The U.S. Preventive Services Task Force, an independent panel of primary care and prevention experts, recently issued new guidelines that recommend individuals of average risk begin colorectal cancer (CRC) screenings at age 45 instead of age 50.
The Task Force said its recommendation was prompted by an increase in the CRC rate in younger people. Colorectal cancer is the second leading cause of U.S. cancer death, and more than 10 percent of all new CRC cases are diagnosed in patients under age 50.
While colorectal cancer screenings are essential, clinicians and patients should understand that not all colonoscopies are equal. In particular, to ensure they receive quality care, before scheduling an appointment, patients should ask their gastroenterologist about the gastroenterologist’s adenoma detection rate (ADR) – a measurement that indicates how often precancerous polyps are found during exams and that contributes to how carefully colonoscopies are performed.
A study by the Polish Ministry of Health recently published in the Annals of Internal Medicine separated colonoscopies into high- and low- quality exams, with a 20 percent ADR as the dividing line. The goal for the GI Quality Improvement Consortium (GIQuIC), which sets the standard in the collection and reporting of quality measures for the practice of gastrointestinal endoscopy, is a 25 percent ADR. The study, the first to include baseline examination quality in the analysis of long-term risk for CRC and mortality after a negative colonoscopy, also defined high-quality colonoscopies as those that include cecal intubation (a term that means the entire colon was examined) and adequate bowel preparation.
The Polish researchers found patients who received just one negative colonoscopy were at a lower risk for colorectal cancer for up to 17.4 years – but only if the patient had a high-quality exam. The study concluded colonoscopies with ADRs higher than 20 percent “provided a profound and stable reduction in both CRC incidence and mortality throughout follow-up.” In other words, if the negative screening came from a clinician with an ADR below 20 percent, future CRC risk was higher.
Specifically, the researchers found high-quality exams resulted in a two-fold reduction in the colorectal cancer incidence rate and a two-fold lower mortality rate. With a low-quality colonoscopy, mortality already was significantly higher the first five years after examination. The researchers determined, “Many cases of CRC arise from lesions missed at baseline examination rather than from newly developed lesions.”
An analysis of U.S. patients by Kaiser Permanente in 2014 resulted in similar findings. Specifically, Kaiser found for each one percent increase in ADR, there was a three percent decrease in colorectal cancer risk. That study, published in The New England Journal of Medicine, said the ADR “was inversely associated with the risks of interval colorectal cancer, advanced-stage interval cancer, and fatal interval cancer.”
The Polish study also concluded high-quality colonoscopies are perhaps even more important for women. “Examination quality particularly affected CRC incidence and mortality in women,” the researchers said. “After low-quality colonoscopy, incidence rates in women were significantly higher than the rates observed in men throughout follow-up.”
In 2019, AMSURG ambulatory surgery centers (ASCs) completed more than 938,000 colonoscopies and identified nearly 360,000 patients with adenomas/cancers. The ADR for AMSURG clinicians participating in GIQuIC is 38.37 percent – nearly double the ADR the Polish study rated as high-quality. (About three-quarters of all AMSURG ASCs participate in GIQuIC.)
“In 2019 AMSURG clinicians identified more than 125,000 additional cancers and adenomas than would be expected if their ADR was simply equal to the national benchmark,” said Dr. Jay Popp, AMSURG Medical Staff Development Lead. “When it comes to colonoscopies, quality can be a life or death matter. By tracking ADR through GIQuIC, our centers provide the information patients need to make informed decisions that will reduce their risk of developing colorectal cancer and will protect their long-term health.”