Presenter of 3 Presentations
WHERE I AM STILL UNCERTAIN WITH RESPONSE (ID 1552)
G-O030 - CAPSULE ENDOSCOPY FINDINGS IN CHILDREN WITH PEUTZ-JEGHERS SYNDROME (ID 410)
Abstract
Objectives and Study
Peutz-Jeghers Syndrome (PJS) is characterized by the development of small intestinal hamartomatous polyps from the first decade of life. Management in children centers on the prevention of polyp-related intussusception. A strategy of surveillance including small bowel capsule (SBC) followed by polypectomy is increasingly being implemented. There is limited understanding of the polyp burden observed on SBC in these individuals. Herein we describe our detailed observations on polyp burden in pediatric patients with PJS.
Methods
We performed a retrospective longitudinal observational study including all patients with PJS followed through our institution who underwent SBC between 1/2010 and 12/2020. The SBCs were read in tandem(JWS/NRF, TMA). Findings were categorized by number of polyps per tertile, total number, largest visualized polyp and % luminal occlusion by largest polyp. Statistical inferences were made utilizing RStudio 2022.07.2.
Results
The cohort included 19 patients (M;12, mean age 14.0 SE 0.46 years) who underwent 65 (Median;3) studies, 54 complete, 41 categorized as good / excellent quality. There was no gender difference in polyp number (Figure 1A) but polyps (Figure 1B) were significantly larger in males (p=0.01). Estimated polyp size and luminal occlusion were directly related (p <0.002). The number of polyps was related to study duration (p = 0.0049). There was no significant relationship between symptoms and either largest polyp size or total polyp number. In contrast with earlier studies, studies following the introduction of a DBE strategy showed largest observed polyp size to be significantly decreased with age, (p = 0.026) when adjusted for gender.
Conclusions
Most polyps observed with SBC in pediatric PJS are smaller than 10 mm, they favor involvement of the middle tertile and are larger in males. Polyp burden does not relate to symptoms. In our cohort, the introduction of an SBC surveillance – DBE strategy was associated with significant overall reduction in polyp burden.
G-O031 - PROTEOMIC INSIGHTS ON POLYP GROWTH IN PEDIATRIC FAMILIAL ADENOMATOUS POLYPOSIS (ID 706)
Abstract
Objectives and Study
Children with Familial Adenomatous Polyposis (FAP) develop adenomatous polyps by the second decade of life, however, there is considerable intra- and inter-patient variability in disease expression including polyp distribution and growth characteristics. Polyp size is a principal determinant of the risk of harboring cancer so that understanding the downstream pathways influencing adenoma growth may identify potential checkpoints amenable to pharmacologic intervention. We have completed a pilot study comparing the protein expression profile from polyp and non-polyp mucosa derived from a single region in the large intestine in patients with pediatric FAP.
Methods
We harvested 6 polyps (mean 14mm diameter) and 4 normal, non-polyp mucosal specimens from the left side of the colon in two patients with FAP undergoing elective colectomy for the standard clinical indications. We carried out a quantitative proteomic and phosphoproteomic analysis on both polyp and non-polyp mucosa. We analyzed the differential protein expression levels of 5253 proteins and 4232 phosphopeptides between the two groups of tissue.
Results
From >500 proteins and phosphopeptides significantly altered in expression between polyps and mucosa, we defined >200 significant differences in protein expression, with several enzymes regulating key pathways found to be differentially expressed in mucosal tissue (Fig. 1A) or polyp tissue (Fig. 1B)
Conclusions
We observed significant differential expression of several key enzymatic regulators of mRNA metabolism as well as protooncogenes involved in the regulation of apoptosis triggered by DNA damage. Our observations suggest that several pharmacologic agents currently undergoing clinical trial may be effective chemopreventive agents in pediatric FAP. In addition, we may have identified a potential interface between microbiome expression and adenomatous polyp growth.