Why 45 is the new 50: The updated playbook for colon cancer screenings

Colon cancer is one of the most common and deadliest types of cancer, and routine screenings are the best way to reduce your chances of becoming a statistic.

The recommended age to begin colon cancer screenings was recently lowered from 50 to 45, and there are now several options for getting screened, making it easier than ever to get checked.

MyNorthwest spoke with Seattle Top Doctor and Western Washington Medical Group (WWMG) Gastroenterologist Dr. James Mu about how early detection is bending the curve for cancer survival rates in Washington.

“In the past three decades, starting in the 90s, the incidence of colon cancer has been rising between the ages of 20 and 49, and this has been a persistent pattern year after year for both men and women,” Mu said. “More recent epidemiology data showed that colon cancer has become the No. 1 cancer death in the younger population of that age group. So because of that strong, strong evidence, the U.S. Preventive Services Task Force changed the guidelines in 2021.”

Colorectal cancer can be symptomless

Colorectal cancer — a term for cancerous growths originating in the colon, including the rectum — is one of the leading causes of cancer-related deaths in the U.S. population. It ranks as the third-most common type of cancer and the second leading cause of death from cancer, according to the National Cancer Institute Surveillance, Epidemiology, and End Results Program.

Abnormal tissue growths on the lining of the colon, called polyps, have the risk of becoming cancerous. Screenings aim to detect polyps and, if found, can be removed during a colonoscopy procedure.

“The warning signs of early colon cancer can be absent,” Mu said. “No symptoms, no signs. It’s a silent process that a benign polyp transforms into cancer. So if you wait for signs to show up, it’s not always an early warning symptom anymore, and might be just late-stage cancer.”

With the disease being so hard to detect by symptoms in its early stages, routine colorectal cancer screenings are the best way for individuals to prevent it.

“I think the colon cancer screening program has been extremely successful,” Mu said. “If we did not have a routine screening to catch those early cancers, the five-year survival of colon cancer would be much, much lower.”

According to the National Cancer Institute Surveillance, Epidemiology, and End Results Program database, the five-year survival rate for early-stage colorectal cancer exceeds 90%. But if the cancer is not diagnosed early and it has spread to other organs like the liver and lungs, the five-year survival rate drops dramatically to approximately 15%.

Types of colorectal cancer screenings provided by Western Washington Medical Group

WWMG provides multiple screening options: colonoscopy, Cologuard, FIT test, and the recently FDA-approved Shield blood test.

“We’re presenting more options to patients who are fearful or reluctant about getting a colonoscopy,” Mu said.

Cologuard and FIT tests are convenient at-home screenings in which patients collect a stool sample and mail the kit back to the lab for testing. Neither requires fasting nor bowel preparations, but each comes with its shortcomings.

Cologuard test has a substantially lower polyp detection rate than colonoscopy, detecting only up to approximately 30% of precancerous polyps; and also carries a relatively high false-positive rate, according to studies published in the New England Journal of Medicine in 2014 and 2024.

FIT tests are also less effective at detecting polyps than a colonoscopy. And a positive FIT or a Cologuard test result requires a follow-up colonoscopy for a definitive diagnosis.

The Shield blood test, which was FDA-approved in 2024, involves a simple blood draw but detects only 65% of Stage I colorectal cancers and about 13% of precancerous polyps.

For Mu and WWMG, colonoscopy remains the gold standard for getting screened for both colon cancer and a precancerous polyps.

“If you want the best protection, it’s recommended to do the colonoscopy and drink that prep once every 10 years,” Mu said.

One of the many benefits a colonoscopy provides is the ability to find and remove any polyps found along the lining of the colon.

“Polyps can be very flat, like a piece of gum stuck on the floor. A colonoscopy can find them more easily compared to a CT colonography,” Mu said. “I can remove the polyps and do the treatment at the same time as the colonoscopy. But we make the different screening options available to patients because there are always people out there who are just die-hard against colonoscopies.”

And any type of screening is better than none at all.

Colorectal cancer screening age drops from 50 to 45

A significant reason for colon cancer being the No. 1 cancer-related death for people between the ages of 20-49, and not for those who are older, is the lack of screenings.

Cancer is generally considered a disease associated with aging. The older you are, the higher your risk for cancer, including colon cancer. So why is the incidence decreasing in people age 50 and older, while rising in younger adults? At first glance, that seems counterintuitive,” Mu said. “The reason is that colorectal cancer screening has been routinely performed in the over-50 population for decades. Through widespread screening, the medical community has successfully bent the curve and reduced colorectal cancer rates in the screening-eligible population.

“Unfortunately, those aged 20 to 49 were not eligible,” Mu continued. “So that’s the natural history. If we did not have that intervention, the age-50 bio population curve would have been rising too. For decades, we’ve been demonstrating how successful colon cancer screenings have been, and, as a result, the guidelines have changed, now dropping the age down to 45 to start colon cancer screening.”

According to the CDC, only about 70% of Americans are up to date with colorectal cancer screening. Recent data also suggest that participation rates among the newly eligible 45–49 age group are approximately 20% lower than those of older adults. This is particularly concerning because many individuals in this age group are primary breadwinners for their families and a vital part of the nation’s workforce.

We must continue educating the public and improving colorectal cancer screening participation rates, particularly among younger, otherwise healthy individuals. If you are age 45 or older and are due for colorectal cancer screening — or are unsure whether you are due or which screening method is most appropriate—please schedule an appointment with your primary care provider to discuss your options.

If you’ve had your screening and need to schedule a colonoscopy, call WWMG’s Gastroenterology department at (425) 259-3122 or request an appointment online.

Don’t wait to get screened. It could literally save your life.

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