A new study from Germany questions whether people can wait longer than the recommended 10 years to repeat a colonoscopy after a negative initial screening for colorectal cancer. The results showed that females and younger people without gastrointestinal symptoms could extend the intervals between screenings, or opt for a less invasive method, such as a stool test.
According to CNN, the researchers looked at 120,000 people ages 65 and older living in Germany from 2013 to 2019 who had a colonoscopy 10 years or more after their initial screening. They compared their results to all colonoscopy screenings conducted on those 65 and older during that time period — most of whom were screened for the first time.
In the study, published in JAMA Internal Medicine, researchers said they found 40% to 50% fewer precancerous or cancerous growths among the people who underwent repeated screenings than among all screening colonoscopies, and advanced growths or cancers in only 4% to 5% of women and 5% to 7% of men 10 or more years after a negative colonoscopy.
In light of the study findings, the authors commented that the current guidelines calling for a colonoscopy every 10 years is safe, and that for females and younger people without any symptoms, the interval between colonoscopies could possibly be extended.
Excluding skin cancers, colorectal cancer is the third most common cancer diagnosed in the U.S., says the American Cancer Society (ACS). Rates of people diagnosed with colon or rectal cancer each year has dropped overall since the mid-1980s, mainly because more people are getting screened and changing their lifestyle-related risk factors. But this downward trend applies more to older adults, says the ACS. In people younger than 50, rates have been increasing by 1% to 2% since the mid-1990s.
Current guidelines recommend screening for colorectal cancer in all adults 45 to 75 years old, says CNN. The recommendations recently changed to start screening at 45 instead of 50 in response to more younger people being diagnosed. If the screening is negative, patients don’t need another colonoscopy for 10 years.
Cancer experts say that the German findings are interesting but would like to see more research back up their results before the guidelines are changed.
“There’s good evidence that screening colonoscopy in asymptomatic individuals at 10-year intervals is effective and cost effective,” said Dr. Robert Bresalier, a gastrointestinal oncologist at MD Anderson Cancer Center. “And I think I’m not ready to change. I would not be ready to change practice in terms of extending the interval based on the study, but it is comforting and provides additional data to strengthen the concept of adhering to these guidelines.
“The overall message from this study is we can feel comfortable with the current guidelines,” he said.
More than a quarter of eligible Americans don’t get screened for colorectal cancer, and they should, say healthcare advocates, since the disease is expected to claim the lives of 52,550 Americans in 2023, says the ACS.
“Right now, the biggest impact we have — and relevant to this discussion — is screening. So, if you haven’t been screened and you’re in that age relevant age group, you should get screened,” said Bresalier. “And that clearly has a larger impact, and the biggest impact we can do right ow in terms of influencing death of colorectal cancer.”