Primary small bowel adenomas and adenocarcinomas-recent advances

Frequency and clinicopathological correlation of gastrointestinal polyps: A six-year single center experience

Background

Most gastrointestinal polyps are asymptomatic; therefore, assessing symptoms associated with cancer and precancerous polyps is essential.

Objectives

The aim of this study was to study the histopathology, number, distribution, and degree of polyps' dysplasia in terms of age, gender, and clinical presentation.

Methods

This study was performed on patients who underwent endoscopy from July 2015 to August 2021 in Sulaimaniyah, Iraq. Surgical pathology records of patients were analyzed for age, sex, nature of the polyps, number, site, histopathology, degree of dysplasia, resection margins and patients' presented clinical data.

Results

The mean patients' age was 51.4 ± 17.1 years, and most were males (51.9%). The most common indications for endoscopy were screening (28.62%), and the least common was weight loss (4.46%). Neoplastic polyps were common among patients with hematemesis (75%), while non-neoplastic were common among those with dyspepsia (60%). Most polyps were solitary in upper (80.8%) and lower gastrointestinal tract (GIT). Most polyps in the upper GIT were non-neoplastic (87.3%), while most lower proximal/distal GIT polyps were neoplastic. Most neoplastic polyps showed low-grade dysplasia (94.4%), and most high-grade dysplasia was a villous type (24.1%).

Conclusions

Initiation of the screening program is highly recommended as a facilitating method for the early detection of multiple and high-grade gastrointestinal polyps. Thus, screening programs can reduce the rate of mortality of carcinoma in this locality.

Immune signature of small bowel adenocarcinoma and the role of tumor microenvironment

In this editorial we comment on the article published "Clinical significance of programmed cell death-ligand expression in small bowel adenocarcinoma is determined by the tumor microenvironment". Small bowel adenocarcinoma (SBA) is a rare gastrointestinal neoplasm and despite the small intestine's significant surface area, SBA accounts for less than 3% of such tumors. Early detection is challenging and the reason arises from its asymptomatic nature, often leading to late-stage discovery and poor prognosis. Treatment involves platinum-based chemotherapy with a 5-fluorouracil combination, but the lack of effective chemotherapy contributes to a generally poor prognosis. SBAs are linked to genetic disorders and risk factors, including chronic inflammatory conditions. The unique characteristics of the small bowel, such as rapid cell renewal and an active immune system, contributes to the rarity of these tumors as well as the high intratumoral infiltration of immune cells is associated with a favorable prognosis. Programmed cell death-ligand 1 (PD-L1) expression varies across different cancers, with potential discrepancies in its prognostic value. Microsatellite instability (MSI) in SBA is associated with a high tumor mutational burden, affecting the prognosis and response to immunotherapy. The presence of PD-L1 and programmed cell death 1, along with tumor-infiltrating lymphocytes, plays a crucial role in the complex microenvironment of SBA and contributes to a more favorable prognosis, especially in the context of high MSI tumors. Stromal tumor-infiltrating lymphocytes are identified as independent prognostic indicators and the association between MSI status and a favorable prognosis, emphasizes the importance of evaluating the immune status of tumors for treatment decisions.

Small Bowel Imaging from Stepchild of Roentgenology to MR Enterography, Part II: The Reliable Disclosure of Crohn's Disease and Non-Inflammatory Small Bowel Disorder Plot through MRI Findings

MRE has become a standard imaging test for evaluating patients with small bowel pathology, but a rigorous methodology for describing and interpreting the pathological findings is mandatory. Strictures, abscess, inflammatory activity, sinus tract, wall edema, fistula, mucosal lesions, strictures, and mesentery fat hypertrophy are all indicators of small bowel damage in inflammatory and non-inflammatory small bowel disease, and they are all commonly and accurately explained by MRE. MRE is a non-invasive modality that accurately assesses the intra-luminal, parietal, and extra-luminal small bowel. Differential MRE appearance allows us to distinguish between Crohn's disease and non-inflammatory small bowel disorder. The purpose of this paper is to present the MRE pathological findings of small bowel disorder.

Mortality in small bowel cancers and adenomas - A nationwide, population-based matched cohort study

BACKGROUND

Small bowel adenocarcinoma (SBA), neuroendocrine tumors (NET) and gastrointestinal stromal tumors (GIST) are neoplastic lesions of the small bowel while small bowel adenomas are precursors of SBA.

AIM

To examine mortality in patients diagnosed with SBA, small bowel adenomas, NET and GIST.

METHODS

We performed a population-based matched cohort study encompassing all individuals with SBA (n = 2289), adenomas (n = 3700), NET (n = 1884) and GIST (n = 509) in the small bowel diagnosed at any of Sweden's 28 pathology departments between 2000 and 2016 (the "ESPRESSO study"). Each case was matched by sex, age, calendar year and county of residence to up to 5 comparators from the general population. Through Cox regression we estimated hazard ratios (HRs) and 95% confidence intervals (95%CIs) for death and cause-specific death adjusting for education.

RESULTS

During follow-up until December 31, 2017, 1836 (80%) deaths occurred in SBA patients, 1615 (44%) in adenoma, 866 (46%) in NET and 162 (32%) in GIST patients. This corresponded to incidence rates of 295, 74, 80 and 62/1000 person-years respectively and adjusted HRs of 7.60 (95%CI=6.95-8.31), 2.21 (2.07-2.36), 2.74 (2.50-3.01) and 2.33 (1.90-2.87). Adjustment for education had a substantial impact on the HR for death in SBA but not for other neoplasias. The predominant cause of excess death was cancer in all groups.

CONCLUSION

This study confirms earlier findings of increased death rates in patients with SBA and NET in a modern study population. We also demonstrate a more than 2-fold increased risk of death in both GIST and the SBA precursor adenoma.

Metastatic Small Bowel Adenocarcinoma Mimicking a Primary Ovarian Mucinous Tumour - Clinical, Radiologic, Pathologic and Molecular Correlation

We describe an interesting case of a patient who presented with a large adnexal mass, first favored to be mucinous carcinoma of the gynecologic origin. The primary tumour site was ascertained after the patient's small bowel was resected by identifying an adenomatous component evolving into an invasive adenocarcinoma identical in morphology and immunophenotype to the ovarian tumour. Notably, both tumours were found to harbor a BRAF K601E mutation, which is extremely rare for a primary of the ovary. BRAF mutations are present in a subset of large bowel and small bowel adenocarcinoma, but our case shows the first instance of a BRAF K601E mutation being present in a small bowel adenocarcinoma, to the best of our knowledge. This case serves as a great illustration of the pivotal role of molecular diagnostics in modern pathology in arriving at the correct diagnosis. Additionally, it is an excellent example of how clinical-radiologic-pathologic-molecular correlation plays into the landscape of molecular pathology to deliver optimal care for the patient.

Bile acids as carcinogens in the colon and at other sites in the gastrointestinal system

Colon cancer incidence is associated with a high-fat diet. Such a diet is linked to elevated levels of bile acids in the gastrointestinal system and the circulation. Secondary bile acids are produced by microorganisms present at high concentrations in the colon. Recent prospective studies and a retrospective study in humans associate high circulating blood levels of secondary bile acids with increased risk of colon cancer. Feeding mice a diet containing a secondary bile acid, so their feces have the bile acid at a level comparable to that in the feces of humans on a high-fat diet, also causes colon cancer in the mice. Studies using human cells grown in culture illuminate some mechanisms by which bile acids cause cancer. In human cells, bile acids cause oxidative stress leading to oxidative DNA damage. Increased DNA damage increases the occurrence of mutations and epimutations, some of which provide a cellular growth advantage such as apoptosis resistance. Cells with such mutations/epimutations increase by natural selection. Apoptosis, or programmed cell death, is a beneficial process that eliminates cells with unrepaired DNA damage, whereas apoptosis-resistant cells are able to survive DNA damage using inaccurate repair processes. This results in apoptosis-resistant cells having more frequent mutations/epimutations, some of which are carcinogenic. The experiments on cultured human cells have provided a basis for understanding at the molecular level the human studies that recently reported an association of bile acids with colon cancer, and the mouse studies showing directly that bile acids cause colon cancer. Similar, but more limited, findings of an association of dietary bile acids with other cancers of the gastrointestinal system suggest that understanding the role of bile acids in colon carcinogenesis may contribute to understanding carcinogenesis in other organs.

Epidemiology, Risk Factors and Diagnosis of Small Bowel Adenocarcinoma

Simple Summary

Small bowel adenocarcinoma is a rare tumor. Diagnosis is often obtained at an advanced stage and prognosis remains poor. The aim of this review is to report the recent epidemiological and risk factor data related to small bowel adenocarcinoma. New diagnostic tools are also described in this review.

Abstract

Adenocarcinomas of the small intestine are rare tumors but their incidence is increasing. There is a slight male predominance. The median age at diagnosis is the 6th decade. The most frequent primary location is the duodenum. There is no clearly identified environmental risk factor, but adenocarcinomas of the small intestine are associated in almost 20% of cases with predisposing diseases (Crohn’s disease, Lynch syndrome, familial adenomatous polyposis, Peutz–Jeghers syndrome and celiac disease).

Gall Bladder Disease and the Risk of Small Bowel Cancer-Results from a Nationwide Swedish Cohort Study

BACKGROUND AND AIMS

Small bowel cancer is a rare but rising malignancy. The etiology is poorly understood and there is a need for large-scale studies. Gallbladder disease (GBD), inducing localized inflammation, has been suggested to increase small bowel cancer risk.

METHODS

We retrieved nationwide data from Sweden's 28 pathology departments on all adults (age 20-79) with pathology-confirmed GBD diagnosed in 1965-2017. In total 156,390 GBD patients were matched with up to 5 matched comparators from the general population and follow-up started one year after GBD diagnosis. We used stratified Cox regression to calculate hazard ratios (HRs) for small bowel adenocarcinoma, adenomas, and carcinoids.

RESULTS

During a median follow-up of 12 years, we identified 92 small bowel adenocarcinomas, 132 adenomas, and 81 carcinoid tumors in the GBD cohort. Corresponding incidence rates were 4.8, 6.9, and 4.2 per 100,000 person-years (PY), compared to 3.2, 3.2, and 1.8 in matched comparators. The adjusted HR was 1.42 (95% CI = 1.08-1.87) for small bowel adenocarcinoma, 1.79 (95% CI = 1.41-2.27) for adenoma, and 2.07 (95% CI = 1.52-2.81) for carcinoid. The excess cancer risk was most pronounced during the first year of follow-up for adenocarcinomas and during the first six years for adenomas while for carcinoids the HR peaked 10-15 years after start of follow-up.

CONCLUSIONS

In this nationwide cohort study, GBD was associated with an increased risk of small bowel cancer. The excess risk of small bowel adenocarcinoma was mainly seen during the first years of follow-up while small bowel carcinoid risk peaked 11-16 years after GBD diagnosis.

Small Bowel Malignancies in Patients Undergoing Capsule Endoscopy for Iron Deficiency Anemia

Small bowel malignancies are rare and usually asymptomatic or symptoms are nonspecific. Therefore, small bowel tumors are difficult to diagnose. In patients with iron deficiency anemia (IDA) who have negative bidirectional endoscopy results, the small bowel may be considered the source of bleeding. However, in asymptomatic IDA patients with negative bidirectional endoscopy results, evidence supporting the routine use of capsule endoscopy (CE) is insufficient. CE can be considered in selected patients with recurrent or persistent IDA. The frequency of small bowel malignancies is low in patients undergoing CE for IDA, but the usefulness of CE for the diagnosis of small bowel malignancies in younger age groups with IDA has been reported. For patients with risk factors for small bowel malignancy, investigation of the small bowel should be considered. Efforts should be made to prevent adverse events, such as capsule retention or capsule aspiration, through meticulous history taking and endoscopic capsule delivery as necessary.

RNA-sequencing identification and validation of genes differentially expressed in high-risk adenoma, advanced colorectal cancer, and normal controls

Distinct gene expression patterns that occur during the adenoma-carcinoma sequence need to be determined to analyze the underlying mechanism in each step of colorectal cancer progression. Elucidation of biomarkers for colorectal polyps that harbor malignancy potential is important for prevention of colorectal cancer. Here, we use RNA sequencing to determine gene expression profile in patients with high-risk adenoma treated with endoscopic submucosal dissection by comparing with gene expression in patients with advanced colorectal cancer and normal controls. We collected 70 samples, which consisted of 27 colorectal polyps, 24 cancer tissues, and 19 normal colorectal mucosa. RNA sequencing was performed on an Illumina platform to select differentially expressed genes (DEGs) between colorectal polyps and cancer, polyps and controls, and cancer and normal controls. The Kyoto Gene and Genome Encyclopedia (KEGG) and gene ontology (GO) analysis, gene-concept network, GSEA, and a decision tree were used to evaluate the DEGs. We selected the most highly expressed genes in high-risk polyps and validated their expression using real-time PCR and immunohistochemistry. Compared to patients with colorectal cancer, 82 upregulated and 24 downregulated genes were detected in high-risk adenoma. In comparison with normal controls, 33 upregulated and 79 downregulated genes were found in high-risk adenoma. In total, six genes were retrieved as the highest and second highest expressed in advanced polyps and cancers among the three groups. Among the six genes, ANAX3 and CD44 expression in real-time PCR for validation was in good accordance with RNA sequencing. We identified differential expression of mRNAs among high-risk adenoma, advanced colorectal cancer, and normal controls, including that of CD44 and ANXA3, suggesting that this cluster of genes as a marker of high-risk colorectal adenoma.

Prognostic Value of Immune Environment Analysis in Small Bowel Adenocarcinomas with Verified Mutational Landscape and Predisposing Conditions

Background: Small bowel adenocarcinoma (SBA) is a rare yet insidious cancer with poor survival. The abundance of tumour-infiltrating lymphocytes is associated with improved survival, but the role of the programmed death-1/programmed death ligand-1 (PD-1/PD-L1) pathway in tumour escape is controversial. We evaluated immune cell infiltration, PD1/PD-L1 expression and their prognostic value in a series of SBAs with previously verified predisposing conditions and exome-wide somatic mutation characterization. Methods: Formalin-fixed paraffin-embedded tissue sections stained for CD3, CD8, PD-L1 and PD-1 were analysed from 94 SBAs. An immune cell score (ICS) was formed from the amount of the CD3 and CD8 positive lymphocytes from the tumour centre and invasive margin. The PD-L1 and PD-1 positive immune cells (ICs) and ICS were combined into a variable called Immunoprofile. Results: High ICS, PD-L1^IC and PD-1, individually and combined as Immunoprofile, were prognostic for better patient outcome. Sixty-five (69%) SBAs expressed ≥1% positive PD-L1^IC. A high tumour mutation burden was common (19%) and associated with immune markers. Immunoprofile, adjusted for TNM stage, mismatch repair status, tumour location, sex and age were independent prognostic markers for disease-specific and overall survival. Conclusions: Analysing tumoral immune contexture provides prognostic information in SBA. Combining ICS, PD-1 and PD-L1^IC as Immunoprofile enhanced the prognostic performance.

[Full thickness resection of a pyloric adenoma in the proximal duodenum in a 67-year-old patient with attenuated polyposis coli]

BACKGROUND

 Pyloric gland adenomas (PGAs) are very rare and underdiagnosed, mostly be founded in the stomach. Similar to colorectal adenomas they have a high risk of malignant transformation to adenocarcinoma up to 12-47 %. Endoscopic resections in the duodenum harbor a significant risk of complications. EMR is the current standard technique for treatment of duodenal non-ampullary adenomas. Complete resection rates are considerably high at about 90 %. Adverse events as bleeding was reported up to 25 %. ESD is not recommended for resection of duodenal lesions since the perforation rate may be as high as 35 %. Use of EFTR in the duodenum are limited to a single case study of 20 patients.

CASE

 A 67 year old patient with attenuated polyposis coli presented for screening. Gastroscopy showed a 20 mm large, non-ampullary lesions in the proximal duodenum (pars I). The margins of the duodenal lesions were marked with a high-frequency (HF) probe. An integrated balloon dilatation (20 mm) of the upper esophageal sphincter and the pylorus was performed to facilitate advancing of the gastroduodenal FTRD^® (Ovesco Endoscopy AG). After pulling the duodenal lesion into the cap with a grasper the FTRD clip was deployed and the lesion immediately resected with the preloaded snare. A single-shot antibiotic prophylaxis with 2 g ceftriaxone i. v. was administered during the intervention. Second-look endoscopy was scheduled 24 h after resection. The resectat showed histologically a gastric type adenoma of 18 mm in the proximal duodenum (immunohistochemistry positive for Mucin-1, Mucin-5, Mib 1).

CONCLUSION

 Herein we present the first case of duodenal EFTR in a patient with attenuated FAP and a PGA. There are currently no specific guidelines for the removal and surveillance. ASGE recommends resection and surveillance endoscopy at 3-5 years interval.

Prognostic factors and treatment outcomes in patients with non-ampullary small bowel adenocarcinoma: Long-term analysis

Small bowel adenocarcinoma (SBA) is a relatively rare malignancy in gastrointestinal tumors. In addition, the difficulty of early diagnosis, its poor prognosis compared to large bowel adenocarcinoma, and inadequate treatment experiences due to lack of prospective randomized trials make it necessary to explore the characteristics of the disease for early diagnosis and treatment.Patients diagnosed with primary malignant tumor of small intestine in West China Hospital of Sichuan University between January 2001 and 2013 were reviewed retrospectively. A total of 208 patients with SBA were selected and 160 patients with duodenal periampullary tumor were excluded. Forty-two cases of patients were finally enrolled for statistical analysis as 6 patients were lost of follow-up. The clinical characteristics, the response to treatment and their overall survival (OS) time were reviewed and analyzed.Of the 42 patients, 11 (26.2%) primary tumors were originated from duodenum, 29 (69.0%) from jejunum, and 2 (4.8%) from ileum. All patients (64.3% male; median age, 54.7 years) included in this study underwent primary resection of the tumor to confirm final diagnosis. Three-year survival rate is 21% and 5-year survival rate is 9%. Median OS were 24.2 months (95% CI: 4.0-72.0). The univariate predictors for prognosis of SBA were as follows: age (P = .021), severe intestinal symptoms at first diagnosis (P < .001), T4 of tumor stage (P = .011), tumor size (P = .004), relatively late clinical stage (P < .001), peritoneal metastasis (P < .001), and no chemotherapy (P = .011). The multivariate predictors for poor prognosis were age of more than 60 years old (P = .035), intestinal obstruction or perforation at first diagnosis (P = .026), relatively late clinical stage (P = .000), and no chemotherapy (P = .027).SBA was a relatively rare malignancy that was difficult for early diagnosis and treatment. Intestinal obstruction was the common clinical manifestation at first diagnosis, with a tendency of early peritoneal metastasis. Precaution of the disease in early phase, radical resection of the primary tumor while resectable, followed with in-time chemotherapy might improve prognosis and survival of patients with SBA.