2894 The Gastrointestinal Phenotype of Cowden’s Syndrome and Effects of Surveillance

Abstract

INTRODUCTION: Cowden’s syndrome is an autosomal dominant hamartoma syndrome characterized by germline mutations in the phosphatase and tensin (PTEN) homolog gene, the protein product of which negatively regulates the PI3K-AKT-mTOR pathway. Clinically, individuals develop multiple hamartomas in body tissues, including the stomach and colon, and have a high risk of developing cancer. To mitigate the risks, individuals undergo upper and lower endoscopic surveillance. The effectiveness of endoscopic surveillance and polypectomy remains unknown. METHODS: 17 individuals who met relaxed international Cowden consortium criteria and had undergone at least two upper or lower endoscopies were included. We describe polyp number, size, location, pathology, and interventions over the surveillance period. RESULTS: The average age was 69 (43-88). 6 were males and 11 females. Average number of upper and lower endoscopies was 2 (1-8) and 5 (2-14), respectively. The average interval between upper and lower endoscopies was noted to be 2.64 years (standard deviation = 1.53) and 3.03 years (standard deviation = 2.14). One patient developed a cancerous polyp that was identified on the second colonoscopy. The polyp was located in the transverse colon and removed via snare polypectomy. Pathology showed invasive adenocarcinoma. Patient underwent colectomy with ileocolic anastomosis without chemotherapy. 68.5% of upper and lower endoscopies had an intervention performed including polypectomy with cold biopsy forceps (n = 40), cold snare (n = 7), hot biopsy forceps (n = 16), and hot snare (n = 33). Polyp pathologies in the stomach and upper intestine included hamartomas (n = 4), hyperplastic (n = 6), adenomas (n = 2), and fundic gland polyps (n = 6). Polyp pathologies in the colon included hamartomas (n = 14), hyperplastic (n = 40), ganglioneuromas (n = 2), adenomas (n = 81), inflammatory (n = 4), and sessile serrated (n = 7). 3 patients had more than one upper endoscopy, 2 of whom had a decrease in polyp size while 1 had no change. In the colon, the sizes of the polyps decreased over time in 11 of the 17 patients, 4 did not change, and 2 had an increase in size. CONCLUSION: We show that the overall size of polyps decrease in both the stomach and colon with endoscopic surveillance. One patient had a malignant polyp treated with endoscopic polypectomy.