At what age should colorectal cancer screening begin for women?

From the Guidelines

Colorectal cancer screening should begin at age 45 for women.

Rationale

• The American Cancer Society (ACS) recommends that adults aged 45 years and older with an average risk of colorectal cancer (CRC) undergo regular screening with either a high-sensitivity stool-based test or a structural (visual) exam, depending on patient preference and test availability 1.
• The ACS updated its guideline for CRC screening in individuals at average risk in 2018, and the recommendation to begin screening at age 45 is a qualified recommendation, based on modeling analyses that identified efficient and model-recommendable strategies that started screening at age 45 years 1.
• Other organizations, such as the USPSTF, ACG, and NCCN, also recommend screening for CRC in adults aged 45 to 49 years, although the strength of the recommendation varies 1.
• The options for CRC screening include fecal immunochemical test (FIT) annually, high sensitivity guaiac-based fecal occult blood test (HSgFOBT) annually, multi-target stool DNA test (mt-sDNA) every 3 years, colonoscopy every 10 years, CT colonography (CTC) every 5 years, and flexible sigmoidoscopy (FS) every 5 years 1.
• Approximately 43% of early-onset (age <50 years) CRC diagnoses are in individuals aged 45 to 49 years, and screening in this population becomes important 1.
• The incidence of regional-stage and distant-stage disease has increased by approximately 3% per year in people with CRC aged <50 years, highlighting the need for early screening 1.
• Key considerations for screening include patient preferences, life expectancy, health status, and prior screening history, particularly for individuals aged 76 through 85 years 1.

From the Research

Colorectal Cancer Screening Age for Women

• The American Cancer Society and the US Preventive Services Task Force recommend initiating colorectal cancer (CRC) screening at 45 years of age to address the increasing incidence of CRC among adults younger than 50 years 2, 3.
• A prospective cohort study using data from the Nurses' Health Study II found that undergoing endoscopy was associated with a significantly lower risk of incident CRC for age at initiation before 45 years, 45 to 49 years, 50 to 54 years, and 55 years or older 3.
• A systematic review of colorectal cancer guidelines for average-risk and high-risk individuals found that most guidelines recommended screening between 45 and 75 years for average-risk individuals 4.
• Models of CRC risk based on lifestyle and environmental factors and genetic variants can determine an optimal age to begin screening, which may differ from the recommended age of 50 years for individuals with no family history of CRC 5.
• The U.S. Preventive Services Task Force recommends against routine screening after 75 years of age, and options for screening include high-sensitivity fecal occult blood testing annually, flexible sigmoidoscopy every five years with high-sensitivity fecal occult blood testing every three years, or colonoscopy every 10 years 6.

Key Findings

• The recommended age to start colorectal cancer screening for women is 45 years old 2, 3, 4.
• Screening before 50 years of age is associated with a reduced risk of CRC, including CRC diagnosed before 55 years of age 3.
• Individualized screening recommendations based on lifestyle, environmental, and genetic risk factors may be more effective than a one-size-fits-all approach 5.