Small-bowel diagnosis in patients with familial adenomatous polyposis: comparison of push enteroscopy, capsule endoscopy, ileoscopy, and enteroclysis

Hereditary Colorectal Cancer Syndromes: Small Bowel Cancer Risk and Endoscopic Surveillance Strategies

Background: Hereditary colorectal cancer syndromes, including familial adenomatous polyposis (FAP), Lynch syndrome (LS), and Peutz-Jeghers syndrome (PJS), are associated with an increased risk of small bowel cancer (SBC). Due to the low incidence and non-specific presentation of SBC, effective surveillance strategies are essential for early detection and management. This review aims to evaluate and compare current endoscopic techniques for small bowel surveillance in these patients. Methods: A comprehensive review was conducted using peer-reviewed studies sourced from PubMed. Various endoscopic modalities, including capsule endoscopy (CE), device-assisted enteroscopy (DAE), and intraoperative enteroscopy (IOE), were assessed for their diagnostic yield, safety, and clinical utility. Surveillance recommendations of the different syndromes were also examined. Results: CE offers high sensitivity but lacks histological sampling capability. DAE, including double-balloon enteroscopy (DBE) and single-balloon enteroscopy (SBE), enables direct visualization, biopsy, and therapeutic interventions, albeit with greater procedural complexity. In FAP, duodenal surveillance follows the Spigelman classification to stratify cancer risk, while jejunal and ileal polyps remain less studied. LS patients have an increased SBC risk, warranting tailored endoscopic approaches. In PJS, surveillance aims to mitigate intussusception risks and allow early malignancy detection. Conclusions: Optimized surveillance strategies in hereditary colorectal cancer syndromes require a multimodal approach, integrating advanced endoscopic techniques with genetic risk stratification. Centralized care in tertiary centers improves outcomes by ensuring standardized surveillance protocols and enhancing early cancer detection. Artificial intelligence (AI) applied to CE and DAE is shaping promising prospects for the future surveillance of small bowel polyps by enhancing diagnostic accuracy and reducing the duration of the diagnostic process. Further research should investigate AI-assisted imaging and molecular biomarkers to optimize screening strategies.

Benign and non-neoplastic tumours of the duodenum

This review study describes the problem of duodenal tumours, which are rare but important in gastrological practice. The most common location of small intestinal tumours is the duodenum, and this observation is probably partly due to the greater diagnostic availability for most proximal segments of the small intestine. Among tumours the following should be mentioned – benign: adenomas, lipomas, haemangiomas, and leiomyomas; and malignant: malignant tumours of epithelial origin, primary gastrointestinal stromal tumours, neuroendocrine tumours and carcinoids, lymphomas, sarcomas, teratomas, and secondary metastases. Early duodenal tumour recognition, especially with histological assessment, plays a crucial diagnostic role with future therapeutic implications. In recent years the prevalence of benign duodenal tumours has been rising due to a higher level of clinicians’ doubts and the convenience of gastrointestinal endoscopy; hence, knowledge of this problem is important in routine clinical practice. The method of duodenal tumour treatment should be selected on an individual basis.

Update on small bowel surveillance in hereditary colorectal cancer syndromes

Despite its rarity in the general population, small bowel adenocarcinoma risk is increased in individuals with hereditary colorectal cancer syndromes (HCCS). In the last decade, the advent of capsule endoscopy and device-assisted balloon enteroscopy procedures in patients with HCCS have allowed to investigate the whole small bowel, increasing the diagnostic yield of small bowel tumor. Nonetheless, there is a significant variability in the international guideline recommendations. The aim of this review is to provide an update on surveillance of small bowel in HCCS and to identify the key points for the clinical management of these patients.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) Guidelines 2016 for the Clinical Practice of Hereditary Colorectal Cancer (Translated Version)

Hereditary colorectal cancer accounts for less than 5% of all colorectal cancer cases. Some of the unique characteristics that are commonly encountered in cases of hereditary colorectal cancer include early age at onset, synchronous/metachronous occurrence of the cancer, and association with multiple cancers in other organs, necessitating different management from sporadic colorectal cancer. While the diagnosis of familial adenomatous polyposis might be easy because usually 100 or more adenomas that develop in the colonic mucosa are in this condition, Lynch syndrome, which is the most commonly associated disease with hereditary colorectal cancer, is often missed in daily medical practice because of its relatively poorly defined clinical characteristics. In addition, the disease concept and diagnostic criteria for Lynch syndrome, which was once called hereditary non-polyposis colorectal cancer, have changed over time with continual research, thereby possibly creating confusion in clinical practice. Under these circumstances, the JSCCR Guideline Committee has developed the "JSCCR Guidelines 2016 for the Clinical Practice of Hereditary Colorectal Cancer (HCRC)," to allow delivery of appropriate medical care in daily practice to patients with familial adenomatous polyposis, Lynch syndrome, or other related diseases. The JSCCR Guidelines 2016 for HCRC were prepared by consensus reached among members of the JSCCR Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR Guidelines 2016 for HCRC.

Genetic risks and familial associations of small bowel carcinoma

Adenocarcinoma of small intestines (SBA) is a relatively rare malignancy with poor outcomes due to delayed diagnosis. Fifty percent of patients have metastases on presentation and therefore early detection and treatment offers the best long term outcomes. Certain genetic polyposis syndromes and familial diseases are associated with increased risks for SBA. These include familial adenomatous polyposis (FAP), Lynch syndromes (LS), Juvenile polyposis syndrome, Peutz-Jeghers syndrome, Crohn's disease (CD) and celiac disease. Mutations in APC gene, Mismatch repair genes, STK11 gene, and SMAD4 gene have been implicated for the genetic diseases respectively. While there are no specific inherited genetic mutations for CD, genome-wide association studies have established over 140 loci associated with CD. CpG island mutations with defects in mismatch repair genes have been identified in celiac disease. Significant diagnostic advances have occurred in the past decade and intuitively, it would seem beneficial to use these advanced modalities for surveillance of these patients. At present it is debatable and no clear data exists to support this approach except for established guidelines to diagnose duodenal polyps in FAP, and LS. Here we discuss the genetic alterations, cancer risks, signaling mechanisms and briefly touch the surveillance modalities available for these genetic and clinical syndromes. English language articles from PubMed/Medline and Embase was searched were collected using the phrases "small-bowel adenocarcinoma, genetics, surveillance, familial adenomatous polyposis, lynch syndromes, Peutz-Jeghers syndrome, juvenile polyposis syndrome, CD and celiac disease". Figures, tables and schematic diagram to illustrate pathways are included in the review.

The prevalence of small intestinal polyps in patients with familial adenomatous polyposis: a prospective capsule endoscopy study

Familial adenomatous polyposis (FAP) is a genetic disorder in which multiple colorectal polyps and cancers develop. However, the prevalence of small intestinal tumors in patients with FAP remains unclear. We elucidated the prevalence of polyps in the small intestine and duodenum using capsule endoscopy (CE). Patients with FAP receiving a periodic screening colonoscopy at Kyoundo Hospital were encouraged to participate in the study. All study participants underwent esophagogastroduodenoscopy (EGD) within 2 weeks before CE. Outcome measurements were the prevalence of duodenal polyps (DP) and small intestinal polyp (SIP), detectability of the ampulla of Vater, and concordance of the duodenal findings between CE and EGD. Twenty-three patients (mean age, 47 years; 15 males) were enrolled in the study. CE showed DPs in 11 patients (52%) and SIPs in nine patients (43 %). The mean numbers of DPs and SIPs was 11.5 ± 6.2 and 11.9 ± 10.9, respectively. SIPs were more often detected in patients with DPs versus those without (62 vs. 13%, P = 0.07). The ampulla of Vater was observed by CE in four patients (21%). EGD showed DPs in 13 patients (62%). EGD missed DPs in two of 11 patients with DPs detected by CE. EGD found DPs in four of 10 patients without DPs using CE. The kappa index was 0.422. Patients with FAP have a high prevalence of polyps in the small intestine. Although the clinical significance of small intestinal polyps remains unclear, patients with FAP seem to be good candidates for CE.

Diagnosis, surveillance, and treatment strategies for familial adenomatous polyposis: rationale and update

Familial adenomatous polyposis is characterized by the development of multiple (>100) colorectal adenomas throughout the colorectum. This disorder can be caused by a germline mutation in the adenomatous polyposis coli gene and can be diagnosed either clinically or genetically. After diagnosis with the condition, patients should undergo prophylactic proctocolectomy with a neoreservoir, usually an ileoanal pouch, at an appropriate time. Individuals with a family history of this disease who have not been diagnosed should be advised to attend genetic counseling and to enroll in appropriate clinical and genetic surveillance programs. Recent progress in endoscopic technology, including high-resolution endoscopy, capsule endoscopy, and double-balloon endoscopy, has made possible more detailed and wide-ranging investigation of the gastrointestinal tract. Although there has been limited evidence, further studies on these new endoscopic technologies might alter the surveillance strategies for familial adenomatous polyposis.

Advanced precancerous lesions in the small bowel mucosa

The small intestine has comparatively low rates of epithelial cancers and is, for the most part, inaccessible to ordinary endoscopic visualization. As a result, few solid data are available on the pathological, clinical, and therapeutic aspects of epithelial dysplasia in the small intestine. In this review, we discuss the duodenal adenoma, the most readily visualized dysplastic lesion of the small intestine and the only one that can be detected in an early phase and resected endoscopically before it progresses to high-grade or invasive carcinoma. Particular emphasis is placed on the relationship between duodenal adenoma and colon neoplasia. Because of their different behaviour, detection and management of ampullary adenomas is discussed separately. Even if the absolute risk remains small, the incidence of adenocarcinoma in the small bowel is increased 32-fold in patients with ileal Crohn's disease. Therefore, the follow up and management of these patients is discussed with particular emphasis on the occurrence of dysplasia in the small bowel mucosa of the post-restorative proctocolectomy patients.

Small bowel endoscopy in familial adenomatous polyposis and Lynch syndrome

Patients with familial adenomatous polyposis (FAP) and patients with Lynch syndrome have an increased risk of developing small intestinal neoplasia. In both conditions, the lifetime risk to develop small bowel cancer is estimated to be around 5%. In FAP, this risk is associated with the degree of duodenal polyposis, classically assessed by the Spigelman classification. For this reason, gastroduodenal surveillance with forward-viewing and side-viewing endoscopy is generally recommended. Studies using video capsule endoscopy and balloon-assisted enteroscopy in FAP patients have revealed that jejunal and ileal polyps occur frequently in FAP, especially in those with extensive duodenal polyposis. Nevertheless, the clinical relevance of small bowel polyps beyond the duodenum appears to be limited. Compared to FAP, little is known about the prevalence and natural history of small bowel neoplasia in Lynch syndrome. Surveillance of the small bowel is not recommended in Lynch syndrome, although recent data using capsule endoscopy provided promising results.

Capsule endoscopy in small-bowel surveillance of patients with hereditary polyposis syndromes

PURPOSE

Familial adenomatous polyposis (FAP) and Peutz-Jeghers syndrome (PJS) are hereditary polyposis syndromes with a high risk for benign small-bowel polyps and cancer. The aim of this study was to assess the prevalence of small-bowel polyps beyond the duodenum in patients with FAP and PJS and to examine the clinical value and the optimal interval of capsule endoscopy (CE) for the surveillance of small-bowel polyps in patients with FAP.

METHODS

Between 2002 and 2009, standard gastroscopy, duodenoscopy, and CE were performed on 19 consecutive patients with hereditary polyposis syndromes (FAP n=15; PJS n=4). The number, size, and location of polyps detected by CE were assessed. Five FAP patients had repeated CEs in intervals of 2-7 years.

RESULTS

In 13 of the 15 (87%) FAP patients, small-bowel polyps were detected by CE ranging from estimated <5 mm to >10 mm in size. Thereof, in four patients, medium-sized (5-10 mm) or large-sized (>10 mm) polyps were seen-all of them located in the proximal jejunum. In three FAP patients with repeated CEs, the latest CE displayed medium- and large-sized polyps in the proximal jejunum, whereas previous CEs had detected only small-sized (<5 mm) polyps. In three of the four PJS patients, large-sized small-bowel polyps were visualized by CE which could then be removed by double-balloon enteroscopy (DBE) or surgical resection.

CONCLUSION

CE is an effective and safe method for small-bowel surveillance in FAP and PJS.

Capsule endoscopy: 10 years on and in the frontline

Capsule endoscopy is a safe, simple, remote method of visualising the gastrointestinal tract without resorting to conventional endoscopic intubation or radiation exposure. In addition, the ability to visualise the small bowel mucosa directly means that it is considerably more sensitive than existing small bowel imaging modalities in detecting subtle abnormalities. It is a firstline investigative modality for suspected small bowel bleeding and is being increasingly used for detecting evidence of other small bowel diseases. In Crohn's disease, it can confirm evidence of activity without recourse to repeated endoscopic intubation or radiation but does not replace MRI and CT which are better suited to defining stricturing disease and transmural complications. The production of different capsule endoscopes to examine the oesophagus, small bowel and colon now means that almost all of the gut can be examined using this technology.