Federal panel says colon cancer screening should start at 45, not 50, as the disease strikes ever-younger adults and even teens

In response to an alarming, long-term increase in colorectal cancer among younger people, an influential federal panel Tuesday lowered the recommended age to start screening from 50 to 45.

The American Cancer Society made the same recommendation three years ago, but with the U.S. Preventive Services Task Force now following suit, health insurers will have to get on board. They have a year to extend coverage of the menu of screening options — including colonoscopy, the gold-standard exam — based on the updated guidance.

The latest studies and mathematical models suggest that finding and treating cancers at age 45 instead of 50 could add 22 to 27 years of life for those who get an earlier diagnosis, with only a small increase in complications, the task force reported in JAMA. For the first time, the models showed equal benefit across gender and races.

Oncologists and patient advocates cheered the change as a step forward but said the real work lies ahead.

Jeffrey Farma, a surgical oncologist specializing in colon cancer at Fox Chase Cancer Center, noted that a third of adults age 50 and up are not up to date with screening, and a quarter have never been checked for colorectal cancer — the second-leading cause of cancer death in the United States. The rate is even worse among nonwhite groups and the poor.

“These numbers are staggering, and we are already seeing that these numbers are going to be much worse because of the COVID-19 pandemic and decreased or delayed screening for all types of cancers,” Farma said.

Meanwhile, physicians generally still assume colorectal cancer is a slow-growing malignancy of advancing age, even though “early onset” disease — meaning before age 50 — is increasingly being diagnosed, often at incurable stages, in people in their 30s, 20s, and younger. Researchers are far from understanding the biological reasons for this trend, although evidence suggests environmental toxins play a role, and may also be tied to the big increase in inflammatory bowel diseases such as Crohn’s disease.

“We should not lose sight of why this guideline is changing,” said Richard Wender, chair of family medicine and community health at Penn Medicine. “For decades now, we’ve been seeing this increase of colorectal cancer in younger age groups. We are now seeing a 16% increase in mortality under age 50.

“We’re still studying why this is happening,” added Wender, the former chief cancer control officer at the American Cancer Society. “It’s likely something in our diet. Overweight and obesity may be contributing to some extent. We need to move the screening age even younger.”

Susan Wysoki, of Richmond, Va, is intimately familiar with the horror and heartbreak of early onset disease. Her daughter, Jessica Joseph, died of it in 2018 at age 17. She had worsening bowel symptoms for three years before a CT scan revealed a baseball-sized metastatic tumor.

“Doctors thought it was irritable bowel syndrome,” recalled Wysoki, interim executive director of the nonprofit foundation that sponsors Colontown.org, an online support community for patients and families. “The doctors said, ‘Eat more fiber. Drink more water.’ So warning about early onset is something I wear like a sandwich board every day of my life. We are adding new cases every week. We have two 11-year-olds. One is going into hospice.”

Colorectal cancer is still very much linked to aging. But it has steadily declined among older adults mostly because of widespread screening colonoscopies, which can detect and remove precancerous polyps before they turn malignant. In contrast, incidence has increased 51% since 1994 among adults under 50.

Adults born around 1990 have twice the risk of colon cancer and four times the risk of rectal cancer as adults born in the 1950s, the American Cancer Society said when it recommended screening at age 45.

In an editorial accompanying the task force’s paper, oncologist Kimmie Ng, director of the Young-Onset Colorectal Cancer Center at Dana-Farber Cancer Institute, wrote that the majority of young-onset cases are aged 45 to 49. However, historical data show colon cancer incidence is increasing at a steeper annual rate among patients in their 20s and 30s than among those in their 40s.

Ultimately, she wrote, prevention and early detection “will require further research into the underlying etiology and risk factors ... which thus far remain elusive but are suspected to possibly be related to environmental exposures early in life.”

Like the cancer society, the task force says the initial test at age 45 could be a stool-based test or one of several other screening methods that are less invasive and costly than a colonoscopy, which requires an unpleasant bowel-cleansing drug regimen. However, an abnormal result on a non-colonoscopy screening test should be followed by a colonoscopy.