Risk of Advanced Colorectal Neoplasia at Follow-up Colonoscopy After Synchronous Adenoma and Clinically Significant...

Area of Science:

• Gastroenterology
• Oncology
• Preventive Medicine

Background:

• Colorectal cancer (CRC) arises from pre-cancerous neoplasia via adenoma-carcinoma and/or serrated pathways.
• Surveillance colonoscopy is recommended for individuals with adenomas or clinically significant serrated polyps (CSSPs) to mitigate CRC risk.
• The specific risk of CRC following synchronous adenoma and CSSP remains under-examined.

Purpose of the Study:

• To determine the risk of advanced neoplasia at follow-up colonoscopy after detecting synchronous adenoma and CSSP.
• To compare this risk against other types of neoplasia found during prior colonoscopies.
• To inform the development of specialized surveillance colonoscopy guidelines.

Main Methods:

• Retrospective analysis of colonoscopy outcomes from 2010-2023 in a South Australian CRC surveillance program.
• Inclusion of 8481 colonoscopy pairs.
• Utilized competing-risk regression to assess the risk of advanced neoplasia based on prior findings.

Main Results:

• Advanced neoplasia was detected in 11% of follow-up colonoscopies.
• The highest risk of advanced neoplasia was observed in patients with advanced synchronous adenoma and CSSP (HR, 4.71) and those with prior advanced CSSP only (HR, 4.45).
• Patients with prior advanced synchronous adenoma and CSSP had a significantly higher risk compared to those with prior advanced adenoma only (HR, 3.19).

Conclusions:

• Synchronous adenoma and CSSP may indicate concurrent activation of both adenoma-carcinoma and serrated pathways.
• These patients exhibit an elevated risk for developing advanced neoplasia compared to those with only adenomas.
• Findings support the need for tailored surveillance colonoscopy protocols for individuals with synchronous adenoma and CSSP.