At what age or risk level does colonoscopy screening typically start for a 45-year-old female, is it based on age, low risk at 50, or high risk at 10 years younger?

From the Guidelines

Colonoscopy screening for a 45-year-old female with average risk should begin at age 45, which means this individual should start screening now. The American Cancer Society and other major medical organizations recently updated their guidelines to recommend that people at average risk for colorectal cancer begin screening at age 45 instead of the previously recommended age 50, as stated in the study by 1. This change was made due to increasing rates of colorectal cancer in younger adults.

For individuals with high-risk factors such as a family history of colorectal cancer or advanced polyps, screening typically begins earlier—often 10 years before the age at which the youngest affected relative was diagnosed, but no later than age 40, as recommended by 1. Other high-risk factors that might warrant earlier screening include personal history of inflammatory bowel disease, certain genetic syndromes like Lynch syndrome, or previous radiation therapy to the abdomen.

Some key points to consider:

• The age to start screening is now 45 for average-risk individuals, as supported by 1 and 1.
• High-risk individuals may need to start screening earlier, as outlined in 1 and 1.
• The decision to continue screening after age 75 should involve a shared decision-making process between a patient and provider, considering prior screening history, life expectancy, CRC risk, and patient preferences, as discussed in 1 and 1.
• The colonoscopy procedure itself involves a thorough bowel preparation and a procedure under sedation where a flexible scope examines the entire colon, with follow-up screenings typically recommended in 10 years for average-risk individuals, as described in the example answer.

Given the information provided and the current guidelines, the correct answer is b) low risk 50, but with the clarification that current recommendations start screening at age 45 for average-risk individuals, as stated in the studies by 1, 1, and 1.

From the Research

Colonoscopy Screening Guidelines

The user's question is about the age or risk level at which colonoscopy screening typically starts for a 45-year-old female. The options provided are:

• a) age
• b) low risk 50
• c) high risk 10 years younger

Screening Age and Risk Level

Based on the provided evidence, the following points can be made:

• The American College of Physicians (ACP) guidelines recommend screening starting at age 50 y, while the United States Preventive Task Force (USPSTF) guidelines recommend screening starting at age 45 y 2.
• A study using the CRC-SPIN microsimulation model found that strategies starting at age 45 y were consistently in the efficiency frontier, while strategies starting at age 50 y with 10-y intervals were never efficient 2.
• Another study found that screening for colorectal cancer with stool tests, endoscopic tests, or computed tomography colonography starting at age 45 years provides an efficient balance of colonoscopy burden and life-years gained 3.
• The ACG Clinical Guidelines for Colorectal Cancer Screening 2021 provide detailed recommendations for CRC screening in average-risk individuals and those with a family history of CRC, but do not specify a specific age or risk level for starting screening 4.

Conclusion Not Allowed, so the answer is

• The correct answer is based on age, as the evidence suggests that colonoscopy screening should start at age 45, as recommended by the USPSTF guidelines 2, 3.
• The options b) low risk 50 and c) high risk 10 years younger are not supported by the evidence.
• Therefore, the correct answer is a) age.