Familial adenomatous polyposis in children and adolescents

Updated Perspectives on the Diagnosis and Management of Familial Adenomatous Polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant cancer predisposition syndrome marked by extensive colorectal polyposis and a high risk of colorectal cancer (CRC). Having access to screening and enrollment programs can improve survival for patients with FAP by enabling them to undergo surgery before the development of colorectal cancer. Provided that there are a variety of surgical options available to treat colorectal polyps in patients with adenomatous polyposis, the appropriate surgical option for each patient should be considered. The gold-standard treatment to reduce this risk is prophylactic colectomy, typically by the age of 40. However, colectomy is linked to morbidity and constitutes an ineffective way at preventing extra-colonic disease manifestations, such as desmoid disease, thyroid malignancy, duodenal polyposis, and cancer. Moreover, extensive studies have been conducted into the use of chemopreventive agents to prevent disease progression and delay the necessity for a colectomy as well as the onset of extracolonic disease. The ideal chemoprevention agent should demonstrate a biologically plausible mechanism of action and provide safety, easy tolerance over an extended period of time and a lasting and clinically meaningful effect. Although many pharmaceutical and non-pharmaceutical products have been tested through the years, there has not yet been a chemoprevention agent that meets these criteria. Thus, it is necessary to develop new FAP agents that target novel pathways, such as the mTOR pathway. The aim of this article is to review the prior literature on FAP in order to concentrate the current and future perspectives of diagnosis and treatment. In conclusion, we will provide an update on the diagnostic and therapeutic options, surgical or pharmaceutical, while focusing on the potential treatment strategies that could further reduce the risk of CRC.

Hepatoblastoma in molecularly defined, congenital diseases

Beckwith-Wiedemann spectrum, Simpson-Golabi-Behmel syndrome, familial adenomatous polyposis and trisomy 18 are the most common congenital conditions associated with an increased incidence of hepatoblastoma (HB). In patients with these genetic disorders, screening protocols for HB are proposed that include periodic abdominal ultrasound and measurement of alpha-fetoprotein levels. Surveillance in these children may contribute to the early detection of HB and possibly improve their chances of overall survival. Therefore, physicians must be aware of the high HB incidence in children with certain predisposing genetic diseases.

Paediatric polyposis syndromes: burden of disease and current concepts

PURPOSE OF REVIEW

Polyposis syndromes are rare but significant entities that often present during childhood and adolescence. Polyposis syndromes should remain high on the differential diagnoses for any child presenting with rectal bleeding, protein-losing enteropathy or intussusception in the setting of multiple polyps in the gastrointestinal tract. There are three primary paediatric polyposis syndromes: Juvenile polyposis syndrome (JPS), Familial adenomatous polyposis (FAP) and Peutz-Jeghers syndrome (PJS). This review will cover recent guidelines for these conditions and advances in genetic testing.

RECENT FINDINGS

The first set of paediatric guidelines were released in 2019 by the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) for FAP, JPS and PJS. Even with advances in genetic testing, a significant proportion of patients with polyposis syndromes have no identifiable genetic mutations. Recent research has shown that polyps behave differently in patients with and without disease-causing variants, emphasizing the role of genetic testing in the diagnosis and management of polyposis syndromes.

SUMMARY

Polyposis syndromes in the paediatric population are growing due to increased recognition and advances in genetic testing. A timely diagnosis and surveillance of a paediatric polyposis syndrome are pivotal for the management of disease burden and early identification of cancers within the gastrointestinal tract and beyond. Paediatricians, paediatric gastroenterologists, paediatric oncologists and paediatric surgeons should be familiar with the presentation and comorbidities of polyposis syndromes in children and adolescents. Further research into genotype-phenotype correlations is needed to tailor the care for paediatric patients with polyposis syndromes.

Polyp Progression in Paediatric Patients With Familial Adenomatous Polyposis: A Single-centre Experience

OBJECTIVES

Prophylactic colectomy at a premalignant stage is the cornerstone of management of familial adenomatous polyposis (FAP). Before surgery, colonoscopy surveillance is recommended in children with FAP. This study aimed to examine the natural history of FAP in children by evaluating adenoma progression and factors influencing timing of colectomy.

METHOD

Patients with FAP younger than 18 years at first surveillance colonoscopy and who had undergone more than 1 colonoscopy were identified. Demographic, endoscopic, genetic, and surgical data were retrieved. Cumulative adenoma (polyp) counts were obtained while accounting for any polypectomies during the study period. The rate of polyp progression and factors influencing the timing of colectomy were evaluated.

RESULTS

Eighty-four patients (50% boys; mean age at first colonoscopy 13 years [standard deviation 1.97]) were identified, of which 83 had a family history of FAP. At first colonoscopy, 67 (79%) had <100 adenomas and 29 (35%) had colonic polyps identified despite rectal sparing. The median rate of polyp progression per patient was 12.5 polyps/year (range 0-145). Of the 45 (54%) patients who had undergone surgery, 41 (91%) underwent colectomy with ileorectal or ileodistal sigmoid anastomosis. Polyp progression did not alter the choice of surgical intervention in any patient.

CONCLUSION

Our results suggest that adenoma number remains relatively stable in the majority of children under surveillance. Tailored surveillance intervals according to phenotype are a more appropriate strategy as recommended by recently published guidelines.

Hepatoblastoma in patients with molecularly proven familial adenomatous polyposis: Clinical characteristics and rationale for surveillance screening

Familial adenomatous polyposis (FAP) due to APC mutation is associated with an increased risk of hepatoblastoma. All cases of hepatoblastoma in patients with FAP reported in the literature were reviewed. One hundred and nine patients were identified. Thirty-five patients (of 49 with data) were diagnosed with hepatoblastoma prior to a later diagnosis of FAP (often in association with advanced colorectal carcinoma), emphasizing a need to identify patients earlier with germline APC mutations for early colorectal carcinoma screening. Hepatoblastoma may present at birth, and screening for hepatoblastoma in infancy in families with FAP prior to APC mutation testing results may be warranted.

Upper GI involvement in children with familial adenomatous polyposis syndrome: single-center experience and meta-analysis of the literature

BACKGROUND AND AIMS

Familial adenomatous polyposis (FAP) is a hereditary syndrome that can affect the entire GI tract. Current screening recommendations include EGD starting at age 25 to 30 years or earlier in symptomatic patients. However, few reports describe upper GI tract involvement in children with FAP that support the notion of early screening. The aim of our study is to understand the prevalence and severity of upper GI involvement in children with FAP.

METHODS

We performed a retrospective review of the Mayo Clinic records, between 1992 and 2016, to identify children with the diagnosis of FAP who underwent EGD examinations. A systematic review of the literature was performed to include published studies reporting children with FAP and upper GI findings.

RESULTS

The retrospective study included 69 children with a mean age of 13.5 years (range, 3-18). Thirty-six children (52%) had duodenal adenoma with low-grade dysplasia. Five children required an ampullectomy secondary to enlarged and polypoid ampullas. Combined with published studies, a total of 206 children with upper GI findings were identified, of which 87 (42%) had duodenal adenoma (1 had high-grade dysplasia). Meta-analysis of 5 series demonstrated duodenal adenoma detection rate of 39% (95% confidence interval, 21%-57%; I² = 85%).

CONCLUSIONS

The available data to date show that children with FAP can have clinically relevant lesions in the upper GI tract earlier than previously foreseen, suggesting that earlier screening may be indicated. Larger multicenter prospective studies are needed to determine the best approach and optimal age for EGD screening in children with FAP.

Phase 1/2 trial of temsirolimus and sorafenib in the treatment of patients with recurrent glioblastoma: North Central Cancer Treatment Group Study/Alliance N0572

BACKGROUND

Mitogen-activated protein kinase (MAPK) activation and mammalian target of rapamycin (mTOR)-dependent signaling are hallmarks of glioblastoma. In the current study, the authors conducted a phase 1/2 study of sorafenib (an inhibitor of Raf kinase and vascular endothelial growth factor receptor 2 [VEGFR-2]) and the mTOR inhibitor temsirolimus in patients with recurrent glioblastoma.

METHODS

Patients with recurrent glioblastoma who developed disease progression after surgery or radiotherapy plus temozolomide and with ≤2 prior chemotherapy regimens were eligible. The phase 1 endpoint was the maximum tolerated dose (MTD), using a cohorts-of-3 design. The 2-stage phase 2 study included separate arms for VEGF inhibitor (VEGFi)-naive patients and patients who progressed after prior VEGFi.

RESULTS

The MTD was sorafenib at a dose of 200 mg twice daily and temsirolimus at a dose of 20 mg weekly. In the first 41 evaluable patients who were treated at the phase 2 dose, there were 7 who were free of disease progression at 6 months (progression-free survival at 6 months [PFS6]) in the VEGFi-naive group (17.1%); this finding met the prestudy threshold of success. In the prior VEGFi group, only 4 of the first 41 evaluable patients treated at the phase 2 dose achieved PFS6 (9.8%), and this did not meet the prestudy threshold for success. The median PFS for the 2 groups was 2.6 months and 1.9 months, respectively. The median overall survival for the 2 groups was 6.3 months and 3.9 months, respectively. At least 1 adverse event of grade ≥3 was observed in 75.5% of the VEGFi-naive patients and in 73.9% of the prior VEGFi patients.

CONCLUSIONS

The limited activity of sorafenib and temsirolimus at the dose and schedule used in the current study was observed with considerable toxicity of grade ≥3. Significant dose reductions that were required in this treatment combination compared with tolerated single-agent doses may have contributed to the lack of efficacy. Cancer 2018;124:1455-63. © 2018 American Cancer Society.

Fundic Gland Polyps in the Pediatric Population: Clinical and Histopathologic Studies

We retrospectively studied the clinical and histologic features of pediatric fundic gland polyps (FGPs) in 16 patients. FGPs had an endoscopic prevalence of 0.25% in 8527 pediatric gastric biopsies. Five patients had familial adenomatous polyposis (FAP). The median age of onset was 17.7 years in FAP and 17.3 years in sporadic patients. All syndromic patients were asymptomatic and FGPs were identified during surveillance for existing or concurrent colon polyps. They did not take antacids. In comparison, all 11 sporadic FGPs were identified during evaluation of symptomatic patients who had taken antacids (median duration 21 months). Syndromic FGPs can be multiple at single endoscopy and were more likely to recur, while sporadic FGPs were often single. None of the sporadic patients had recurrence of FGPs or a subsequent diagnosis of FAP during a median follow-up of 20.5 months. The dilated fundic glands were lined by parietal and chief cells only in a majority (22/41, 53.7%) of syndromic FGPs, while additional tall mucinous lining cells were found in all sporadic FGPs. Syndromic FGPs did not have parietal cell hypertrophy in the background oxyntic mucosa. Nuclear immunopositivity for beta-catenin was essentially absent in all the FGPs. In conclusion, FGPs were rare in pediatric patients. In syndromic patients, FGPs are asymptomatic and did not precede colon polyps. Prolonged antacid intake seems to be associated with development of sporadic FGPs. Cellular components of dilated fundic glands and background parietal cell hypertrophy can be useful features to eliminate concern for syndromic polyposis.

Colonic polyposis in a 15 year-old boy: Challenges and lessons from a rural resource-poor area

INTRODUCTION

Colorectal polyps usually present with rectal bleeding and are associated with increased risk of colorectal carcinoma. Evaluation and management in resource-poor areas present unique challenges.

PRESENTATION OF CASE

This 15 year-old boy presented with 9 years of painless rectal bleeding and 2 years of a prolapsing rectal mass after passing stool. He had 3 nephews with similar symptoms. On clinical assessment and initial exam under anesthesia, an impression of a polyposis syndrome was made and a biopsy taken from the mass that revealed inflammatory polyps with no dysplasia. He was identified during a pediatric surgical outreach to a rural area with no endoscopy, limited surgical services, and no genetic testing available, even at a tertiary center. He subsequently had a three-stage proctocolectomy and ileal pouch anal anastomosis with good outcome after referral to a tertiary care center. The surgical specimen showed many polyps scattered through the colon.

DISCUSSION

In the absence of endoscopic surveillance and diagnostic services including advanced pathology and genetic testing, colorectal polyposis syndromes are a significant challenge if encountered in these settings. Reports from similar settings have not included this surgical treatment, often opting for partial colectomy. Nonetheless, good outcomes can be achieved even given these constraints. The case also illustrates the complexity of untreated chronic pediatric surgical disease in rural resource-poor areas with limited health care access.

CONCLUSION

Polyposis syndromes in children present unique challenges in rural resource-poor settings. Good outcomes can be achieved with total proctocolectomy and ileal pouch anastomosis.

Risk-reduction surgery in pediatric surgical oncology: A perspective

OBJECTIVE

A small percentage of pediatric solid cancers arise as a result of clearly identified inherited predisposition syndromes and nongenetic lesions. Evidence supports preemptive surgery for children with genetic [multiple endocrine neoplasia type 2 (MEN2), familial adenomatous polyposis syndrome (FAP), hereditary nonpolyposis colorectal cancer (HNPCC), and hereditary diffuse gastric cancer (HDGC) and nongenetic [thyroglossal duct cysts (TGDC), congenital pulmonary airway malformations (CPAM), alimentary tract duplication cysts (ATDC), and congenital choledochal cysts (CCC)] developmental anomalies. Our aim was to explore the utility of risk reduction surgery to treat and prevent cancer in children.

METHODS

A systematic review of the available peer-reviewed literature on PubMed was performed using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) search strategy, where possible. Search items included "risk reduction surgery", "hereditary cancer predisposition syndrome", "multiple endocrine neoplasia type 2", "familial adenomatous polyposis", "hereditary nonpolyposis colorectal cancer", "hereditary diffuse gastric cancer", "thyroglossal duct cysts", congenital pulmonary airway malformations", "alimentary tract duplication cysts", "malignant transformation", and "guidelines".

RESULTS

We identified 67 articles that met the inclusion criteria describing the indications for prophylactic surgery in surgical oncology. For the genetic predisposition syndromes, 7 studies were related to professional endorsed guidelines, 7 were related to surgery for MEN2, 11 were related to colectomy for FAP, 6 were related to colectomy for HNPCC, and 12 related to gastrectomy for HDGC. Articles for the nongenetic lesions included 5 for techniques related to TGDC resection, 9 for surgery for CPAMs, and 10 for resection of ATDCs. Guidelines and strategies varied significantly especially related to the extent and timing of surgical intervention; the exception was for the timing of thyroidectomy in children with MEN2.

CONCLUSION

Current evidence supporting prophylactic surgery in the management of pediatric cancer predisposition syndromes and nongenetic lesions is best delineated for thyroidectomy to prevent medullary thyroid cancer in children with MEN2 (Strength of Recommendation Grade B/C). Despite the lack of pediatric specific evidence-based recommendations regarding the appropriate extent and timing for risk-reduction surgery for FAP, HNPCC, HDGC and nongenetic anomalies, our review represents an opportunity towards understanding the postgenomic development of these lesions and provides current indications and techniques for preemptive cancer prevention surgery in children.

Early onset of dysplasia in polyps in children with familial adenomatous polyposis: case report and literature review

Familial adenomatous polyposis (FAP) is one of the most common hereditary syndromes associated with an increased risk of colorectal cancer. Onset of polyp formation and cancer in childhood is very unusual but has recently been associated with a specific mutation at codon 1309 in exon 15 where a more severe phenotype is sometimes observed .We report a 12-year-old girl who presented with haematochezia. The girl's mother and aunt had died of colon cancer which developed from untreated FAP. The other two aunts also had FAP and underwent colectomy. Endoscopy showed extensive polyps presented on the luminal surface of the entire colon. Histomorphology confirmed a low grade of intraepithelial neoplasia (IEN) in three polyps and the patient underwent colectomy. We present a review of the literature focussed on early onset of IEN in polyps in children with FAP.

CONCLUSION

Clinicians should take note of the family history and be prepared to consider much earlier intervention if symptoms occur in a child with a family history of FAP.

Gastrointestinal bleeding

• On the basis of strong research evidence, children with severe upper gastrointestinal tract bleeding should be treated with intravenous proton pump inhibitors. • On the basis of some research evidence and consensus, children with severe gastrointestinal bleeding should be evaluated by endoscopy. • On the basis of some research evidence and consensus, children in whom endoscopy has not been able to confirm a bleeding source should be considered for capsule endoscopy.

Gastrointestinal bleeding

• On the basis of strong research evidence, children with severe upper gastrointestinal tract bleeding should be treated with intravenous proton pump inhibitors. • On the basis of some research evidence and consensus, children with severe gastrointestinal bleeding should be evaluated by endoscopy. • On the basis of some research evidence and consensus, children in whom endoscopy has not been able to confirm a bleeding source should be considered for capsule endoscopy.

A case of a child with an APC pathogenic mutation, aberrant expression of splice variants and positive family history of FAP

Familial adenomatous polyposis is an autosomal dominant hereditary disease characterized by the appearance of hundreds to thousands of colorectal adenomatous polyps; if left untreated, there is nearly a 100% lifetime risk of colorectal cancer. In the present case, adenomatous polyps were observed at 6 years of age. Unlike our previous assumption, adenomatous polyps were detected by colonoscopy at <10 years of age. Considering the clinical importance of early diagnosis, we report this case involving germline adenomatous polyposis coli mutation (c.1958G > C, GenBank: M74088.1) that caused an increase in the isoform without exon 15. Although this isoform has been reported previously, it remains controversial whether the variant is pathogenic or not because it was observed both in patients with familial adenomatous polyposis and in normal controls. Nonetheless, due to quantitative distortion of splice variants in adenomatous polyposis coli transcripts and the early development of adenomatous polyps, we believe that this variant may be pathogenic.

Is laparoscopic surgery an option to support prophylactic colectomy in adolescent patients with Familial Adenomatous Polyposis (FAP)?

BACKGROUND

Prophylactic surgery is still considered the standard treatment for patients with Familial Adenomatous Polyposis (FAP). Laparoscopic (Lap) surgery has been introduced as an alternative approach. The aim was to evaluate the feasibility and short- to long-term outcomes after prophylactic FAP surgery in adolescent.

PROCEDURES

A retrospective review of a database of adolescent patients with FAP identified through the Hereditary Colorectal Tumor Registry in a single Institution between 2005 and 2011. Patients underwent Lap total colectomy (TC) with ileo-rectal anastomosis (IRA) or proctocolectomy (PC) with ileal-pouch anal anastomosis (IPAA). The main outcomes were: Hospital stay, postoperative complications, desmoid tumor rates, tumor recurrence, long-term complications.

RESULTS

Sixteen consecutive patients with median age 16 (range 13-19) and median BMI 22 (17-29) underwent surgery. [correction made here after initial online publication]. Of them 14 patients had LAP TC with IRA and 2 had PC with IPAA. Operative time (median, range) was TC/IRA 270 (210-330) minutes; PC/IPAA 370 (360-380) minutes. Length of extraction site was cm (median, range) 6(5-8). Lymph Node harvest (median, range) 81 (32-139). Postoperative stay days (median, range) were 6 (4-24). Five patients (31.2%) showed dysplasia on the pathological report and 3 of them showed severe dysplasia. Median follow-up time (FU) was 39 months, range (10-82). The anastomotic leak rate for 30 days was 2 (12.5%). Pouch failure was 0. Post-surgical desmoid tumors rate was 1 (6.2%) and there was no tumor recurrence. Anastomotic stricture, SBO and mortality were zero.

CONCLUSIONS

Lap approach is feasible and shows acceptable postoperative outcomes. Lap surgery can be an appealing alternative for prophylactic surgery in adolescent FAP patients. Pediatr Blood Cancer 2012; 59: 1223-1228. © 2012 Wiley Periodicals, Inc.

Management of colorectal carcinoma in children and young adults

Colorectal Carcinoma (CRC) is rare in patients less than 20 years of age. Although presenting symptoms are similar to adults, this diagnosis is rarely considered in the initial differential diagnosis of young patients. We will review what is published about the incidence, epidemiology, and clinical presentation of CRC in children, adolescents and young adults. Because of its rarity in this age group, few pediatric oncologists will have experience with CRC, and clinical trials will rarely be available. The treatment of CRC in adults is evolving rapidly and consultation with medical oncologists experience in treating adults with CRC is essential to develop the best treatment plan for a young patient diagnosed with CRC.