According to the World Health Organization's data in 2020, colorectal cancer is the third most common cancer after breast cancer and lung cancer, and is ranked second in cancer-related deaths after lung cancer. Approximately 1.9 million people were diagnosed and more than 900,000 patients died of colorectal cancer worldwide. The most common regions with the highest incidence and mortality rates include Europe, Australia, New Zealand, North America, and Eastern Asia.
Once diagnosed at an early stage, colorectal cancer has an impressive survival rate of over 90% at 5 years. However, when it is detected at a late stage that the tumor has spread to other parts of the body, the survival rate is significantly diminished to 14% at 5 years. In 2021, the United States Preventive Services Task Force has lowered the starting age for screening from 50 years old to 45 years old. Among screening tests, colonoscopy is a unique tool that can be used for screening and treatment at the same time if there are any polyps, premalignant, or early malignant lesions detected.
Important components of high-quality colonoscopy include effectiveness in detecting colorectal cancer and precancerous lesions, safety to minimize complications, and value to avoid unnecessary costs. In 2021, the American Gastroenterological Association published clinical practice on strategies to improve the quality of screening and surveillance colonoscopy.
This clinical practice update was authored by experts from Northwestern University Feinberg School of Medicine in Illinois, the University of North Carolina School of Medicine, and Darthmouth-Hitchcock Medical Center in New Hampshire. The authors have proposed 15 quality metrics.
Advice # 1: the quality of bowel prep
Advice # 2: how you prep the bowel
Advice # 3: detailed instructions for bowel prep for all patients
Advice # 4: the type of the endoscopes used
Advice # 5: the rate of completion of colonoscopy
Advice # 6: how careful your colonoscopists are about performing the procedure for you
Advice # 7: how well your colonoscopist examines your right-sided colon
Advice # 8: the rate of detection of premalignant colonic lesions
Advice # 9: the target of adenoma detection rate
Advice # 10: the early detection of very flat colonic lesions called "serrated lesions"
Advice # 11: the methods of removing colonic polyps
Advice # 12: the management of large polyps
Advice # 13: the details of the endoscopic reports
Advice # 14: endoscopy units and staff that should inform patients undergoing colonoscopy of the potential for complications, warning symptoms, and emergency contact information
Advice # 15: intervals for screening and surveillance colonoscopy
Best practice advice # 1: the quality of bowel prep
The colon is a tube-like structure, in an inverted U shaped pattern, starting from the anus, going up to the left side of the abdomen, across the abdomen, then going down along the right side of the abdomen. When you get a colonoscopy, your endoscopist will rate the quality of the bowel preparation for each segment. This is very important so that your doctors can identify any subtle findings, especially on the right side where the polyps tend to be very flat and can be easily missed without great quality of bowel prep.
Best practice advice # 2: how you prep the bowel
The current clinical practice update suggested splitting the dose of bowel preparation as the standard preparation strategy for undergoing colonoscopy. For those who prefer a morning schedule for the procedures, they can get one half to three quarters in the evening before colonoscopy, and the remainder 4-6 hours before the start of colonoscopy. At Bumrungrad International Hospital, patients who prefer to have a colonoscopy done around noon or in the afternoon can consider preparing their bowels in the endoscopy unit, and finishing two to four hours before the scheduled appointment. We have provided a private restroom for each of our patients. These strategies do not improve only tolerability, but also the quality of bowel prep, when compared to traditional evening-before dosing.
Best practice advice # 3: detailed instructions for bowel prep for all patients
At Bumrungrad International Hospital, we provide in-person interpreting services for international patients during the scheduling process and throughout the procedure day, including, but not limited to English, simplified Chinese, traditional Chinese, Arabic, Bahasa, Bengali, Espanol, French, German, Kmer, Mongolian, Korean, Vietnamese, and others. Our patients can also contact a local referral office in many countries in advance.
Best practice advice # 4: the type of the endoscopes used
At Bumrungrad International Hospital, in addition to our state-of-the-art endoscopy unit, we have exclusively used high definition Olympus colonoscopes for both screening and surveillance colonoscopies. Using high-definition colonoscopes has been shown to improve the quality of examination in precancerous lesions called adenoma, very flat polyps called serrated polyps, and advanced precancerous lesions.
Best practice advice # 5: the rate of completion of colonoscopy
As mentioned previously, the colon's anatomy is similar to an inverted u-shape, while the end of the right side of the colon was confirmed by two findings, the connection between the large bowel, or colon, to the small bowel, and the opening of the appendix. This area at the end of the colon is called the cecum. Experts have proposed that the cecal intubation rate should be 90% or greater, with an aspirational goal of 95% or greater. This is important because right sided colon lesions are usually flat, easily missed, and can grow to malignancy at faster rates.
Best practice advice # 6: how careful your colonoscopists are about performing the procedure for you
Once the colonoscope reaches the cecum, the colonoscopist will start withdrawing the colonoscope. This is where the examination takes action. The vast majority of colonic lesions are detected during this withdrawal period. A threshold value of 6 minutes or longer enhances the rate of detection of both premalignant and malignant colonic conditions, and is linked to a lower rate of colorectal cancer after a colonoscopy. In addition, withdrawal time of 9 minutes or greater can enhance the rate of detection of premalignant lesions and very flat colonic lesions called serrated lesions. Look at your most recent colonoscopy, and see if colonoscope withdrawal time was documented.
Best practice advice # 7: how well your colonoscopist examines your right-sided colon
As mentioned previously, the right-sided colon tends to have premalignant polyps that could turn into cancer at faster rates, and sometimes these polyps can be very flat and easily missed. A second look at the right colon can increase the rate of detection of premalignant or early malignant colonic lesions by up to 5 to 20%. A second look exam can be done in two ways. First, after inserting the colonoscope into the base of the cecum, a colonoscopist withdraws the colonoscope to the level of the hepatic flexure, which is the junction between the right sided portion of the colon and the horizontal part of the inverted U shape of the colon. Then the colonoscope was reintubated into the cecum while a colonoscopist slowly withdraws the colonoscope again. This way, it is like when you look through the front mirror of the car twice. The other option is that a colonoscopist can make a curve on the colonoscope in 180 degree fashion, so that they can also examine behind the folds of the colon, like you look through the front mirror once, and the other time with the rear mirror. A second look is particularly important if there were any polyps on the first look. If you have the report of your most recent colonoscopy, you could consider checking if this second look of the right colon was done at the time.
Best practice advice # 8: the rate of detection of premalignant colonic lesions
One of the quality metrics in the field of colonoscopy and colorectal cancer screening is to measure adenoma detection rate. The adenoma detection rate is calculated by dividing the number of colonoscopies with a confirmed detected premalignant colonic polyp called an adenoma by the total number of screening colonoscopies. This quality metric varies up to 5-fold among colonoscopists. Every colonoscopist should be able to keep records of this quality metric for every 250 screening colonoscopies performed. In addition, the endoscopy unit should keep track of this quality metric at the unit level. A good system and endoscopy unit should be able to provide an audit and feedback process to be able to enhance the quality. Perhaps it is the time to ask your colonoscopist’s adenoma detection rate or the endoscopy unit’s track record prior to scheduling your next one.
Best practice advice # 9: the target of adenoma detection rate
Interval colorectal cancer can be reduced once the adenoma detection rate is 35% or greater. Currently, the American Gastroenterological Association has set the goal that the adenoma detection rate for an individual endoscopist should be at 30% or greater, with an aspirational target of 35% or greater. You might double-check this quality metric with your provider for your next colonoscopy as it may help to enhance the benefit of colorectal cancer screening.
Best practice advice # 10: the early detection of very flat colonic lesions called "serrated lesions"
As we discussed previously, the right-sided colon tends to harbor not only premalignant polyps called adenoma, but also very flat lesions called serrated lesions, that can put you at risk of developing colorectal cancer if left untreated. The serrated lesion detection rate is calculated and is similar to that of the adenoma detection rate. The American Gastroenterological Association has proposed the goal for serrated lesion detection rates on an endoscopist and unit level. The goal of serrated lesion detection rate for an individual endoscopist should be 7% or greater, with an aspirational goal of 10% or greater. This is perhaps another quality metric to ask your endoscopy unit and your endoscopist prior to scheduling your next colonoscopy for colorectal cancer screening.
Best practice advice # 11: the methods of removing colonic polyps
A quality technique to remove colonic polyps is variable in clinical practices and residual tissues can be found at an approximate rate of 14%. This is critical because leaving residual neoplastic tissue behind can complicate subsequent removal and provide patients with false assurance that the polyps were removed and their risk of colorectal cancer was reduced. A preferred method of choice for polyps with sizes ranging 3 to 9 millimeters is cold snare polypectomy. A cold snare polypectomy is a technique in which your endoscopist uses a small metal wire to encircle a polyp and remove it without using heat. Polyps with sizes ranging from 3 to 9 millimeters are most commonly encountered during screening colonoscopies. Therefore, if your last polyps were removed using a different technique, especially in the setting that the vast majority of the polyps were removed with other techniques such as using forceps, you may want to consider a repeat colonoscopy sooner rather than later. In addition, the pathology report should be able to inform you that the margins of the polyps resected were clear of premalignant tissues.
Best practice advice # 12: the management of large polyps
As per the most recent update from the American Gastroenterological Association, patients with complex polyps without overt malignant endoscopic features or pathology consistent with invasive cancer should be evaluated by an expert in polypectomy to attempt endoscopic resection. At Bumrungrad International Hospital, in addition to the latest versions of colonoscopes that can help us identify the characteristics of these large polyps, our advanced endoscopists can provide the full range of complex tissue resection that can even treat early stage colon cancer, so that patients can avoid surgery. For appropriate patients with suitable complex polyp conditions, endoscopic resection can be more cost-effective, with a lower rate of complications than surgical resections.
Best practice advice # 13: the details of the endoscopic reports
This is pretty much a summary of how a colonoscopist documents the details of the patient, procedure indication, extent of examination, bowel preparation quality, findings and interventions, and follow-up plan with rationale. You might consider to touch base with your colonoscopist if your next colonoscopy interval is different from the guidelines, such as inadequate bowel preparation, so that you can discuss strategies to improve the quality of bowel preparation next time, or incomplete polyp resection so that you can consider a referral to an expert endoscopist for subsequent procedures.
Best practice advice # 14: endoscopy units and staff that should inform patients undergoing colonoscopy of the potential for complications, warning symptoms, and emergency contact information
At Bumrungrad International Hospital, we have implemented a scheduled phone call for follow-up after procedures to monitor any delayed complications, including perforation, bleeding, hospital readmission, 30-day mortality, and interval colorectal cancer cases. At administrative level, we have reported and discussed these data on a regular basis to ensure that our patients will receive the highest quality of care possible. Bumrungrad International Hospital was the first hospital in Asia since 2002 to be accredited by the Joint Commission International, or JCI, the world's leader in healthcare accreditation, especially for patient safety. With over 350 standards on the international standards of requirements, we have achieved accreditation five consecutive times ever since.
Best practice advice # 15: intervals for screening and surveillance colonoscopy
The United States multi-society task force recently published risk stratification and interval assignments for several conditions. If you have a large polyp that was resected in a small piece-by-piece called a piecemeal fashion, or you have a significantly high number of premaliganant colonic polyps called adenomas of greater than 10, the task force has recommended a repeat colonoscopy at 1 year to avoid late surveillance in high-risk patients. On the other hand, for those with only one or two small adenomas, the task force has recommended repeating a colonoscopy for surveillance every 7 to 10 years. For those with normal colonoscopy or with only non-neoplastic polyps called hyperplastic polyps in the left colon, the next colonoscopy for screening could be done in 10 years. If you are not sure when you should get your next colonoscopy, bring a full colonoscopy report with color pictures along with pathology reports and discuss this with your gastroenterologists.
We really hope that these great tips from the American Gastroenterological Association can help you build the plan and identify your risk of colorectal cancer, with the guidance from your local experts. The best protection is early detection.
Clinical Assoc. Prof. Dr. Tossapol Kerdsirichairat
Bumrungrad’s Digestive Disease (GI) Center
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