Screening Relevance of Sessile Serrated Polyps

Area of Science:

• Gastroenterology
• Oncology
• Molecular Pathology

Background:

• Colorectal cancer (CRC) arises from precursor lesions, historically focusing on conventional adenomas.
• The chromosomal instability pathway was thought to account for most CRCs, originating from adenomas.
• Emerging evidence highlights the serrated pathway as a significant contributor to CRC, particularly post-colonoscopy.

Purpose of the Study:

• To evaluate the significance of sessile serrated polyps (SSPs) as colorectal cancer precursors.
• To assess the role of the serrated pathway in CRC development.
• To determine the screening relevance of SSPs in colorectal cancer prevention.

Main Methods:

• Review of current literature on colorectal cancer precursor lesions.
• Analysis of the characteristics and prevalence of sessile serrated polyps (SSPs).
• Evaluation of the association between SSPs and the serrated pathway, including genetic markers like BRAF mutations and CpG island methylation.

Main Results:

• Conventional adenomas account for only about two-thirds of CRCs.
• The serrated pathway, characterized by BRAF mutations and high methylation, is responsible for a significant portion of remaining CRCs.
• SSPs exhibit characteristics, including prevalence, dwell time, and association with neoplasia, that support their equivalence to adenomas in CRC screening.

Conclusions:

• Sessile serrated polyps (SSPs) are critical screening-relevant colorectal cancer precursors.
• The serrated pathway, involving SSPs, plays a major role in CRC development and post-colonoscopy CRC.
• SSPs are highly relevant for colorectal cancer prevention strategies due to their precursor potential and association with increased neoplasia risk.