Clinical efficacy of metformin in familial adenomatous polyposis and the effect of intestinal flora.

BACKGROUND AND AIMS: Metformin has been reported to inhibit the occurrence and development of colorectal cancer (CRC) by mediating changes in intestinal flora. Studies have also indicated that the occurence of familial adenomatous polyposis (FAP) may also be associated with changes in the intestinal flora. Therefore, we investigated the efficacy and safety of metformin in treating FAP and the association with intestinal flora. RESULTS: Compared with the baseline, the mean number and load of polyps in the areas of nanocarbon labeling and postoperative residuals in the test group were lower than those in the placebo group, while the diversity of intestinal flora species was increased. At the genus level, the relative abundance of g_Ruminococcus in the test group was lower than that at baseline, whereas the relative abundance of g_Lactobacillus was higher. These changes were statistically significant (P < 0.05). CONCLUSION: One-year metformin therapy for FAP is safe and effective, potentially mediated by modulating the intestinal flora. This study provides new insights and strategies for preventing adenomatous polyp carcinogenesis in FAP and explores possible preventive action.

Risk of gastric adenoma and adenocarcinoma in patients with familial adenomatous polyposis in Japan: a nationwide multicenter study.

BACKGROUND: Patients with familial adenomatous polyposis (FAP) have an increased risk of developing gastric neoplasms. However, the clinical course of FAP with these gastric lesions has not yet been fully clarified. The present study aimed to clarify the changes in the incidence risk of developing gastric adenoma or gastric cancer during the lifespan of patients with FAP. METHODS: Four hundred forty-three patients with data regarding gastric adenoma and gastric cancer retrospectively registered in a nationwide Japanese multicenter study were enrolled. The cumulative incidences and hazard rates (HRs) of gastric neoplasms were evaluated. RESULTS: The cumulative incidence rates in 50-year-old patients with FAP were 22.8% for gastric adenoma and 7.6% for gastric cancer, respectively. No significant association was found between gastric neoplasms and the colonic phenotype. The peak age for the HR of gastric adenoma was 65 years, with the highest HR (0.043). Regarding the incidence of gastric cancer, the HR increased moderately up to the age of 40 years, but the increase accelerated from the age of 50 years (HR = 0.0067). CONCLUSION: Careful surveillance of the upper gastrointestinal tract in elderly patients with FAP, such as shortening the interval of follow-up according to age, may be helpful for early diagnosis of gastric cancer.

[The structure of pathogenic germline variants in colorectal cancer in Moscow patients]. / Struktura patogennykh germinal'nykh variantov pri kolorektal'nom rake v vyborke patsientov Moskvy.

OBJECTIVE: Describe the structure of pathogenic germline variants and clinical and anatomical features in colorectal cancer patients in Moscow. MATERIAL AND METHODS: The whole genome sequencing results of patients with suspected hereditary cancer syndrome were evaluated. All identified genetic variants were validated using Sanger sequencing. RESULTS: The study included 238 patients with colorectal cancer, 41/238 (17.2%) patients have pathogenic germline variants associated with hereditary cancer syndromes or increased cancer risk. Lynch syndrome accounts for 8% of all colorectal cancer cases (19/238), and familial adenomatous polyposis - 1.7% (4/238). 5 new genetic variants were described for the first time in a Russian colorectal cancer patients: MLH1 c.1921dup (p.Leu641fs), APC c.2929C>T (p.Gln977Ter), PMS2 c.327del (p.Ala110LeufsTer2), MSH2 c.1857dup (p. Val620CysfsTer24), ATM c.895G>T (p.Glu299Ter). In 197 of 238 patients, no significant variants were identified or variants with an uncertain clinical underlying cause were identified. CONCLUSION: According to the results of the study, an earlier manifestation of a malignant neoplasm and a more frequent occurrence of high-grade carcinomas in the presence of pathogenic germline mutations were noted compared to the group of patients without clinically significant varianrs, while in the group with identified mutations, the frequency of regional and distant metastasis was not increased.

Low adenoma burden in unselected patients with a pathogenic APC variant.

PURPOSE: Genomic screening can improve clinical outcomes, but presentation of individuals with risk for polyposis identified via genomic screening is unknown. To inform assessment of clinical utility of genomic screening for polyposis risk, clinical presentation of individuals in an unselected health care system cohort with an APC pathogenic or likely pathogenic (P/LP) variant causative of familial adenomatous polyposis are described. METHODS: Electronic health records of individuals with an APC P/LP variant identified via the MyCode program (MyCode APC+) were reviewed to assess adenoma burden and compare it among individuals with a clinical diagnosis of familial adenomatous polyposis and matched variant-negative controls. RESULTS: The prevalence of APC P/LP variants in this health care cohort is estimated to be 1 in 2800. Twenty-four MyCode APC+ individuals were identified during the study period. Median age at result disclosure was 53 years. Rate of clinical polyposis was 8%. Two of six participants with a classic region variant and none of those with an attenuated region variant had polyposis. MyCode APC+ participants did not differ from controls in cumulative adenoma count. CONCLUSION: APC P/LP variant prevalence estimate in the MyCode cohort is higher than prior published prevalence rates. Individuals with APC P/LP variants identified via genomic screening had a low adenoma burden.

The Cumulative Incidence and Progression of Ileal Pouch Adenomas in Patients With Familial Adenomatous Polyposis.

BACKGROUND: Patients with familial adenomatous polyposis who have undergone restorative proctocolectomy can develop adenomas in the pouch. OBJECTIVE: To review experience with pouch surveillance and create a classification system for polyposis severity. DESIGN: A retrospective review of patients undergoing IPAA and follow-up at 1 institution. SETTING: A center for hereditary colorectal cancer within a quaternary referral center. PATIENTS: All patients undergoing IPAA and followed endoscopically after surgery by the center. INTERVENTIONS: Yearly pouchoscopy and treatment of polyps as required. MAIN OUTCOME MEASURES: Primary outcome measure was incidence and severity of pouch neoplasia and its changes with time. METHODS: A retrospective study of patients who had a restorative proctocolectomy for familial adenomatous polyposis at Cleveland Clinic. Severity of polyposis was classified on the basis of size, number, and histology. RESULTS: One hundred sixty-five patients were analyzed. The median age at IPAA was 31 years and 52% were male. The median follow-up was 10.1 years; the median number of pouchoscopies per patient was 4. The median interval between pouchoscopies was 21.9 months. Overall, the incidence of pouch adenomas was found in 47 patients (28.5%). The median time from pouch to first pouch adenoma diagnosis was 10.3 years. The estimated cumulative incidence rates of pouch adenoma at 5, 10, 15, 20, and 30 years after IPAA were 5.9%, 21.7%, 40%, 54.8%, and 69.9%, respectively. At the first diagnosis of pouch adenoma, 25 patients had stage 1, 10 had stage 2, 8 had stage 3, and 4 had stage 4. Twenty of 47 patients progressed to a higher stage. No patient developed cancer. LIMITATIONS: Genotype was not available for all patients. CONCLUSIONS: There is an increasing incidence of pouch neoplasia after restorative proctocolectomy, reaching a plateau at 25 years. The polyposis is usually mild but sometimes increases in severity. LA INCIDENCIA ACUMULADA Y LA PROGRESIN DE LOS ADENOMAS DE LA BOLSA ILEAL EN PACIENTES CON POLIPOSIS ADENOMATOSA FAMILIAR: ANTECEDENTES:Los pacientes con poliposis adenomatosa familiar que se han sometido a una proctocolectomía restauradora pueden desarrollar adenomas en la bolsa.OBJETIVO:Revisamos nuestra experiencia con la vigilancia de la bolsa y creamos un sistema de clasificación para la gravedad de la poliposis.DISEÑO:Una revisión retrospectiva de pacientes sometidos a anastomosis de bolsa ileoanal y seguimiento en una institución.ESCENARIO:Un centro para el cáncer colorrectal hereditario dentro de un centro de referencia cuaternarioPACIENTES:Todos los pacientes sometidos a anastomosis reservorio ileoanal y seguidos por vía endoscópica tras la cirugía por el centro.INTERVENCIONES:Bolsascopia anual y tratamiento de pólipos según sea necesarioPRINCIPALES MEDIDAS DE RESULTADO:Primaria: Incidencia y gravedad de la neoplasia del reservorio y sus cambios con el tiempo.MÉTODOS:Un estudio retrospectivo de pacientes que se sometieron a una proctocolectomía restauradora por poliposis adenomatosa familiar en la Clínica Cleveland. La gravedad de la poliposis se clasificó según el tamaño, el número y la histología.RESULTADOS:Se analizaron 165 pacientes. La mediana de edad del IPAA fue de 31 años y el 52% eran hombres. La mediana de seguimiento fue de 10,1 años; número medio de reservorioscopias por paciente = 4. El intervalo medio entre reservorioscopias fue de 21,9 meses. Incidencia global de adenomas de reservorio = 47/165 (28,5%). Tiempo mediano desde el reservorio hasta el primer diagnóstico de adenoma en reservorio = 10,3 años. La tasa de incidencia acumulada estimada de adenoma de bolsa a los 5, 10, 15, 20, y 30 años después de la IPAA es del 5,9%, 21,7%, 40%, 54,8%, y 69,9%, respectivamente. En el primer diagnóstico de adenoma de la bolsa, 25 pacientes tenían estadio 1, 10 estadio 2, 8 estadio 3 y 4 estadio 4. 20/47 pacientes progresaron a un estadio superior Ningún paciente desarrolló cáncer.LIMITACIONES:Genotipo no disponible para todos los pacientesCONCLUSIONES:Hay una incidencia creciente de neoplasia de la bolsa después de la proctocolectomía restauradora, alcanzando una meseta a los 25 años. La poliposis suele ser leve, pero a veces aumenta en severidad. (Traducción-Dr. Yesenia Rojas-Khalil ).

Cancer in Patients With Familial Adenomatous Polyposis: A Nationwide Danish Cohort Study With Matched Controls.

BACKGROUND & AIMS: Familial adenomatous polyposis (FAP) is a hereditary disorder that predisposes patients to colorectal cancer (CRC). Prophylactic colectomy has greatly reduced the risk of CRC. However, new associations between FAP and the risk of other cancers have subsequently emerged. In this study, we assessed the risk of specific primary and secondary cancers among patients with FAP compared with matched controls. METHODS: All known patients with FAP up until April 2021 were identified in the nationwide Danish Polyposis Register and paired with 4 unique controls matched by birth year, sex, and postal code. The risk of overall cancers, specific cancer types, and risk of a second primary cancer was assessed and compared with controls. RESULTS: The analysis included 565 patients with FAP and 1890 controls. The overall risk of cancer was significantly higher for patients with FAP than for controls (hazard ratio [HR], 4.12; 95% confidence interval [CI], 3.28-5.17; P < .001). The increased risk was mainly due to CRC (HR, 4.61; 95% CI, 2.58-8.22; P < .001), pancreatic cancer (HR, 6.45; 95% CI, 2.02-20.64; P = .002), and duodenal/small-bowel cancer (HR, 14.49; 95% CI, 1.76-119.47; P = .013), whereas no significant difference was observed for gastric cancer (HR, 3.29; 95% CI, 0.53-20.23; P = .20). Furthermore, the risk of a second primary cancer was significantly higher for patients with FAP (HR, 1.89; 95% CI, 1.02-3.50; P = .042). Between 1980 and 2020, the risk of cancer among patients with FAP decreased by ∼50%. CONCLUSIONS: Despite an absolute reduction in the risk of developing cancer among patients with FAP, the risk remained significantly higher than for the background population due to colorectal, pancreatic, and duodenal/small-bowel cancers.

Incidental cancer in colectomy specimens from patients with familial adenomatous polyposis: single centre experience and literature review.

BACKGROUND: Since cancer development is inevitable in patients with familial adenomatous polyposis (FAP), we aimed to determine the incidence of incidental malignancy in prophylactic colectomy specimens. METHODS: The files of patients who underwent prophylactic surgery for FAP between 2010 and 2020 were retrospectively reviewed. The incidence of incidental malignancy in histopathological specimens was examined and a comprehensive literature review was made. RESULTS: Fifty-five patients were included in the study, of whom 30 patients had a diagnosis of primary malignancy. Prophylactic colectomy was performed on 25 patients. The pathology results indicated that the specimens were benign in 12 patients (48%) and revealed carcinoma in situ in 11 patients (44%). Incidental malignancy was detected in 2 patients (8%). In the literature review, there were 243 patients who underwent prophylactic colectomy and incidental cancer was detected in 25 patients (10.3%) with the stages of 1 (7.4%), 2 (2.1%), and 3 (0.8%), respectively. CONCLUSIONS: Incidental cancer is not rare in patients who have undergone prophylactic colectomy for FAP. Hopefully. they are usually at early stages and unexpected advanced cancers are seen rarely.

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.

Microbiome insights into pediatric familial adenomatous polyposis.

BACKGROUND: Individuals with familial adenomatous polyposis (FAP) harbor numerous polyps with inevitable early progression to colon cancer. Complex microbiotic-tumor microenvironment perturbations suggest a dysbiotic relationship between polyp and microbiome. In this study, we performed comprehensive analyses of stool and tissue microbiome of pediatric FAP subjects and compared with unaffected cohabiting relatives through 16S V4 region amplicon sequencing and machine learning platforms. RESULTS: Within our FAP and control patient population, Firmicutes and Bacteroidetes were the predominant phyla in the tissue and stool samples, while Proteobacteria dominated the polyp/non-polyp mucosa. A decline in Faecalibacterium in polyps contrasted with a decline in Bacteroides in the FAP stool. The alpha- and beta-diversity indices differed significantly within the polyp/non-polyp groups, with a concurrent shift towards lower diversity in polyps. In a limited 3-year longitudinal study, the relative abundance of Proteobacteria and Fusobacteria was higher in polyps compared to non-polyp and stool specimens over time. Through machine learning, we discovered that Archaeon_enrichment_culture_clone_A13, Micrococcus_luteus, and Eubacterium_hallii in stool and PL-11B10, S1-80, and Blastocatellaceae in tissues were significantly different between patients with and without polyps. CONCLUSIONS: Detection of certain bacterial concentrations within stool or biopsied polyps could serve as adjuncts to current screening modalities to help identify higher-risk patients.

Cumulative incidence and risk factors for pouch adenomas associated with familial adenomatous polyposis following restorative proctocolectomy.

BACKGROUND: The emergence of restorative total proctocolectomy has significantly reduced the lifetime colorectal cancer risk associated with familial adenomatous polyposis (FAP). However, adenomas may develop in the ileal pouch over time and may even progress to carcinoma. We evaluated the cumulative incidence, time to development, and risk factors associated with ileal pouch adenoma. AIM: To evaluate the cumulative incidence, time to development, and risk factors associated with pouch adenoma. METHODS: In this retrospective, observational study conducted at a tertiary center, 95 patients with FAP who underwent restorative proctocolectomy at our center between 1989 and 2018 were consecutively included. The mean follow-up period was 88 mo. RESULTS: Pouch adenomas were found in 24 (25.3%) patients, with a median time of 52 mo to their first formation. Tubular adenomas were detected in most patients (95.9%). There were no high-grade dysplasia or malignancies. Of the 24 patients with pouch adenomas, 13 had all detected adenomas removed. Among the 13 patients who underwent complete adenoma removal, four (38.5%) developed recurrence. Among 11 (45.8%) patients with numerous polyps within the pouch, seven (63.6%) exhibited progression of pouch adenoma. The cumulative risks of pouch adenoma development at 5, 10, and 15 years after pouch surgery were 15.2%, 29.6%, and 44.1%, respectively. Severe colorectal polyposis (with more than 1000 polyps) was a significant risk factor for pouch adenoma development (hazard ratio, 2.49; 95% confidence interval: 1.04-5.96; P = 0.041). CONCLUSION: Pouch adenomas occur at a fairly high rate in association with FAP after restorative proctocolectomy, and a high colorectal polyp count is associated with pouch adenoma development.

Serrated polyposis syndrome; epidemiology and management.

Serrated colorectal polyps, long considered innocent, are currently recognized as the precursors to one-third of all colorectal cancers (CRC). Serrated polyposis syndrome (SPS), characterized by accumulation of multiple and/or large serrated polyps, symbolizes the highest expression of serrated pathway of carcinogenesis, leading to a high risk of CRC when it is not detected or treated on time. Although previously considered uncommon, SPS is now acknowledged as the most prevalent colorectal polyposis. This syndrome has attracted increasing interest over the past decade and has become a hot topic in the field of gastrointestinal oncology. Besides a small proportion of cases caused by germline mutations in RNF43, no clear genetic cause has been identified. Both epigenetic and environmental factors, especially smoking, have been related to this syndrome, but the etiology of SPS remains uncertain and diagnosis is based on endoscopic criteria. Recent studies on SPS have focused on identifying the underlying risk-factors for CRC, defining the best endoscopic techniques for surveillance and establishing optimal preventive strategies aimed at reducing CRC-incidence without exposing patients to unnecessary procedures. The purpose of this chapter is to review, from a practical perspective, current knowledge and future directions in the diagnosis and management of serrated polyposis syndrome.

Ileoanal pouch cancers in ulcerative colitis and familial adenomatous polyposis: A systematic review and meta-analysis.

INTRODUCTION: Restorative proctocolectomy results in the formation of a pouch that adapts to a more colonic phenotype. The incidence of cancer of the pouch is thought to be low with most societal guidelines differing on their recommendations for surveillance. AIMS: We conducted a systematic review with meta-analysis to report the incidence of cancer in all pouch patients. METHODS: The Embase, Embase classic and PubMed databases were searched between June 1979- June 2021. A random effects model was performed to find the pooled incidence of pouch cancer. In addition, we also looked for risk factors for pouch cancers. RESULTS: Forty-six studies were included. In 19,964 patients with Ulcerative Colitis (UC) the pooled incidence of pouch cancer was 0.0030 (95% CI: 0.0016 -0.0055). In 3741 patients with Familial Adenomatous Polyposis (FAP) the pooled incidence of pouch cancer was 0.01 (95% CI: 0.01 - 0.02). In UC most pouch cancers were found to occur in the pouch body (0.59 (95% CI: 0.29-0.84)). CONCLUSIONS: The findings suggest that the pooled incidence of pouch cancer in UC is similar to that which was previously published, and this is the first meta-analysis to report a pooled incidence for pouch cancer in FAP.

Thyroid Nodules in Children With Familial Adenomatous Polyposis.

INTRODUCTION: Ultrasound screening for thyroid cancer is recommended in familial adenomatous polyposis (FAP). This study investigated the prevalence of thyroid neoplasia in children with FAP. METHODS: Cross-sectional study of children with FAP at an academic hospital. Clinical and ultrasound data were analyzed for the prevalence of thyroid nodules and cancer. RESULTS: Of 37 children with FAP, 8 (22%) had thyroid nodules and 2 (5%) had thyroid cancer. Nodules (30%) and cancer (9%) were more common among female subjects and rare among male subjects. DISCUSSION: Thyroid ultrasound screening in adolescence may benefit female subjects with FAP but has limited utility in male subjects.

Clinicopathological characteristics of colorectal serrated polyposis syndrome (SPS): results of a multicenter study by the SPS Study Group in Japan.

BACKGROUND: Serrated polyposis syndrome (SPS), a type of colorectal polyposis characterized by multiple serrated polyps, is associated with a high risk of colorectal carcinoma (CRC). This study aimed to clarify the clinicopathological characteristics of SPS in Japan. METHODS: We investigated the clinicopathological characteristics of patients with SPS from the "Multicenter Study on Clinicopathological Characteristics of SPS (UMIN 000032138)" by the Colorectal Serrated Polyposis Syndrome (SPS) Study Group. In this study, patients were diagnosed with SPS based on the 2019 World Health Organization (WHO) SPS diagnostic criteria. RESULTS: Ninety-four patients were diagnosed with SPS in 10 institutions between January 2001 and December 2017. The mean number (± standard deviation [SD]) of resected lesions per patient was 11.3 ± 13.8. The mean age at diagnosis of SPS was 63.3 ± 11.6 years, and 58 patients (61.7%) were male. Eighty-seven (92.6%) and 16 (17.0%) patients satisfied WHO diagnostic criteria I and II, respectively. Nine patients (9.6%) satisfied both criteria I and II. Carcinoma (T1-T4) were observed in 21 patients (22.3%) and 24 lesions. Of the 21 patients with CRC, 19 (90.4%) satisfied diagnostic criterion I, 1 (4.8%) satisfied diagnostic criterion II, and 1 (4.8%) satisfied diagnostic criteria I and II. There was no notable difference in the prevalence of CRC among patients who met diagnostic criterion I, II, and both I and II. CONCLUSIONS: Patients with SPS have a high risk of CRC and should undergo regular surveillance colonoscopy. Raising awareness of this syndrome is crucial.

A comparison of panoramic radiographic findings in patients with familial adenomatous polyposis and the general population: a multicenter study.

OBJECTIVES: Familial adenomatous polyposis (FAP) is a hereditable disorder characterized by early and unremitting development of intestinal polyps and extraintestinal manifestations requiring multidisciplinary surveillance. Herein we describe a multicenter cross-sectional analysis of the dento-osseous radiographic findings of patients with FAP from North and South America. STUDY DESIGN: Groups I and II included individuals with FAP diagnosed by standard clinical criteria. Patients were paired with age- and sex-matched participants without FAP. Panoramic radiograph of both cohorts, including children and adults, were analyzed. RESULTS: Of 114 panoramic radiographs, 38 were from patients with FAP, composed of group I (n = 22) and group II (n = 16), and 76 were from matched control participants. Evaluators had excellent agreement on key findings (intraclass correlation coefficient = 0.89). The prevalence of osseous anomalies was higher in adults (75%) than in children (65.4%). Dental anomalies were also higher in children with FAP with a prevalence of 15.4%. CONCLUSIONS: We describe important and significant differences in the prevalence of dento-osseous anomalies in children compared with adult patients with FAP. These findings warrant careful consideration and may influence multidisciplinary management of the condition. Conversely, the presence of these abnormalities in pediatric dental patients even if not diagnosed with FAP should be borne in mind as possibly indicating de novo or unrecognized disease.

Risk of extracolonic malignancies and metachronous rectal cancer after colectomy and ileorectal anastomosis in familial adenomatous polyposis.

BACKGROUND: Analysis of long-term clinical outcomes of patients with familial adenomatous polyposis is critical in reducing or preventing the incidence of extracolonic malignancies after initial surgery. The aim of the present study was to clarify the long-term outcomes, and establish a surveillance strategy for surgically treated familial adenomatous polyposis patients. METHODS: Between January 1967 and March 2020, retrospective data were collected from 37 patients with familial adenomatous polyposis treated or monitored in our department. Occurrence of metachronous cancers, including rectal cancers and extracolonic malignancies, and other diseases was analyzed. RESULTS: The median follow-up duration after the first surgery was 13.8 years. Initially, 16 patients underwent total proctocolectomy with ileal pouch-anal anastomosis, 18 underwent total colectomy with ileorectal anastomosis, and three underwent other procedures. A secondary proctectomy was performed for 9 of the 18 patients who underwent ileorectal anastomosis. Rectal cancer was diagnosed in 6 patients who underwent ileorectal anastomosis. In addition, 5 gastric cancer, 2 duodenal cancer, 1 gallbladder cancer, and 1 thyroid cancer cases were diagnosed. The age at which the extracolonic malignancies were diagnosed was >50 years. 4 patients died due to metachronous rectal cancer, gastric cancer, or gallbladder cancer. CONCLUSION: Careful consideration should be paid before choosing ileorectal anastomosis as the treatment procedure for familial adenomatous polyposis patients because completion proctectomy was eventually necessary for half of the patients. Long-term surveillance, with more frequent gastric surveillance for patients over 50 years, is important for the prevention and treatment of extracolonic malignancies in familial adenomatous polyposis patients.

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.

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 of adenomatous polyposis in a fecal immunochemical test-based colorectal cancer screening program and risk of advanced neoplasia during follow-up.

BACKGROUND : Current guidelines recommend genetic counseling and intensive colonoscopy surveillance for patients with ≥ 10 colorectal adenomas based on scarce data. We investigated the prevalence of this condition in a fecal immunochemical test (FIT)-based colorectal (CRC) screening program, and the incidence of metachronous lesions during follow-up. METHODS: We retrospectively included all FIT-positive participants with ≥ 10 adenomas at index colonoscopy between 2010 and 2018. Surveillance colonoscopies were collected until 2019. Patients with inherited syndromes, serrated polyposis syndrome, total colectomy, or lacking surveillance data were excluded. The cumulative incidence of CRC and advanced neoplasia were analyzed by Kaplan-Meier analysis. Risk factors for metachronous advanced neoplasia were investigated by multivariable logistic regression analysis. RESULTS: 215 of 9582 participants (2.2 %) had ≥ 10 adenomas. Germline genetic testing was performed in 92 % of patients with ≥ 20 adenomas, identifying two inherited syndromes (3.3 %). The 3-year cumulative incidence of CRC and advanced neoplasia were 1 % and 16 %, respectively. In 39 patients (24.2 %), no polyps were found on first surveillance colonoscopy. The presence of an advanced adenoma was independently associated with a higher risk of advanced neoplasia at first surveillance colonoscopy (odds ratio 3.91, 95 %CI 1.12-13.62; P = 0.03). Beyond the first surveillance colonoscopy, the risk of metachronous advanced neoplasia was lower. CONCLUSIONS: The prevalence of ≥ 10 adenomas in a FIT-based CRC screening program was 2.2 %; a small proportion of inherited syndromes were detected, even amongst those with ≥ 20 adenomas. A low rate of post-colonoscopy CRC was observed and the risk of advanced neoplasia beyond the first surveillance colonoscopy tended to progressively decrease throughout successive follow-ups.

Natural history of ampullary adenomas in familial adenomatous polyposis: a long-term follow-up study.

BACKGROUND AND AIMS: Ampullary adenomas (AAs), common in familial adenomatous polyposis (FAP), are precursors to ampullary carcinoma. We assessed the natural history of AAs and factors associated with clinically significant progression (CSP). METHODS: Consecutive FAP patients with AAs and at least 2 EGDs were identified from a hereditary GI cancer registry. We assessed the incidence of CSP (increase in size to ≥10 mm and/or development of advanced histology) of AAs. Clinical, endoscopic, and pathologic features between patients with CSP and nonprogressors were compared. RESULTS: One hundred forty-three patients with AAs were included. Over a median follow-up of 7.8 years (interquartile range, 4.3-11.1), 41 patients (28.6%) developed CSP for an incidence of 35 per 1000 patient-years. Of 143 patients, 22 (15.6%) progressed to AAs ≥10 mm, 12 (8.5%) progressed to advanced histology, and 7 (4.9%) progressed both in size and histology. Two patients (1.4%) developed ampullary cancer. Male gender, abnormal appearance of the papilla at initial AA detection, prior cholecystectomy, and personal history of extracolonic malignancy were associated with CSP. Neither Spigelman stage nor the adenomatous polyposis coli gene pathogenic variants were associated with CSP. An intervention specifically for AA and not duodenal polyposis was performed in 24% of patients with AAs, including endoscopic papillectomy in 23 patients and duodenectomy in 3 patients at a median observation of 8.2 years. CONCLUSIONS: Most FAP patients with AAs did not experience CSP or require resection over 8 years of surveillance. Ampullary cancer was rare. Male gender, abnormal appearance of the papilla at AA detection, cholecystectomy, and history of extracolonic malignancy were associated with CSP. Our findings favor endoscopic surveillance of AAs over expedited resection for most patients with FAP.