Extended Colonoscopy Intervals Can Reduce Invasive Examinations for Colorectal Cancer
An Emerging Study
Colonoscopy screening intervals could potentially be extended for individuals without a family history of colorectal cancer (CRC), according to a recent study. This extension, backed by evolving evidence, suggests longer screening intervals of up to 15 years for those who initially test negative for CRC, without leading to adverse consequences.
Advancing the Screening Guidelines
The research, published in the reputable JAMA Oncology journal, casts new light on the historical 10-year screening interval intended for average-risk individuals. Dr. Mahdi Fallah and colleagues from the German Cancer Research Center in Heidelberg report, “This study provides evidence for recommending a longer colonoscopy screening interval than what is currently recommended in most guidelines for populations with no familial risk of CRC.”
Colorectal cancer, ranking third worldwide in terms of occurrence and second in cancer-related deaths, calls for effective screening strategies.
Redefining the Risk Assessment
Existing colorectal cancer screening guidelines typically endorse a 10-year screening interval for individuals with a previous colonoscopy showing no abnormal findings. This consensus is based on the time frame for a benign tumor to progress into carcinoma.
While emerging evidence continues to challenge this time frame, researchers focused on scrutinizing the largest and most comprehensive national family cancer dataset to investigate further.
Large-Scale Data Study
An extensive study conducted in Sweden involved over 110,000 individuals aged 45 to 69 with no family history of CRC and who tested negative in their first colonoscopy. These participants were then compared against a control group of nearly two million individuals who either did not undergo colonoscopies or had colonoscopies with subsequent CRC diagnoses.
Encouraging Findings
After a maximum of 29 years of follow-up, the group with negative colonoscopy findings experienced lower risks of CRC incidence and CRC-related deaths compared to the control group.
The 10-year cumulative risk of CRC by year 15 for participants with a first negative colonoscopy was 72% of the control group. Similarly, the risk of death from CRC was 55% of the control group.
Benefits and Considerations
Extending the recommended screening interval from 10 to 15 years is estimated to result in witnessing merely 2.4 additional CRC cases and 1.4 additional CRC-related deaths per 1000 individuals. Hence, it holds potential in eliminating the need for additional colonoscopies for those concerned, without sacrificing early detection benefits.
However, prolonging the screening interval from 15 to 16 years or beyond could potentially increase the number of missed invasive CRC cases and deaths, raising concerns about potential harm.
Global Implications and Future Confirmation
Several experts, Rashid Lui and Andrew Chan, PhD, from the Chinese University of Hong Kong, highlight the significance of validating these findings in non-European populations. They emphasize the importance of confirming these results in various regions worldwide, particularly in Asian countries that have initiated widespread CRC screening more recently.
Lui and Chan emphasize, “Not only is it possible that the timing of the adenoma-carcinoma sequence may differ in non-European populations, but variation in the background incidence of CRC will significantly impact the number of incident CRCs prevented associated with a given screening interval.”
As researchers delve deeper into understanding the benefits and possible risks associated with extended colonoscopy intervals, these findings have opened avenues for reassessing existing screening guidelines and tailoring them to individual risk profiles.
