Excerpted by the National Guideline Clearinghouse (NGC)
Note from the guideline developers: These guidelines
differ from those published in 1997 in several ways:
- They recommend against rehydrating fecal occult blood tests
- The screening interval for double-contrast barium
enema has been shortened to 5 years
- Colonoscopy is the preferred test for the
diagnostic investigation of patients with findings on screening and for
screening patients with a family history of hereditary nonpolyposis colorectal
cancer
- Recommendations for people with a family history
of colorectal cancer make greater use of risk stratification
- Guidelines for genetic testing are included
- Guidelines for surveillance are also included
- Follow-up of postpolypectomy patients relies now on
colonoscopy, and the first follow-up examination has been lengthened from 3 to
5 years for low-risk patients
General Recommendations
Screening programs should begin by classifying the individual patient’s level
of risk based on personal, family, and medical history, which will determine the
appropriate approach to screening in that person.
Men and women at average risk should be offered screening for colorectal
cancer and adenomatous polyps beginning at age 50 years.
They should be offered options for screening, with information about the
advantages and disadvantages associated with each approach, and should be given
an opportunity to apply their own preferences in selecting how they should be
screened.
If the result of a screening test is abnormal, physicians
should recommend a complete structural examination of the colon and rectum by
colonoscopy (or flexible sigmoidoscopy and double contrast barium enema if
colonoscopy is not available).
Surveillance with colonoscopy should be considered for
patients who are at increased risk because they have been treated for colorectal
cancer, have an adenomatous polyp diagnosed, or have a disease that predisposes
them to colorectal cancer, such as inflammatory bowel disease.
Health care providers who perform the tests should have appropriate
proficiency, and the tests should be performed correctly. To achieve these aims,
care systems should establish standards and operating procedures.
Screening should be accompanied by efforts to optimize the participation of
patients and health care providers--both with screening tests and appropriate
diagnostic evaluation of abnormal screening test results--and to remind patients
and providers about the need for rescreening at recommended intervals.
Risk Stratification
Clinicians should determine an individual patient’s risk
status well before the earliest potential initiation of screening (typically
around age 20 years, but earlier if there is a family history of familial
adenomatous polyposis) (see figure 1 in the original guideline document). The
individual’s risk status determines when screening should be initiated and what
tests and frequency are appropriate. Risk stratification can be accomplished by
asking several questions aimed at uncovering the risk factors for colorectal
cancer:
- Has the patient had colorectal cancer or an
adenomatous polyp?
- Does the patient have an illness (e.g., inflammatory
bowel disease) that predisposes him or her to colorectal cancer?
- Has a family member had colorectal cancer or an adenomatous polyp? If so,
how many, was it a first-degree relative (parent, sibling, or child), and at
what age was the cancer or polyp first diagnosed?
A positive response to any of these questions should prompt further efforts
to identify and define the specific condition associated with increased risk.
Recommendations for Screening People at Average Risk
Men and women at average risk should be offered screening with one of the following
options beginning at age 50 years. The rationale for presenting multiple
options is that no single test is of unequivocal superiority and that giving
patients a choice allows them to apply personal preferences and may increase
the likelihood that screening will occur. The strategies are not equal with regard to evidence of effectiveness, magnitude of effectiveness, risk, or up-front costs. Reviewing the rationale section for each screening test (presented in the original guideline document) will provide clinicians with information that they can use in presenting the relative effectiveness of each test to patients.
Fecal Occult Blood Testing
Offer yearly screening with fecal occult blood test (FOBT) using a
guaiac-based test with dietary restriction or an
immunochemical test without dietary restriction. Two samples from
each of 3 consecutive stools should be examined
without rehydration. Patients with a positive test on any specimen
should be followed up with colonoscopy.
Sigmoidoscopy
Offer flexible sigmoidoscopy every 5
years.
Combined FOBT and Flexible Sigmoidoscopy
Offer screening with FOBT every year
combined with flexible sigmoidoscopy every 5 years. When both tests are
performed, the FOBT should be done first.
Colonoscopy
Offer colonoscopy every 10 years.
Double-Contrast Barium Enema
Offer double-contrast barium enema (DCBE) every 5 years.
Recommendations for Screening People at Increased Risk
People With a Family History of Colorectal Cancer or Adenomatous
Polyps
People with a first-degree relative (parent, sibling, or child) with colon cancer or adenomatous polyps diagnosed at age <60 years or 2 first-degree relatives diagnosed with colorectal cancer at any age should be advised to have screening colonoscopy starting at age 40 years or 10 years younger than the earliest diagnosis in their family, whichever comes first, and repeated every 5 years (see Table 3 in the original guideline document).
People with a first-degree relative with colon cancer or adenomatous polyp
diagnosed at age >60 years or 2 second-degree relatives with colorectal cancer should be advised to be screened as average risk persons, but beginning at age 40 years.
People with 1 second-degree relative (grandparent, aunt, or uncle) or
third-degree relative (great-grandparent or cousin) with colorectal cancer
should be advised to be screened as average risk persons.
Familial Adenomatous Polyposis
People who have a genetic diagnosis of familial adenomatous polyposis (FAP), or are at risk of having FAP but genetic testing has not been performed or is not feasible, should have annual sigmoidoscopy, beginning at age 10-12 years, to determine if they are expressing the genetic abnormality. Genetic testing should be considered in patients with FAP who have relatives at risk. Genetic counseling should guide genetic testing and considerations of colectomy.
Hereditary Nonpolyposis Colorectal Cancer
People with a genetic or clinical diagnosis of hereditary nonpolyposis colorectal cancer (HNPCC) or who are at increased risk for HNPCC should have colonoscopy every 1-2 years beginning at age 20-25 years, or 10 years earlier than the youngest age of colon cancer diagnosis in the family--whichever comes first. Genetic testing for HNPCC should be offered to first-degree relatives of persons with a known inherited mismatch repair (MMR) gene mutation. It should also be offered when the family mutation is not already known, but 1 of the first 3 of the modified Bethesda Criteria is met (see Table 5 in the original guideline document).
Surveillance of People at Increased Risk
People with a History of Adenomatous Polyps
Patients who have had 1 or more adenomatous polyps removed at colonoscopy should be managed according to the findings on that colonoscopy. Patients who have had numerous adenomas, a malignant adenoma (with invasive cancer), a large sessile adenoma, or an incomplete colonoscopy should have a short interval follow-up colonoscopy based on clinical judgment. Patients who have advanced or multiple adenomas (>3) should have their first follow-up colonoscopy in 3 years. Patients who have 1 or 2 small (<1 cm) tubular adenomas should have their first follow-up colonoscopy at 5 years. It is not unreasonable, given available evidence, to choose even longer intervals. However, the evidence is still evolving. Future evidence may clarify the intervals more precisely.
The timing of the subsequent colonoscopy should depend on the pathology and
number of adenomas detected at follow-up colonoscopy. For example, if the first
follow-up colonoscopy is normal or only 1 or 2 small (<1 cm) tubular adenomas
are found, the next colonoscopy can be in 5 years.
People With a History of Colorectal Cancer
Patients with a colon cancer that has been resected with curative intent should have a colonoscopy around the time of initial diagnosis to rule out synchronous neoplasms. If the colon is obstructed preoperatively, colonoscopy can be performed approximately 6 months after surgery. If this or a complete preoperative examination is normal, subsequent colonoscopy should be offered after 3 years, and then, if normal, every 5 years.
People With Inflammatory Bowel Disease
In patients with long-standing, extensive inflammatory bowel disease, surveillance colonoscopy with systematic biopsies should be considered. This applies to both ulcerative colitis and Crohn’s colitis because the cancer risk is similar in both diseases.
