Endoscopic Evaluation of PET/CT Abnormalities in the Gastrointestinal Tract: Yield and Approach.

BACKGROUND: Unexpected hypermetabolic activity is often encountered in the gastrointestinal tract when PET/CT is performed for various indications, prompting endoscopic evaluation. Our aim was to characterize the types of lesions seen in segments of the gastrointestinal tract with unexpected PET/CT abnormalities as well as clinically significant lesions seen on endoscopy which did not produce a PET/CT abnormality to guide the endoscopist tasked with evaluating these imaging findings. METHODS: We retrospectively reviewed a database of endoscopies performed at City of Hope Comprehensive Cancer Center between January 1, 2016 and September 30, 2021 for an indication of "abnormal PET." We divided the gastrointestinal tract into segments and defined categories of endoscopic/histologic findings for each segment. We counted the number of segments with an abnormal PET/CT finding and corresponding endoscopic/histologic abnormality as well as the number of segments with an endoscopic/histologic abnormality but normal PET/CT. RESULTS: PET/CT identified 209 segments with hypermetabolic activity, 109 of which had corresponding endoscopic/histologic abnormalities. In the jejunum and ileum, all corresponding lesions were malignant. Seventy-three percent of corresponding lesions in the stomach were H. pylori positive. PET/CT failed to detect 34.7% of clinically significant lesions diagnosed endoscopically, including 1 malignancy in the transverse colon and many inflammatory or low-risk premalignant lesions. CONCLUSION: PET/CT abnormalities seen in the small bowel should be evaluated urgently as nearly all correlates were malignant, while abnormalities in the stomach should prompt workup for H. pylori. Most lesions missed by PET/CT were inflammatory or low-risk premalignant yet clinically significant, confirming the need to inspect the entirety of the upper or lower gastrointestinal tract during endoscopy.

Flexible sigmoidoscopy may be sufficient for initial evaluation of suspected immunotherapy-mediated colitis: A cross-sectional study.

BACKGROUND AND AIM: Immune checkpoint inhibitors (ICIs) have shown promise in treating a variety of cancers. Their increased use coincides with increased incidence of immunotherapy-mediated colitis (IMC), a common adverse effect. Optimal strategy for endoscopic evaluation of IMC (full colonoscopy or flexible sigmoidoscopy) is not well-defined. METHODS: Retrospective review of all patients at City of Hope referred to gastroenterology for evaluation of IMC due to gastrointestinal symptoms was performed. Patients with an existing histologic diagnosis of IMC established at an outside hospital or a diagnosis of infectious or chronic colitis were excluded. RESULTS: We identified 51 symptomatic patients on ICIs prompting evaluation for IMC with colonoscopy (47/51) or flexible sigmoidoscopy (4/51). All distal rectosigmoid biopsies during flexible sigmoidoscopy demonstrated histologic evidence of IMC. In full colonoscopy, IMC was either present in all segments of colon simultaneously (35/47) or absent from all segments (12/47). No isolated proximal colonic biopsies demonstrated IMC. Endoscopically normal mucosa demonstrated histologic evidence of IMC up to 68.6% of the time. Endoscopically abnormal right, transverse, and left colon had low sensitivity (35.3%, 34.3%, and 41.7%, respectively) and high specificity (100.0%, 100.0%, and 91.7%, respectively) for histological presence of IMC. CONCLUSIONS: Distal colon biopsies in patients on ICI therapy with diarrhea and suspected IMC were sufficient for diagnosing IMC in our cohort. Further, we found histologic evidence of IMC in biopsies taken from normal-appearing mucosa in a number of patients, suggesting that a normal endoscopic appearance does not preclude the presence of IMC and biopsies should be taken from both normal and abnormal-appearing mucosa.

Effect of I-scan Electronic Chromoendoscopy on Detection of Adenomas During Colonoscopy.

BACKGROUND & AIMS: I-scan is an electronic chromoendoscopy technology that improves resolution of epithelial and mucosal surfaces and vessels. We performed a randomized controlled trial to compare detection of adenomas by i-scan vs standard high-definition white-light (HDWL) colonoscopy. METHODS: From February 1 through December 31, 2017, 740 outpatients (50-75 years old) undergoing screening and surveillance for colorectal neoplasia were randomly assigned to groups that received colonoscopies with i-scan 1 (surface and contrast enhancement) or HDWL. When lesions and polyps were detected, endoscopists could switch between i-scan 1 and HDWL imaging to confirm their finding; polyps were collected and analyzed by histology. The primary outcome was adenoma detection rate (ADR, proportion of subjects with at least 1 adenoma of any size); secondary outcomes included detection of sessile serrated polyps and neoplasias, along with location, size, and morphology of polyps. We performed intent to treat and per-protocol analyses (on 357 patients evaluated by i-scan and 358 evaluated by HDWL colonoscopy) to assess the primary and secondary outcomes. RESULTS: There were no differences in baseline characteristics between the groups. In the intent to treat analysis, the ADR was significantly higher in the i-scan 1 group (47.2%) than in the HDWL colonoscopy group (37.7%) (P = .01). In the per-protocol analysis, the ADR in the i-scan 1 group (47.6%) was also significantly higher than in the HDWL group (37.2%) (P = .005), but this effect was not consistent among all endoscopists. There was no difference between groups in detection of sessile serrated polyps. However, the rate of neoplasia detection was significantly higher in the i-scan 1 group (56.4%) than in the than the HDWL group (46.1%) (P = .005). In secondary analyses, the increase in ADR was associated with improved detection of diminutive flat adenomas in the right colon. CONCLUSION: In a prospective randomized trial, higher proportions of patients with adenomas were identified in a group that underwent colonoscopy with i-scan 1 than in a group evaluated by HDWL colonoscopy. This effect was mainly due to improved detection of diminutive, flat right sided adenomas. I-scan 1 technology may benefit some endoscopists. ClinicalTrials.gov no: NCT02811419.

Differences in neuropsychological and behavioral parameters and brain structure in patients with familial adenomatous polyposis: a sibling-paired study.

BACKGROUND: Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary colon cancer syndrome caused by mutations in adenomatous polyposis coli (APC) with both colonic and extra-colonic manifestations. Case reports have noted an association with FAP and intellectual disability and animal studies have shown that APC is implicated in neural development and function, but no studies have investigated neuropsychological, behavioral, or structural brain characteristics of patients with FAP. METHODS: We undertook a pilot, sibling-pair study comparing three patients with FAP to their sex-matched siblings without FAP. Each sibling pair underwent neuropsychological testing by a blinded examiner, high resolution brain MRI scans, and the mother of each pair rated her children's adaptive life skills and behavioral and emotional characteristics. Given the small number of study participants in this pilot study, quantitative comparisons of results were made by subtracting the score of the non-FAP sibling from the FAP patient on the various neuropsychological tests and parent rating questionnaires to calculate a difference, which was then divided by the standard deviation for each individual test to determine the difference, corrected for the standard deviation. Diffusion numbers in multiple regions of the brain as assessed by MRI were calculated for each study participant. RESULTS: We found similarity between siblings in all three pairs on a wide range of neuropsychological measures (general intelligence, executive function, and basic academic skills) as tested by the psychologist as well as in descriptions of adaptive life skills as rated by mothers. However, mothers' ratings of behavioral and emotional characteristics of two of the three pairs showed differences between the siblings, specifically that the patients with FAP were found to have more behavioral and emotional problems compared to their siblings. No differences in brain structure were identified by MRI. CONCLUSION: We report the first study exploring neuropsychological, behavioral, emotional, and structural brain characteristics of patients with FAP and found subjective differences as assessed by maternal perception in behavioral and emotional characteristics in patients with FAP compared to their siblings. Larger studies are needed to elucidate the relationship, if any, between FAP and brain function.

Selective Versus Universal Screening for Lynch Syndrome: A Six-Year Clinical Experience.

BACKGROUND: Lynch syndrome is the most common cause of hereditary colorectal cancer (CRC) and confers increased risk of other cancers. Identification of patients improves morbidity and mortality. Screening tumors for absent mismatch repair (MMR) protein expression by immunohistochemistry (IHC) is a recommended approach. Despite guidelines advocating universal screening, significant variation in clinical practice exists. AIMS/METHODS: A retrospective study of two different IHC-based Lynch syndrome screening protocols at an urban, university hospital was performed. Outcomes from a "selective" screening strategy utilized from August 2007-July 2010 on CRC tumors from patients with high-risk features were compared with a "universal" strategy of screening all CRC tumors from July 2010-August 2013. Positively screened patients were referred for genetic counseling and offered germline testing. RESULTS: A total of 392 patients with CRC were screened: 107 selectively and 285 universally. The prevalence of Lynch syndrome was 3.1 %, with no difference by strategy. There was a trend (p = 0.06) toward fewer universally screened patients agreeing to genetic counseling compared with those selectively screened. Selective criteria failed to identify one of eight cases of Lynch syndrome from the universal group, though the universal strategy screened 166 additional tumors to find this additional patient. CONCLUSIONS: Selective screening for Lynch syndrome has similar outcomes as universal screening in terms of identifying Lynch syndrome, despite screening far fewer patients. In addition, fewer eligible patients in our study agreed to undergo genetic counseling and germline testing than in prior studies. These lower rates may better reflect uptake of these services in clinical practice.

Computed Tomography Angiography and Conventional Angiography for the Diagnosis and Treatment of Non-variceal Gastrointestinal Bleeding at a Tertiary Cancer Center.

INTRODUCTION: To evaluate the diagnostic value of computed tomography angiography (CTA) and conventional angiography (CA) and the therapeutic value of transarterial embolization for acute gastrointestinal bleeding in patients with malignancy. METHODS: A retrospective review of 100 patients who underwent CTA and/or CA for gastrointestinal bleeding at a comprehensive cancer center between the years 2011-2021 was performed. Clinical and patient outcome data were collected and analyzed using Kruskal-Wallis tests for continuous variables and chi-square tests or Fisher's exact tests (whichever is appropriate) for categorical variables in univariate analysis. All tests were two-sided at a significance level of 0.05. Analyses were performed using SAS version 9.4 (SAS Institute, Cary, NC). RESULTS: Fifty-two percent of our patients underwent CTA alone, 29% underwent CA alone, and 19% underwent both procedures. Overall, CTA was positive in 11.3% (8/71) of patients and CA was positive in 22.9% (11/38) of patients. Of patients who underwent both studies, 52.6% (10/19) were positive for both. ICU admission was associated with CTA and/or CA positivity (p=0.015). Of 48 patients with data for embolization, 50% of patients underwent transarterial embolization for bleeding, 11 patients had identifiable bleeding on CA, and 13 patients underwent prophylactic embolization at the site of suspected bleeding. Rebleeding following embolization was found in 33.3% (8/24) of patients, including six patients who underwent prophylactic embolization and two patients who were treated for visualized bleeding. CONCLUSION: CTA and CA are two critical studies for patients with GI bleeding and a history of malignancy. Neither alone can effectively exclude an identifiable source of bleeding. In patients with a history of malignancy, transarterial embolization may be an effective treatment of both angiographically visible and occult sources of GI bleeding.

Episodic, severe abdominal pain due to isolated jejunal Crohn's disease.

Small bowel Crohn's disease can present with episodic, relapsing, and remitting symptoms and delays in the diagnosis are common. We present a case of a young woman with three years of intermittent abdominal pain and nausea with negative previous evaluations. On presentation, inflammatory markers were elevated, and repeat imaging showed jejunal inflammation, with histopathological examination showing non-caseating granulomas of the small bowel consistent with Crohn's disease. This case highlights the importance of gastroenterologist recognizing the alarm signs in a patient with unexplained symptoms and adds to the literature on the clinical presentation of a rare diagnosis of isolated jejunal Crohn's disease.