Diffuse familial adenomatous intestinal polyposis in childhood: current state of the problem and case report.

OBJECTIVE: Aim: To explore the prevalence, clinical characteristics, and diagnostic aspects of diffuse familial adenomatous polyposis in childhood. This objective is accomplished through an extensive review of recent literature, and the presentation of case report from our clinical practice. PATIENTS AND METHODS: Materials and Methods: We analyzed 75 scientific papers, the findings of which have been documented in the PubMed database. Our search criteria included keywords such as ≪diffuse familial adenomatous intestinal polyposis,≫ ≪children,≫ and ≪diagnosis.≫ Then we conducted a second-stage analysis that involved a detailed review of a practical case - the medical records of inpatient Kh.V. who had been diagnosed with familial adenomatous polyposis. CONCLUSION: Conclusions: The analysis of the literature data is consistent with the findings from our clinical observations of familial adenomatous polyposis in a patient with complicated family anamnesis. It is worth noting that clinical features do not significantly differ across various types of polyposis. In cases of suspected familial adenomatous polyposis in adolescents, genetic testing is crucial.

[A Case of Desmoid-Type Fibromatosis of the Mesentery of Small Intestine].

Desmoid-type fibromatosis is a relatively rare disease, often associated with familial adenomatous polyposis and a history of abdominal surgery. A 43-year-old male patient presented with abdominal pain and contrast-enhanced CT showed a mass in the lower abdomen. The mass was a 4×4×3 cm white, dense tumor with a wreath-like arrangement of eosinophilic spindle-shaped cells. Immunostaining showed KIT(-), CD34(-), desmin(-), ß-catenin(+), SMA(few+), and the diagnosis was desmoid-type fibrosis. Six months after surgery, there was no apparent recurrence.

Microenvironmental changes in familial adenomatous polyposis during colorectal cancer carcinogenesis.

Familial adenomatous polyposis (FAP) is a heritable disease that increases the risk of colorectal cancer (CRC) development because of heterozygous mutations in APC. Little is known about the microenvironment of FAP. Here, single-cell RNA sequencing was performed on matched normal tissues, adenomas, and carcinomas from four patients with FAP. We analyzed the transcriptomes of 56,225 unsorted single cells, revealing the heterogeneity of each cell type, and compared gene expression among tissues. Then we compared the gene expression with that of sporadic CRC. Furthermore, we analyzed specimens of 26 FAP patients and 40 sporadic CRC patients by immunohistochemistry. Immunosuppressiveness of myeloid cells, fibroblasts, and regulatory T cells was upregulated even in the early stages of carcinogenesis. CD8+ T cells became exhausted only in carcinoma, although the cytotoxicity of CD8+ T cells was gradually increased according to the carcinogenic step. When compared with those in the sporadic CRC microenvironment, the composition and function of each cell type in the FAP-derived CRC microenvironment had differences. Our findings indicate that an immunosuppressive microenvironment is constructed from a precancerous stage in FAP.

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.

Correlation Between the Severity of Adhesions and Desmoid Disease in Patients With Familial Adenomatous Polyposis: A Prospective Cohort Study.

BACKGROUND: Clinical experience teaches that intraperitoneal adhesions are more severe in patients with familial adenomatous polyposis than in patients without it. This impression may come from the common association of familial adenomatous polyposis with desmoid disease. OBJECTIVES: This study aimed to determine whether patients with familial adenomatous polyposis and desmoid disease develop more severe adhesions than those without desmoid disease. DESIGN: Prospectively collected data study. SETTINGS: Hereditary colorectal cancer center in a tertiary referral hospital. PATIENTS: Patients undergoing first reoperative intra-abdominal surgery for familial adenomatous polyposis; controls were those having their initial abdominal surgery. INTERVENTIONS: Surgery and adhesiolysis. MAIN OUTCOME MEASURES: Presence and type of desmoid disease; presence and severity of nondesmoid intraperitoneal adhesions. Where patients had multiple operations, only the first reoperative surgery was chosen. Desmoid disease was noted as reaction (sheet) or mass. Adhesions were graded as none, mild (<10 min for mobilization), average (10-30 min), and severe (>30 min or significant bowel damage). Patients having their first abdominal surgery for familial adenomatous polyposis were used as a control group. RESULTS: A total of 211 patients had no prior surgery; 5% had desmoids and 1% had adhesions. One hundred thirty-seven patients underwent reoperative surgery: 39% had desmoid disease ( p < 0.05 vs no prior surgery), the highest rate being in patients after IPAA (57%), and 45% had severe adhesions ( p < 0.01 vs no prior surgery), worst after Koch pouch (89%), and total proctocolectomy with ileostomy (82%). Thirty-six percent of patients without desmoid disease had severe adhesions. Desmoid reaction was associated with severe adhesions in 47% of cases and desmoid tumors in 66% of cases. LIMITATIONS: Possible limitations include the potential overlap between desmoid adhesions and nondesmoid adhesions and the potential for inaccuracy in defining the time of adhesiolyses. CONCLUSIONS: Familial adenomatous polyposis is associated with severe postoperative adhesions after reoperative abdominal surgery, especially in patients who develop desmoid disease. See Video Abstract . CORRELACIN ENTRE LA GRAVEDAD DE LAS ADHERENCIAS Y LA ENFERMEDAD DESMOIDEA EN PACIENTES CON POLIPOSIS ADENOMATOSA FAMILIAR ESTUDIO PROSPECTIVO DE COHORTES: ANTECEDENTES:La experiencia clínica demuestra que las adherencias intraperitoneales son más graves en pacientes con poliposis adenomatosa familiar que en pacientes sin enfermedad desmoidea. Esta impresión puede provenir de la asociación común de poliposis adenomatosa familiar con enfermedad desmoidea.OBJETIVOS:Ver si los pacientes con poliposis adenomatosa familiar y enfermedad desmoidea desarrollan adherencias más graves que aquellos sin enfermedad desmoidea.DISEÑO:Estudio de datos recolectados prospectivamente.AJUSTES:Centro de cáncer colorrectal hereditario en un hospital de referencia terciario.PACIENTES:Pacientes sometidos a una primera cirugía intraabdominal de caracter reoperatorio por poliposis adenomatosa familiar: los controles fueron los que se sometieron a su cirugía abdominal inicial.INTERVENCIONES:Cirugía y adhesiolisis.PRINCIPALES MEDIDAS DE RESULTADO:Presencia y tipo de enfermedad desmoidea; presencia y severidad de adherencias intraperitoneales no desmoideas. Cuando los pacientes tenían múltiples operaciones, solo se eligió la primera cirugía reoperatoria. La enfermedad desmoidea se anotó como reacción (hoja filamentosa) o masa. Las adherencias se calificaron como ninguna, leve (<10 minutos para la movilización), promedio (10 a 30 minutos) y severa (>30 minutos o daño intestinal significativo). Los pacientes sometidos a una primera cirugía abdominal por poliposis adenomatosa familiar se utilizaron como grupo de control.RESULTADOS:211 pacientes no tenían cirugía previa: 5% desmoideos y 1% adherencias. 137 pacientes se sometieron a cirugía reoperatoria: 39% tenía enfermedad desmoidea ( p < 0,05 frente aquellos sin cirugía previa), la tasa más alta se presentó en aquellos pacientes después de una anastomosis ileoanal con reservorio (57%) donde el 45% tenía adherencias graves ( p < 0,01 frente aquellos sin cirugía previa), peores resultados se observaron después de la confección de un reservorio de Koch (89%) y luego de proctocolectomía total con ileostomía (82%). El 36% de los pacientes sin enfermedad desmoidea tenían adherencias graves. La reacción desmoidea se asoció con adherencias graves en el 47% de los casos, y los tumores desmoides se asociaron con adherencias graves en el 66% de los casos.LIMITACIONES:Superposición potencial entre adherencias desmoideas y adherencias no desmoideas. Posible inexactitud en la definición del tiempo de adhesiolisis.CONCLUSIONES:La poliposis adenomatosa familiar se asocia con adherencias postoperatorias graves después de una cirugía abdominal reoperatoria, especialmente en pacientes que desarrollan enfermedad desmoidea. (Traducción-Dr. Xavier Delgadillo ).

Risk of Proctectomy After Ileorectal Anastomosis in Familial Adenomatous Polyposis in the Modern Era.

BACKGROUND: Prophylactic surgery for familial adenomatous polyposis has evolved over several decades. Restorative proctocolectomy with IPAA provides an alternative to total abdominal colectomy with ileorectal anastomosis. We have previously shown that the rate of proctectomy and rectal cancer after total abdominal colectomy with ileorectal anastomosis in the "pre-pouch era" was 32% and 13%, respectively. OBJECTIVE: To determine the rate of proctectomy and rectal cancer among familial adenomatous polyposis patients and relative rectal sparing (fewer than 20 rectal polyps) selected for total abdominal colectomy with ileorectal anastomosis in the modern era. DESIGN: Retrospective cohort study. SETTING: Single tertiary care institution with a hereditary colorectal cancer registry. PATIENTS: Patients with familial adenomatous polyposis who underwent total abdominal colectomy with ileorectal anastomosis between 1993 and 2020. MAIN OUTCOME MEASURES: Incidence of proctectomy for any indication and rectal cancer. RESULTS: A total of 197 patients with a median age of 24 years (range, 10-67) were included. The median follow-up after total abdominal colectomy with ileorectal anastomosis was 13 years (interquartile range, 6-17). Sixteen patients (8%) underwent proctectomy. Indications included rectal cancer in 6 patients (3%; 2 stage I and 4 stage III), polyps with high-grade dysplasia in 4 (2%), progressive polyp burden in 3 (1.5%), defecatory dysfunction in 2 (1%), and anastomotic leak in 1 (0.5%). Among 30 patients (18%) with 20 or more rectal polyps at the time of total abdominal colectomy with ileorectal anastomosis, 8 patients (26%) underwent proctectomy and 3 patients developed rectal cancer (10%). Among 134 patients (82%) with fewer than 20 polyps, 8 patients (6%) underwent proctectomy and 3 patients developed rectal cancer (2%). Number of rectal polyps at the time of total abdominal colectomy with ileorectal anastomosis was associated with the likelihood of proctectomy (OR 1.1, p < 0.001) but not incident rectal cancer ( p = 0.3). LIMITATION: Retrospective data collection. CONCLUSIONS: Patients with familial adenomatous polyposis selected for total abdominal colectomy with ileorectal anastomosis by rectal polyp number have low rates of proctectomy and rectal cancer compared to historical controls. With appropriate selection criteria and surveillance, total abdominal colectomy with ileorectal anastomosis remains an important and safe treatment option for patients with familial adenomatous polyposis. See Video Abstract . RIESGO DE PROCTECTOMA DESPUS DE ANASTOMOSIS ILEORRECTAL EN POLIPOSIS ADENOMATOSA FAMILIAR EN LA ERA MODERNA: ANTECEDENTES:La cirugía profiláctica para la poliposis adenomatosa familiar (PAF) ha evolucionado durante varias décadas. La proctocolectomía restauradora con anastomosis anal con bolsa ileal (IPAA) proporciona una alternativa a la colectomía abdominal total con anastomosis ileorrectal (TAC/IRA). Anteriormente hemos demostrado que la tasa de proctectomía y cáncer de recto después de TAC/IRA en la era "pre-bolsa" era del 32% y el 13%, respectivamente.OBJETIVO:Determinar la tasa de proctectomía y cáncer de recto entre pacientes con PAF y pacientes con preservación rectal relativa (<20 pólipos rectales) seleccionados para TAC/IRA en la era moderna.DISEÑO:Estudio de cohorte retrospectivo.ÁMBITO:Institución única de atención terciaria con un registro de cáncer colorrectal hereditario.PACIENTES:Pacientes con PAF que se sometieron a TAC/IRA entre 1993 y 2020.MEDIDAS DE RESULTADO PRINCIPALES:Incidencia de proctectomía por cualquier indicación y cáncer de recto.RESULTADOS:Se incluyeron 197 pacientes con una mediana de edad de 24 años (rango 10-67). La mediana de seguimiento tras TAC/IRA fue de 13 años (RIC 6-17). 16 pacientes (8%) fueron sometidos a proctectomía. Las indicaciones incluyeron cáncer de recto en 6 (3%) (2 en estadio I y 4 en estadio III); pólipos con displasia de alto grado en 4 (2%); carga progresiva de pólipos en 3 (1,5%), disfunción defecatoria en 2 (1%); y fuga anastomótica en 1 (0,5%). Entre 30 pacientes (18%) con ≥20 pólipos rectales en el momento de TAC/IRA, 8 pacientes (26%) se sometieron a proctectomía y 3 pacientes desarrollaron cáncer de recto (10%). Entre 134 pacientes (82%) con <20 pólipos, 8 pacientes (6%) se sometieron a proctectomía y 3 pacientes desarrollaron cáncer de recto (2%). El número de pólipos rectales en el momento de TAC/IRA se asoció con la probabilidad de proctectomía (OR 1,1, p <0,001), pero no con la incidencia de cáncer de recto (p = 0,3).LIMITACIÓN:Recopilación de datos retrospectivos.CONCLUSIÓN:Los pacientes con PAF seleccionados para TAC/IRA por el número de pólipos rectales tienen tasas bajas de proctectomía y cáncer de recto en comparación con los controles históricos. Con criterios de selección y vigilancia adecuados, TAC/IRA sigue siendo una opción de tratamiento importante y segura para los pacientes con PAF. (Pre-proofed version ).

Atypical hypertrophy of retinal pigment epithelium manifesting as the first sign of familial adenomatous polyposis.

A female patient in her 20s presented to a routine ophthalmology appointment. Medical history was unremarkable. Family history was notable for intestinal cancer of a second-degree relative, diagnosed in her late 60s. Fundus examination revealed bilateral, multiple, flat, oval, pigmented lesions with an irregular halo of atrophy. The patient was diagnosed with atypical congenital hypertrophy of retinal pigmented epithelium. Investigation of extraocular associations was performed, including upper and lower endoscopy, which revealed 500-1000 colonic polyps with a maximum size 25 mm. Pathology did not reveal submucosal invasion. Genetic testing detected an adenomatous polyposis coli mutation (heterozygotic variant c.3183_3187delACAAA p.(Gln1062*)).

Two Cases, Too Little, Too Late: Surveillance for Gastric Cancer in Patients with FAP.

Familial adenomatous polyposis is an autosomal dominant disease due to a mutation in the adenomatous polyposis coli (APC) gene. The disease, characterized by the development of adenomas throughout the colon and rectum, is also associated with extracolonic manifestations including gastric fundic polyps and cancer. In this report, we describe two patients with FAP with advanced gastric adenocarcinoma who received systemic chemotherapy. We reviewed the literature published over the past two decades on gastric cancer in FAP patients to assess the clinical course of this disease. Due to its recent increased incidence in Western countries, close endoscopic surveillance to detect early gastric neoplastic lesions is recommended.

Predicting Duodenal Cancer Risk in Patients with Familial Adenomatous Polyposis Using Machine Learning Model.

BACKGROUND/AIMS: The aim of this study was to both classify data of familial adenomatous polyposis patients with and without duode- nal cancer and to identify important genes that may be related to duodenal cancer by XGboost model. MATERIALS AND METHODS: The current study was performed using expression profile data from a series of duodenal samples from familial adenomatous polyposis patients to explore variations in the familial adenomatous polyposis duodenal adenoma-carcinoma sequence. The expression profiles obtained from cancerous, adenomatous, and normal tissues of 12 familial adenomatous polyposis patients with duodenal cancer and the tissues of 12 familial adenomatous polyposis patients without duodenal cancer were compared. The ElasticNet approach was utilized for the feature selection. Using 5-fold cross-validation, one of the machine learning approaches, XGboost, was utilized to classify duodenal cancer. Accuracy, balanced accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F1 score performance metrics were assessed for model performance. RESULTS: According to the variable importance obtained from the modeling, ADH1C, DEFA5, CPS1, SPP1, DMBT1, VCAN-AS1, APOB genes (cancer vs. adenoma); LOC399753, APOA4, MIR548X, and ADH1C genes (adenoma vs. adenoma); SNORD123, CEACAM6, SNORD78, ANXA10, SPINK1, and CPS1 (normal vs. adenoma) genes can be used as predictive biomarkers. CONCLUSIONS: The proposed model used in this study shows that the aforementioned genes can forecast the risk of duodenal cancer in patients with familial adenomatous polyposis. More comprehensive analyses should be performed in the future to assess the reliability of the genes determined.

Intensive endoscopic resection strategy for multiple duodenal polyposis associated with familial adenomatous polyposis.

BACKGROUND AND AIM: Multiple duodenal polyposis associated with familial adenomatous polyposis (FAP) is a high risk of duodenal cancer development. We evaluated the feasibility of intensive endoscopic resection that is a comprehensive treatment strategy combining multiple kinds of endoscopic treatments. METHODS: This is a retrospective observational study. From January 2012 to July 2022, a total of 28 consecutive patients in FAP who underwent endoscopic resection for multiple duodenal polyposis more than twice were included. Various endoscopic treatments, such as cold polypectomy (CP), endoscopic mucosal resection (EMR), underwater EMR (UEMR), endoscopic submucosal dissection (ESD), and endoscopic papillectomy (EP), were applied depending on lesions size and location. We evaluated individual information from patients' medical records, including patient characteristics, lesion characteristics, details of endoscopic treatment, pathologic findings, and Spigelman index (SI). We compared the differences in the number of treatments and observation periods with and without SI decrease. RESULTS: A total of 1040 lesions were removed by 138 sessions of endoscopic resections. The median follow-up period was 3.2 years. At the beginning of the endoscopic intervention, median SI was 9 (6-11) and the proportion of Spigelman stage (SS) IV was 61%. Repeated endoscopic treatments finally reduced SI in 26 patients (93%), and the proportion of SS IV significantly decreased to 13% with every endoscopic treatment. The mean SI change was -4.2 points per year (95% confidence interval: -0.6 to -5.9). There were no patients required surgical duodenectomy during the follow-up period. CONCLUSION: Intensive resection has a potential of downstaging duodenal lesions associated with FAP.

Familial intestinal polyposis and device assisted enteroscopy: where do we stand?

INTRODUCTION: Hereditary polyposis syndromes are a group of inherited disorders associated with a high risk of developing colorectal cancer. The best known ones are familial adenomatous polyposis (FAP), Peutz-Jeghers (PJS), juvenile polyposis and Cowden syndromes, as well as conditions predisposing to cancer, such as Lynch syndrome. Some of them are characterized by an increased risk of small bowel polyps occurrence. AREAS COVERED: Literature search in PubMed was performed in November 2022 and a narrative review was carried out. Since performing small bowel polypectomy is important in such patients, device assisted enteroscopy (DAE) is the key for this procedure. A screening strategy for small bowel polyps is recommended only for PJS. Guidelines endorse either magnetic resonance imaging (MRI) or videocapsule endoscopy (VCE) every 1-3 years, according to the phenotype of the disease. Enteroscopy should be considered for therapeutic purpose in patients with a positive VCE or MRI. DAE has a central role in the resection of polyps larger than mm or causing symptoms of subocclusion or intussusception. Both single (SBE) and double balloon enteroscopy (DBE) are indicated and able to resect polyps up to 6-10 cm. American guidelines have restricted the indications to small bowel enteroscopy only to FAP patients with grade IV Spiegelman. EXPERT OPINION: Only some groups of patients (PJS, FAP with demonstrated small bowel polyp burden) may benefit from DAE.

Current Status and Surgical Technique for Restorative Proctocolectomy with Ileal Pouch Anal Anastomosis

Restorative proctocolectomy with ileal pouch-anal anastomosis (RP/IPAA) is the procedure of choice for patients with ulcerative colitis (UC), some patients with colonic Crohn's disease (CD), and those with familial adenomatous polyposis (FAP); albeit, owing to its complexity, it should be performed by experienced professionals. RP/IPAA is the recommended surgical treatment for UC when the standard medical therapy is ineffective. This procedure has been demonstrated to provide patients with a good quality of life, such as in FAP patients with extensive disease in the rectum. The CD has been associated with higher rates of perianal involvement and disease recurrence, but some patients with CD limited to the large intestine and minimal perianal or ileal disease may also be considered for this operation. First, all patients undergo a detailed preoperative evaluation that includes a review of previous imaging, pathology, and colonoscopy findings, a perianal examination, an evaluation of the anorectal functions, mechanical bowel preparation, and prophylaxis against deep venous thrombosis and infectious complications. A staged approach is the most commonly preferred technique for RP/IPAA, which can be performed in 2 or 3 stages. The IPAA can be performed by laparoscopic, robotic, or open approach. The type of approach is determined based on the patient's condition, medication used, elective or emergency setting, and the surgeon's expertise level. A successful IPAA requires tension-free pouch anastomosis. The most common IPAA pouch types are the J or S pouches; alternatively, an H pouch may be created, which is mainly used in redo pouches. In experienced centers, > 95% of the patients become stoma-free in 10 years. IPAA is a complex procedure, and the complications after pouch surgery are pouchitis, pelvic sepsis, pouch failure, or anastomotic stricture. The majority of long-term complications can be prevented in such cases with a comprehensive preoperative evaluation and through the use of appropriate surgical techniques and postoperative care conducted at experienced centers. The techniques for performing RP/IPAA with their long-term outcomes have been reviewed in this article.

Future directions in imaging pouches.

The sections of this special issue on the ileal pouch demonstrate that in the nearly 45 years since the ileal pouch has been utilized to treat patients with colitis and familial adenomatous polyposis, a substantial number of patients experience both short- and long-term morbidity and that imaging plays an important role in their management. Further, referral centers are encountering an increasing number of patients with pouch and peri-pouch complications and dysfunction. Many of these patients have had their pouches for years, and many have experienced a reduced quality of life as a result of their symptoms.As we look to the future, what are the specific questions that arise from this compilation of experience from institutions that see large numbers of patients with an ileal pouch? In what areas are we deficient? In what areas are we using the wrong methods? What should we be doing differently?

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.

Desmoid Tumors in Familial Adenomatous Polyposis Patients: Favorable Outcomes with Multidisciplinary Management.

OBJECTIVE: In this study, we aimed to describe the clinical features, management, and outcomes of desmoid tumors (DTs) in familial adenomatous polyposis (FAP) patients at a high-volume sarcoma center. METHODS: Consecutive patients with FAP and DTs were identified from our institutional databases (1985-2021). Patient demographics, treatment, and outcomes were described. Categorical data were compared using Fisher's exact test, and Kaplan-Meier curves were used to estimate progression-free survival (PFS). RESULTS: Forty-five patients with 67 DTs were identified: 39 mesenteric or retroperitoneal (58.2%), 17 abdominal wall (25.4%), 4 extremity (6%), 4 breast (6%) and 3 back (4.4%). Severe DT symptoms were present in 12 patients (26.7%). Initial treatments per tumor were observation in 30 (44.8%) DTs, chemotherapy in 15 (22.4%) DTs, surgery in 10 (14.9%) DTs, and other systemic therapies in 10 (14.9%) DTs. The majority of DTs remained stable with observation or a single intervention (77.8%). Median PFS was 23.4 years (95% confidence interval 7.6-39.2). In the 12 severely symptomatic patients, four patients required more than two interventions for DT control. At a median follow-up of 6.0 years (range 0.7-35.8 years), 33 (73.3%) patients were alive with disease, 7 (15.6%) were alive without disease, and 5 (11.1%) died of other causes. No patients died of DT-related complications. CONCLUSIONS: The majority of DTs in FAP patients remained stable with observation or a single intervention. There were no DT-related deaths; however, 12 of 45 patients (26.7%) experienced significant tumor morbidity and required more interventions for disease control. Further studies on quality of life are required.

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.

Biology of Precancers and Opportunities for Cancer Interception: Lesson from Colorectal Cancer Susceptibility Syndromes.

Hereditary gastrointestinal cancer is associated with molecular and neoplastic precursors which have revealed much about sporadic carcinogenesis. Therefore, an appreciation of constitutional and somatic events linked to these syndromes have provided a useful model for the development of risk models and preventative strategies. In this review, we focus of two of the best characterized syndromes, Lynch syndrome (LS) and familial adenomatous polyposis (FAP). Our understanding of the neoplasia-immune interaction in LS has contributed to the development of immune mediated therapies including cancer preventing vaccines and immunotherapy for cancer precursors. Chemoprevention in LS with aspirin and nonsteroidal anti-inflammatory drugs has also translated into clinical cancer, however the efficacy of such agents in FAP remains elusive when cancer is applied as an endpoint in trials rather than the use of 'indirect' endpoints such as polyp burden, and requires further elucidation of biological mechanisms in FAP. Finally, we review controversies in gastrointestinal surveillance for LS and FAP, including limitations and opportunities of upper and lower gastrointestinal endoscopy in the prevention and early detection of cancer.