for primary colorectal cancer, the two screening methods each provided an improved rate of surgical treatment of cancer recurrence compared with minimal follow-up.
Scientists at the University of Southampton (UK) assessed detection of recurrence using two common screening methods: measurement of a glycoprotein used as a tumor marker, the blood carcinoembryonic antigen (CEA), and computed tomography (CT). They randomized 1,202 patients from 39 hospitals in England into one of four groups: 300 patients with CEA only, 299 with CT only, 302 who had both tests, and 301 who had minimal follow up. The study was carried out between January 2003 and August 2009.
The CEA analysis was performed using an ADVIA Centaur XP analyzer (Siemens; Camberley, UK). If a patient’s blood CEA level was 7 µg/L or more above the level at trial entry, the test was repeated as soon as possible; if the second test result was also greater than this threshold, the patient’s general practice physician was asked to refer the patient urgently to the local hospital.
Cancer recurrence was detected in 199 participants (16.6%) during the period of observation for recurrence (average 4.4 years), and 5.9% of participants with recurrence underwent surgery for cure. The investigators found that surgical treatment of recurrence with curative intent was higher in each of the three more intensive follow-up groups compared with the minimum follow-up group. Compared with minimum follow-up, the absolute difference in the number treated with curative intent in the CEA group was 4.4%, 5.7% in the CT group, and 4.3% in the group who had both tests. The number of deaths was not significantly higher in the more intensive follow-up groups compared with the minimum follow-up group, as was the number of disease-specific colorectal cancer deaths.
The authors concluded that the benefits of follow-up appear to be independent of diagnostic stage, because although there are fewer recurrences with better-stage tumors, they are more likely to be curable. This suggests that stage-specific follow-up strategies may not be necessary. However, thorough staging investigation at the end of primary treatment to detect residual disease is still important because a large number of “recurrences” reported in routine series are probably residual disease that should be detected and treated before embarking on follow-up.
The study was published on January 15, 2014, in the Journal of the American Medical Association.