Incidence of rectosigmoid adenomatous polyps in subjects without prior colorectal adenoma or cancer: a prospective...

Area of Science:

• Gastroenterology
• Oncology
• Preventive Medicine

Background:

• Colorectal cancer (CRC) screening is vital as 85% of cases occur in individuals without known adenomas or cancer.
• Screening the general population is essential for reducing CRC mortality.

Purpose of the Study:

• To determine the incidence rate of rectosigmoid adenomas in subjects without a history of colorectal adenomas or cancer.
• To inform the development of targeted screening strategies for colorectal cancer.

Main Methods:

• Prospective cohort study involving 450 subjects without prior adenomas or cancer.
• Subjects underwent fiber endoscopy every three years, with data collected on adenoma incidence and patient characteristics.
• Longitudinal follow-up with a mean of 39 months between the second and third endoscopies.

Main Results:

• The incidence rate of rectosigmoid adenomas was 1.50% per patient-year at the second examination and 1.75% per patient-year at the third.
• The cumulative incidence at six years was 7.3%, with a mean annual rate of 1.2%.
• Adenoma incidence increased with age and was higher in men than women after adjustment.

Conclusions:

• Incidence rates of rectosigmoid adenomas in this low-risk population are significantly lower than in patients with a history of adenomas.
• Findings support the need for refined screening strategies for colorectal cancer, potentially focusing on specific demographic groups.