Principal Investigator

• Dennis Ahnen, MD
  University of Colorado

Participating Institutions

• Cancer Genetics Network Institutions:
  • University of Colorado
  • Huntsman Cancer Institute at University of Utah
• Colon Cancer Family Registry Institutions:
  • University of Colorado
  • University of Arizona
  • University of North Carolina
  • University of Minnesota
  • University of Southern California
  • Cleveland Clinic
  • Fred Hutchinson Cancer Research Center

Synopsis

Early detection and treatment of CRC and its precursor lesion, the adenomatous polyp, is currently the best available strategy for reducing CRC mortality. For families at increased risk for CRC, both HNPCC and non-HNPCC families, colonoscopy is recommended as the CRC screening method of choice. The optimal interval for colonoscopic screening among individuals with a strong family history of CRC (that do not meet HNPCC criteria) is not known but recommendations range from every 3-5 to every 5-10 years if the initial colonoscopy is negative.

For individuals within HNPCC or HNPCC-like families the current recommendation is to begin colonoscopy screening at age 20-25, or 10 years younger than the youngest colon cancer in the family (Burt, 2000; Giardiello et al 2001; Lynch and Lynch, 2000; Rex et al, 2000). There is some variability in the recommended screening intervals in HNPCC but all of the major recommendations include colonoscopy every 1 or 2 years. Burt (2000) and Lynch and Lynch (2000) recently reviewed all of the recommendations for CRC screening and suggested consensus guidelines of colonoscopy every 1-2 years in members of HNPCC families.

Survey data indicates that CRC screening rates in the U.S. are substantially lower than for other cancers for which screening is recommended (JAMA, 2001). For average risk subjects screening rates for any form of CRC screening are about 40% compared to about 75% for mammography. In our previous study (RO1 CA 68099), we found a 45% overall rate of adherence to any form of CRC screening in FDRs of patients with sporadic CRC, and only 22% had had colonoscopic screening. The limited data reported in HNPCC or the Non-HNPCC high-risk families also indicate relatively low rates of CRC screening. Jarvinen (2000) was only able to convince 53% of the at-risk members of 22 HNPCC families to get colonoscopic screening despite repeated attempts. Our preliminary survey of participants who would be eligible for this study found that 50% had never had colonoscopy and another 13% had their most recent colonoscopy three or more years previously. These data highlight the importance of developing exportable interventions to improve adherence to colonoscopic screening in these high-risk groups.

The long-range goal of this study is to develop an exportable intervention to promote regular colonoscopic surveillance among individuals at increased risk for developing colorectal cancer. We propose to enroll eligible members of high-risk families defined as those that have a single FDR with colon cancer below age 50 or 2 or more FDRs with CRC. The families will be drawn from two NCI-funded national cancer registries, the Cancer Genetics Network (CGN) and the Colon Cancer Family Registry (CCFR).

View the protocol summary report.