Colorectal Cancer Screening and Colonoscopies

Orlando—As screening rates for colorectal cancer have increased in recent years, the incidence and death rates due to the disease have declined. Still, approximately 22 million people in the United States have never been screened, and the survival rate for late stage colorectal cancer remains small.

At DDW, physicians discussed the importance of colonoscopies and screening during a satellite symposium titled Optimizing CRC Screening: Discussion on Challenges and Methods to Improve Colonoscopy Outcomes. Ferring Pharmaceuticals sponsored the session.

Carol A. Burke, MD, director of the Center for Colon Polyp and Cancer Prevention at the Cleveland Clinic, said that between 2003 and 2007, screening prevented half of the anticipated new cases and deaths related to colorectal cancer. She added that an additional 1000 deaths could be avoided if the targets set by the US Department of Health & Human Services are met. As of now, half of colorectal cancer diagnoses are at a late stage when prognosis is poor, according to Dr. Burke, who mentioned that there is a 96% cure rate if colorectal cancer is diagnosed at an early stage.

There are different methods of colorectal cancer screening, including those recommended by the United States Multi-Society Task Force, the United States Preventive Services Task Force, and the American College of Gastroenterology (ACG). In each instance, patients are advised to undergo screening beginning at 45 or 50 years of age, have a fecal occult blood test every year, have flexible sigmoidoscopy every 5 years, and undergo a colonoscopy every 10 years.

The benefits of screening were observed in the National Polyp Study [N Engl J Med 2012; 366:687-696], a trial that included patients prospectively referred for an initial colonoscopy between 1980 and 1990 and who had polyps, either adenomas or nonadenomas. After a follow-up period of up to 23 years, the authors found that colonoscopies were associated with benefits such as reduced colorectal cancer incidence, reduced overall death rate, and reduced colorectal cancer death rate.

According to Dr. Burke, the ACG guidelines for high quality colonoscopies include split-dose bowel preparation, documented cecal intubation, an average withdrawal time of at least 6 minutes, the use of effective techniques for polyp removal, and a close follow-up period following the piecemeal resection of large sessile lesions. She said that adenoma detection rates are an important quality indicator as well. The targeted adenoma detection rates are at least 25% in men and at least 15% in women.

Although adenoma detection rates are crucial, Dr. Burke said more than 70% of interval colorectal cancer cases are attributed to missed lesions. During the screening colonoscopy, there are numerous reasons for missing lesions and interval cancers, including incomplete bowel preparation, incomplete colonoscopy, short withdrawal time, incomplete adenoma resection, and rapid tumor progression.

Dr. Burke noted that adenoma detection rates are not the same as the serrated polyp detection rate. She defined sessile serrated adenomas as clinically significant lesions. There are 3 subtypes of serrated polyps: (1) hyperplastic polyps, (2) sessile serrated adenomas/polyps, and (3) traditional serrated adenomas. Hyperplastic polyps are very common, are located in the left colon, and are not precancerous. Sessile serrated adenomas/polyps and traditional serrated adenomas are precancerous, though, and are less common than hyperplastic polyps.

A cited study found that there was a modest accuracy of polyp histology and surveillance interval prediction. Before a 1-hour training session, 577 people correctly predicted surveillance intervals. After the training, 654 people had the right predictions. Another study revealed that endoscopists who were proficient in detecting nonpolypoid colorectal neoplasms had significantly higher adenoma detection rates for polypoid and flat adenomas.

Dr. Burke concluded that colonoscopy is a highly operator-dependent procedure and added that the causes of variable detection and how to correct low-level detection remain unclear.

Bowel Preparation

Philip O. Katz, MD, chairman of gastroenterology and nutrition at the Einstein Medical Center in Philadelphia, Pennsylvania, followed with a discussion of inadequate bowel preparation, which he described as a persistent problem associated with colonoscopies. In fact, he mentioned studies have shown that most patients believed laxative bowel preparation was the most burdensome part of colonoscopies.

Dr. Katz then discussed Prepopik^™ (sodium picosulfate, magnesium oxide, and anhydrous citric acid), which comes in powder form and is mixed with cold water to help cleanse the colon in adults preparing for colonoscopy. The FDA approved sodium picosulfate, magnesium oxide, and anhydrous citric acid in July 2012.

The drug is contraindicated in patients with severely reduced renal function, gastrointestinal obstruction, bowel perforation, toxic colitis, gastric retention, and those with a known allergy to any of the drug’s ingredients. Dr. Katz said the approval was based on two phase 3, randomized, assessor-blinded, multicenter studies that demonstrated noninferiority and superior cleansing efficacy with split-dose and day-before regimens.

Gastrointestinal Quality Measures

Glenn M. Eisen, MD, a gastroenterologist with The Oregon Clinic in Portland, Oregon, discussed the importance of collecting data to improve the quality of care. He cited the American Gastroenterological Association (AGA) Digestive Health Outcomes Registry^®, which captures patient data, identifies areas for improvement, and minimizes participation overhead and data entry time. Its quality measures include documented colorectal cancer screening risk assessment before screening, colonoscopy within an appropriate follow-up interval, adverse events within 2 days of the procedure, colonoscopy completion rate, and adenoma detection rate.

The AGA and the American Society of Anesthesiology (ASA) have collaborated to form the GI Quality Improvement Consortium, Ltd., a nonprofit organization that has benchmarking reports and 84 data points and 11 measures. The measures include medical history and physical documentation; informed consent documentation; adequacy of bowel preparation; written discharge instructions for outpatients; ASA risk stratification; documentation of indication; cecal intubation with photo documentation; adenoma detection rates and immediate adverse events; and withdrawal time.

Dr. Eisen said healthcare professionals are currently using the Gastrointestinal Improvement Consortium, Ltd., to monitor training of fellows, for clinical research, as a resource quality measure, and in development for the Centers for Medicare & Medicaid Services and private sector health insurers.

Whereas physicians are typically paid based on the volume of care, Dr. Eisen noted in the future they will be compensated based on the quality of care they deliver as well as their efficiency and patient satisfaction. He said there are already a few programs in place focused on quality. For example, physicians participating in a Blue Cross and Blue Shield plan in North Carolina are required to submit data from a gastrointestinal specialty registry in order to be in the network for a client that covers 120,000 lives.

Although the Patient Protection and Affordable Care Act contains several provisions related to quality, the definition of quality healthcare is vague and debated by various parties, according to Dr. Eisen. He recommended that physicians, not payers, define quality because they will be dealing with the measures for years to come.

“Healthcare reform is changing the way we practice," Dr. Eisen said.