Intensive follow-up after surgery for colorectal cancer is common practice but is based on limited evidence.
Professor David Mant and colleagues from the United Kingdom assessed the effect of scheduled blood measurement of carcinoembryonic antigen (CEA) and computed tomography (CT) as follow-up to detect recurrent colorectal cancer treatable with curative intent.
The research team performed a randomized clinical trial in 39 National Health Service hospitals in the United Kingdom.
The team recruited 1202 eligible participants between 2003 and 2009 who had undergone curative surgery for primary colorectal cancer, including adjuvant treatment if indicated, with no evidence of residual disease on investigation.
Participants were randomly assigned to 1 of 4 groups, including 300 patients in the CEA only group, 299 in the CT only group, 302 in the CEA+CT group, and 301 patients in the minimum follow-up group.
|Surgical treatment of recurrence with curative intent was 7% in the CEA group|
|Journal of the American Medical Association|
Blood CEA was measured every 3 months for 2 years, then every 6 months for 3 years.
CT scans of the chest, abdomen, and pelvis were performed every 6 months for 2 years, then annually for 3 years.
The team reported that the minimum follow-up group received follow-up if symptoms occurred.
The team's main outcomes included surgical treatment of recurrence with curative intent.
The researcher's secondary outcomes were mortality, time to detection of recurrence, and survival after treatment of recurrence with curative intent.
After a mean 4 years of observation, cancer recurrence was detected in 199 participants overall.
The research team treated 71 of 1202 participants for recurrence with curative intent, with little difference according to Dukes staging.
Surgical treatment of recurrence with curative intent was 2% in the minimum follow-up group, 7% in the CEA group, 8% in the CT group, and 7% in the CEA+CT group.
Compared with minimum follow-up, the absolute difference in the percentage of patients treated with curative intent in the CEA group was 4%, in the CT group was 6%, and in the CEA+CT group was 4%.
The team observed that the number of deaths was not significantly different in the combined intensive monitoring groups vs the minimum follow-up group.
Professor Mant's team concluded, "Among patients who had undergone curative surgery for primary colorectal cancer, intensive imaging or CEA screening each provided an increased rate of surgical treatment of recurrence with curative intent compared with minimal follow-up."
"There was no advantage in combining CEA and CT."
"If there is a survival advantage to any strategy, it is likely to be small."