How do they catch it? Colonoscopy standards of gastroenterologists
Prevention is the Best Medicine
Colorectal cancer is one of the most common types of cancer and is the 2nd leading cause of cancer-related death, and is especially dangerous because symptoms of colorectal cancer are not noticeable until polyps reach a size that is large enough to impede the passage of feces. At this point, polyps have reached a stage that is precancerous or has already developed into an adenocarcinoma, which is the stage right before colorectal cancer metastasizes. The potential for colorectal cancer to sneak up on patients until nearly fully developed is why the colonoscopy, a procedure that uses a colonoscope with a camera to examine the large intestine and colon for polyps and remove them for later lab analysis, is so important. It functions as the first line of prevention and detection of colorectal cancer that is also safe, accurate, and harmless when quality standards, or indicators of quality, are met. Thus, it is quite important to continue to develop standards for colonoscopy procedures for gastroenterologists to follow so that colorectal cancer can be properly prevented and minimal harm is done to patients (audio-visual component).
To this end, a group of doctors from the American Society for Gastrointestinal Endoscopy (ASGE)/American College of Gastroenterology (ACG) Quality Assurance in Endoscopy Committee updated a 2006 list of quality indicators published by the ASGE/ACG with new quality indicators and prioritized clinically relevant quality indicators. Quality indicators provide a benchmark to measure how often individual or groups of gastroenterologists meet performance standards and are categorized into preprocedure, intraprocedure, and postprocedure quality indicators. Only strongly recommended preprocedure and intraprocedure quality indicators will be analyzed in depth due to the strong documentation focus in postprocedure indicators. Quality indicators are graded on a scale from 1A to 3 with 1A to 1C+ denoting strong recommendations applicable to most practice settings and situations. 1C and 2A denote intermediate-strength recommendations that may change if stronger evidence appears and depend on patients’ values, respectively. 2B and below denotes weak recommendations that have alternative approaches or are likely to change with further data. It should be noted that quality indicators for colonoscopies differ from those for endoscopies in terms of grade of recommendation, a similar procedure where a tube is used to examine the stomach and small intestine.
Proper Preparation
Quality indicators for colonoscopies include more than the procedure itself, and are used to judge the interactions between the medical team and the patient before colonoscopy. Proper frequency of colonoscopy procedures and informed consent make up the preprocedure quality indicators. The highest recommended preprocedure quality indicator is the frequency of colonoscopies after polyp removal or cancer resectioning of the colon and for patients with normal risk levels of colorectal cancer. This is critical, as the frequency of colonoscopies ensures that colorectal cancer can be caught without unneeded risk and cost to the patient when optimized. A colonoscopy every 10 years for people 45 and above without risk factors for colorectal cancer (recently amended from 50+ years by the ACG) is recommended by the doctors, and more frequent colonoscopies of 3 to 6 months and a year after detection are recommended for stable polyps greater than 2 cm large. Knowledge of this quality indicator is high in the United States, and thus any deviance from this quality indicator is of an unknown cause.
The frequency with which informed consent is obtained and the frequency at which colonoscopies are performed in response to patient abnormalities add additional stipulations to the frequency of colonoscopies. Informed consent must be obtained for colonoscopies to proceed so that patients are aware of the benefits, risks, and alternatives to the procedure. In conjunction with the other quality indicators, risks like bleeding and perforation of the intestine and colon are reduced greatly. In addition, the frequency of colonoscopies has to be adjusted and usually increased when diagnoses of abnormal conditions are made, such as unexplained gastrointestinal bleeding and Crohn’s colitis, a disease that causes inflammation of the colon. However, an excess of colonoscopies can pose a problem as well and have been observed in European facilities that perform high volumes of colonoscopies. This would expose patients to more risk than is needed and increase the burden of the cost of those procedures.
Inside the Operating Room
Intraprocedural quality indicators are used to judge the performance of the colonoscopy procedure extending from the insertion to the removal of the colonoscope, and make up the bulk of the quality indicators. They can be split into three different groupings based on the grade of recommendation. The first grouping of intraprocedural quality indicators has a 1C rating and covers one of the most important quality indicators, the adenoma detection rate (ADR). The second grouping are weakly recommended 2C quality indicators involving the time it takes for a colonoscopy to be performed and the number of biopsy samples taken for specific patients. The third, and least strongly recommended, group of 3 quality indicators regulate the removal of small polyps and the level of patient preparation before the procedure.
The first grouping is widely applicable and consists of the confirmation of examination of the cecum, the ADR, and the biopsy sampling of patients with ulcerative colitis and Crohn’s colitis. Studies have shown that a large amount of cancerous polyps in the colorectal area are concentrated in the cecum, an area at the end of the large intestine right before the small intestine, so photodocumentation that the gastroenterologist has examined the cecum is of the greatest importance. Fortunately, the performance target of cecal examination in 95% or greater amount of cases has been met with a 97% cecal examination rate in the U.S.
The ADR describes the percentage of colonoscopies in which cancerous polyps are detected and is especially important to maintain at the 25% performance target in the adenoma-prone cecum. Just a 1% increase of ADR of gastroenterologists was associated with a 3% reduction in colorectal incidence and a 5% reduction of cancer mortality. This is explained by the relationship between ADR and frequency of follow-up colonoscopies in which gastroenterologists with high ADRs operate on patients for more frequent colonoscopies and those with low ADRs fail to clear the colon of potentially cancerous polyps and schedule inappropriately infrequent follow up colonoscopies. There are several issues with solely relying on ADR, as it could encourage prioritization of detecting a lesion while disregarding inspection quality and the “one and done” approach where a gastroenterologist stops examining the intestine and colon as carefully after detecting one polyp. Alternatives to ADR include a polyp detection rate that is easier to implement and a adenoma per colonoscopy rate that is more accurate than ADR, but both require more research before recommendation.
The final strongly recommended intraprocedure quality indicator is not related to colorectal cancer, and requires mandatory biopsy sampling of the colon to evaluate the extent and distinguish between ulcerative colitis and Crohn’s colitis.
What Does This Mean For Me?
The good news is that the ASGE and ACG are constantly updating quality indicators for colonoscopies, a procedure that the vast majority of the population will go through in their life. The most recent set of quality indicators are all-encompassing and emphasize the frequency of colonoscopies, cecum examination, and the ADR to ensure that highly effective colonoscopies are scheduled frequently enough to catch colorectal cancer without burdening patients with extra costs and increased exposure to risks associated with colonoscopies. Significant improvements have been made from the 2006 list of quality indicators to this most recent list, but further research is required to refine the quality indicators. For example, adenoma per colonoscopy is more accurate than ADR at measuring colonoscopy effectiveness but is as of yet unproven in terms of cost and practicality. Polyp detection rate offers a more streamlined alternative to ADR as a quality indicator but lacks the necessary correlations to cement it as a feasible alternative. Furthermore, the failure of gastroenterologists to follow guidelines for the frequency of colonoscopies needs to be identified to better encourage adherence to quality indicators. With more research and continual updates to quality indicators, colonoscopies will continue to evolve as a powerful preventive tool of colorectal cancer.
References:
American College of Gastroenterology. (2021). Colorectal Cancer: You Can Prevent It. American College of Gastroenterology, https://webfiles.gi.org/links/committees/Public%20Relations/2021CRC-infographic.pdf
Rex, D. K., Schoenfield, P. S., Cohen, J., Pike, I. M., Adler, D. G., Fennerty, M. B., Lieb, J. G., Park, W. G., Rizk, M. K., Sawhney, M. S., Shaheen, N. J., Wani, S., & Weinberg, D. S. (2015). Quality indicators for colonoscopy. Quality Indicators for GI Endoscopic Procedures, 81(1), 31–53. https://doi.org/10.1016/j.gie.2014.07.058
Simon, K. (2016). Colorectal cancer development and advances in screening. Clinical Interventions in Aging, 11, 967–976. https://doi.org/10.2147/CIA.S109285
