Familial adenomatous polyposis and the small bowel: a loco-regional review and current management strategies

Endoscopic management of duodenal adenomas in patients with familial adenomatous polyposis

BACKGROUND AND AIMS

Almost all patients with familial adenomatous polyposis (FAP) develop duodenal adenomas, with a 4% to 18% risk of progression into duodenal cancer. Prophylactic endoscopic resection of duodenal adenomas may prevent cancer and is considered safer than surgical alternatives; however, data are limited. Therefore, the aim of this study was to assess safety and effectiveness of endoscopic duodenal interventions in patients with FAP.

METHODS

We performed a historical cohort study including patients with FAP who underwent an endoscopic duodenal intervention between 2002 and 2018. Safety was defined as adverse event rate per intervention and effectiveness as duodenal surgery-free and duodenal cancer-free survival. Change in Spigelman stage was assessed as a secondary outcome.

RESULTS

In 68 endoscopy sessions, 139 duodenal polypectomies were performed in 49 patients (20 men; median age, 43). Twenty-nine patients (14 men; median age, 49) underwent a papillectomy. After polypectomy, 9 (13%) bleedings and 1 (2%) perforation occurred, all managed endoscopically. Six (21%) bleedings (endoscopically managed), 4 (14%) cases of pancreatitis, and 1 (3%) perforation (conservatively treated) occurred after papillectomy. Duodenal surgery-free survival was 74% at 89 months after polypectomy and 71% at 71 months after papillectomy; no duodenal cancers were observed. After a median of 18 months (interquartile range, 10-40; range, 3-121) after polypectomy, Spigelman stages were significantly lower (P < .01).

CONCLUSIONS

In our FAP patients, prophylactic duodenal polypectomies were relatively safe. Papillectomies showed substantial adverse events, suggesting its benefits and risk should be carefully weighted. Both were effective, however, because surgical interventions were limited and none developed duodenal cancer.

Management of Familial Adenomatous Polyposis in Children and Adolescents: Position Paper From the ESPGHAN Polyposis Working Group

Familial adenomatous polyposis (FAP) is a well-described inherited syndrome, characterized by the development of hundreds to thousands of adenomas in the colorectum, with implications in children and adolescents. Almost all adult patients will develop colorectal cancer if they are not identified and treated early enough. Identifying and screening for FAP commences in adolescence. The syndrome is inherited as an autosomal dominant trait and caused by mutations in the adenomatous polyposis (APC) gene. This European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) position paper provides a guide for diagnosis, assessment, and management of FAP in children and adolescents.This is the first position paper regarding FAP published by ESPGHAN. Literature from PubMed, Medline, and Embase was reviewed and in the absence of evidence, recommendations reflect the opinion of paediatric and adult experts involved in the care of polyposis syndromes. Because many of the studies that form the basis for the recommendations were descriptive and/or retrospective in nature, these of the recommendations are supported on expert opinion. This position paper will instruct on the appropriate management and timing of procedures in children and adolescents with FAP.

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.

Surveillance using capsule endoscopy is safe in post-colectomy patients with familial adenomatous polyposis: a prospective Japanese study

The utility of capsule endoscopy (CE) for the surveillance of small intestinal lesions in familial adenomatous polyposis (FAP) patients has been reported. However, few studies have investigated the safety of CE in FAP patients who have undergone colon surgery. We aimed to assess the safety of surveillance CE in post-colectomy FAP patients and the endoscopic findings associated with small intestinal lesions. We assessed the safety of CE surveillance of small intestinal lesions in 41 FAP patients who had undergone colectomies. Forty-two CEs were performed in 41 patients at our facility from April 2012 to July 2014. CE was conducted safely and none of the capsules were retained, despite the inclusion of patients who had undergone several abdominal surgeries previously. Thirty-nine out of 42 capsules (93 %) were retrieved within the examination timeframe; hence, the retrieval rate was favorable. The findings from this study indicate that surveillance CE can be safely conducted in post-colectomy FAP patients.

Utility of models of the gastrointestinal tract for assessment of the digestion and absorption of engineered nanomaterials released from food matrices

Engineered metal/mineral, lipid and biochemical macromolecule nanomaterials (NMs) have potential applications in food. Methodologies for the assessment of NM digestion and bioavailability in the gastrointestinal tract are nascent and require refinement. A working group was tasked by the International Life Sciences Institute NanoRelease Food Additive project to review existing models of the gastrointestinal tract in health and disease, and the utility of these models for the assessment of the uptake of NMs intended for food. Gastrointestinal digestion and absorption could be addressed in a tiered approach using in silico computational models, in vitro non-cellular fluid systems and in vitro cell culture models, after which the necessity of ex vivo organ culture and in vivo animal studies can be considered. Examples of NM quantification in gastrointestinal tract fluids and tissues are emerging; however, few standardized analytical techniques are available. Coupling of these techniques to gastrointestinal models, along with further standardization, will further strengthen methodologies for risk assessment.

Risk of ileal pouch neoplasms in patients with familial adenomatous polyposis

Restorative proctocolectomy is the most common surgical option for patients with familial adenomatous polyposis (FAP). However, adenomas may develop in the ileal pouch mucosa over time, and even carcinoma in the pouch has been reported. We therefore reviewed the prevalence, nature, and treatment of adenomas and carcinoma that develop after proctocolectomy in the ileal pouch mucosa in patients with FAP. In 25 reports that were reviewed, the incidence of adenomas in the ileal pouch varied from 6.7% to 73.9%. Several potential factors that favor the development of pouch polyposis have been investigated, but many remain controversial. Nevertheless, it seems certain that the age of the pouch is important. The risk appears to be 7% to 16% after 5 years, 35% to 42% after 10 years, and 75% after 15 years. On the other hand, only 21 cases of ileal pouch carcinoma have been recorded in the literature to date. The diagnosis of pouch carcinoma was made between 3 to 20 years (median, 10 years) after pouch construction. Although the risk of malignant transformation in ileal pouches is probably low, it is not negligible, and the long-term risk cannot presently be well quantified. Regular endoscopic surveillance, especially using chromoendoscopy, is recommended.

Prevalence and risk factors for adenomas in the ileal pouch and the afferent loop after restorative proctocolectomy for patients with familial adenomatous polyposis

BACKGROUND

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) has become the treatment of choice in familial adenomatous polyposis (FAP) to prevent the risk of colorectal cancer. However, it currently is recognized that adenomas may develop in the ileal pouch. The risk of adenoma occurring in the afferent ileal loop above the pouch is less clearly identified. This study aimed to evaluate the difference in prevalence of adenomas between the ileal pouch and the afferent ileum after IPAA in FAP.

METHODS

The study analyzed 442 endoscopies performed between 2003 and 2008 for 139 FAP patients. The patients had undergone an IPAA in 118 cases, an ileorectal anastomosis in 13 cases, or an ileostomy in 8 cases.

RESULTS

Among the 118 IPAA patients, 57 (48.3 %) had pouch adenomas a median of 15 years after surgery. The risk factors for pouch adenomas were delay since pouch construction [odds ratio (OR), 1.11; p = 0.016] and presence of advanced duodenal adenomas (OR, 4.35; p = 0.011). Seven patients had pouch adenomas with high-grade dysplasia. Only nine patients had afferent ileal loop adenomas (6.5 %). The only significant risk factor for ileal adenomas was the presence of pouch adenomas (OR, 2.16; p = 0.007).

CONCLUSION

After restorative proctocolectomy in FAP, adenoma recurrence is frequent in the pouch, with a higher risk for patients with advanced duodenal adenomas and an increasing risk over time, whereas adenomas are rarely found in the afferent ileal loop. This finding may help to propose redo ileal pouch anal anastomosis if required.

[Gastrointestinal polyposis syndromes]

Hereditary gastrointestinal polyposis syndromes account for around 1% of all colorectal cancers; most of them are associated with a broad spectrum of extracolonic tumors. The initial diagnosis is based on endoscopic findings and polyp histology. Molecular genetic screening is important for the delineation of conditions with a similar phenotype such as autosomal dominant familial adenomatous polyposis (FAP) and autosomal recessive MUTYH-associated polyposis (MAP). Identification of the germline mutation in an affected person is a prerequisite for the exact evaluation of the recurrence risk in relatives and the predictive testing of asymptomatic persons at risk. Beside cases with attenuated adenomatosis or few colorectal adenomas, diagnostic difficulties are common among the hamartomatous polyposes such as the juvenile polyposis syndrome due to their broad clinical overlap and uncertainties in histological assessment. Several poorly defined nonhereditary polyposis syndromes and those with an as yet unknown etiology exist including hyperplastic polyposis syndrome. Early detection and accurate classification are essential since effective methods for surveillance and treatment are available.

The differential diagnosis and surveillance of hereditary gastrointestinal polyposis syndromes

BACKGROUND

Hereditary gastrointestinal polyposis syndromes account for about 1% of all cases of colorectal cancer and are associated with a broad spectrum of extracolonic tumors. The early detection and accurate classification of these syndromes are essential, since effective methods for surveillance and treatment are available.

METHODS

This review article is based on a selective literature search, the author's own work, and evidence-based guidelines and recommendations.

RESULTS AND CONCLUSIONS

The diagnosis is initially suspected on the basis of the endoscopic findings and polyp histology. Because different syndromes can resemble each other phenotypically, e.g., autosomal dominant familial adenomatous polyposis and autosomal recessive MUTYH-associated polyposis, molecular genetic studies are important for differential diagnosis and for assessing the risk of recurrence. Identification of the familial mutation in an affected patient is a prerequisite for predictive testing in asymptomatic persons at risk and sometimes enables prognostication. In recent years, the rate of detection of mutations has risen by 10% to 30%, and clinically relevant genotype-phenotype correlations have been described for juvenile polyposis syndrome. Except in cases of mild adenomatous polyposis, phenotypic overlap among the hamartomatous polyposes often causes difficulties in differential diagnosis. Thus, in unclear cases, a pathologist with special expertise in gastrointestinal disorders should be consulted for the evaluation of polyp tissue. Aside from the monogenic polyposes, there are many other types of polyposis that are non-hereditary or of unknown cause, including the hyperplastic and mixed polyposis syndromes. Risk-adapted surveillance programs have been established for the more frequently occurring polyposes.