In patients with stage II or III colorectal cancer (CRC), frequent follow-up testing with CT scans and serum carcinoembryonic antigen (CEA) screening provides no significant overall or cancer-specific survival benefits at 10 years, according to findings from a secondary analysis.

"This secondary analysis of the COLOFOL randomized clinical trial found that, among patients with stage II or III colorectal cancer, more frequent follow-up testing with CT scan and CEA screening, compared with less frequent follow-up, did not result in a significant rate reduction in 10-year overall mortality or colorectal cancer-specific mortality," the authors concluded. "The results of this trial should be considered as the evidence base for updating clinical guidelines."

The study, led by Henrik Toft Sørensen, MD, PhD, DMSc, DSc, Aarhus University Hospital and Aarhus University, Aarhus, Denmark, was published online in JAMA Network Open.

The staff turnover at recruitment centers potentially affected protocol adherence. The inability to blind patients and physicians to the follow-up frequency was another limitation. The low-frequency follow-up protocol was less intensive than that recommended in the current guidelines by the National Comprehensive Cancer Network and the American Society of Clinical Oncology, potentially limiting comparisons to current standard practices.

The initial trial received unrestricted grants from multiple organizations including the Nordic Cancer Union, A.P. Møller Foundation, Beckett Foundation, Danish Cancer Society, and Swedish Cancer Foundation project. The authors reported no relevant conflicts of interest.