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Currently, most people over age 45 are recommended to get a colonoscopy once every 10 years. lechatnoir/Getty Images
  • If you have had a negative colonoscopy for colorectal cancer and have no family history, you might not need another screening for 15 years.
  • Ten years between colonoscopies is the typical guideline recommendation, but healthy individuals could be able to wait longer.
  • Changing colorectal cancer guidelines would ideally reduce the cost and potential harm of unnecessary colonoscopies while still maintaining cancer prevention.

Most colorectal cancer screening guidelines suggest a colonoscopy every 10 years, but healthy individuals with no family history of the disease may have the option to wait even longer.

A Swedish population study suggests that adults who have tested negative for colorectal cancer after an initial colonoscopy and have no family history, may not need another screening for 15 years.

The results of the study were published today inJAMA Oncology.

“Fifteen years between a first negative colonoscopy and a second one might be just as safe and effective as the current 10-year recommendation. This could save people from unnecessary procedures and free up resources for important colon cancer screening programs,” Mahdi Fallah, MD, PhD, a researcher at the German Cancer Research Center in Heidelberg, Germany, and senior author of the study, told Healthline.

However, other experts pushed back on the findings, noting that while it was robust, its conclusion may not be easily generalized to more diverse populations that live outside of Sweden, such as those in the United States.

“This is an excellently performed study from a large database and their recommendations seem valid for their population. Whether or not these are translatable to the US or other populations, there’s reason to believe they may not be,” Reid Ness, MD, MPH, an Associate Professor of Medicine at Vanderbilt Health, told Healthline. Ness wasn’t affiliated with the study.

How 15-year interval for colonoscopies could impact overall health

Fallah and his co-researchers leveraged several large Swedish health and population databases to sift through cancer outcomes across nearly three decades.

The team’s goal was to compare colorectal cancer outcomes among individuals with no family history of the disease and had received an initial negative colonoscopy versus those who never received a colonoscopy.

The study involved more than 110,000 Swedish adults (nearly 60% of whom were female) who received their first colonoscopy between 1990 and 2016 in one population. The average age of participants was 59. Additionally, participants also did not have inflammatory bowel disease, a documented risk factor for colorectal cancer.

Members of this group were then matched against members of a control group, who did not receive a colonoscopy, to compare outcomes.

Researchers looked at two in particular: 10-year standardized incidence ratio and 10-year standardized mortality ratio. That means the prevalence of colorectal cancer (incidence) and how often deaths (mortality) related to colorectal cancer occurred in the populations.

They found that the group that received negative first colonoscopies had a “significantly lower” risk of both developing colorectal cancer and dying from it over the following 10-year period. Their findings allowed them to further extend the standard 10-year window between colonoscopies and conclude that a 15-year interval for this healthy population could be sufficient.

“If we waited 15 years instead of 10 years for a second colonoscopy in this population, we might only miss catching two extra cases of colorectal cancer and one colorectal cancer death out of 1000 people. But it would save a lot of unnecessary colonoscopies — about one per person,” said Fallah.

Why reduce cancer screenings?

If you’re reading this and wondering why doctors are proposing to do fewer colorectal cancer screenings and not more, that’s a valid question. As with any kind of medical procedure, colorectal cancer screening and colonoscopies have risks and benefits that need to be evaluated.

“Ultimately screening recommendations are a value judgment that society makes. What is the acceptable risk in CRC [colorectal cancer] diagnoses and mortality that justifies extending the interval and decrease in the inconvenience in the cost of colonoscopies? There’s never, I think, truly a right or wrong answer,” Christopher Chen, MD, an Assistant Professor of Oncology and Director of Early Drug Development at the Stanford Cancer Institute, Stanford Medicine, told Healthline. Chen wasn’t involved with the research.

The goal of redefining colorectal cancer screening recommendations is about creating the most benefit in detecting cancer early while also reducing potential harm from unnecessary colonoscopies.

Colonoscopies have their own potential harms, so reducing how frequently someone should get one is a legitimate concern. In addition to the burden of having to schedule, prepare, and pay for a colonoscopy, there are also physical harms, however unlikely, that can occur as well. Bleeding and perforation are the most common complications of colonoscopy; perforation occurs in about 3 in 10,000 procedures.

“Obviously, it’s not a trivial issue,” said Chen.

“First of all, there’s the risk of injury from the procedure. Then there’s the cost to society. The cost of additional colonoscopies is significant,” adds Ness.

What is colorectal cancer?

Colorectal cancer affects the cells of the rectum and colon. It is the second-leading cause of all cancer-related deaths. Colorectal cancer most often starts out as small growths known as polyps. While most polyps may be benign, some will eventually develop into cancer.

Colorectal cancer is a serious and deadly cancer, but many Americans still do not follow recommended screening guidelines that require regular testing. Less than 60% of adults between the ages of 45 and 75 receive screenings, either in the form of a colonoscopy or a take-home test for colon cancer. It is estimated that 35,000 deaths from colorectal cancer could be prevented annually through adherence to regular screening.

The American Cancer Society recommends that adults start colorectal cancer screening at age 45 and continue through age 75.

Colonoscopy is considered the “gold standard” for colorectal cancer screening.

The bottom line

If you’ve had a negative colorectal cancer colonoscopy and have no family history of the disease, you could wait 15 years until your next screening, concludes a novel Swedish population-based study.

The findings add an additional five years to the standard 10-year recommendation between screenings.

Experts caution, however, that the findings may not be generalizable to more diverse populations, such as that of the United States.