Volume 6, No. 8, August 2008
Abstract of the Month
Colorectal Cancer Screening and Surveillance
What
to do with patients with polyps, by Dr. Hope Baluh
Periodic screening for colon cancer in asymptomatic patients results in decreased mortality from this common and frequently fatal disease. As public awareness of the benefits of colon cancer screening has increased so has the demand for colonoscopy services. Evidence-based guidelines developed separately by the US Preventive Services Task Force, a consortium of five US medical and surgical GI societies, and the American Cancer Society recommend that all asymptomatic, average-risk people over age 50 years be offered screening with annual fecal occult blood tests and/ or flexible sigmoidoscopy every 5 years because these options are strongly supported by direct scientific studies. Colonoscopy is recommended when either of these tests is positive. The guidelines also include doing direct screening with air-contrast barium enema every 5 years or colonoscopy every 10 years. Periodic colonoscopy is also recommended for patients with an above average risk for colorectal cancer. Patients with an increased risk profile include those with a personal or family history of colorectal cancer or adenomatous polyps, as well as those with longstanding chronic inflammatory bowel disease.
Public surveys indicate that less than 40% of the at-risk population has yet to be screened. Once screened, patients with increased risk factors benefit from surveillance. Determining optimal intervals for surveillance often requires knowing the patient’s family history and findings from initial screening procedures including pathology reports.
The following are guidelines for screening and surveillance:
Indication | Interval |
Screening | |
Average risk | 10 y(begin at age 50 y) |
Single first degree relative (FDR) with cancer (or adenomas) at age > 60 y | 10 y (begin at age 40 y) |
> 2 FDRs with cancer (or adenomas) or 1 FDR Diagnosed at age <60 y | 5 y (begin at age 40 y or 10 y younger, whichever is earlier) |
Prior endometrial or ovarian cancer diagnosed at age <50 y |
5 y |
Hereditary nonpolyposis colorectal cancer (HNPCC) begin age 20-25 |
1-2 y |
Postadenoma resection |
5-10 y |
3-10 adenomas or adenoma with villous features, > 1 cm with high grade dysplasia |
3 y |
> 10 adenomas | < 3 y |
Sessile adenoma of > 2 cm, removed piecemeal (in order to inspect site for residual polyp) |
2-6 months |
Other Follow-Up Postcancer resection |
Clear colon, then 1 y then 3 y, then 5 y, |
Ulcerative colitis, Crohn’s colitis surveillance |
2-3 y until 20 y after onset of symptoms, then 1 y |
Davila RE et al ASGE guideline: colorectal cancer screening and surveillance. Gastrointest Endosc. 2006 Apr;63(4):546-57 Erratum in: Gastrointest Endosc. 2006 May;63(6):892.
http://www.ncbi.nlm.nih.gov/pubmed/16564851
OB/GYN CCC Editorial comment:
AI/AN peoples are more likely to be diagnosed with advanced stage disease
I would like to thank Dr. Hope Baluh, the IHS Chief Clinical Consultant for Surgery, for reviewing the current recommendations for colonoscopy screening and the appropriate intervals for follow-up of polyps and other high-risk conditions. Colon cancer screening guidelines are only one example of the guidelines available online at http://www.guidelines.gov/. At this website it is possible to view and download a wide range of guidelines as well as to make comparisons between recommendations from several organizations.
The overall incidence of colon cancer for American Indians and Alaska Natives (AI/AN) is declining as is the trend nationally for the general population. However AI/AN peoples are more likely to be diagnosed with advanced stage disease and there are wide disparities in access to care. For example the prevalence of endoscopy services for Native Americans in the Southwest has been half that of those available to non-Hispanic whites. 1 Efforts are underway at many health care sites to improve these screening rates.
For those of us whose focus is women’s health care, it is also worthwhile to review the recent Committee Opinion of the American College of Obstetricians and Gynecologists. In this document, ACOG now recommends colonoscopy as the preferred method of colon cancer screening. 2
1 Espey DK , Wu XC, Swan J, et al, Annual report to the nation on the status of cancer, 1975-2004, featuring cancer in American Indians and Alaska Natives. Cancer. 2007 Nov 15;110(10):2119-52.
http://www.ncbi.nlm.nih.gov/pubmed/17939129
2 American College of Obstetricians and Gynecologists. Colonoscopy and Colorectal Cancer Screening and Prevention. ACOG Committee Opinion No. 384. Obstet Gynecol 2007;110:1199-1202. http://www.ncbi.nlm.nih.gov/pubmed/17978144
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OB/GYN
Dr. Neil Murphy is the Obstetrics and Gynecology Chief Clinical Consultant (OB/GYN C.C.C.). Dr. Murphy is very interested in establishing a dialogue and/or networking with anyone involved in women's health or maternal child health, especially as it applies to Native or indigenous peoples around the world. Please don't hesitate to contact him by e-mail or phone at 907-729-3154.