More frequent testing does not translate to increased survival in colorectal cancer

Increasing the frequency of CT scan and carcinoembryonic antigen (CEA) testing does not appear to produce a significant reduction in 10-year overall mortality or colorectal cancer–specific mortality for patients with stage II or III colorectal cancer (CRC), according to a study.

A total of 2,555 patients with stage II or III CRC who underwent curative surgery were randomly allocated to undergo follow-up testing with CT scans and serum CEA at 6, 12, 18, 24, and 36 months after surgery (high-frequency group, n=1,227) or at 12 and 36 months after surgery (low-frequency group, n=1,229).

Intention-to-treat analysis included 2,509 patients, of whom 2,456 (97.9 percent, median age 65 years, 55.2 percent male) were included in this post-trial analysis.

The 10-year overall mortality rate was 27.1 percent (95 percent confidence interval [CI], 24.7–29.7) vs 28.4 percent (95 percent CI, 26.0–31.0) in the high-frequency group (risk difference, 1.3 percent, 95 percent CI, −2.3 to 4.8). The 10-year colorectal cancer–specific mortality rate was 15.6 percent (95 percent CI, 13.6–17.7) vs 16.0 percent (95 percent CI, 14.0–18.1), respectively (risk difference, 0.4 percent, 95 percent CI, −2.5 to 3.3).

Results were consistent in the per-protocol analysis.

The present data should be considered when updating clinical guidelines.