Evan Mosier, MD1, Christian S. Jackson, MD2, Gerald A. Cox, II, MD3, Darren Browning, PhD4, Kenneth J. Vega, MD5; 1Loma Linda University, Los Angeles, CA; 2VA Loma Linda Healthcare System, Loma Linda, CA; 3Loma Linda University Medical Center, Loma Linda, CA; 4Augusta University, Augusta, GA; 5Augusta University Medical College of Georgia, Augusta, GA
Introduction: Phosphodiesterase-5 inhibitor use has been suggested to reduce the risk of colorectal cancer (CRC) through guanylate cyclase and cGMP pathway.The primary aim of this study was to characterize the effects of sildenafil use (a phosphodiesterase-5 inhibitor) based on colonoscopy findings including low and high-risk colon polyps and CRC. Methods: This is a retrospective study which analyzed inpatient and outpatient medical records endoscopic and pathology reports from Veteran Affairs Loma Linda Healthcare System (VALLHCS) from July 1, 2014 through June 30, 2019. Men with recurrent sildenafil use who had colonoscopies performed during the study period were compared against a control group of patients without phosphodiesterase inhibitor use.Data was analyzed with independent t-tests and chi-square tests. This study was approved by the institutional review board of the VALLHCS. Results: 493 patients who were regularly prescribed and used sildenafil who had colonoscopies performed during the study period, was compared against 1003 control patients. Sildenafil use was associated with a lower mean number of total adenomatous and sessile serrated polyps of all sizes (3.31 vs 3.91, p=0.038), tubular adenomas and sessile serrated polyps less than 1cm (3.18 vs 4.72, p=< 0.001), total adenomatous and sessile serrated polyps greater than or equal to 1cm (0.118 vs 0.350, p=< 0.001), tubulovillious adenomas (0.0791 vs 0.171, p=0.002), and CRC (0.0101 vs 0.0339 p=0.001).There was a lower incidence of both right sided colon polyps (1.18 vs 1.73 p=< 0.001) and left sided colon polyps (0.558 vs 0.918 p=< 0.001) with sildenafil use. Discussion: This is the first large study evaluating the effect of sildenafil and the presence of neoplasia on colonoscopy. Our data suggests that use of sildenafil may decrease colonic neoplasia. Multicenter, randomized studies will need to be performed to determine how phosphodiesterase-5 inhibition may affect the pathways of development of adenomatous as well as sessile serrated adenomas and polyps.
Figure 1: Study Criteria
Figure 2: Colonoscopy Findings
Disclosures: Evan Mosier indicated no relevant financial relationships. Christian Jackson indicated no relevant financial relationships. Gerald Cox indicated no relevant financial relationships. Darren Browning indicated no relevant financial relationships. Kenneth Vega indicated no relevant financial relationships.