What are hyperplastic colon polyps?

From the Guidelines

Hyperplastic colon polyps are benign growths in the colon that typically don't require treatment unless they're large or numerous, and patients with small hyperplastic polyps are considered to have normal colonoscopies, with a recommended follow-up colonoscopy in 10 years. These polyps are the most common type found during colonoscopies, appearing as small, pale bumps on the colon lining, usually less than 5mm in size. They form due to excessive cell growth in the colon's mucosal lining. While hyperplastic polyps themselves aren't cancerous and have very low malignant potential, their presence may indicate a need for regular screening as they can sometimes be associated with other types of polyps that do have cancer risk. If hyperplastic polyps are found during a colonoscopy, they're typically removed through polypectomy for examination.

Key Points

• Follow-up colonoscopies are recommended based on the number, size, and location of polyps found, usually every 5-10 years for typical hyperplastic polyps 1.
• Patients with numerous polyps, larger polyps, or those located in the right colon may need more frequent surveillance.
• Lifestyle modifications including a high-fiber diet, regular exercise, maintaining healthy weight, limiting alcohol, and avoiding smoking can help reduce the risk of developing more polyps.

Surveillance Recommendations

• The NCCN guidelines recommend repeat colonoscopy in 10 years for low-risk adenoma patients with polyps <1 cm, and in 5 years for low-risk SSP patients with no dysplasia and polyps <1 cm 1.
• High-risk patients with advanced or multiple polyps should have repeat colonoscopy in 3 years.
• Patients with large (≥1 cm) hyperplastic polyps should be considered for management similar to patients with SSPs, particularly if they have not been reviewed by an expert gastrointestinal pathologist 1.

From the Research

Definition and Characteristics of Hyperplastic Colon Polyps

• Hyperplastic colon polyps are a type of colorectal polyp that has been regarded as harmless for decades 2.
• However, recent studies suggest that hyperplastic polyps may serve as precursors to colorectal cancer (CRC), particularly those with DNA methylation and deficient DNA mismatch repair 2.
• Hyperplastic polyposis (HP) is a condition characterized by the presence of multiple hyperplastic polyps in the colon, with a median of 90 polyps per person and 15 polyps per procedure 3.

Risk of Cancer Development

• The risk of cancer development in hyperplastic polyps is still unclear, but studies suggest that patients with hyperplastic polyposis syndrome (HPS) have an increased risk of CRC 4.
• A study found that 35% of patients with HPS developed CRC, with 28.5% detected at initial endoscopy and 6.5% detected during surveillance 4.
• The cumulative risk of CRC under surveillance was 7% at 5 years, and an increasing number of hyperplastic polyps and serrated adenomas was significantly associated with CRC presence 4.

Location and Size of Hyperplastic Polyps

• Hyperplastic polyps are more frequently found in the distal colon than the proximal colon (74% vs 26%, p < 0.001) 3.
• The median size of hyperplastic polyps is 4 mm, with 51 polyps >10 mm identified in 10 patients 3.
• Large serrated polyps (≥10 mm) are associated with an increased risk of CRC, with a hazard ratio of 3.35 (95% CI 1.37-8.15) 5.

Surveillance and Prevention

• Colonoscopic surveillance at intervals of 1-3 years is recommended for patients with hyperplastic polyposis, depending on the number and size of both adenomatous and hyperplastic polyps 3.
• The use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a reduced risk of adenomatous polyps and hyperplastic polyps, particularly baby aspirin 6.
• Adequate detection and removal of all polyps seems advisable to prevent malignant progression, and surgical resection should be considered if this is not feasible 4.