1 In 3 People Skip This Screening — But It Could Be Life-Saving

There are plenty of things we do in the name of longevity that require real effort. We strength train several times a week, pay attention to our blood sugar, prioritize sleep, and spend money on supplements and tests that promise to tell us more about how we're aging.

Then there are the decidedly less exciting parts of preventive health: scheduling the mammogram, getting your cholesterol checked, or completing the screening kit that's been sitting on the bathroom counter.

These things aren't particularly glamorous, but they're also some of the most proven tools we have for living longer. Cancer screening is a perfect example. Colorectal cancer is highly treatable when caught early, yet many people who are eligible for screening still don't follow through.

The study, published in JAMA Network Open, looked at 376,511 adults in Sweden who were part of a population-based colorectal cancer screening program.

Participants were between 60 and 69 years old and were either invited to participate in screening between 2008 and 2012 or placed in a comparison group that was invited later or wasn't invited during the study period. Researchers then tracked colorectal cancer deaths for up to 14 years.

The screening itself was relatively simple. Participants completed a fecal occult blood test, or FOBT, which looks for tiny amounts of blood in stool that aren't necessarily visible to the eye. A positive result doesn't mean someone has cancer, but it signals that further evaluation, typically with a colonoscopy, is needed.

The researchers were particularly interested in separating the effect of simply being offered screening from what happened when people actually completed it. After all, receiving a free test in the mail can only help if you actually use it.

After accounting for differences between the groups, researchers estimated that being invited to participate in colorectal cancer screening was associated with a 26% lower risk of dying from the disease.

But among people who actually participated in screening, the estimated reduction was even greater, to 43%.

That difference may be the most useful part of the study. Screening programs can only work when people use them, and roughly one-third of the people offered screening didn't complete it.

The benefit of colorectal cancer screening comes largely from finding problems earlier. Stool-based tests can detect microscopic bleeding that may be associated with colorectal cancer or precancerous growths before someone has obvious symptoms. When something suspicious turns up, a colonoscopy can provide a closer look and allow doctors to remove certain polyps before they have the chance to become cancerous.

And this conversation isn't only relevant to people in their 60s. Colorectal cancer rates have been rising among younger adults, which is one reason screening recommendations have shifted earlier. In the U.S., average-risk adults are generally advised to begin colorectal cancer screening at age 45, although people with a family history or other risk factors may need to start sooner.

For some people, the idea of getting a colonoscopy is enough to keep putting screening off. But a colonoscopy isn't the only option for everyone.