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

Incidence and natural history of gastric high-grade dysplasia in patients with familial adenomatous polyposis syndrome

BACKGROUND AND AIMS

Familial adenomatous polyposis (FAP) is characterized by high risks of colonic and extracolonic tumors. Recent studies have suggested a rising risk for gastric cancer (GC). We sought to define the spectrum of premalignant gastric polyps in FAP, focusing on high-grade dysplasia (HGD).

METHODS

The gastric phenotypes of 118 patients diagnosed with FAP or attenuated FAP in our Hereditary Gastrointestinal Cancer Registry were retrospectively reviewed. To analyze the clinical features associated with the diagnosis of HGD, we established an age- and sex-matched control group of FAP patients from our cohort without gastric HGD in a 4:1 ratio.

RESULTS

The spectrum and frequency of gastric polyps in individuals with FAP included fundic gland polyps (67.9%), hyperplastic polyps/foveolar hyperplasia (19.6%), tubular adenomas (15.2%), foveolar adenomas (10.7%), and pyloric gland adenomas (6.3%). Ten patients (8.9%) exhibited gastric HGD at a mean age of 55 ± 13 years, and HGD was seen in all polyp types. When compared with control subjects, HGD was associated with a high diversity of gastric polyp histology, prior low-grade dysplasia, severe gastric polyposis, and prior Whipple surgery (P = 2.0E-5, .003, .024, and .04, respectively). Two patients (1.7%) with HGD were diagnosed with GC. However, the remaining 8 patients with HGD have been under surveillance for an average of 5.8 ± 4.5 years without progression to GC.

CONCLUSIONS

Gastric HGD in FAP may be more common than previously appreciated. The natural history of HGD is variable, and most patients with HGD do not appear to progress to GC.

Role of Endoscopy in Management of Upper Gastrointestinal Cancers

Upper gastrointestinal (GI) malignancy is a leading cause of cancer-related morbidity and mortality. Upper endoscopy has an established role in diagnosing and staging upper GI cancers, screening for pre-malignant lesions, and providing palliation in cases of advanced malignancy. New advances in endoscopic techniques and technology have improved diagnostic accuracy and increased the therapeutic potential of upper endoscopy. We aim to describe the different types of endoscopic technology used in cancer diagnosis, summarize the current guidelines for endoscopic diagnosis and treatment of malignant and pre-malignant lesions, and explore new potential roles for endoscopy in cancer therapy.

Strong Hereditary Predispositions to Colorectal Cancer

Cancer is one of the most common causes of death worldwide. A strong predisposition to cancer is generally only observed in colorectal cancer (5% of cases) and breast cancer (2% of cases). Colorectal cancer is the most common cancer with a strong genetic predisposition, but it includes dozens of various syndromes. This group includes familial adenomatous polyposis, attenuated familial adenomatous polyposis, MUTYH-associated polyposis, NTHL1-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis syndrome, Cowden syndrome, Lynch syndrome, and Muir-Torre syndrome. The common symptom of all these diseases is a very high risk of colorectal cancer, but depending on the condition, their course is different in terms of age and range of cancer occurrence. The rate of cancer development is determined by its conditioning genes, too. Hereditary predispositions to cancer of the intestine are a group of symptoms of heterogeneous diseases, and their proper diagnosis is crucial for the appropriate management of patients and their successful treatment. Mutations of specific genes cause strong colorectal cancer predispositions. Identifying mutations of predisposing genes will support proper diagnosis and application of appropriate screening programs to avoid malignant neoplasm.

Endoscopic Findings and Treatment of Gastric Neoplasms in Familial Adenomatous Polyposis

PURPOSE

Gastric neoplasia is a common manifestation of familial adenomatous polyposis (FAP). This study aimed to elucidate the clinical characteristics, endoscopic features including fundic gland polyposis (FGPsis), and treatment outcomes of gastric neoplasms (GNs) in patients with FAP.

MATERIALS AND METHODS

A total of 35 patients diagnosed with FAP, including nine patients from four pedigrees who underwent esophagogastroduodenoscopy (EGD), were investigated regarding patient characteristics, GN morphology, and treatment outcomes.

RESULTS

Twenty-one patients (60.0%) had 38 GNs; 33 (86.8%) and 5 (13.2%) were histologically diagnosed with adenocarcinoma and adenoma, respectively. There were no specific patient characteristics related to GNs. Nodule-type GNs were more prevalent in patients with FGP than without (52.2% vs. 0.0%, P=0.002) in the upper body of the stomach. Conversely, depressed-type GNs were fewer in patients with FGPsis than in those without (13.0% vs. 73.3%, P<0.001). Slightly elevated-type GNs were observed in both groups (34.8% vs. 20.0%, P=0.538). Even within pedigrees, the background gastric mucosa and types of GNs varied. In total, 24 GNs were treated with endoscopic submucosal dissection (ESD) and eight with endoscopic mucosal resection (EMR). EMR was selected for GNs with FGPsis because of the technical difficulty of ESD, resulting in a lower en bloc resection rate (62.5% vs. 100%, P=0.014).

CONCLUSIONS

Our study indicates the necessity of routine EGD surveillance in patients diagnosed with FAP. Notably, the morphology and location of GNs differed between patients with and without FGPsis. Endoscopic treatment and outcomes require more attention in cases of FGPsis.

Novel Endoscopic Polypectomy Surveillance Technique for Fundic Gland Polyps in Familial Adenomatous Polyposis Can Improve Early Detection of Dysplasia and Gastric Cancer

INTRODUCTION

Fundic gland polyps (FGPs) are commonly found in patients with familial adenomatous polyposis (FAP) and are considered benign. Biopsies are not routinely performed, and conventional forceps may be time-consuming and/or yield nonrepresentative histology. The purpose of this study was to evaluate the role of a novel endoscopic polypectomy surveillance (EPS), a large volume cold-snare polypectomy technique of random FGPs, in the incidence of dysplasia and gastric cancer (GC) in FAP.

METHODS

This is a retrospective longitudinal cohort of patients with FAP referred to a tertiary care center for duodenal adenoma surveillance and who underwent EPS of FGPs between 2001 and 2019. Demographic, endoscopic, and clinicopathologic information was reviewed.

RESULTS

Thirty-five patients with FAP were identified at initial endoscopy by the mean age of 43.4 years (±12.8). One hundred thirteen surveillance endoscopies were performed in total using EPS. Dysplasia of FGPs was present on initial esophagogastroduodenoscopy in 7 patients (20%), and 13 additional patients (46.4%) progressed to low-grade dysplasia. Three patients (15%) who subsequently had progression to GC were found to have signet ring cell cancer within the foci of FGPs through EPS. One patient presented as metastatic GC. Progression from nondysplastic FGP to low-grade dysplasia occurred over 63 months (±46.3) with further progression to GC over 34 months (±8.5). Endoscopic risk factors for cancer were polyps &gt;10 mm in size ( P &lt; 0.001) and carpeting of polyps ( P &lt; 0.001). The 5-year cumulative incidence of developing dysplasia was 35.7%.

DISCUSSION

We identified that the incidence of dysplasia and GC is higher than previously reported in patients with FAP. Our study used a novel EPS technique and was able to identify GC within the foci of FGPs. Upper endoscopic guidelines should include a more rigorous sampling method for FGPs, such as EPS, to optimize early detection of dysplasia and GC.

Combination of Sulindac and Eflornithine Delays the Need for Lower Gastrointestinal Surgery in Patients With Familial Adenomatous Polyposis: Post Hoc Analysis of a Randomized Clinical Trial

BACKGROUND

Colectomy and proctocolectomy are the initial standard of care for patients with familial adenomatous polyposis. Pharmacotherapy to prevent the progression of polyposis and surgeries in the lower GI tract would be beneficial to patients with this disease.

OBJECTIVE

This analysis aimed to evaluate the impact of eflornithine-sulindac combination versus monotherapy in delaying time to disease progression in the lower GI tract of patients with familial adenomatous polyposis.

DESIGN

This is a post hoc analysis of a randomized phase 3 trial.

SETTING

This study was conducted in 21 hospitals in 7 countries treating patients with familial adenomatous polyposis.

PATIENTS

Adults with familial adenomatous polyposis were randomly assigned 1:1:1 into 3 arms.

INTERVENTIONS

Patients received either eflornithine (750 mg), sulindac (150 mg), or both once daily for up to 48 months.

MAIN OUTCOME MEASURES

Efficacy was evaluated as the time from randomization to predefined primary disease progression end points.

RESULTS

A total of 158 patients were included in the study. Disease progression was observed in 2 of 54 (3.7%), 9 of 53 (17.0%), and 10 of 51 (19.6%) patients with at least partial lower GI tract in the combination, sulindac, and eflornithine arms, corresponding to risk reductions of 80% (p = 0.02) and 83% (p = 0.01) between combination and sulindac or eflornithine. When endoscopic excision of adenomas ≥10 mm in size was censored, the need for major surgery was observed in 0 of 54, 7 of 53 (13.2%), and 8 of 51 (15.7%) patients in the combination, sulindac, and eflornithine arms, corresponding to risk reductions approaching 100% between combination and sulindac (p = 0.005) or combination and eflornithine (p = 0.003).

LIMITATIONS

This was a post hoc analysis, the sample size was small, and there were fewer than expected events.

CONCLUSIONS

Eflornithine-sulindac combination therapy was superior to either drug alone in delaying or preventing the need for lower GI tract surgery in patients with familial adenomatous polyposis. See Video Abstract at http://links.lww.com/DCR/B658.

REGISTRATION

ClinicalTrials.gov, NCT01483144; EU Clinical Trials Register, EudraCT 2012-000427-41.

LA COMBINACIN DE SULINDAC Y EFLORNITINA RETRASA LA NECESIDAD DE CIRUGA DEL TUBO DIGESTIVO BAJO EN PACIENTES CON PAF ANLISIS POSTHOC DE UN ENSAYO CLNICO ALEATORIZADO

ANTECEDENTES:La colectomía y la proctocolectomía son el estándar inicial de atención para los pacientes con poliposis adenomatosa familiar. La farmacoterapia para prevenir la progresión de la poliposis y las cirugías en el tracto gastrointestinal inferior sería beneficiosa para los pacientes con esta enfermedad.OBJETIVO:Este análisis tuvo como objetivo evaluar el impacto de la combinación de eflornitina-sulindac versus la monoterapia en el retraso del tiempo hasta la progresión de la enfermedad en el tracto gastrointestinal inferior de pacientes con poliposis adenomatosa familiar.DISEÑO:Este es un análisis posthoc de un ensayo de fase 3 aleatorizado.ENTORNO CLINICO:Veintiún hospitales en 7 países que tratan a pacientes con poliposis adenomatosa familiar.PACIENTES:Adultos con poliposis adenomatosa familiar fueron aleatorizados 1: 1: 1 en 3 brazos.INTERVENCIONES:Los pacientes recibieron eflornitina (750 mg), sulindac (150 mg) o ambos una vez al día durante un máximo de 48 meses.PRINCIPALES MEDIDAS DE VALORACION:La eficacia se evaluó como el tiempo desde la aleatorización hasta los criterios de valoración primarios predefinidos de progresión de la enfermedad.RESULTADOS:Los resultados se informan para la población de estudio excluyendo a los pacientes que se habían sometido a ileostomías permanentes (n = 158). Se observó progresión de la enfermedad en 2/54 (3,7%), 9/53 (17,0%) y 10/51 (19,6%) pacientes con al menos tracto gastrointestinal inferior parcial en los brazos de combinación, sulindac y eflornitina, respectivamente, correspondientes al riesgo de reducciones del 80% (p = 0,02) y del 83% (p = 0,01) entre la combinación y el sulindaco o la eflornitina, respectivamente. Cuando se censuró la escisión endoscópica de adenomas ≥10 mm de tamaño, se observó la necesidad de cirugía mayor en 0/54, 7/53 (13,2%) y 8/51 (15,7%) pacientes en la combinación, sulindac y eflornitina, respectivamente, correspondientes a reducciones de riesgo cercanas al 100% entre combinación y sulindac (p = 0,005) o combinación y eflornitina (p = 0,003).LIMITACIONES:Este fue un análisis posthoc, el tamaño de la muestra fue pequeño y hubo menos eventos de los esperados.CONCLUSIONES:La terapia de combinación de eflornitina-sulindac fue superior a cualquier fármaco solo para retrasar o prevenir la necesidad de cirugía del tracto gastrointestinal inferior en pacientes con poliposis adenomatosa familiar. Consulte Video Resumen en http://links.lww.com/DCR/B658.

Risk for Surgery in Patients with Polyposis Syndrome after Therapy by Device-Assisted Enteroscopy (DAE): Long-Term Follow Up

Background and aim of the study: Polyposis syndromes such as Peutz–Jeghers (PJ) and familial adenomatous polyposis (FAP) are associated with the growth of small bowel polyps; the risk is approximately 60–90% for PJ and 40–70% for FAP. The primary aim of this study was to evaluate the efficacy of device-assisted enteroscopy (DAE) in the detection and treatment of small bowel polyps to reduce the risk of surgery. The secondary objective was to study complications and mortality. Methods: We conducted a retrospective cohort study by analyzing a structured database. Between September 2006 and October 2019, we observed and followed 42 consecutive patients with polyposis syndromes; they underwent device-assisted enteroscopy and three were excluded from elective surgery after the exam. The endoscopic exams were performed for diagnostic and therapeutic purposes. Results: Thirty-nine patients were evaluated with a mean follow up of 6.7 years (±SD 2.7), 79.5% were female with a mean age of 43.8 years (±SD 15.02), and 68 enteroscopies were performed with the removal of 64 polypoid lesions. One bleeding episode occurred after operative enteroscopy, and the need for subsequent surgery occurred in six patients with PJ and in five patients with FAP. The surgical indications in PJ patients were the presence of large polyps (three patients) and three cases of intussusception, one of which was a patient with a polyp in the proximal ileum, not reachable with the scope. One patient with PJ died from pancreatic cancer during follow up. The surgical indications in patients with FAP were the presence of four large polyps with high-grade dysplasia and one ampullary neoplasia recurrence. Conclusions: In PJ patients, the endoscopic treatment of small bowel polyps was safe. During the follow-up period, the patients with successful endoscopic treatment did not need surgery. In FAP patients treated with DAE, none developed cancer.

Trabecular and cortical mandibular bone investigation in familial adenomatous polyposis patients

Mandibular cortical and trabecular bone abnormalities in patients with familial adenomatous polyposis (FAP) were evaluated using dental panoramic radiographs (DPR) radiomorphometric indices and fractal dimension (FD). Sixty DPRs from 15 FAP patients and 45 healthy controls were evaluated. FAP group was composed of 33.3% females and 66.6% males, age_mean = 37.2 years (SD 15.79). The non-FAP group was paired by gender and sex. The parameters analyzed were: FD of the trabecular bone in four regions of interest (ROI), mandibular cortical index (MCI) and width (MCW). FD values were lower for the FAP group. Statistically significance differences were shown by ROI 2 and 3 anteriorly to the mental foramen bilaterally, p = 0.001, and p = 0.006. The ROI 1 and 4, at the mandibular angle trabeculae, indicated statistical significances on the right side (p = 0.036) and no differences on the left side (p = 0.091). There was no significant difference in MCI and MCW when the groups were compared, MCW (L) p = 0.247, and MCW (R) p = 0.070. Fractal values of FAP patients' mandibular trabecular bone were lower than healthy controls. The radiomorphometric indices MCI and MCW were not useful for analyzing the cortical bone pattern. Therefore, FD is a promising tool for detection of abnormal bone structure in DPRs and for supporting the appropriate referral of FAP patients.

Molecular Oncology in Management of Colorectal Cancer

Colorectal cancers are the third most common cancers in the world. Management of both primary and metastatic colorectal cancers has evolved over the last couple of decades. Extensive research in molecular oncology has helped us understand and identify these complex intricacies in colorectal cancer biology and disease progression. These advances coupled with improved knowledge on various mutations have helped develop targeted chemotherapeutics and has allowed planning an effective treatment regimen in this era of immunotherapy with precision. The diverse chemotherapeutic and biological agents at our disposal can make decision making a very complex process. Molecular profile, including CIN, RAS, BRAF mutations, microsatellite instability, ctDNA, and consensus molecular subtypes, are some of the important factors which are to be considered while planning an individualized treatment regimen. This article summarizes the current status of molecular oncology in the management of colorectal cancer and should serve as a practical guide for the clinical team.

High cumulative risk of colorectal cancers and desmoid tumours and fibromatosis in South Asian APC mutation carriers

Management of familial adenomatous polyposis (FAP) is guided by the cumulative risk of colorectal cancer (CRC) and aggressive fibromatosis/desmoid (AF/D). The first non-Caucasian FAP cohort with cumulative risk estimates for CRC and AF/D shows distinct differences with the Caucasian and other Asian cohorts. The strong correlation between the adenomatous polyposis coli (APC) mutation location with the FAP phenotype and the geoethnic differences in APC mutation spectrum, genetic constitution, lifestyle and sporadic CRC rates, mandates the use of population-specific cumulative risk estimates for CRC and desmoid for counselling and risk management. On genotype-phenotype correlation in 83 individuals with classical FAP and a confirmed pathogenic/likely Pathogenic (P/LP) APC variant (n=76) or obligate carrier of the family variant (n=7), we observed a high cumulative CRC risk of 40% and 85% by 40 and 60 years, respectively. The observed 30% cumulative risk by 50 years for desmoids was higher than previous European and Asian cohorts and was significantly associated with prophylactic surgery (OR: 4.58, 95% CI 1.06 to 19.78) and APC mutation 3' of codon 1309 (OR: 13.07, 95% CI 3.58 to 47.56) and also 3' of codon 1444 (OR: 8.0, 95% CI 1.83 to 34.94). Global cooperation is required to establish FAP genotype-phenotype associations and population-specific risk estimates to guide genetic counselling and risk management.

Prevalence and endoscopic treatment outcomes of upper gastrointestinal neoplasms in familial adenomatous polyposis

BACKGROUND

Although upper gastrointestinal (GI) neoplasms are not rare in patients with familial adenomatous polyposis (FAP), few studies have focused on them and the long-term outcomes of their treatment by endoscopy. Therefore, we aimed to investigate the prevalence and endoscopic treatment outcomes of upper GI neoplasms in patients with FAP.

METHODS

Among 215 patients diagnosed with FAP between January 1991 and December 2019, 208 who underwent esophagogastroduodenoscopy were eligible. The clinical features and endoscopic treatment outcomes of upper GI neoplasms were retrospectively investigated and analyzed.

RESULTS

Among the enrolled patients, 113 (54.3%) had one or more upper GI neoplasms: gastric adenoma (n = 34), gastric cancer (n = 7), nonampullary duodenal adenoma (n = 86), and ampullary adenoma (n = 53). Among patients with gastric neoplasms (n = 37), 24 (64.9%) underwent treatment (endoscopic treatment: 22, surgery: 2). No tumor-related mortality occurred during median follow-up of 106 months (interquartile range [IQR] 63-174). Endoscopic treatment was performed in 47 (54.7%) of 86 patients with nonampullary duodenal adenoma and in 32 (60.4%) of 53 patients with ampullary adenoma. No patient underwent surgery for duodenal neoplasms, and no tumor-related mortality occurred during median follow-up of 88 months (IQR 42-145). The proportion of patients with increased Spigelman stage at 2 years after the initial diagnosis or treatment was significantly higher in untreated group than in the group treated for duodenal neoplasms (27.3% vs. 0.0%, p = 0.001).

CONCLUSION

Endoscopic surveillance in FAP patients is important for the detection and treatment of upper GI neoplasms in early stage. In particular, endoscopic therapy for duodenal neoplasms can reduce the severity of duodenal polyposis.

A review of inherited cancer susceptibility syndromes

Inherited cancer syndromes are caused by genetic mutations that place patients at an increased risk for developing cancer. Although most cancers are not caused by genetic inheritance, clinicians must understand these syndromes and be able to recognize their common characteristics. A thorough family history and identification of common patterns as well as specific clinical signs and symptoms can help with early recognition. This article describes symptoms of the more common cancer syndromes, including hereditary breast and ovarian cancer, Li-Fraumeni, Lynch, familial adenomatous polyposis, retinoblastoma, multiple endocrine neoplasia, and von Hippel-Lindau. Important patient education regarding genetic testing also is covered.

Analysis of expression levels of markers associated with tumor proliferation and angiogenesis in familial adenomatous polyposis

Background

Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary disease with colorectal adenomatous polyps as the main clinical manifestations. The objective of this study was to analyze and compare the expression levels of tumor proliferation and angiogenesis‐related genes in different tissue sections of FAP patients through qPCR, western blot, and immunohistochemistry (IHC) analysis.

Methods

Seventeen patients with FAP admitted to Tianjin Union Medical Center from January 2010 to June 2015 were selected, and then, normal intestinal mucosa, polyp tissue, or cancerous polyp tissue were collected. QPCR, western blot, and IHC were used to detect the expression level of genes or proteins correlated with tumor proliferation.

Results

The mRNA expression of CD31 in large polyp tissue was significantly higher than that in normal tissue and small polyp tissue. Compared with normal tissue and polyp tissue, the expression level of KI67 mRNA in cancer tissue was remarkably increased. The VEGFA mRNA and CDH5 mRNA expression in both polyp and cancer tissues were prominently lower than those in normal tissue. The expression of CD31 protein in cancer tissue was lower than that in normal tissue and polyp tissue, whereas the expression levels of VEGF, CDH5, and KI67 protein were widely higher than that in normal tissue and polyp tissue.

Conclusion

Abnormal expressions of CD31, KI67, VEGF(A), and CDH5 were associated with the carcinogenesis of FAP.

Effects of aspirin on the gastrointestinal tract: Pros vs. cons

Acetylsalicylic acid, also known as aspirin, is often used in clinical antipyretic, analgesic and antiplatelet therapy. Aspirin can cause numerous side effects in the gastrointestinal (GI) tract, ranging from unpleasant GI symptoms without gastric mucosal lesions to ulcer bleeding and even death. However, recent studies have found that aspirin can significantly prevent GI tumors. Despite impressive advances in cancer research, screening and treatment options, GI tumors remain a leading cause of death worldwide. Prevention is a far better option than treatment for tumors. Therefore, the present review assesses the pros and cons of aspirin on the GI tract and, on this the basis, the appropriate dose of aspirin to protect it.

Isoperistaltic Jejunal Loop Interposition after Total Gastrectomy for Gastric Cancer in Patients with Familial Adenomatous Polyposis

Gastric cancer is a rare condition affecting patients with familial adenomatous polyposis (FAP). The mainstay of treatment is total gastrectomy. Since duodenal cancer is the most common cause of death after total colectomy in FAP, endoscopic surveillance for duodenal cancer is mandatory. Here, we describe the use of an isoperistaltic jejunal loop interposition technique to reconstruct the digestive tract after total gastrectomy in 2 patients with FAP. There were no early or late complications. Both patients are still alive and in good clinical condition. They did not experience weight loss or symptoms of dumping syndrome. Duodenal endoscopic surveillance after this technique was easier than after the classical Roux-en-Y reconstruction. Hence, regular follow-up was possible for both patients.

An APC Mutation in a Large Chinese Kindred With Familial Adenomatous Polyposis Was Identified Using Both Next Generation Sequencing and Simple STR Marker Haplotypes

Background

Familial adenomatous polyposis (FAP) is an autosomal dominant disorder characterized primarily by the development of numerous adenomatous polyps in the colon and a high risk for colorectal cancer. FAP is caused by germline mutations of the adenomatous polyposis coli (APC) gene. The proband in this family was a 39-year-old female patient with the pathologic diagnosis of adenomatous polyps, and then a five-generation kindred with FAP was characterized in the following years. This article identified an APC mutation, and demonstrated the practical use of APC-linked STR markers, which could be used to reduce misdiagnosis of prenatal diagnosis or preimplantation genetic diagnosis resulted from contamination or allele drop-out.

Methods

Next-generation sequencing (NGS) was used to identify the possible APC mutations in an affected individual from a family with autosomal dominant colon cancer. Targeted sequencing then used to identify additional related individuals with the mutation. Three short tandem repeat (STR) loci, D5S299, D5S134, and D5S346, were used for PCR-based microsatellite analysis of the APC gene in the extended family.

Results

We identified an APC: p.W553X mutation. The STR haplotype at the APC locus, A1B4C1, was shared by all clinically affected individuals with the APC: p.W553X mutation. In addition, the APC: p.D1822V variant was observed in 40% affected individuals and in two unaffected individuals.

Conclusion

We described a protein truncation mutation, APC: p.W553X; demonstrated the value of APC-linked STR markers (D5S299, D5S134, and D5S346) haplotypes; and suggested the potential role of these haplotypes in detecting loss of heterozygosity of the APC gene.

Clinical and Molecular Investigation of Familial Multiple Lipomatosis: Variants in the HMGA2 Gene

Background

Familial multiple lipomatosis (FML) is an autosomal dominant disorder characterized by the slow growth of encapsulated nodules spread across the trunk and limbs. Currently, there is no specific etiology; therefore, its molecular and biological bases need to be better understood. High-throughput sequencing technologies appear to be a cost-effective tool and have a pivotal role in elucidating different genodermatoses.

Objective

This study aimed to perform a clinical and molecular characterization of constitutional DNA of seven individuals belonging to five unrelated families diagnosed with FML.

Patients and methods

Clinical aspects were obtained from medical records and physical examination. HMGA2 gene was investigated using Sanger sequencing method. Mutational analysis of other genes associated with syndromic lipomatosis AKT1, APC, PIK3CA, MEN-1, and PTEN was performed through next-generation sequencing.

Results

In this series, FML was predominant among women who were overweight and reaching the age of thirty and was associated with gastrointestinal comorbidity. Histopathological diagnosis of biopsies revealed typical features of both lipoma and angiolipoma. We identified two identical novel variants with unknown significance in exon 5 of the HMGA2 gene in two participants of different families. There were no additional changes in exons 1 to 4 of the HMGA2 gene. Multi-gene panel was normal in all cases.

Conclusion

Variants found in exon 5 of the HMGA2 gene have not been described and have an uncertain significance in the genesis of FML. Further studies, including a more significant number of affected individuals and functional analysis of the novel variants of HGMA2 gene, should be undertaken to better understand its biological role in FML.

Gastrointestinal Polyposis in Pediatric Patients

Gastrointestinal polyps are mucosal overgrowths that, if unchecked, can undergo malignant transformation. Although relatively uncommon in the pediatric age group, they can be the harbingers of multiorgan cancer risk and require close management and follow-up. Additionally, as many polyposis syndromes are inherited, appropriate genetic testing and management of relatives is vital for the health of the entire family. In this review, we discuss both common and uncommon childhood gastrointestinal polyposis syndromes in terms of clinical presentation, management, and surveillance. We also detail any additional malignancy risk and surveillance required in the pediatric age group (<21 years old). Through this review, we provide a framework for gastroenterologists to manage the multifaceted nature of pediatric polyposis syndromes.

Diffuse Intense Intestinal FDG Activity in a Patient With Familial Adenomatous Polyposis

Familial adenomatous polyposis is a rare autosomal dominant intestinal syndrome with a high rate of malignant transformation. Here, we report a 20-year-old woman with a diagnosis of familial adenomatous polyposis by pathologic examination after colonoscopy biopsy, who underwent an F-FDG PET/CT to assess the extent of this disease. The images showed diffuse elevated FDG uptake along the entire colorectum. Additionally, focal enlarged lymph nodes with increased FDG uptake were noted. These findings promoted proctocolectomy and lymphadenectomy.

Intestinal Inflammation and Tumor Burden as Determinants for Bone Fragility in APC-Driven Tumorigenesis

BACKGROUND

Colorectal cancer (CRC) is a major cause of cancer-related deaths, and tumor-related comorbidities additionally lower life quality and survival. Mutations in the tumor suppressor adenomatous polyposis coli (APC) are associated with sporadic CRC and familial adenomatous polyposis (FAP), which results in the growth of multiple intestinal cancer lesions. In some cases, inflammatory bowel diseases (IBDs) are additionally observed in CRC patients. Although APC mutations have been shown to increase bone mineral density (BMD), inflammation is associated with reduced BMD and an elevated fracture risk in IBD patients.

METHODS

To determine the consequences of APC-driven intestinal tumorigenesis and additional inflammation on bone parameters, we utilized an APC1638N/+ mouse model. We treated 1 cohort of APC wild-type and mutant animals with dextran sodium sulfate (DSS) to induce colorectal inflammation. All mice were killed at the same age and stratified according to their tumor burden.

RESULTS

As expected, a heterozygous APC mutation increased intestinal tumor numbers and the cortical BMD. This effect on bone was abrogated in mice with high intestinal tumor numbers. Moreover, we found that high tumor burden elevated bone fragility in APC-mutated mice. After DSS treatment, there were no significant changes in bone parameters of control mice. In contrast, in combination with inflammation, bone biomechanical properties severely deteriorated at high tumor burdens in APC1638N/+ animals.

CONCLUSIONS

Together, not only were bone parameters affected by APC status and inflammation, but also high intestinal tumor numbers, especially when combined with inflammation, were associated with an osteoporotic phenotype.

A novel APC mutation identified in a large Chinese family with familial adenomatous polyposis and a brief literature review

Familial adenomatous polyposis (FAP), an autosomal dominant disease, is a colon cancer predisposition syndrome that manifests as a large number of adenomatous polyps. Mutations in the Adenomatous polyposis coli (APC) gene are responsible for the majority of cases of FAP. The purpose of the present study was to report the clinical features of a Chinese family with FAP and screen for novel mutations using the targeted next‑generation sequencing technology. Among the 29 family members, 12 were diagnosed of FAP. Based on an established filtering strategy and data analyses, along with confirmation by Sanger sequencing and co‑segregation, a novel frameshift mutation c.1317delA (p.Ala440LeufsTer14) in exon 10 of the APC gene was identified. To the best of our knowledge, this mutation has not been reported prior to the present study. In addition, it was correlated with extra‑colonic phenotypes featuring duodenal polyposis and sebaceous cysts in this family. This novel frameshift mutation causing FAP not only expands the germline mutation spectrum of the APC gene in the Chinese population, but it also increases the understanding of the phenotypic and genotypic correlations of FAP, and may potentially lead to improved genetic counseling and specific treatment for families with FAP in the future.

Congenital Hypertrophy of Retinal Pigment Epithelium for Diagnosis of Familial Adenomatous Polyposis - the First FAP registry in Iran

Objective: Familial adenomatous polyposis (FAP), an autosomal dominant inherited disorder is characterized by the presence of multiple adenomatous colorectal polyps, which can develop into cancer during early adulthood. Therefore, early diagnosis is essential. Most FAP patients have several extracolonic manifestations, including congenital hypertrophy of the retinal pigment epithelium (CHRPE). Whereas genetic markers may provide the main route to detection of ‘‘at risk’’ subjects , at present this approach is clearly limited and searches for a noninvasive phenotypic marker continue to be high priority.The aim of this study was to describe the pattern of distribution of CHRPE lesions and evaluate their diagnostic value in FAP patients and their family members in a local population. Methods: A total of 23 FAP patients and 26 relatives belonging to 12 families at high risk of developing FAP were subjected to colonoscopic and ophthalmological examination. Result: Retinal examinations demonstrated prevalences of CHRPE in FAP patents and their siblings of 78% and 38%, respectively. We were able to illustrate a significant correlation between FAP disease and the presence of retinal lesions. Sensitivity and specificity of CHRPE as a screening test to detect the presence of FAP are 78.3% and 61.5%, respectively, with a positive predictive value of 64.3% and a negative predictive value of 76.2 %. A “lesion form” significant difference was found between FAP and normal participants.Spearman nonparametric analysis revealed no correlation between age and number or size of lesions. Conclusion: Multiple CHRPE lesions are a diagnostic feature of FAP patients They are specific and sensitive clinical markers of this disease (specificity 60% and sensitivity 77%).

An Unusual Case of Familial Adenomatous Polyposis Presenting with Gout and Jaundice

We highlight an unusual case of familial adenomatous polyposis (FAP) presenting initially with gout, jaundice and a periampullary carcinoma. This case may be of interest to clinicians involved in the diagnosis and management of FAP and follow-up of patients after surgical resection.

The genetic basis of familial adenomatous polyposis and its implications for clinical practice and risk management

Familial adenomatous polyposis (FAP) is an inherited disorder that represents the most common gastrointestinal polyposis syndrome. Germline mutations in the APC gene were initially identified as responsible for FAP, and later, several studies have also implicated the MUTYH gene as responsible for this disease, usually referred to as MUTYH-associated polyposis (MAP). FAP and MAP are characterized by the early onset of multiple adenomatous colorectal polyps, a high lifetime risk of colorectal cancer (CRC), and in some patients the development of extracolonic manifestations. The goal of colorectal management in these patients is to prevent CRC mortality through endoscopic and surgical approaches. Individuals with FAP and their relatives should receive appropriate genetic counseling and join surveillance programs when indicated. This review is focused on the description of the main clinical and genetic aspects of FAP associated with germline APC mutations and MAP.