Nine-year follow-up of a patient with attenuated familial adenomatous polyposis treated with cyclo-oxygenase-2 inhibitors

Familial adenomatous polyposis (FAP) is caused by germline mutations in the adenomatous polyposis coli (APC) gene with onset of florid polyposis in childhood and development of colorectal cancer by age 30. Colectomy is advised because of the high risk of developing colorectal cancer. Attenuated FAP (AFAP) is a variant of this condition with a later age of onset and milder clinical phenotype; however, colectomy is advised once polyposis develops and polyps cannot be managed endoscopically. We report a case of a patient with AFAP and previously resected colonic carcinoma that was treated with chemoprophylaxis with long-term cyclooxygenase-2 (COX-2) inhibitors after declining colectomy. Colonoscopic examination demonstrated regression of polyps by 18 months. After 9 years of follow-up, there was no evidence of colorectal cancer development or progression of polyposis. This is the first case report on long-term treatment with COX-2 inhibition in a patient with AFAP and previous colonic carcinoma.     

Colonic interposition in a woman with attenuated familial adenomatosis polyposis: does the location of the colon affect polyp formation?

Attenuated familial adenomatous polyposis (AFAP) is a rare but well-established cause of colorectal carcinoma and multiple polyps. The present paper describes a case of a woman diagnosed with colorectal cancer at 34 years of age and subsequently found to have AFAP by genetic testing. During infancy, the patient underwent surgical correction of esophageal atresia with colonic interposition. While she had developed adenomatous polyps in her native cecum, there was no evidence of polyps or cancer in the segment of large intestine interposed between her upper esophagus and stomach. Therefore, various environmental differences between the upper and lower gastrointestinal tract may play a role in the expression of AFAP phenotype.     

A Novel Germline Mutation in Exon 15 of the APC Gene in Attenuated Familial Adenomatous Polyposis: A Report of Two Cases

Attenuated familial adenomatous polyposis (AFAP) is a variant of familial adenomatous polyposis with fewer than one hundred colorectal polyps and a later age of onset of the cancer. Here, we report two cases of AFAP within family members. Each patient demonstrated the same novel germ line mutation in exon 15 of the adenomatous polyposis coli (APC) gene and was successfully managed with sulindac after refusal to perform colectomy: a 23-year-old man with incidentally diagnosed gastric adenoma and fundic gland polyps underwent colonoscopy, and fewer than 100 colorectal polyps were found; a 48-year-old woman who happened to be the mother of the 23-year-old man also showed fewer than 100 colorectal polyps on colonoscopy. Genetic analysis revealed a novel frameshift mutation in exon 15 of the APC gene. The deletion of adenine-guanine with the insertion of thymine in c.3833-3834 resulted in the formation of stop codon 1,287 in both patients. The patients were treated with sulindac due to their refusal to undergo colectomy. The annual follow-up upper endoscopy and colonoscopy in the following 2 years revealed significant regression of the colorectal polyps in both patients.     

Novel Germline APC Mutations in Swedish Patients with Familial Adenomatous Polyposis and Gardner Syndrome

Background: Familial adenomatous polyposis (FAP) is a familial cancer syndrome in which affected individuals develop multiple adenomatous polyps and are thereby at greatly increased risk of developing colorectal cancer. Gardner syndrome is a variant of FAP, in which the patients also develop extraintestinal tumors, in particular osteomas and desmoid tumors. An attenuated form of the disease (AFAP) is associated with fewer polyps, but still a high risk for colorectal cancer. Germline mutations in the adenomatosis polyposis coli (APC) gene cause FAP and Gardner syndrome and have recently been associated also with the development of AFAP. Methods: We have analysed the entire APC gene for germline mutations in 7 patients with FAP and in 6 patients with suspected AFAP. Mutation screening was performed by direct sequencing of exons 1-14 and using the protein truncation test for analysis of exon 15. Results: Novel disease-causing germline mutations, all of which resulted in truncation of the APC protein, were identified in 6 of the 7 patients with FAP or Gardner syndrome. No APC mutation was detected in any of the 6 patients with suspected AFAP. Conclusions: This study reports novel FAP- and Gardner syndrome-causing mutations in the APC gene. The lack of APC mutations in patients with multiple polyps at young age indicates that other genetic defects may cause this phenotype.     

Novel germline APC mutations in Swedish patients with familial adenomatous polyposis and Gardner syndrome

BACKGROUND: Familial adenomatous polyposis (FAP) is a familial cancer syndrome in which affected individuals develop multiple adenomatous polyps and are thereby at greatly increased risk of developing colorectal cancer. Gardner syndrome is a variant of FAP, in which the patients also develop extraintestinal tumors, in particular osteomas and desmoid tumors. An attenuated form of the disease (AFAP) is associated with fewer polyps, but still a high risk for colorectal cancer. Germline mutations in the adenomatosis polyposis coli (APC) gene cause FAP and Gardner syndrome and have recently been associated also with the development of AFAP. METHODS: We have analysed the entire APC gene for germline mutations in 7 patients with FAP and in 6 patients with suspected AFAP. Mutation screening was performed by direct sequencing of exons 1-14 and using the protein truncation test for analysis of exon 15. RESULTS: Novel disease-causing germline mutations, all of which resulted in truncation of the APC protein, were identified in 6 of the 7 patients with FAP or Gardner syndrome. No APC mutation was detected in any of the 6 patients with suspected AFAP. CONCLUSIONS: This study reports novel FAP- and Gardner syndrome-causing mutations in the APC gene. The lack of APC mutations in patients with multiple polyps at young age indicates that other genetic defects may cause this phenotype.     

The patient with multiple intestinal polyps

The management of patients with multiple intestinal polyps may be difficult and greatly depends on the correct classification. Polyposis syndromes account for less than 1% of newly diagnosed colorectal cancers. In addition the risk for extracolonic cancer is increased in most syndromes. Here we report the case of a difficult patient with severe gastric polyposis and we present a review of polyposis syndromes such as classical and attenuated familial adenomatous polyposis (FAP), MYH-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis as well as rare polyposis syndromes. The most practical approach for the diagnostic workup in patients with newly diagnosed gastrointestinal polyposis is based on the histological typing of polyps. In addition, a detailed family history regarding cancer, polyps and congenital abnormalities should be obtained from every polyposis patient. Patients with multiple adenomas are most likely to suffer from FAP, AFAP or MAP. Of these, younger age and higher polyp count are most likely a diagnosis of typical FAP. Older age and fewer polyps favour a diagnosis of AFAP or MAP. Germline testing of the APC gene is suggested, and if negative, MYH gene testing should be done. In patients with hamartomas, extraintestinal features should be evaluated and reference histology should be initiated. In addition panintestinal imaging should be performed with EGD, colonoscopy and small bowel imaging (PE, CE, and MR) enteroclysis. For diagnostic and therapeutic problems a familial colorectal cancer center should be consulted. Using this algorithm, correct classification and adequate treatment should be possible for every polyposis patient.     

Colonic polyps in children and adolescents.

Colonic polyps most commonly present with rectal bleeding in children. The isolated juvenile polyp is the most frequent kind of polyp identified in children. 'Juvenile' refers to the histological type of polyp and not the age of onset of the polyp. Adolescents and adults with multiple juvenile polyps are at a significant risk of intestinal cancer. The challenge for adult and pediatric gastroenterologists is determining the precise risk of colorectal cancer in patients with juvenile polyposis syndrome. Attenuated familial adenamatous polyposis (AFAP) can occur either by a mutation at the extreme ends of the adenomatous polyposis coli gene or by biallelic mutations in the mutY homologue (MYH) gene. The identification of MYH-associated polyposis as an autosomal recessive condition has important implications for screening and management strategies. Adult and pediatric gastroenterologists need to be aware of the underlying inheritance patterns of polyposis syndromes so that patients and their families can be adequately evaluated and managed. Colonic polyps, including isolated juvenile polyps, juvenile polyposis syndrome, FAP, AFAP and MYH-associated polyposis, are discussed in the present review.     

The AAPC case,with an early onset of colorectal cancer

Introduction Attenuated adenomatous polyposis coli (AAPC) is a variant of the familial adenomatous polyposis (FAP) characterized by the occurrence of sparse polyps in the colon, stomach, and duodenum with a late onset of colorectal cancer. The AAPC syndrome is associated with mutations at the 5′ region of the APC gene. Until recently, the fragment encompassing codons 157 and 170 was considered as boundary for the described cases of AAPC and FAP syndromes. Materials and methods This study describes a case of the AAPC syndrome caused by a CCTT deletion at codon 173, with polyps diagnosed at the age of 17. The father and grandfather of the proband died of colorectal cancer (CRC), which developed from untreated polyps, at the age 35 and 40, respectively. Results and discussions In the case of the proband’s father, the untreated polyps led to death after 12 years. The proband revealed a low number of polyps and an extra colon feature characteristic of AAPC, but the polyps onset and the death of CRC of two family members, who refused colectomy, was very early and characteristic for FAP. An atypical course of AAPC must be taken into consideration both in genetic counseling and in qualifying the patients with AAPC for the surgical treatment.     

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.ConclusionClinicians 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.     

Hereditary colorectal cancer]

Hereditary syndromes cause approximately 5 to 15% of overall colorectal cancer (CRC) cases. Hereditary CRC is conventionally divided into two major categories: hereditary non-polyposis colorectal cancer (HNPCC) and those related to polyposis syndromes including familial adenomatous polyposis (FAP), Peutz-Jegher syndrome (PJS), and juvenile polyposis (JP). The screening for the cancer and methods of treatment applied to patients with hereditary CRC are quite different from those applied to the general population. The genes responsible for these syndromes has recently identified, as a result, genetic testing has become the most important determining factor in clinical decisions. Germ-line mutation of the APC gene induces FAP, an autosomal dominant disorder, characterized by the development of hundreds to thousands of colonic adenomas. CRC appears in almost all affected individuals by the time they are 50 years of age. An affected individual should undergo colectomy by his/her late teens. Furthermore, according to the findings of genetic testing, at-risk family members also need endoscopic surveillance and surgery. Recently, a mutation on the MYH gene is increasingly being investigated in patients with multiple polyps, and autosomal recessive MYH polyposis is considered to be a new category of polyposis. More common than FAP, HNPCC is caused by germ-line mutations in DNA mismatch repair genes, mainly MLH1 and MSH2. Although there is no polyposis, polyps seem to be more villous and dysplastic and appear to grow rapidly into CRCs. The aggregate lifetime risk of CRC is about 80% for mutation carriers. The risk for other types of cancer, such as endometrial, ovarian, small bowel, and transitional cell cancer, is also increased. The Amsterdam criteria and Bethesda guidelines are the best-known tools for diagnosis and genetic testing, and colectomy followed by endoscopic follow-up is the standard treatment. PJS and JP are reported to be characterized by hamartomatous polyps throughout the GI tract and germ-line mutations in the STK11 gene (PJS) and the DPC4/BMPR1A gene (JP).     

Attenuated familial adenomatous polyposis: an evolving and poorly understood entity.

PURPOSE: Familial adenomatous polyposis is a well-described, autosomal dominant, inherited syndrome characterized by diffuse polyposis of the colon and rectum as well as various upper gastrointestinal and extraintestinal manifestations. A subset of patients present with fewer colorectal polyps, later age of onset of polyps and cancer, and a predilection toward involvement of the proximal colon. This variant of familial adenomatous polyposis is known as attenuated familial adenomatous polyposis. The purpose of this review is to summarize current knowledge regarding this poorly understood entity and propose guidelines for diagnosis, surveillance, and surgical management. METHODS: The MEDLINE database was searched from 1985 onward using the keywords, "attenuated familial adenomatous polyposis," "AFAP," "adenomatous polyposis coli gene," and "APC gene." Additional articles were identified through the reference sections of retrieved papers. All papers that pertained to attenuated familial adenomatous polyposis or mutations in the APC gene producing an attenuated phenotype were included. RESULTS: Attenuated familial adenomatous polyposis is transmitted in an autosomal dominant fashion. Several distinct mutations within the APC gene have been associated with an attenuated phenotype, but variability of disease expression within kindreds possessing identical mutations makes classification difficult. Polyps are diagnosed at a mean age of 44 years, with cancer diagnosed at a mean of 56 years of age. Frequent involvement of the proximal colon necessitates the use of colonoscopy for surveillance, and infrequent involvement of the rectum supports the role of a total abdominal colectomy and ileorectal anastomosis. CONCLUSIONS: Although currently recognized as a distinct clinical entity, attenuated familial adenomatous polyposis may be part of a spectrum of disease that includes familial adenomatous polyposis and is caused by different mutations within the APC gene. Because of its unique characteristics, yet apparent overlap with familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer, increased awareness of attenuated familial adenomatous polyposis should improve diagnosis, surveillance, and treatment strategies in this unique subset of familial polyposis syndromes.     

Familial adenomatous polyposis complicated by chronic myelogenous leukemia: response to imatinib mesylate

Familial adenomatous polyposis (FAP) is an autosomal dominant disorder characterized by colonic polyposis and a predisposition for developing colorectal cancer. FAP is frequently complicated by extracolonic disease, but complications of leukemia are rare. We present the first case of FAP complicated by chronic myelogenous leukemia (CML) in a 38-year-old man. The patient had numerous adenomas in the colorectum and a family history compatible with FAP. He was diagnosed as having FAP in February 2000. Two years after the diagnosis, he developed leukocytosis with the Philadelphia chromosome abnormality, indicating complication with CML. Imatinib mesylate was administered for the treatment of CML, and hematologic and cytogenetic remission of CML was achieved in 6 months. Numerous polyps, 2 to 3 mm in diameter, observed in the rectum prior to the administration of imatinib, regressed in size, but not in number, after 1 year of treatment with imatinib. Eighteen months later, however, the polyps were enlarged. In this patient, imatinib administration led to the remission of CML and might also have been responsible for the temporary regression of adenomatous polyps of FAP.     

The genetics of familial adenomatous polyposis (FAP) and MutYH-associated polyposis (MAP)

FAP is characterized by 100-1000s of adenomatous polyps in colon and rectum, and is in 70% of the patients associated with extracolonic manifestations. Attenuated FAP (AFAP) is a less severe form of FAP, marked by the presence of < 100 polyps and a later onset of colorectal cancer (CRC). (A)FAP is caused by autosomal dominantly inherited mutations in the APC (Adenomatous polyposis coli) gene, a tumour suppressor gene that controls beta-catenin turnover in the Wnt pathway. De novo occurrence is reported in 30-40% of the patients. Mutations are detected in 85% of classical FAP families, while only 20%-30% of AFAP cases will exhibit a germline APC mutation. MUTYH is the second (A)FAP-related gene and is involved with base-excision repair of DNA damaged by oxidative stress. MUTYH mutations are inherited in an autosomal recessive way and account for 10%-20% of classical FAP cases without an APC mutation and for 30% of AFAP cases. Genotype-phenotype correlations exist for mutations in the APC gene, however, contradictions in the literature caution against the sole use of the genotype for decisions regarding clinical management. Once the family's specific APC mutation is identified in the proband, predictive testing for first degree relatives is possible from the age of 10 to 12 years on. For AFAP, relatives are tested at age 18 and older. Opinions about the appropriate ages at which to initiate genetic testing may vary. Physicians must have a discussion about prenatal testing with patients in childbearing age. They may either opt for conventional prenatal diagnosis (amniocentesis or chorionic villous sampling) or for preimplantation genetic diagnosis (PGD).     

Germline mutations of the MYH gene in Korean patients with multiple colorectal adenomas

Background Most investigations on MutY human homolog (MYH)-associated polyposis (MAP) have been conducted in Western countries. Limited data on MAP in Asia are currently available. The present study investigated germline mutations of the MYH gene among patients with 10 to 99 adenomatous colorectal polyps and familial adenomatous polyposis (FAP) without adenomatous polyposis coli (APC) germline mutations in Korea. Materials and methods The study population included 46 patients with 10 to 99 adenomatous polyps in the colorectum and 16 FAP patients with no identified APC germline mutations. Subjects were screened for MYH germline mutations, and we additionally screened for MYH mutations in 96 normal control individuals. Results Two of 46 (4.3%) patients with multiple polyps displayed heterozygous biallelic germline mutations of the MYH gene. A 39-year-old male patient with biallelic MYH mutations (p.G272E and p.A359V) received total proctocolectomy for rectal cancer and 36 colorectal polyps. A 58-year-old female patient with biallelic MYH mutations (p.Q253X and p.Q440P) received right hemicolectomy for ascending colon cancer and 16 colonic polyps. The frequency of biallelic MYH mutation in 14 of 46 multiple-polyp patients, who had 15 to 99 polyps, was 14.3% (2 of 14). No biallelic MYH mutations were detected in the 32 patients with 10 to 14 colorectal polyps, 16 FAP patients, or 96 normal controls. Conclusion We identified biallelic MYH germline mutations in 2 of 14 (14.3%) Korean patients with 15 to 99 colorectal polyps. In this study, there was no Y165C or G382D hot-spot mutation, which had been reported most frequently in previous studies.     

Hepatocellular adenoma associated with familial adenomatous polyposis coli

Hepatocellular adenoma (HCA) is a benign liver tumor that most frequently occurs in young women using oral contraceptives. We report a rare case of HCA in a 29 years old female with familial adenomatous polyposis (FAP). The first proband was her sister, who under-went a total colectomy and was genetically diagnosed as FAP. A tumor, 3.0 cm in diameter, was detected in the right lobe of the liver during a screening study for FAP. A colonoscopy and gastroendoscopy revealed numerous adenomatous polyps without carcinoma. The patient underwent a total colectomy and ileoanal anastomosis and hepatic posterior sectoriectomy. The pathological findings of the liver tumor were compatible with HCA. The resected specimen of the colon revealed multiple colonic adenomatous polyps. Examination of genetic alteration revealed a germ-line mutation of the adenomatous polyposis coli (APC) gene. Inactivation of the second APC allele was not found. Other genetic alterations in the hepatocyte nuclear factor 1 alpha and β-catenin gene, which are reported to be associated with HCA, were not detected. Although FAP is reported to be complicated with various neoplasias in extracolic organs, only six cases of HCA associated with FAP, including the present case, have been reported. Additional reports will establish the precise mechanisms of HCA development in FAP patients.     

Attenuated familial adenomatous polyposis presenting as ampullary adenocarcinoma

The risk of periampullary cancer in patients with classic familial adenomatous polyposis (FAP) is significantly increased compared with the general population. However, the incidence of this extracolonic manifestation in attenuated FAP (AFAP) is unknown. We report the case of a 38 year old woman with no known family history of polyposis or colorectal cancer, who presented with ampullary adenocarcinoma. Diagnosis of AFAP was made only after evaluation of the patient's extended family history and genetic testing. This case report suggests that AFAP should be included in the differential diagnosis of patients with ampullary/duodenal tumours.     

Genetic testing and phenotype in a large kindred with attenuated familial adenomatous polyposis

BACKGROUND & AIMS: An attenuated form of familial adenomatous polyposis has been described, but the phenotype remains poorly understood. METHODS: We performed genetic testing on 810 individuals from 2 attenuated familial adenomatous polyposis kindreds harboring an identical germline adenomatous polyposis coli gene mutation. Colonoscopy was performed on mutation-positive persons. RESULTS: The disease-causing mutation was present in 184 individuals. Adenomatous polyps were present in 111 of 120 gene carriers who had colonoscopy at an average age of 41 years. The median number of adenomas was 25 (range, 0-470), with striking variability of polyp numbers and a proximal colonic predominance of polyps. Colorectal cancer occurred in 27 mutation carriers (average age, 58 years; range, 29-81 years), with 75% in the proximal colon. The cumulative risk of colorectal cancer by age 80 was estimated to be 69%. An average of 3.4 recurrent polyps (range, 0-29) were found in the postcolectomy rectal remnant over a mean of 7.8 years (range, 1-34 years), with 1 rectal cancer. CONCLUSIONS: This investigation shows that attenuated familial adenomatous polyposis in the kindreds examined shows a much smaller median number of polyps than typical familial adenomatous polyposis, a wide variability in polyp number even at older ages, and a more proximal colonic location of polyps and cancer, yet it is associated with an extremely high risk of colon cancer. The phenotype of attenuated familial adenomatous polyposis mimics typical familial adenomatous polyposis in some cases but in others is difficult to distinguish from sporadic adenomas and colorectal cancer, thus making genetic testing particularly important.     

Effect of sulindac treatment for attenuated familial adenomatous polyposis with a new germline APC mutation at codon 161: report of a case

INTRODUCTION: Patients with familial adenomatous polyposis develop colorectal cancers if left untreated. As indicated in patients with familial adenomatous polyposis, prophylactic colectomy has been recommended even in a milder colonic phenotype referred to as attenuated familial adenomatous polyposis. However, therapeutic strategies in attenuated familial adenomatous polyposis are still controversial. METHODS: We report a patient with attenuated familial adenomatous polyposis who has been treated with sulindac for five years. During the period of observation, she has been carefully followed up by chromoscopic and radiographic surveillance. Immunohistochemical study for cyclooxygenase-2 and genetic analysis in the adenomatous polyposis coli gene was also performed. RESULTS: Continuous administration of sulindac resulted in obvious regression of both colorectal adenomatous polyps and gastric fundic gland polyps, and no cancers developed during the observation period. Immunohistochemical study showed the decrease of cyclooxygenase-2-positive epithelial cells in colorectal polyps by the treatment. The genetic analysis revealed a C to A substitution at nucleotide 481 of her germline adenomatous polyposis coli gene, which resulted in a nonsense mutation at codon 161. CONCLUSIONS: Our case suggests that treatment with sulindac accompanied by intensive colonoscopic surveillance may be a choice of management for attenuated familial adenomatous polyposis.     

Ulcerative colitis with inflammatory polyposis in a teenage boy:A case report

Ulcerative colitis in addition to inflammatory polyposis is common.The benign sequel of ulcerative colitis can sometimes mimic colorectal carcinoma.This report describes a rare case of inflammatory polyposis with hundreds of inflammatory polyps in ulcerative colitiswhich was not easy to distinguish from other polyposis syndromes.A 16-year-old Chinese male suffering from ulcerative colitis for 6 mo underwent colonoscopy,and hundreds of polyps were observed in the sigmoid,causing colonic stenosis.The polyps were restricted to the sigmoid.Although rectal inflammation was detected,no polyps were found in the rectum.A diagnosis of inflammatory polyposis and ulcerative colitis was made.The patient underwent total colectomy and ileal pouch anal anastomosis.The patient recovered well and was discharged on postoperative day 8.Endoscopic surveillance after surgery is crucial as ulcerative colitis with polyposis is a risk factor for colorectal cancer.Recognition of polyposis requires clinical,endoscopic and histopathologic correlation,and helps with chemoprophylaxis of colorectal cancer,as the drugs used postoperatively for colorectal cancer,ulcerative colitis and polyposis are different.