Delayed Colonoscopies After Positive FIT Results Raise Colorectal Cancer Risk

As part of the national colorectal cancer screening program, individuals aged 50 to 74 (with age as the sole risk factor) receive a fecal immunochemical test (FIT) every two years to detect occult blood in the stool. A positive FIT result necessitates a colonoscopy within a specific timeframe. However, recent data indicates that a significant number of individuals do not undergo timely colonoscopy following a positive FIT, with potentially serious consequences.

Alarmingly Low Colonoscopy Completion Rates

Researchers analyzing data from over 530,000 individuals in mainland France who received positive FIT results between 2016 and 2020 found that only 4.7% completed a colonoscopy within one month of the positive test. While this proportion increased to 52.2% after three months and 87% after 24 months, a substantial 13% had not undergone the follow-up examination even after two years.

Disparities in Access and Timeliness

Significant territorial and social inequalities exist in colonoscopy completion rates. Access to timely colonoscopy varied considerably by region, ranging from 26% in the Territoire de Belfort to 71% in Morbihan within three months. Individuals residing in municipalities with higher social disadvantage indices experienced longer delays between a positive FIT and colonoscopy completion. Younger age was also associated with delays.

Women were more likely to undergo colonoscopy than men, regardless of the timeframe. Individuals aged 60-69 were most likely to promptly complete a colonoscopy after a positive FIT, potentially due to greater awareness, functional autonomy, and ability to navigate the healthcare system. Conversely, those aged 70-75 had a lower probability of undergoing colonoscopy within 24 months, likely due to comorbidities and potential reluctance from healthcare professionals or patients.

The Risks of Delaying Colonoscopy

Delaying or foregoing colonoscopy after a positive FIT significantly increases the risk of death from colorectal cancer. Studies demonstrate a doubling of this risk. While a delayed procedure may cause anxiety, the risk of diagnosing carcinoma at an advanced stage increases significantly when colonoscopy occurs more than ten months after a positive test, compared to a delay of 8-30 days. Some studies indicate this risk increase begins as early as six months post-positive FIT.

However, one study analyzing data from 2016-2019 found no increased risk of colorectal cancer, or advanced colorectal cancer, in the 12 months following a positive FIT.

Addressing Systemic Challenges and Potential Adjustments to Guidelines

Researchers attribute the low completion rates and delays to organizational constraints, including the need for pre-colonoscopy anesthesia consultations, bowel preparation, and limited availability of colonoscopy appointments. Unequal access to care across different regions also contributes to the problem.

Given these challenges, some experts suggest revisiting the current 31-day deadline for colonoscopy following a positive FIT, proposing a more realistic timeframe of 3 to 6 months.

Source: Destination Santé