High prevalence of sessile serrated adenomas with BRAF mutations: a prospective study of patients undergoing...

Area of Science:

• Gastroenterology
• Oncology
• Molecular Pathology

Background:

• Sporadic colorectal cancers with high microsatellite instability are linked to BRAF mutations and serrated polyps.
• Previous serrated polyp studies were limited by selection bias and retrospective designs.
• This study prospectively investigates sessile serrated adenoma (SSA) prevalence and mutation status.

Purpose of the Study:

• To determine the prevalence of sessile serrated adenomas (SSAs) in an unselected patient cohort.
• To identify the incidence of BRAF and K-ras mutations in various polyp types.
• To understand the clinical associations of SSAs.

Main Methods:

• A prospective study of 190 patients undergoing magnifying chromoendoscopy.
• Detailed recording of polyp location, size, and histology.
• Screening all polyps for BRAF V600E and K-ras mutations.

Main Results:

• Sessile serrated adenomas (SSAs) were found in 9% of patients, predominantly in the proximal colon and often larger than 5 mm.
• BRAF mutations were highly prevalent in SSAs (78%) and other serrated lesions, but rare in traditional adenomas (0.4%).
• SSA presence correlated with increased polyp burden and female sex.

Conclusions:

• Sessile serrated adenomas (SSAs) account for approximately 9% of polyps found during colonoscopy.
• SSAs are strongly associated with BRAF mutations, proximal colon location, female patients, and multiple polyps.
• Endoscopic identification and removal of SSAs are vital for colorectal cancer prevention.