Colon and Rectal Cancers

Description

Alternative Names

Follow-up Testing

The American Society of Clinical Oncology (ASCO) sets guidelines for follow-up testing to detect recurring cancer after treatment has been completed. These ASCO guidelines may not apply to particular patients. Although they are based on the best available evidence, rigorous studies are still needed to determine which tests can best cost-effectively detect recurrence at its earliest stage.

Physical Examination and Colonoscopy

After surgery, patients should have a physical examination every three to six months for the first three years. Some guidelines recommend colonoscopy within six months of surgery, performed again at 18 months, and then less frequently (e.g., 18 to 24 months), depending on individual factors. There is some debate about whether there should be more frequent colonoscopies for the first few years after colon surgery. In one 2002 study, patients with Stage II and III cancers had a 1.5% chance of developing a new primary colon cancer within two years after surgery. Experts suggested that the frequency of colonoscopies may not need to be increased, but the examinations themselves should certainly be very meticulous.

CEA Levels

CEA levels should be measured every two to three months after surgery for two years in Stage II or III patients. An elevated CEA level, confirmed by retesting, warrants further evaluation for return of metastatic disease. It should be noted that almost a third of all recurring cancers do not produce abnormal CEA levels.

Imaging Techniques

An advanced imaging technique called a fluorodeoxyglucose positron emission tomography (FDG-PET) scan may be used to detect recurrent or metastasized colorectal cancer in the setting of an elevated CEA. This test is proving to be very sensitive in detecting diseased areas.

Other Tests

There appears to be no additional benefit for anyone from routine follow-up liver function tests, fecal occult blood tests (FOBT), or computed tomography (CT) scans. There is some debate about whether chest x-rays should be administered annually; they appear to detect recurring cancers but not early enough to be very helpful for the great majority of patients.