BRAF, K-ras and BAT26 mutations in colorectal polyps and stool

Area of Science:

• Molecular oncology
• Gastroenterology
• Cancer biomarkers

Background:

• Colorectal cancer (CRC) screening is crucial for early detection and prevention.
• Current screening methods can be invasive or have limitations in sensitivity.
• Identifying non-invasive molecular markers in stool is a key research area for CRC.

Purpose of the Study:

• To evaluate the feasibility of using BRAF, K-ras, and BAT26 genes as stool-based molecular markers.
• To detect colorectal adenomas and hyperplastic polyps (HPs) non-invasively.
• To assess the sensitivity and specificity of these genetic markers in stool samples.

Main Methods:

• Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing for BRAF mutations.
• Primer-mediated restriction fragment length polymorphism (RFLP) and mutant-enriched PCR for K-ras mutations.
• Analysis of microsatellite instability (MSI) using the BAT26 marker in polyps and paired stool samples.

Main Results:

• BRAF, K-ras, and BAT26 mutations were detected in 40%, 16%, and 12% of adenoma tissues, respectively.
• Corresponding mutations were found in 75-100% of stool samples from patients with adenomas.
• Mutations were also detected in hyperplastic polyps (HPs) and their corresponding stool samples, with high sensitivity (80% for adenomas, 100% for HPs) and specificity (92% for adenomas, 100% for HPs).

Conclusions:

• BRAF, K-ras, and BAT26 genes are potential non-invasive molecular markers for colorectal adenomas and HPs.
• Stool-based detection of these genetic alterations offers a promising avenue for colorectal polyp screening.
• This approach could enhance early detection and management of precancerous colorectal lesions.