Colonoscopy effects on serum prostate specific antigen levels

Area of Science:

• Urology
• Gastroenterology
• Clinical Chemistry

Background:

• Prostate-specific antigen (PSA) is a key biomarker for prostate health.
• Colonoscopy is a common medical procedure with potential systemic effects.
• Understanding the impact of colonoscopy on PSA levels is crucial for accurate prostate cancer screening.

Purpose of the Study:

• To evaluate the effect of colonoscopy on serum levels of total and free prostate-specific antigen (PSA).
• To assess changes in the PSA ratio following colonoscopy.
• To identify patient subgroups potentially affected by the procedure.

Main Methods:

• A study involving 30 men (median age 68) undergoing colonoscopy.
• Serum PSA (total and free) was measured 24 hours before and 24 hours, 7 days, and 30 days after the procedure.
• PSA ratio was analyzed in patients with baseline PSA in the 'gray zone' (4-10 ng/ml).

Main Results:

• 47% of patients showed significantly increased total PSA levels 24 hours post-colonoscopy (p=0.045).
• Elevated PSA levels were observed in 43-47% of patients at 7 and 30 days, though not always statistically significant.
• A near-significant increase in PSA ratio was noted in 23% of patients with "gray zone" PSA levels 24 hours after the procedure (p=0.063).

Conclusions:

• Flexible colonoscopy can alter serum PSA levels in a subset of patients.
• Patients with baseline PSA levels in the "gray zone" require special consideration regarding post-colonoscopy PSA monitoring.
• The findings highlight the need for awareness of procedural effects on PSA biomarkers.