INTENSIVE MONITORING FOR COLORECTAL CANCER

NEW YORK (Reuters Health) Jan 14 - After surgery for colorectal cancer, regular monitoring with either carcinoembryonic antigen (CEA) testing or CT is effective for detecting recurrences and there is no advantage in combining the two, according to new data.

"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), suggesting that stage-specific follow-up strategies may not be necessary," the researchers say.

"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," they add.

Intensive follow-up after curative surgery for colorectal cancer is "common practice but is based on limited evidence," the investigators, led by Dr. John N. Primrose of the University of Southampton in England, note in a January 15 JAMA report.

The UK National Institute for Health Research Health Technology Assessment Program commissioned the FACS (Follow-up After Colorectal Surgery) trial to assess the effect of three to five years of scheduled CEA and CT monitoring to detect recurrence.

Participants included 1,202 patients from 39 hospitals in the UK who had curative surgery for primary colorectal cancer, including adjuvant treatment if indicated, with no evidence of residual disease.

Patients were randomly assigned to either a minimum follow-up group that received follow-up only if symptoms occurred or to one of three intensive interventions: CEA measurement every three months for two years, then every six months for three years; CT scans of the chest, abdomen, and pelvis every six months for two years, then annually for three years; or both CEA and CT.

Recurrence was detected in 199 participants (16.6%) during an average 4.4 years of follow-up.

The proportion of patients who underwent surgical treatment of recurrence with curative intent (the primary outcome) was higher in each of the three intensive follow-up groups compared with the minimum follow-up group: CEA (20 of 300, 6.7%); CT (24 of 299, 8%); and CEA+CT (20 of 302, 6.6%) vs. 7 of 301 (2.3%) in the minimum follow-up group.

Adjusted ORs for treatment with curative intent ranged from 3.00 to 3.63 for intensive follow-up with each protocol vs. minimum follow-up.

The number of deaths was non-significantly higher in the three combined intensive follow-up groups (164/901, 18.2%) than in the minimum follow-up group (48/301, 15.9%). The authors note, however, that the size of the trial provides "limited precision" in estimating survival.

They also say that the three intensive interventions tended to detect recurrence earlier, although the differences in earlier detection were not statistically significant. There were no recurrences treatable with curative intent detected in the minimum follow-up group after the second year. Two-thirds of recurrences (65.3%) were detected by a scheduled follow-up investigation, while the remainder were "interval cases, presenting symptomatically or incidentally during investigation of concurrent illness," they explain.

In an email to Reuters Health, Dr. Primrose advised clinicians to stage patients well before follow-up and perform chest and pelvis CT and CEA and ensure a clean colon.

"Follow-up with CT or CEA increases the number of detected recurrences that can be treated with curative intent; use CEA or CT but no advantage to both. The caveat is that CEA patients also had a 12-18 month CT," he added. "Follow-up all stages, even early stage as the benefit of follow-up is independent of stage. Early stage disease has fewer recurrences but more are likely to be curatively treated."

"Although we have not yet presented health economic data, it is likely that a single CT at 12-18 months with regular CEA measurement is most likely to be the most cost effective whilst minimizing radiation dose," Dr. Primrose said.

SOURCE: http://bit.ly/1doL31M

JAMA 2014;311(3):263-270.