One Quarter of 30–49-Year-Olds Have Abnormal Colonoscopy Results

Pam Harrison

June 07, 2021

More than one quarter of colonoscopies carried out in Americans aged 30 to 49 years reveal some type of neoplasm, and slightly over 6% of these patients have advanced cancer, results of a nationally representative endoscopic registry show.

"This is the largest study to date that has looked at the prevalence of what you find at colonoscopy in people younger than the age of 50," Steven Itzkowitz, MD, professor of medicine, oncological sciences, and medical education, Icahn School of Medicine at Mount Sinai, in New York City, told Medscape Medical News.

"And the point is that our data do justify lowering the new screening age to 45 — we like to say 45 is the new 50 — and physicians need to start talking to patients before they reach the age of 45, because people procrastinate before they actually come in for screening," he added.

The study was jointly carried out by the Icahn School of Medicine at Mount Sinai and AMSURG, a division of Envision Healthcare, and was presented during the Digestive Disease Week (DDW) 2021 virtual scientific meeting.

Quality Improvement Consortium

For this study, Itzkowitz and colleagues analyzed a subset of the GI Quality Improvement Consortium registry of outpatient colonoscopies, focusing on individuals who had undergone a screening or a diagnostic colonoscopy between 2014 and 2021.

In total, the dataset contained 3 million colonoscopies, from which investigators selected the first recorded colonoscopy for patients aged 18 to 54 years. Patients were excluded if they had previously undergone a colonoscopy or they had a personal history of colorectal polyps, cancer, inflammatory bowel disease, or an inherited colorectal cancer (CRC) syndrome. Patients whose colonoscopy was of low quality as well as those who underwent surveillance or therapeutic procedures were also excluded.

"This left 563,000 procedures in the analyzable dataset — 146,000 of which were performed on patients aged 18 to 44, and 80,000 of which were performed on patients aged 45 to 49," the investigators observe.

Among patients between 45 and 49 years of age, the most frequent indication for the colonoscopy was for routine screening, at over 41%, they note.

The investigators used standard definitions of advanced adenoma and advanced sessile serrated polyp and grouped them either as advanced premalignant lesions (APL) or advanced colorectal neoplasia (APL plus CRC).

"The prevalence of all neoplastic findings progressively increased with increasing age, ranging from over 15% for 30- to 34-year-olds to over 37% for 50–54-year-olds," the investigators report.

Each 1-year increase in age was associated with an 8% greater risk of finding an advanced colorectal neoplasia (ACRN). Predictors of early-onset ACRN included male sex, which was associated with a 67% higher risk of detecting early-onset pathology.

Most importantly, in light of the new lower age limit for CRC screening, 7.5% of those between 45 and 49 years of age had APL, and 0.58% had frank CRC.

Table. Prevalence of Neoplasia by Age Group

Age group Any neoplasia APL CRC
30–34 15.2% 2.8% 0.22%
35–39 20.3% 4.3% 0.36%
40–44 26.5% 5.7% 0.53%
45–49 32.1% 7.5% 0.58%
50–54 37.7% 9.4% 0.32%


"As you might expect, people with a family history of colon cancer had higher rates of neoplasia than those without a family history," Itzkowitz said.

Among 40-year-olds who had a family history of CRC, the prevalence of pathology was similar to that among 45-year-old patients who did not have a family history — "so if you have a positive family history of CRC, it's almost as if you are 5 years older," he emphasized.

For example, for patients aged 45 to 49, approximately 10% of those with a family history of CRC were diagnosed with APL, compared to only about 7% of those who did not have a family history. Paradoxically, fewer patients between the ages of 45 and 49 had a positive family history had CRC, at only 0.27%, compared with 0.61% for those without a family history.

Itzkowitz explained that the majority of patients between the ages of 18 and 49 who had a positive family history underwent screening colonoscopy, suggesting that incident cancers were prevented among patients with a positive family history who underwent screening colonoscopy.

"We need a lot more data on family history in younger people, but there is no doubt that having a family history of CRC puts you at higher risk, so early messaging is key for everyone but especially if patients have a positive family history," Itzkowitz emphasized.

John Popp, MD, medical director for AMSURG, echoed these sentiments, saying: "These data support efforts to begin screening at age 45 and communicate the importance of on-time screening by early messaging to patients and providers."

Itzkowitz has received research support and consulting fees from Exact Sciences Corporation and research support from Freenome. Popp is an employer of AMSURG, a leading provider of colonoscopies in the United States.

Digestive Disease Week (DDW) 2021: Abstract 871. Presented May 23, 2021.

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