The American College of Obstetricians and Gynecologists (ACOG) has released a committee opinion encouraging obstetrician-gynecologists to recommend colorectal cancer screening for women, which is diagnosed in more women than all gynecologic cancers combined. The report points to colonoscopy as the recommended procedure but suggests other satisfactory alternatives.
The committee opinion appears in the March issue of Obstetrics & Gynecology.
Each year in the United States alone, more than 70,000 women are diagnosed with colorectal cancer, and more than 24,000 women die of the disease. It is the third leading cause of cancer death in women, after lung cancer and breast cancer.
There is a consensus among healthcare organizations that screening can reduce these numbers, primarily by reducing the incidence of advanced disease by detecting early-stage adenocarcinomas and removing adenomatous polyps. Prospective randomized trials have confirmed this benefit, showing reductions in mortality rates associated with early detection of colorectal cancer and removal of polyps.
Despite these benefits, a recent study of women 50 years and older in the United States reported that only 63% had undergone colonoscopy or sigmoidoscopy in the past 10 years or a fecal occult blood test within the past year. Screens remain underused in many population segments, and in other cases they are inappropriately ordered for patients younger than 50 years or are ordered at too frequent intervals.
ACOG recommends colonoscopy for colorectal cancer screening among average-risk women at age 50 years. The report provides a review of available screening methods suitable for obstetrician-gynecologists to discuss with their patients.
Tests that detect adenomatous polyps and cancer include the following:
- Colonoscopy: The recommended interval is 10 years and requires complete bowel preparation. Patients are typically consciously sedated and can expect to miss 1 day of work. Potential risks are rare but include perforation, bleeding, and death. Polypectomy accounts for most of the risk.
- Flexible sigmoidoscopy with insertion to 40 cm or to the splenic flexure: The recommended interval is every 5 years, and the procedure requires complete or partial bowel preparation. Sedation is usually not used, which can lead to discomfort during the splenic flexure procedure. The procedure does not examine the entire colon, and positive results usually lead to a colonoscopy.
- Double-contrast barium enema: The recommended interval is every 5 years, and it requires complete bowel preparation. If polyps are found that are larger than 6 mm, colonoscopy will be recommended. The procedure is low risk, although there have been rare reports of perforation.
- Computed tomography colonography: The recommended interval is every 5 years, and the procedure requires complete bowel preparation. If polyps larger than 6 mm are found, colonoscopy will be recommended. Risks are very low, with rare cases of perforation. The potential increased lifetime risk from cumulative radiation has not been evaluated completely.
Tests that primarily detect cancer include the following:
- Guaiac-based fecal occult blood test with high sensitivity for cancer: The procedure is recommended to be undergone annually. Stool samples must be collected at home for later testing.
- Fecal immunochemical test with high sensitivity for cancer: The procedure is recommended to be undergone annually. Positive test results indicate an increased risk for colon cancer and advanced neoplasia and result in a recommendation for a colonoscopy. One-time testing is likely to be ineffective.
- Stool DNA test with high sensitivity for cancer: There is no recommended interval. A stool sample must be obtained and preserved for shipping to the laboratory. The cost is significantly higher than other stool tests. Positive results will result in a recommendation of a colonoscopy.
The guidelines suggest that the generalist obstetrician-gynecologist should recommend colonoscopy as the preferred method because the colon and rectum can be thoroughly examined in a single session, and a biopsy or polypectomy can be performed at the same time.
Other methods should be discussed to identify the alternative that is most acceptable to each individual woman.
The study authors have disclosed no relevant financial relationships.
Citation Information: Obstet Gynecol. 2011;117:766-771. Extract0