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Routine CT scans and CEA useful in follow-up of colorectal cancer
Last Updated: May 13, 2004



NEW YORK (Reuters Health) - Surveillance CT scans and serum
carcinoembryonic antigen (CEA) measurements yield valuable
information in the postoperative management of patients after
adjuvant chemotherapy for colorectal cancer (CRC), according to a
report in the April 15th Journal of Clinical Oncology.


Follow-up of patients with resected stage II or III CRC aims to
detect resectable metastases, resectable local recurrences, or second
primary (metachronous) CRC, the authors explain, but the frequency or
modality of such follow-up remains controversial.

Dr. David Cunningham and colleagues from Royal Marsden Hospital,
Surrey, UK and colleagues investigated the value of regular serum CEA
measurement and CT scans 12 and 24 months after commencement of
chemotherapy in 530 patients with resected stage II and III CRC.

Among the 155 patients (29%) with disease relapses, only 65 presented
with symptoms, the authors report. Recurrences were detected first by
CT in 49 patients and by elevated serum CEA in 45 patients.

More than two-thirds of the asymptomatic patients in the CT-detected
group had normal serum CEA levels, the report indicates, so their
relapses would not have been detected apart from the surveillance CT.

CT was used to confirm 24 sites of relapse in 31 patients with
relapses detected by CEA, the researchers note, whereas PET scan was
required to confirm the remaining relapse sites.

Median overall survival from the date of randomization did not differ
according to the principal detection method, the results indicate,
but median overall survival from the time of relapse was longer after
CEA detection (19.2 months) and CT detection (26.4 months) than after
symptomatic presentation (12.6 months).

In a multivariate analysis, relapse detection by CT was associated
with a trend towards improved survival (compared with symptomatic
presentation), but time to disease relapse did not predict survival
after relapse.

"This survival advantage could partly be as a result of lead time
bias from earlier diagnoses because the CT group had a median time to
recurrence that was 6.8 months less than the symptomatic group," the
investigators speculate. "This survival advantage was probably more
related to the fact that CT scanning was able to identify patients
with small volume metastases amenable to radical resection."

Nearly 8 times as many asymptomatic patients with relapses detected
by CT (23.8%) underwent curative resections of liver or lung
metastases as did patients with symptomatic recurrence (3.1%), the
report indicates.

"CT scanning should now be considered to be the surveillance imaging
of choice after curative resection of colorectal cancer," the authors
conclude.

"It is indisputable that individual patients derive value--in the
conventional sense of the term--by detection and treatment of
recurrent colorectal cancer, but it is not at all clear whether
populations of patients derive value from a high-intensity
surveillance strategy rather than a low-intensity one," write Dr.
Frank E. Johnson from St. Louis University, St. Louis, Missouri and
colleagues in a related editorial. "We urge the American Society of
Clinical Oncology and other organizations to become active advocates
for the funding of investigations in this area."





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This online resource is supported by: Sanofi-Synthelabo
www.asco.org