Screening for colorectal cancer from a younger age, to start at age 45, has been recommended in a draft statement by the U.S. Preventive Services Task Force (USPSTF).

While the grade A recommendation for screening 50 to 75 year olds remains in place, the USPSTF has made a grade B recommendation to lower the starting age because of a shift in CRC risk to younger people.

“Although the absolute risk of developing colorectal cancer is much lower in adults younger than age 50 years (20.0 new colorectal cancer cases per 100,000 persons ages 40 to 49 years, 47.8 new cases per 100,000 persons ages 50 to 59 years, and 105.2 new cases per 100,000 persons age 60 years and older), age-period-cohort analysis indicates a recent trend for increasing risk of colorectal cancer in adults younger than age 50 years,” the USPSTF said.

“Additionally, modelling performed by the Cancer Intervention and Surveillance Modeling Network (CISNET) suggests that starting colorectal cancer screening at age 45 years can moderately increase life-years gained and decrease colorectal cancer cases and deaths compared to beginning screening at age 50 years.”

A grade C recommendation is that clinicians also selectively offer screening for colorectal cancer in adults ages 76 to 85 years.

“Evidence indicates that the net benefit of screening all persons in this age group is small. In determining whether this service is appropriate in individual cases, patients and clinicians should consider the patient’s overall health and prior screening history,” the USPSTF said.

“Limited evidence suggests harms from colonoscopy, such as perforation and bleeding, and extracolonic findings on CT colonography increase with age.”

The USPSTF said despite strong evidence that screening for colorectal cancer is effective, about a quarter of people aged 50 to 75 years have never been screened.

“Unfortunately, not enough people in the U.S. receive this effective preventive service that has been proven to save lives,” Task Force chair Professor Alex Krist said.

“We hope that this recommendation to screen people ages 45 to 75 for colorectal cancer will encourage more screening and reduce people’s risk of dying from this disease.”

As previously reported in the limbic, the American Cancer Society already recommends colorectal cancer screening from age 45 years.

In Australia, the 50-74 age range is considered the most cost-effective with a balanced ratio of benefits to harms.

“Reducing the starting age to 45 years would present with a less favourable benefits-to-harms balance and require more colonoscopies for each extra cancer death prevented,” the National Cancer Control Policy says.

The USPSTF draft recommendations note that earlier age screening may preferentially benefit black Americans who have the highest incidence of colorectal cancer and are currently more likely to die from the disease.

Public comment on the USPSTF recommendations closes November 23.