1. Colonoscopy Significantly Protects Against Colon Cancer in Both the Left and Right Colon
Still, Right-Sided Risk Reduction May be Limited to Older Patients
Under highly standardized conditions, colonoscopy has been shown to reduce the risk for colorectal cancer (CRC) by up to 90 percent. In the community setting, colonoscopy appears to be less effective. Some recent community-based studies show a significant risk reduction in CRC among patients who have had colonoscopy, but the benefit was limited to left-sided cancers. The effectiveness of colonoscopy in preventing cancers in the right colon remains uncertain. The current study improves on previous community-based studies and included 1,688 case patients with colorectal cancer and 1,932 control participants age 55 or older. The researchers conducted their study in Germany where colonoscopy has been a primary screening offer for patients 55 and older since 2002, and colonoscopy training and quality assurance measures have been introduced. The researchers found that patients that had a colonoscopy in the preceding 10 years had a 77 percent risk reduction for CRC. Risk reduction was particularly pronounced for left-sided cancers, but a substantial (50 percent) risk reduction was also seen for cancers on the right side. However, in the right side, patient age was a factor in risk reduction, with only moderate (26 percent) and statistically nonsignificant risk reduction in persons younger than 60. According to the author of an accompanying editorial, "less effective" risk reduction is not the same as "ineffective." The editorialist concludes that the study results offer reassurance that high quality colonoscopy can provide substantial protection against CRC in both the left and right side.
2. Testing for Gene Mutation May Inform Treatment Decisions for Advanced Colon Cancer
Up to 80 percent of colorectal cancer patients (CRC) are diagnosed with advanced disease. Often, monoclonal antibodies that target the epidermal growth factor receptor (EGFR) are used alone or in combination with chemotherapy to improve overall and progression-free survival in patients with advanced CRC. While these treatments have been proven effective, they also are expensive and can cause serious adverse effects. In addition, they do not benefit all patients. Researchers believe that aberrations of the genes encoding downstream effectors of EGFR-mediated signaling could be associated with resistance to anti-EGFR antibody therapy. Among all EGFR effectors, Kristen-RAS (KRAS), a member of the rat sarcoma virus (ras) gene family of oncogenes, is particularly suspect. Researchers reviewed published data to determine whether KRAS mutation status affects success of anti-EGFR-based treatments for patients with advanced CRC and whether KRAS status predicts clinical outcomes in these patients. They found that KRAS mutations were consistently associated with reduced overall and progression-free survival and increased anti-EGFR treatment failure. The authors conclude that patients with tumors that test positive for KRAS mutation should not be treated with anti-EGFR agents.
Perspectives: The Patient-Centered Medical Neighborhood
3. Annals Readers Comment on ACP Position Paper on the Patient-Centered Medical Neighborhood
In October, the American College of Physicians (ACP) released a position paper (www.acponline.org/advocacy/where_we_stand/policy/pcmh_neighbors.pdf) introducing the term Patient-Centered Medical Home Neighbor (PCMH-N), which refers to the interaction of the subspecialist practice and the Patient-Centered Medical Home (PCHM). The PCHM is a clinical practice that functions as the central hub of patient information, primary care, and care coordination. ACP's position paper provided a framework to categorize the different types of interactions between PCMH and sunspecailty practices. It also defined a set of principles to facilitate coordination and integration between the practices to provide efficient, high-quality patient care. The current issue of Annals includes invited commentary on the ACP position paper from an internist and a subspecialist. Christine A. Sinsky, MD, a general internist, identifies the next steps that need to be taken in order for the Patient-Centered Medical Neighborhood to work. She says technology needs to changes so that information can be accessed quickly, easily, and safely. She also mentions that families and policy makers need to be adequately engaged. Hal F. Yee, Jr., MD, PhD, a subspecialist, points to PCMH and PCMH-N communication challenges as a key roadblock to success. Annals editors encourage all readers to review the ACP position paper and submit their comments.
Journal
Annals of Internal Medicine