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.

Development of Desmoid Tumors After Ileorectal Anastomosis Versus Ileal Pouch-Anal Anastomosis in Familial Adenomatous Polyposis.

BACKGROUND & AIMS: Desmoid tumors (DT) are an important cause of morbidity and mortality in patients with familial adenomatous polyposis (FAP). DT development might be related to the type and approach of colectomy. We aimed to compare DT development after colectomy with ileorectal anastomosis (IRA) and proctocolectomy with ileal pouch-anal anastomosis (IPAA). METHODS: We performed an international historical cohort study in patients with FAP who underwent IRA or IPAA between 1961 and 2020. The primary outcome was the incidence of abdominal DT (either mesenteric, retroperitoneal, or abdominal wall). Patients with a DT diagnosis before or at colectomy were excluded. Time to DT was considered censored at an eventual secondary proctectomy after IRA. We used multivariable Cox regression modelling to adjust for potential confounders. RESULTS: We analyzed data from 852 patients: 514 after IRA and 338 after IPAA (median follow-up, 21 and 16 years, respectively). DTs were diagnosed in 64 IRA patients (12%) and 66 IPAA patients (20%). The cumulative DT incidence at 5 and 10 years was 7.5% and 9.3% after open IRA and 4.7% and 10.9% after laparoscopic IRA. These estimates were 13.6% and 15.4% after open IPAA and 8.4% and 10.0% after laparoscopic IPAA. The postoperative risk was significantly higher after IPAA (P < .01) in multivariable analysis, whereas approach did not significantly influence the risk. CONCLUSIONS: The risk of developing an abdominal DT was found to be significantly higher after IPAA than after IRA. Postoperative DT risk should be taken into account when choosing between IRA and IPAA in FAP.

Psychiatric and Educational Aspects of Familial Adenomatous Polyposis: A Nationwide Danish Cohort Study With Matched Nonexposed Individuals.

INTRODUCTION: Familial adenomatous polyposis (FAP) is an autosomal, dominantly inherited disorder that predisposes to colorectal cancer. An increased risk of cancer may affect mental health, but the magnitude of this effect remains unknown. We assessed the psychosocial functioning, including the educational level attained and risk of psychiatric comorbidity, of patients with FAP by comparing them with matched nonexposed individuals. METHODS: All Danish patients with FAP diagnosed before April 2021 were identified in the Danish Polyposis Register and paired with 4 matched nonexposed individuals. Educational history, psychiatric contacts or diagnoses ( International Classification of Disease, 10th Revision ), and treatment with antidepressants, anxiolytics, or antipsychotics were compared between patients with FAP and nonexposed individuals. RESULTS: The analysis included 445 patients with FAP and 1,538 nonexposed individuals. The highest educational level reached was significantly lower for patients with FAP ( P < 0.001). When comparing patients with FAP and nonexposed and adjusting for a cancer diagnosis, an increased risk was observed for a psychiatric contact (1.69, 95% confidence interval [CI] 1.25-2.29, P < 0.001), any psychiatric prescription (1.39, 95% CI 1.17-1.66, P < 0.001), a psychiatric diagnosis (1.64, 95% CI 1.19-2.26, P = 0.002), and experiencing any psychiatric event (hazard ratio 1.42, 95% CI 1.20-1.68, P < 0.001). An increased risk was specifically seen for mood (affective) disorders (1.76, 95% CI 1.09-2.83, P = 0.02) and behavioral and emotional disorders (2.01, 95% CI 1.10-3.69, P = 0.02) and the need for antidepressants (1.59, 95% CI 1.24-2.03, P < 0.001) and antipsychotics (1.85, 95% CI 1.26-2.70, P = 0.002). DISCUSSION: Compared with nonexposed individuals, patients with had significantly less education and an increased risk of developing mood and behavioral disorders, with an increased likelihood of needing antidepressants and antipsychotics.

Cancer Risks in Attenuated and Classical Familial Adenomatous Polyposis: A Nationwide Cohort with Matched, Non-Exposed Individuals: Cancer and surgery in AFAP and FAP patients.

INTRODUCTION: Familial adenomatous polyposis (FAP) is caused by pathogenic variants in the APC gene. FAP is usually categorized according to phenotype: classical FAP (CFAP) and attenuated FAP (AFAP); the latter is considered to have a milder disease course. We aimed to assess the risk of overall and specific cancers in CFAP and AFAP patients compared to matched, non-exposed individuals. METHODS: All known Danish FAP patients were classified as either CFAP or AFAP and assigned four matched, non-exposed individuals. The risk of overall and specific cancers, and mortality were analyzed. RESULTS: The analysis included 311 CFAP patients, 134 AFAP patients, and 1,600 non-exposed individuals. The overall cancer risk was significantly higher for both CFAP and AFAP patients than for non-exposed individuals, with hazard ratios (HR) of 4.77 (95% confidence interval (CI), 3.61-6.32; P<0.001) for CFAP and 3.22 (95% CI, 2.16-4.80; P<0.001) for AFAP. No significant difference was observed when comparing CFAP and AFAP (HR=1.48; 95% CI, 0.98-2.25; P=0.0646). The HR of colonic cancer was 2.16 (95% CI, 0.99-7.72; P=0.0522) and 2.72 (95% CI, 1.19-6.22; P=0.0177 for CFAP and AFAP), respectively compared to non-exposed and did not differ between CFAP and AFAP patients (HR=0.80; 95% CI, 0.32-2.00; P=0.6278). Mortality was significantly higher in CFAP (HR=2.96; 95% CI, 2.04-4.28; P<0.001), but not in AFAP (HR=1.40; 95% CI, 0.73-2.69; P=0.311). CONCLUSION: Nationwide data reveal differing risk profiles for specific cancers and mortality in AFAP and CFAP compared to non-exposed individuals. The cancer burden of AFAP necessitates consistent monitoring of these patients.

Danish guidelines for management of non-APC-associated hereditary polyposis syndromes.

Hereditary Polyposis Syndromes are a group of rare, inherited syndromes characterized by the presence of histopathologically specific or numerous intestinal polyps and an increased risk of cancer. Some polyposis syndromes have been known for decades, but the development in genetic technologies has allowed the identification of new syndromes.. The diagnosis entails surveillance from an early age, but universal guideline on how to manage and surveille these new syndromes are lacking. This paper represents a condensed version of the recent guideline (2020) from a working group appointed by the Danish Society of Medical Genetics and the Danish Society of Surgery on recommendations for the surveillance of patients with hereditary polyposis syndromes, including rare polyposis syndromes.

Colorectal Cancer in Individuals With Familial Adenomatous Polyposis, Based on Analysis of the Danish Polyposis Registry.

BACKGROUND & AIMS: Familial adenomatous polyposis (FAP) is an autosomal dominant disorder that increases risk for colorectal cancer (CRC). We assessed changes in the incidence and prevalence of CRC, and survival times, of patients with FAP participating in the Danish follow-up study. METHODS: We collected data from the Danish Polyposis Registry, a nationwide, complete registry of patients with FAP that includes clinical information, surgical procedures, follow-up findings, and pathology reports. We compared data between the periods of 1990-1999 and 2000-2017. In 2017, the registry contained 226 families with 721 individuals with FAP. Probands were defined as patients diagnosed based on bowel symptoms, without any knowledge of hereditary bowel disease. Call-up patients were defined as those found to have FAP during screening and due to a diagnosis of FAP in first-degree relatives. RESULTS: Although the mean incidence rate of FAP was stable from 1990-1999 (0.19/100,000/year) to 2000-2017 (0.32/100,000/year) (P = .91), the point prevalence increased from 4.86/100,000 in 1999 to 6.11/100,000 by the end of 2017 (P = .005). During 2000-2017, 25 of 72,218 CRC cases were associated with FAP (0.03%)-this was a significant decrease from 1990-1999 (26/30,005 cases; 0.09%) (P = .001). The risk of CRC was significantly higher for probands (n = 191; 61.6%) than call-up cases (n = 5; 1.9%) (P < .001). All CRCs in call-up patients were detected at the diagnosis of FAP (no cases were identified in the follow-up program). The median life expectancy for call-up patients was 72.0 years (95% CI, 63.3-80.7), compared to 55.0 years for probands (95% CI, 51.2-58.8) (P < .001). Therefore, the tracing and follow-up program increased life expectancy by 17.0 years for first-degree family members. CONCLUSION: The Danish Polyposis Registry enables close monitoring of patients with FAP, reducing risk of CRC and prolonging life.

A proposed staging system and stage-specific interventions for familial adenomatous polyposis.

BACKGROUND AND AIMS: It is not possible to accurately count adenomas in many patients with familial adenomatous polyposis (FAP). Nevertheless, polyp counts are critical in evaluating each patient's response to interventions. However, the U.S. Food and Drug Administration no longer recognizes the decrease in polyp burden as a sufficient chemoprevention trial treatment endpoint requiring a measure of "clinical benefit." To develop endpoints for future industry-sponsored chemopreventive trials, the International Society for Gastrointestinal Hereditary Tumors (InSIGHT) developed an FAP staging and intervention classification scheme for lower-GI tract polyposis. METHODS: Twenty-four colonoscopy or sigmoidoscopy videos were reviewed by 26 clinicians familiar with diagnosis and treatment of FAP. The reviewers independently assigned a stage to a case by using the proposed system and chose a stage-specific intervention for each case. Our endpoint was the degree of concordance among reviewers staging and intervention assessments. RESULTS: The staging and intervention ratings of the 26 reviewers were highly concordant (ρ = 0.710; 95% credible interval, 0.651-0.759). Sixty-two percent of reviewers agreed on the FAP stage, and 90% of scores were within ±1 stage of the mode. Sixty percent of reviewers agreed on the intervention, and 86% chose an intervention within ±1 level of the mode. CONCLUSIONS: The proposed FAP colon polyposis staging system and stage-specific intervention are based on a high degree of agreement on the part of experts in the review of individual cases of polyposis. Therefore, reliable and clinically relevant means for measuring trial outcomes can be developed. Outlier cases showing wide scatter in stage assignment call for individualized attention and may be inappropriate for enrollment in clinical trials for this reason.

Re-evaluating the genotypes of patients with adenomatous polyposis of unknown etiology: a nationwide study.

In the Danish Polyposis Register, patients with over 100 cumulative colorectal adenomas of unknown genetic etiology, named in this study colorectal polyposis (CP), is registered and treated as familial adenomatous polyposis (FAP). In this study, we performed genetic analyses, including whole genome sequencing (WGS), of all Danish patients registered with CP and estimated the detection rate of pathogenic variants (PV). We identified 231 families in the Polyposis Register, 31 of which had CP. A polyposis-associated gene panel was performed and, if negative, patients were offered WGS and screening for mosaicism in blood and/or adenomas. Next-generation sequencing (NGS) was carried out for 27 of the families (four declined). PVs were detected in 11 families, and WGS revealed three additional structural variants in APC. Mosaicism of a PV in APC was detected in two families. As the variant detection rate of eligible families was 60%, 93% of families in the register now have a known genetic etiology.

Single-port access laparoscopic surgery for rectal cancer: initial experience with 10 cases.

BACKGROUND: Single-port access laparoscopic surgery is emerging as a method to improve the morbidity and cosmetic benefits of conventional laparoscopic surgery and minimize the surgical trauma. However, the feasibility of this procedure in rectal surgery has not yet been determined. OBJECTIVE: This study aimed to evaluate our initial experience using single-port access in laparoscopic rectal surgery. DESIGN: This investigation was designed as a prospective clinical study. SETTINGS: The study took place in a university hospital. PATIENTS: Ten patients with nonmetastatic rectal cancer underwent rectal resections. MAIN OUTCOME MEASURES: The main outcome measures are perioperative data including intraoperative and postoperative complications, pathological outcome, length of stay, and short-term follow-up. RESULTS: The median age of the patients was 67 (range, 49-83) and the median body mass index was 23.5 kg/m (range, 20-25 kg/m). Six patients had previously had abdominal surgery. The operations were 6 low anterior resections (4 receiving diverting ileostomy), 2 anterior resections, 1 Hartmann procedure, and 1 abdominoperineal resection. The median operative time was 229 minutes (range, 185-318), and blood loss ranged from 0 to 100 mL. In 2 cases, it was necessary to add an extra 5-mm port to deal with intraoperative complications. The median hospital stay was 7 days (range, 4-14). There were no anastomotic leaks and no mortality. All of the resection margins were clear, and the circumferential resection margin was a median of 11 mm (range, 2.5-25). The median number of lymph nodes examined was 14 (range, 3-20). LIMITATIONS: This study's limitations include the lack of registration of postoperative pain, immunological parameters, and long-term clinical and oncological outcome. The small sample size makes it difficult to ascertain complication and conversion rates. CONCLUSIONS: Single-port access laparoscopic surgery for rectal cancer can be performed safely in slim patients with a small tumor. This technique can be an alternative option for selected patients in the hands of skilled laparoscopic surgeons. Prospective comparative studies are needed to determine the role for this technique approach in the future.

[New hereditary polyposis syndromes in the patient with intestinal polyps].

Hereditary polyposis syndromes (HPS) are a group of rare, inherited syndromes characterised by the presence of histopathological specific or numerous intestinal polyps and a high risk of intestinal and extraintestinal cancer. During the last decade, several new HPS have been discovered, as it is possible to detect pathogenic germline variants in genes not previously known to be associated with polyposis. This review summarises the current knowledge on the syndromes and discusses genetic testing as part of the diagnostic pipeline when suspecting a polyposis syndrome.

Filiform serrated adenomatous polyposis arising in a diverted rectum of an inflammatory bowel disease patient.

A 54-year-old man, previously colectomized for inflammatory bowel disease, developed carcinoma in the inflamed rectum stump. The malignant growth was surrounded by a filiform polyposis, grossly considered as pseudopolyps. The histology disclosed, however, a morphology corresponding to the recently described filiform subset of serrated adenoma (FSA). The clustering of the FSA amounted to a filiform serrated adenomatous polyposis, a hitherto unreported observation. It is speculated that neoplastic transformation of pre-existing pseudopolyps and prolaps-related events lead to this peculiar morphology. Minor zones with a villous structure were admixed as were small areas of traditional serrated adenoma and patches of flat dysplasia. Although a combined gastric and intestinal (positivity for MUC5AC, MUC2, MUC6, CDX2) immunoprofile characterized the adenomatous component, a downregulation of the gastric mucin along with a loss of the serrated attribute accompanied the malignant transformation. An added dynamic shift during the adenoma carcinoma sequence included the acquisition of CK7 expression in the malignant portion. Gastric mucin may play a role in the initial step of the neoplastic evolution and CK7 may denote neoplastic progression. This case confirms the notion of a widely variegated morphology of precursor lesions of colorectal carcinoma arising in a chronically inflamed bowel as opposed to the generally more monotonous appearance of adenomas in a sporadic context.