Deaths from colorectal carcinoma (CRC) have diminished in recent years; the absolute annual decrease is 1.5% per year.1 Approximately 131,000 new cases were diagnosed in 1998.2 Sixty percent of patients had stage II or III disease; of these, approximately 35% to 40% will have recurrence with metastatic or locally invasive disease. Extrapolation of these figures to prior and subsequent years suggests that hundreds of thousands of patients with resected CRC are candidates for surveillance.
Follow-up schedules for survivors of CRC depend on the likelihood of recurrence. The recurrence rate of stage I disease is approximately 13%; stage II, 32%; and stage III, 61%.3 CRC may recur locally-which necessitates monitoring of the anastomotic site by colonoscopic surveillance-and as metastatic disease. In patients with colon cancer, the liver is often the first site of metastatic spread; rectal cancers tend to spread to the lungs.
Because metastatic disease is usually fatal, significant effort has focused on detecting recurrence while patients are still asymptomatic. Colonoscopy, CT, and chest radiography and carcinoembryonic antigen (CEA), liver function, and fecal occult blood tests have been used in the hope of reducing the incidence of terminal metastatic disease. The wide variation in findings from studies of postoperative surveillance of patients with CRC has resulted in significant variability in follow-up practice.
In response to this lack of standardization of follow-up, the American Society of Clinical Oncology (ASCO) issued surveillance guidelines based on data from controlled clinical trials.2 These recommendations are not intended to supersede your judgment about individual patients.
Here we review the ASCO guidelines and selected recent studies. In a previous issue (CONSULTANT, November 2002, page 1559), we discussed the ASCO recommendations for follow-up of breast cancer survivors.
The follow-up of CRC survivors includes a history taking and physical examination, colonoscopic surveillance, and CEA testing. Type and grading of evidence are reviewed in Table 1; a summary of the recommendations appears in Table 2.
History taking and physical examination. According to the ASCO guidelines, there are no data that directly assess the value of the history and physical examination in the follow-up of survivors of CRC. However, the expert panel consensus was that a clinical history taking and physical examination should be performed every 3 to 6 months for the first 3 years and annually thereafter.2 Note changes in bowel habits and symptoms-such as bleeding, abdominal pain, or fever-that suggest recurrent disease.
This surveillance schedule can be modified according to the disease stage.For patients with Duke stage I or II disease, a history taking and physical examination may be performed every 6 months for 5 years, then annually. Patients with Duke stage III disease require a history taking and physical examination every 3 months for 2 years, then every 6 months for 3 years, then annually.
Colonoscopy. A study that evaluated the use of endoscopic procedures during 4 years of follow-up of more than 5700 patients with CRC found a significant degree of variability, which was attributed to a lack of consensus about optimal follow-up.4
The ASCO guidelines do not recommend routine colonoscopic evaluation for all patients but suggest colonoscopy every 3 to 5 years to detect new cancers and polyps.2 The American Gastroenterological Association panel recommends that a colonoscopy be performed within 1 year after resection if the colon was not fully examined before surgery. If this or a complete preoperative examination is otherwise normal, the next colonoscopy should be offered in 3 years and then, if normal, every 5 years.5 Some experts recommend that asymptomatic patients undergo colonoscopy 5 years after resection.6
A prospective blinded comparison of colonoscopy and double-contrast barium enema as surveillance after colonoscopic polypectomy concluded that colonoscopic examination is more effective because it reveals adenomas (surrogate markers for CRC) at a significantly smaller size.7
CEA. The ASCO guidelines recommend postoperative serum CEA testing every 2 to 3 months for 2 years for patients with stage II or III CRC in whom hepatic resection is an option if liver metastases develop.2
The rationale for CEA monitoring comes from studies showing that elevations of CEA levels may indicate early tumor recurrence. However, there is conflicting evidence about whether resection of isolated hepatic metastases affects outcome. One study found that resection improved survival time compared with no resection or chemotherapy.8 A prospective study of 1017 survivors of CRC who underwent CEA monitoring failed to show an increase in survival following the resection of isolated hepatic metastases.9 However, a meta-analysis of 7 nonrandomized studies that involved more than 3200 patients found that those who were intensively followed up had a 5-year survival rate that was 9% better than that of patients who had minimal or no follow-up-but only if the intensive follow-up included CEA measurements.10
Others question the impact of follow-up surveillance on mortality and suggest that appropriate quality assessment and patient support can be provided by primary care clinicians rather than surgeons.11
PROCEDURES NOT RECOMMENDED
Published data do not support the use of liver function tests, abdominal CT, chest radiography, or complete blood cell count in the routine surveillance of survivors of CRC. Regular monitoring with these tests does not improve outcome.2,6,12
The ASCO guidelines also advise against periodic fecal occult blood testing in the follow-up of patients.2 (The guidelines suggest that this test is more useful as a screen-ing tool.) A number of studies have shown that fecal occult blood is a poor marker for colorectal neoplasia in survivors of CRC.13,14
The role of dietary fiber and other lifestyle measures in the primary and secondary prevention of CRC (Box) has yet to be determined.