What are the guidelines for colonoscopy screening at age 45 versus 50?

From the Guidelines

Colorectal cancer screening should begin at age 45 for average-risk individuals, as recommended by the most recent guidelines from the American Cancer Society and the US Multi-Society Task Force 1. This updated guideline applies to all adults without a family history of colorectal cancer, personal history of inflammatory bowel disease, or genetic syndromes that increase risk. The screening can be done through various methods, with colonoscopy being the gold standard that should be repeated every 10 years if results are normal. Alternative screening options include:

• Fecal immunochemical testing (FIT) annually
• Stool DNA testing every 3 years
• CT colonography every 5 years
• Flexible sigmoidoscopy every 5-10 years The age recommendation was lowered because colorectal cancer rates have been increasing in younger adults, and studies show that beginning screening at 45 saves more lives through earlier detection of precancerous polyps and cancer 1. For those with a family history of colorectal cancer or advanced polyps, screening should begin earlier—typically at age 40 or 10 years before the youngest diagnosed first-degree relative 1. After age 75, the decision to continue screening should be individualized based on overall health, prior screening results, and life expectancy 1.

The most recent guidelines from the American College of Gastroenterology and the US Preventive Services Task Force also support starting screening at age 45 for average-risk individuals 1. The American Cancer Society estimates that 140,250 new cases of colorectal cancer will be diagnosed in 2018, and 50,630 people will die from the disease 1. Early detection and prevention through screening can significantly reduce the incidence and mortality of colorectal cancer. Therefore, it is essential to follow the updated guidelines and start screening at age 45 for average-risk individuals to improve outcomes and reduce the burden of the disease.

In terms of specific recommendations, the American College of Gastroenterology suggests screening in average-risk persons aged 45 to 49 years (conditional recommendation) and recommends screening average-risk persons aged 50 to 75 years (strong recommendation) 1. The US Preventive Services Task Force recommends screening adults between ages 50 and 75 years (Grade A) and beginning screening adults between ages 45 and 49 years (Grade B) 1. Overall, the evidence supports starting colorectal cancer screening at age 45 for average-risk individuals to improve outcomes and reduce the burden of the disease.

From the Research

Colonoscopy Guidelines: 45 vs 50

• The American Cancer Society has recommended initiating colorectal cancer (CRC) screening at age 45 years instead of 50 years 2.
• A systematic review of colorectal cancer guidelines found that most guidelines recommended screening between 45 and 75 years for average-risk individuals 3.
• The U.S. Multi-Society Task Force on Colorectal Cancer suggests average-risk CRC screening begin at age 45, based on the increasing disease burden among individuals under age 50 and emerging data on the prevalence of advanced colorectal neoplasia 4.
• Modeling studies have demonstrated that lowering the age to start screening to 45 is cost-effective, with a reduction in CRC incidence and mortality 5, 2.

Screening Modalities and Intervals

• Colonoscopy is a frequently suggested screening modality, with recommended intervals of every 10 years for average-risk individuals and every 5-10 years for high-risk individuals 3.
• Other screening modalities, such as FIT and CTC, are also recommended, with varying intervals depending on risk level 3.
• A study found that adenoma detection rates (ADR) in average-risk screening patients aged 45 to 49 were lower than those aged 50 to 54, but still surpassed the established benchmark of 25% 6.

Considerations for Decision Making

• Policy makers can use a worksheet to assess the expected increase in healthcare resources required for earlier screening initiation 5.
• Improving screening rates to 80% in persons who are 50-75 years old could avert nearly 3-fold more CRC deaths at one third the incremental cost 2.
• Ongoing national monitoring is essential to comprehensively evaluate the impact of updated guidelines 6.