Guidelines for the management of hereditary colorectal cancer from the British Society of Gastroenterology (BSG)/Association of Coloproctology of Great Britain and Ireland (ACPGBI)/United Kingdom Cancer Genetics Group (UKCGG)

Guidelines for Familial Adenomatous Polyposis (FAP): challenges in defining clinical management for a rare disease

Recent updated management guidelines for Familial Adenomatous Polyposis (FAP) have been published by professional bodies internationally. These recommendations reflect the diverse needs and capabilities of varying health systems worldwide, including thresholds for intervention and population health priorities. Whilst guidelines are closely aligned in many regards, there are areas of disparity. However, alongside discrepancies in guideline recommendations, common challenges also face professional bodies across the globe. Generation of a robust evidence-base in the environment of limited data is difficult in rare diseases such as FAP, underscored by the fact that expert consensus opinion underpins virtually all guidelines. The presence of a wide phenotypic spectrum in FAP and the other hereditary gastrointestinal polyposis syndromes, whilst now well recognised, further complicates the creation of universal recommendations. In this review we draw comparison between the various international guidelines for the management of FAP, using examples to focus on thematic areas of agreement and divergence. However, beyond this, we also wish to highlight the persisting evidence gaps in clinical management, and any areas of ongoing debate among clinicians, where we are yet to establish the optimal approach.

The role of health economic evidence in clinical practice guidelines for colorectal cancer: a comparative analysis across countries

Aim: Colorectal cancer (CRC) is among the most prevalent malignancies globally and causes massive resource consumption and economic burden. Health economic evidence (HEE) has been used in clinical practice guidelines (CPGs) for cancer to facilitate the rational allocation of health resources. However, in certain guideline development organizations, HEE is not yet utilized as a formal decision-making criterion. This study aimed to compare the discrepancies in the utilization of health economics as evidence in CRC CPGs across different countries and review specific features of economic evidence concerning the guidelines' applicability. Materials & methods: A systematic review was conducted using databases including Medline, Embase, CNKI, WanFang, and other guidelines databases to identify CPGs for CRC published in English or Chinese from January 2017 to September 2023. Data on the incorporation and application of HEE were extracted, and the method and quality of cost-effectiveness analysis (CEA) studies were evaluated. Descriptive analyses were used to summarize the results. Results: Out of 53 CPGs from 14 countries, most originated from the USA (n = 17 of 53 [32%]) and Canada (n = 9 of 53 [17%]). Sixty-eight percent (36/53) considered cost justification, and 57% (30/53) incorporated health economics studies as evidence. The included HEE cited in CPGs ranged from 1990 to 2021 and were not aligned with the countries in which the guidelines were issued. Among these CEA studies, 52% (26/50) were related to screening strategies, and 32% (16/50) pertained to treatment measures. The Markov model was the most frequently used (n = 27 of 50 [54%]). Based on the CHEQUE tool, the methodological quality of these CEA studies was inadequate in areas such as multiple data sources, approaches to select data sources, assessing the quality of data, and relevant equity or distribution. Conclusion: In summary, 57% of guidelines incorporated health economics studies as evidence, with a variation between different countries. The included HEE still had deficiencies in methodology and reporting quality. In the future, it is suggested that health economics research should use a standardized methodology and reporting approach to assist in clinical decision making.

Addressing uncertainty in hereditary colorectal cancer: the role of a regional expert multidisciplinary team meeting

There is frequent uncertainty in both the precise quantification of risk, and the application of clinical interventions, designed to mitigate increased heritable colorectal cancer (CRC) susceptibility. We evaluated the role of a collaborative specialist multidisciplinary team meeting (MDM) for familial and hereditary CRC, led by the St Mark's Hospital Centre for Familial Intestinal Cancer specifically in supporting the clinical management of uncertainty. A retrospective thematic analysis of meeting outcomes from inception in June 2020 until March 2023 was performed. Descriptive statistics were employed to ascertain clinicopathological data, clinical queries and whether MDM recommendations were outside the scope of current guidelines. In total 260 cases were discussed from 13 regional institutions. A prior personal history of cancer was present in 215 (82.6%), and a family history of CRC in 107(41.2%) and non-CRC 27(10.4%) cases. In thematic analysis uncertainty related to indications for genetic testing was considered in 148 (56.9%) of cases, with unexplained mismatch repair deficiency (u-dMMR) in 78 (30%) of cases, and resolution of molecular interpretation in 61 (23.5%). Surveillance related queries represented 55 (21.1%), and mainstreaming 29 (11%) of cases. Management was recommended beyond the scope of existing guidelines in 64 (24.6%) cases. This regional hereditary CRC MDM provides clinicians with support in areas of uncertainty in diagnosis and clinical management, supporting clinical decision-making where evidence and clinical guidelines may be limited. This model could be replicated to support complexity in clinical care in other geographical regions or other health conditions.

The impact of patient-reported factors of endoscopic screening experience on attendance at future examinations and distal colorectal cancer incidence

BACKGROUND

Endoscopic examinations can reduce colorectal cancer (CRC) burden through early detection and removal of precancerous lesions; however, after initial endoscopy, some patients do not attend subsequent examinations.

AIMS

To investigate the impact of patient experience of endoscopic screening on attendance at future examinations and distal CRC incidence.

METHODS

In a cohort study including 40,141 participants who received flexible sigmoidoscopy (FS) screening in the UK FS Screening Trial, median follow-up was 16.8 years. We examined family history of CRC, bowel preparation quality, segment of bowel reached, and responses to patient-reported post-examination questionnaires. We estimated multivariable odds ratios (OR) for attendance at future examinations by logistic regression and hazard ratios (HR) for associations between patient experience at FS and distal CRC incidence.

RESULTS

Of those recommended a future endoscopy, 7.1% did not attend repeat FS, 3.4% did not attend colonoscopy, 18.3% did not attend surveillance, and 0.5% developed distal CRC. Symptoms of faintness/dizziness (OR = 5.10 95%CI 1.49-17.42) were associated with non-attendance at repeat FS. Non-attendance at surveillance was associated with whether participants felt they had made the right decision to take the tests; that taking the tests was tempting fate; that they needed the tests; or that they would rather have let nature take its course. A FS more painful than expected (HR = 0.57 95%CI 0.37-0.88) was inversely associated with distal CRC incidence.

CONCLUSIONS

We identified aspects of patient experience at endoscopy that could be used to improve attendance at future endoscopic examinations, which in turn could reduce CRC incidence.

TRIAL REGISTRATION NUMBER

ISRCTN28352761. Trial registration date: April 2000.

Lynch Syndrome: Similarities and Differences of Recommendations in Published Guidelines

BACKGROUND

In this review, we aimed to compare the recommendations for Lynch syndrome (LS).

METHODS

We compared the LS's guidelines of different medical societies, including recommendations for cancer surveillance, aspirin treatment, and universal screening.

RESULTS

Most guidelines for LS patients recommend intervals of 1-2 years for performing colonoscopy, though there is disagreement regarding the age to begin CRC screening (dependent on status as a MLH1/MSH2 or MSH6/PMS2 carrier). There are inconsistencies between LS guidelines for gastric cancer surveillance. Most guidelines do not recommend routine surveillance of the pancreas and small bowel. Most but not all of the guidelines support endometrial and ovarian surveillance with transvaginal ultrasound and endometrial biopsy. Only two societies recommend urological surveillance, while others recommend surveillance among high-risk carriers with family history only. There is significant disagreement between the guidelines about the recommendation for limited or extended bowel resection among patients with CRC. Aspirin use is recommended by most societies, though some with reservations, and most of them recommend universal screening.

CONCLUSIONS

There are significant disparities and disagreements in the guidelines and recommendations for patients with LS, causing confusion and difficulties for clinicians. Harmonization and cooperation are needed between the societies creating LS guidelines.

Single-cell spatial immune profiling for precision immunotherapy in Lynch syndrome

Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) predisposition syndrome, characterized by a high mutational burden and microsatellite instability-high (MSI-H) tumors. Immunology of LS-associated CRC (LS-CRC) is unique, with significant implications for treatment. Despite well-established knowledge of LS immunology, immunotherapy dose and treatment response can vary significantly based on local tumor immunity and specific germline pathogenic variant of LS genes. This variability necessitates tailored surveillance strategies and new personalised immunotherapy approaches for LS patients. LS-CRC often benefits from immunotherapy due to the distinct tumor microenvironment (TME) and the variety of tumor infiltrating lymphocytes (TILs). This perspective discusses a novel approach of analysing spatial TILs at a single-cell level using tumor whole slide images (WSIs) that accounts for the distinct TME of LS-CRC. By emphasizing the necessity of personalized medicine in hereditary cancer syndromes, the future research and clinical practices that enhance patient outcomes through precision oncology is inspired.

Influence of Lifestyles on Polyp Burden and Cancer Development in Hereditary Colorectal Cancer Syndromes

BACKGROUND

Whether the progression of precursor lesions or the occurrence of cancer is influenced by lifestyle factors in carriers of genetic mutations has not been fully investigated, especially in Asian patients of hereditary colorectal cancer (CRC) syndrome.

METHODS

Patients at a high risk of hereditary CRC were included. For polyposis CRC syndromes, colorectal polyp burden was measured using at least 60 images per colonoscopy in each patient and classified into five stages using the International Society for Gastrointestinal Hereditary Tumours staging system according to the polyp number and size. Increase in tumor burden stage for polyposis CRC syndrome and the occurrence of CRC or any cancer for Lynch syndrome were analyzed according to lifestyle factors.

RESULTS

Ninety-six patients with suspected hereditary polyposis CRC syndrome and 106 patients with Lynch syndrome were recruited. For polyposis CRC syndromes, multivariate analysis showed that exposure to smoking and > 100 polyps independently predicted a high risk of increased polyp burden (p = 0.008 and p = 0.012, respectively). Significant genetic mutations or phenotype of polyposis syndromes were significantly associated with an increased polyp burden. For Lynch syndrome, smokers showed to be diagnosed with CRC in younger age than never-smokers (42.2 years vs. 49.0 years; p = 0.021), and heavy drinkers had high risk for occurrence of CRC (HR, 2.381, 95% CI, 1.338-4.236; p = 0.003) and any cancer (HR, 2.254; 95% CI, 1.334-3.806; p = 0.002).

CONCLUSIONS

The lifestyle factors (smoking and alcohol consumption) were associated with increasing precursor lesions and occurrence of cancer in patients with hereditary CRC syndrome. Lifestyle modifications may reduce the risk of hereditary CRC in carriers.

Lynch Syndrome-Impact of the Type of Deficient Mismatch Repair Gene Mutation on Diagnosis, Clinical Presentation, Surveillance and Therapeutic Approaches

In today's world, with its continuing advancements in genetics, the identification of Lynch syndrome (LS) increasingly relies on sophisticated genetic testing techniques. Most guidelines recommend a tailored surveillance program, as well as personalized prophylactic and therapeutic approaches, according to the type of dMMR gene mutation. Carriers of path_MLH1 and path_MSH2 genes have a higher risk of developing colorectal cancer (CRC), despite intensive colonoscopic surveillance. Conversely, carriers of path_MSH6 and path_PMS2 genes have a lower risk of developing CRC, which may be due to their lower penetrance and later age of onset. Thus, carriers of path_MLH1 or path_MSH2 would theoretically derive greater benefits from total colectomy, compared to low-risk carriers (path_MSH6 and path_PMS2), in which colonoscopic surveillance might achieve an efficient prophylaxis. Furthermore, regarding the risk of endometrial/ovarian cancer development, there is a global agreement to offer both hysterectomy and bilateral salpingo-oophorectomy to path_MLH1, path_MSH2 and path_MSH6 carriers after the age of 40. In patients with CRC, preoperative knowledge of the diagnosis of LS is of tremendous importance, due to the high risk of metachronous CRC. However, this risk depends on the type of dMMR gene mutation. For carriers of the high-risk variants (MLH1, MSH2 and EPCAM) who have already developed colon cancer, it is strongly recommended a subtotal or total colectomy is performed, while partial colectomy followed by endoscopic surveillance is an appropriate management approach to treat colon cancer in carriers of the low-risk variants (MSH6 and PMS2). On the other hand, extended surgery for index rectal cancer (such as total proctocolectomy) is less effective than extended surgery for index colon cancer from the point of view of metachronous CRC risk reduction, and is associated with a decreased quality of life.

Adenoma detection rate by colonoscopy in real-world population-based studies: a systematic review and meta-analysis

BACKGROUND

Adenoma detection rate (ADR) is a quality indicator set at a minimum of 25% in unselected populations by the European Society of Gastrointestinal Endoscopy (ESGE). Nevertheless, a lack of pooled observational data resembling real-world practice limits support for this threshold. We aimed to perform a systematic review with meta-analysis to evaluate the pooled rates for conventional adenoma detection, polyp detection (PDR), cecal intubation, bowel preparation, and complications in population-based studies.

METHODS

The PubMed, Scopus, and Web of Science databases were searched until May 2023 for populational-based studies reporting overall ADR in unselected individuals. A random-effects model was used for meta-analysis.

RESULTS

31 studies were included, comprising 3 644 561 subjects. A high quality of procedures was noticeable, with a high cecal intubation rate and low complication rate. The overall pooled ADR, PDR, and rate of cancer detection were 26.5% (95%CI 23.3% to 29.7%), 38.3% (95%CI 32.5% to 44.1%), and 2.7% (95%CI 1.5% to 3.9%), respectively. ADR varied according to indication: screening 33.3% (95%CI 24.5% to 42.2%), surveillance 42.9% (95%CI 36.9% to 49.0%), and diagnostic 24.7% (95%CI 19.5% to 29.9%), with subgroup analysis revealing rates of 34.4% (95%CI 22.0% to 40.5%) for post-fecal occult blood test and 26.6% (95%CI 22.6% to 30.5%) for primary colonoscopy screening. Diminutive conventional adenomas yielded a pooled rate of 59.9% (95%CI 43.4% to 76.3%). The pooled rate for overall serrated lesion detection was 12.4% (95%CI 8.8% to 16.0%). Male sex and higher age were significantly associated with an ADR above the benchmark.

CONCLUSION

This first meta-analysis relying on real-world observational studies supports the ESGE benchmark for ADR, while suggesting that different benchmarks might be used according to indication, sex, and age.

Adrenocortical tumors and hereditary syndromes

INTRODUCTION

Adrenocortical tumors (ACTs) are frequently encountered in clinical practice. They vary in clinical and biological characteristics from nonfunctional to life threatening hormone excess, from benign to highly aggressive malignant tumors. Most ACTs appear to be benign and nonfunctioning. It has been controversial how these apparently benign and nonfunctioning tumors should be monitored. Over the past few decades, significant advances have been made in understanding the regulation of growth and tumorigenesis in adrenocortical cells. Defining the molecular pathomechanisms in inherited tumor syndromes led to the expansion of research to sporadic ACTs. Distinct molecular signatures have been identified in sporadic ACTs and a potential genomic classification of ACT has been proposed.

AREAS COVERED

In this review, we discuss the various adrenocortical pathologies associated with hereditary syndromes with special focus on their molecular pathomechanisms, the understanding of which is important in the era of precision medicine.

EXPERT OPINION

Identifying the molecular pathomechanisms of the adrenocortical tumorigenesis in inherited syndromes has led to the understanding of the alterations in different signaling pathways that help explain the wide variations in the biology and behavior of ACTs.

The Evolving Role of Genomics in Colorectal Cancer

Approximately 75% of colorectal cancers (CRCs) harbour an identifiable driver mutation, 5% of which are heritable. These drivers have recognised implications for prognosis and therapy selection. In addition, potential germline mutations require investigations to inform testing of relatives, as well as surveillance for other malignancies. With increasing numbers of targeted drugs being approved, judicious testing is required to ensure sufficient tumour sample is available for testing and at the right point in the cancer pathway. Liquid biopsy with circulating tumour DNA (ctDNA) in the blood presents an exciting adjunct to tumour tissue testing for molecular drivers, as well as escalation and de-escalation of therapy. Here, we review the most frequent molecular alterations in CRC, how genomic testing should be integrated into the treatment pathway for CRC, and sources of further education.

Risk of Cancer and Reoperation After Ileorectal Anastomosis and Ileal Pouch-Anal Anastomosis in Familial Adenomatous Polyposis

INTRODUCTION

To prevent colorectal cancer, most patients with familial adenomatous polyposis (FAP) undergo (procto)colectomy with ileorectal anastomosis (IRA) or ileal pouch-anal anastomosis (IPAA). After surgery, these patients remain at risk of developing cancer in the remnant rectum or rectal cuff/pouch. We aimed to compare the long-term risk of cancer after IRA or IPAA in FAP.

METHODS

We performed an international multicenter historical cohort study of FAP patients undergoing IRA or IPAA from 1990 to 2023. The proportion of patients developing cancer after surgery was estimated using the Kaplan-Meier method.

RESULTS

(Procto)colectomy was performed in 685 patients (53.6% female); 366 (53.4%) had IRA, and 319 (46.6%) had IPAA. Median age at IRA and IPAA was 23 and 27 years, and the median follow-up was 12 and 15 years, respectively. Overall, 8 patients (2.2%) developed rectal and/or rectal cuff/pouch cancer after IRA and 0.9% after IPAA. The estimated 10- and 20-year cancer incidence after IRA vs IPAA was 1.6% vs 0.4% and 2.5% vs 0.9%, respectively (log-rank P = 0.15). Reoperations, mainly for extensive polyposis, were performed in 39 (10.7%) patients with an IRA and 24 (7.5%) patients after IPAA. The number of postoperative endoscopic surveillance endoscopies was higher in patients with an IRA compared with those with an IPAA ( P < 0.001).

DISCUSSION

Over the past 3 decades, few patients were diagnosed with cancer in the rectum or rectal cuff/pouch after (procto)colectomy in FAP. This might be due to an improved selection of the type of (procto)colectomy and close endoscopic surveillance including prophylactic polypectomies.

Optimizing genetic testing strategy for suspected attenuated adenomatous polyposis: effective solutions in public health systems

BACKGROUND

APC and MUTYH genes are key in hereditary attenuated adenomatous polyposis syndromes. Guidelines recommend genetic testing based on polyp count, often overlooking age despite its impact on polyp prevalence.

AIM

To enhance genetic testing strategies for suspected attenuated adenomatous polyposis by combining polyp count and age in a probability calculator.

METHODS

Retrospective study of adult patients referred to NGS genetic testing for suspected attenuated adenomatous polyposis (accumulated history of < 100 adenomas) (discovery cohort, N = 138). Data included age, adenoma count, and test results. A multivariable logistic regression model was developed to associate positive genetic test results with age and adenoma count. The model was externally validated with 259 patients from two tertiary hospitals in our region (validation cohort, N = 259).

RESULTS

In the discovery cohort, 13 (9.4%) patients had pathogenic mutations, being younger (OR:0.91, 95%CI 0.86-0.96) and having more adenomas (OR:1.08, 95%CI 1.04-1.13) compared to negative cases. The logistic regression model combining age and polyp count demonstrated an AUC of 0.92. Using a cutoff probability of 3.5%, the model achieved 100% sensitivity and 58% specificity in identifying positive cases. In the external validation, the model accurately predicted 14 out of 16 positive cases (88%). The remaining two positive cases were a patient with an AXIN2 mutation in heterozygosis, and a patient with a NTHL1 mutation in homozygosis. Performance evaluation of both hospitals yielded AUC values of 0.77 and 0.90.

CONCLUSIONS

Older individuals with fewer polyps are less likely have hereditary syndromes. Including age in genetic testing criteria can enhance patient selection and cost-effectiveness.

Localized Rectal Cancer: Indian Consensus and Guidelines

The rising incidence of colorectal cancer (CRC) in India, particularly the prevalence of rectal cancer over colon cancer (0.7:1), has been a growing concern in recent decades; especially notable is the trend of increasing cases among young CRC patients. Given the diverse treatment approaches for rectal cancer globally and the varying economic capacities of patients in low to middle-income countries (LMICs) like India, it is essential to establish consensus guidelines that are specifically tailored to meet the needs of these patients. To achieve this, a panel comprising 30 eminent rectal cancer experts convened to conduct a comprehensive and impartial evaluation of existing practices and recent advancements in the field. Through meticulous scrutiny of published literature and a consensus-building process that involved voting on pertinent questions, the panel formulated management strategies. These recommendations are the result of a rigorous, evidence-based process and encapsulate the collective wisdom and judgment of leading authorities in the field.

Who has the responsibility to inform relatives at risk of hereditary cancer? A population-based survey in Sweden

OBJECTIVES

Hereditary cancer has implications not only for patients but also for their at-risk relatives (ARRs). In current clinical practice, risk disclosure to ARRs involves collaboration between patients and healthcare providers (HCPs). However, the specific responsibilities of each party are intertwined and at times unclear. In this study, we explored public attitudes regarding moral and legal responsibilities to disclose familial risk information to uninformed ARRs.

DESIGN

In an online cross-sectional survey, participants were prompted with a hypothetical scenario where a gender-neutral patient learnt about their familial risk of colorectal cancer. The patient was advised to regularly undergo colonoscopy screening, and this recommendation was extended to both their siblings and cousins. While the patient informed their siblings, they had not spoken to their cousins in 20 years and did not want to contact them. The survey assessed respondents' views on the patient's and HCPs' ethical responsibility and legal obligation to inform the cousins (ARRs).

PARTICIPANTS

A random selection of 1800 Swedish citizens 18-74 years of age were invited. Out of those, 914 (51%) completed the questionnaire.

RESULTS

In total, 75% believed that HCPs had a moral responsibility to inform ARRs, while 59% ascribed this moral responsibility to the patient. When asked about the ultimate responsibility for risk disclosure to ARRs, 71% placed this responsibility with HCPs. Additionally, 66% believed that HCPs should have a legal obligation to inform ARRs, while only 21% thought the patient should have such an obligation. When prompted about a scenario in which the patient actively opposed risk disclosure, a majority believed that HCPs should still inform the ARRs.

CONCLUSION

Our study indicates that the Swedish public ascribes moral responsibility for informing ARRs to both the patient and HCPs. However, contrary to current practice, they believe HCPs hold the ultimate responsibility. The majority of respondents support disclosure even without patient consent.

Lynch syndrome diagnostic testing pathways in endometrial cancers: a nationwide English registry-based study

BACKGROUND

For female patients with Lynch syndrome (LS), endometrial cancer (EC) is often their first cancer diagnosis. A testing pathway of somatic tumour testing triage followed by germline mismatch repair (MMR) gene testing is an effective way of identifying the estimated 3% of EC caused by LS.

METHODS

A retrospective national population-based observational study was conducted using comprehensive national data collections of functional, somatic and germline MMR tests available via the English National Cancer Registration Dataset. For all EC diagnosed in 2019, the proportion tested, median time to test, yield of abnormal results and factors influencing testing pathway initiation were examined.

RESULTS

There was an immunohistochemistry (IHC) or microsatellite instability (MSI) test recorded for 17.8% (1408/7928) of patients diagnosed with EC in 2019. Proportions tested varied by Cancer Alliance and age. There was an MLH1 promoter hypermethylation test recorded for 43.1% (149/346) of patients with MLH1 protein IHC loss or MSI. Of patients with EC eligible from tumour-testing, 25% (26/104) had a germline MMR test recorded. Median time from cancer diagnosis to germline MMR test was 315 days (IQR 222-486).

CONCLUSION

This analysis highlights the regional variation in recorded testing, patient attrition, delays and missed opportunities to diagnose LS, providing an informative baseline for measuring the impact of the national guidance from the National Institute for Health and Care Excellence on universal reflex LS testing in EC, implemented in 2020.

Germline pathogenic variants in RNF43 in patients with and without serrated polyposis syndrome

Serrated Polyposis Syndrome (SPS) is characterized by multiple and/or large serrated polyps in the colon and an increased risk of colorectal cancer (CRC). The etiology is largely unknown, but in a subset of patients with SPS, monoallelic pathogenic variants in RNF43 are detected. To date, however, the penetrance and phenotypic spectrum of patients carrying pathogenic variants (PV) in RNF43 are poorly described. We present eight patients both with and without serrated polyps from four unrelated families with likely pathogenic variants (LPV) in RNF43 and compare the results to current literature. The patients were referred to genetic counseling due to suspicion of hereditary cancer. They underwent genetic testing with custom NGS gene panels including RNF43 as part of a routine genetic work-up. Three LPVs, one multi-exon deletion and two nonsense variants, were detected in four families. Family I had a history of CRC and serrated polyps, but in the three other families (II‒IV) there was no history of CRC or serrated polyps. Colonoscopies in the probands of these families did not reveal any serrated polyps and/or CRC despite some of them being relatively old. Our findings suggest that the penetrance of RNF43-related disease is much lower than previously thought, and raise questions about the connection between RNF43 and disease. The results highlight the complexity of genetic counseling in RNF43 positive families- particularly in families without polyposis. Further research is needed to elucidate the role of RNF43 in the risk of SPS and CRC.

Mainstreaming cancer genetics: feasibility of an advanced nurse practitioner-led service diagnosing Lynch syndrome from colorectal cancer in Ireland

Colorectal cancer (CRC) is a common cancer in Ireland. Of all CRCs, 2-4% are attributable to Lynch Syndrome (LS), the most common CRC predisposition syndrome. LS is caused by constitutional pathogenic variants (PVs) affecting mismatch repair (MMR) genes with resultant MMR protein deficiency (dMMR). Screening of all CRCs with MMR immunohistochemistry (IHC) testing is advocated to increase the detection of LS. However, successful implementation requires appropriate downstream management. In Ireland the traditional pathway involves referral to cancer genetics services to assess eligibility for genetic testing. Cancer genetics services in Ireland face many challenges in providing uniform access to timely healthcare with current wait times for assessment in excess of 1 year. An increasingly adopted pathway is that of mainstreaming, whereby genetic testing is managed locally by a multidisciplinary team member. Our institution therefore implemented an Advanced Nurse Practitioner (ANP)-led service with responsibility for the LS Diagnostic Pathway and mainstream genetic testing. Data was extracted from a prospectively maintained database of all newly diagnosed CRC patients discussed at our institutions CRC multidisciplinary meeting (MDM) between January 1st, 2023, and May 31st, 2024. MMR IHC testing was performed in 97.9% of the 385 patients diagnosed with CRC. The median time from histological confirmation of CRC to the availability of the MMR IHC report was 6 days. All 51 patients (100%) who required sequential tumor testing underwent BRAF V600 ± MLH1 promoter methylation testing. Additionally, 100% of the 14 patients eligible for mainstream genetic testing were referred to the ANP-led genetics service. The median time from the initial MDM discussion to the initiation of genetic testing was 69 days, while the median time from testing to the availability of results was 19 days. Patients received their results within a median of 21 days. MMR IHC testing increases the detection of LS through identification of dMMR tumours. Successful downstream delivery of clinical services, however, requires appropriate subsequent management, in a resource-limited environment. Our institutional experience demonstrates the feasibility, efficiency, and effectiveness of an ANP-led mainstreaming model of care for hereditary colorectal cancer.

Large-scale application of ClinGen-InSiGHT APC-specific ACMG/AMP variant classification criteria leads to substantial reduction in VUS

Pathogenic constitutional APC variants underlie familial adenomatous polyposis, the most common hereditary gastrointestinal polyposis syndrome. To improve variant classification and resolve the interpretative challenges of variants of uncertain significance (VUSs), APC-specific variant classification criteria were developed by the ClinGen-InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (VCEP) based on the criteria of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP). A streamlined algorithm using the APC-specific criteria was developed and applied to assess all APC variants in ClinVar and the International Society for Gastrointestinal Hereditary Tumours (InSiGHT) international reference APC Leiden Open Variation Database (LOVD) variant database, which included a total of 10,228 unique APC variants. Among the ClinVar and LOVD variants with an initial classification of (likely) benign or (likely) pathogenic, 94% and 96% remained in their original categories, respectively. In contrast, 41% ClinVar and 61% LOVD VUSs were reclassified into clinically meaningful classes, the vast majority as (likely) benign. The total number of VUSs was reduced by 37%. In 24 out of 37 (65%) promising APC variants that remained VUS despite evidence for pathogenicity, a data-mining-driven work-up allowed their reclassification as (likely) pathogenic. These results demonstrated that the application of APC-specific criteria substantially reduced the number of VUSs in ClinVar and LOVD. The study also demonstrated the feasibility of a systematic approach to variant classification in large datasets, which might serve as a generalizable model for other gene- or disease-specific variant interpretation initiatives. It also allowed for the prioritization of VUSs that will benefit from in-depth evidence collection. This subset of APC variants was approved by the VCEP and made publicly available through ClinVar and LOVD for widespread clinical use.

Digital innovation for cancer risk assessment allows large-scale service redevelopment of regional cancer genetics service delivery

Family-history assessment can identify individuals above population-risk for cancer to enable targeted Screening, Prevention and Early Detection (SPED). The online patient-facing cancer Family History Questionnaire Service (cFHQS) is a digitalised, resource efficient tool for family history data capture to facilitate this. The capturing of digital data from cFHQS allows for data interrogation of patients referred to Clinical Genetics for the purposes of service improvement. Digital data from 4,044 cFHQS respondents over a three-year period was collected and interrogated with respect to the number and type of familial tumour diagnoses to enable service improvement and streamlining of referral pathways. 81% of colorectal and 71% of breast screening assessments were population- or moderate-risk. Most patients who completed cFHQS reported more than one diagnosis of cancer/tumour/polyps in their family. 2.5% of family history assessment patients had a second indication that required assessment that would have been missed if single tumour type assessment was undertaken. Implementation of an innovative, digital family history data collection pathway has allowed large scale interrogation of referral patterns and assessment outcomes to enable service development. The high volume of inappropriate referrals to Clinical Genetics for population and moderate risk patients highlighted the need for dedicated secondary care pathway provision for these patients. The use of cFHQS streamlined family history assessment allows for redistribution of resources to improve equity and access to genetic cancer risk assessment.

Colonoscopic surveillance in Lynch syndrome: guidelines in perspective

Lynch syndrome predisposes to a high risk of colorectal cancer and colonoscopy remains the primary preventive strategy. The prevention of colorectal cancer through colonoscopy relies on identifying and removing adenomas, the main precursor lesion. Nevertheless, colonoscopy is not an optimal strategy since post-colonoscopy colorectal cancer remains an important issue. In continuation of a 2021 journal review, the present article seeks to offer an updated perspective by examining relevant articles from the past 3 years. We place recent findings in the context of existing guidelines, with a specific focus on colonoscopy surveillance. Key aspects explored include colonoscopy quality standards, timing of initiation, and surveillance intervals. Our review provides a comprehensive analysis of adenoma-related insights in Lynch syndrome, delving into emerging technologies like virtual chromoendoscopy and artificial intelligence-assisted endoscopy. This review aims to contribute valuable insights into the topic of colonoscopy surveillance in Lynch syndrome.

Classification of fundic gland polyps for predicting gastric neoplasms in Helicobacter pylori-negative patients with familial adenomatous polyposis

BACKGROUND

In familial adenomatous polyposis (FAP) patients, fundic gland polyps (FGPs) have been considered a risk factor for gastric neoplasms. We speculated that FGPs in FAP patients spread directionally from the greater to the lesser curvature of the gastric body and investigated the relationship between the distribution of FGPs and gastric neoplasm development.

METHODS

We extracted 195 FAP patients from two institutions and reviewed their medical records. Gastric polyposis was classified based on the FGP distribution (P0, no FGPs; P1, localized in the fundus or greater curvature of the gastric body; P2, spreading to the anterior or posterior wall; P3, involving the proximal half of the lesser curvature; and P4, spreading from P3 to the anal side of the lesser curvature).

RESULTS

The 195 eligible patients were divided into the neoplasm group (n = 54, 28%) and the non-neoplasm group (n = 141, 72%). Overall, 24% of the patients were Helicobacter pylori (H. pylori)-positive. In the FGP distribution, the rate of patients with gastric neoplasm tended to increase significantly with each step towards an increasingly wide distribution from P0 to P4 in H. pylori-negative patients, but not in H. pylori-positive ones. In addition, in H. pylori-negative patients, the likelihood of neoplasm increased consistently from P0 to P4, with the highest odds ratio (95% confidence interval) at P4 of 14.1 (2.5-154.4). Furthermore, multivariate analysis showed P4 and Spigelman stage ≥III were significantly associated with gastric neoplasm development.

CONCLUSION

FGP distribution was correlated with gastric neoplasm development in FAP patients.

Characteristics of Cancer in Subjects Carrying Lynch Syndrome-Associated Gene Variants in Taiwanese Population: A Hospital-Based Study in Taiwan

Lynch syndrome (LS) is an autosomal dominant disorder characterized by increased risks of colorectal and endometrial cancers. LS is defined by pathogenic variants in mismatch repair (MMR) genes, including MLH1, MSH2, and MSH6. Data on the prevalence and associated cancer risks of LS in the Han Chinese population remain limited. In this study, using a broad biobank approach through the Taiwan Precision Medicine Initiative (TPMI), we identified LS-associated MMR gene variants within a cohort of 42,828 participants from a Taiwanese medical center. A total of 89 individuals were found to carry pathogenic MMR variants: MLH1 (n = 22, 25%), MSH2 (n = 47, 53%), and MSH6 (n = 20, 22%). The overall prevalence of MMR variants was calculated, and cancer incidence rates among carriers were determined. The prevalence of MMR variants in the study population was 1 in 481. The distribution of MLH1, MSH2, and MSH6 variants were 24.7%, 52.8%, and 22.5%, respectively. Cumulative cancer incidence rates of carriers were 40.9% for MLH1 carriers, 29.8% for MSH2, and 40% for MSH6. Among the 19 individuals who underwent colonoscopy screening, the prevalence of polyps was similar to that of the control group (adenoma detection rate: 32% vs 26%, p = 0.585). A meticulous analysis of the detected polyps in seven participants, considering factors such as location, size, morphology, and pathological features, showed no significant differences from controls. A significant cancer risk is associated with LS-related MMR variants in the Taiwanese population. The apparent under diagnosis of LS highlights the urgent need for enhanced surveillance and genetic counseling in this demographic. Our findings suggest that adjustments in the current screening protocols may be warranted to better identify and manage at-risk individuals.

Diagnostic Performance of Faecal Immunochemical Testing (FIT) in Patients with Lynch Syndrome Scheduled for Colonoscopic Surveillance

BACKGROUND AND AIMS

Lynch syndrome (LS) carries a substantial lifetime risk of colorectal cancer which is currently mitigated by biennial colonoscopy surveillance. Paramount to the surveillance programme is the removal of adenomas before malignant transformation but there is an associated service burden and morbidity of repeated endoscopy. We investigated if faecal immunochemical testing (FIT) for faecal haemoglobin has the diagnostic performance to replace colonoscopy.

METHODS

In this retrospective cohort study, patients due to undergo planned surveillance for LS between November 2020 and April 2022 were sent two FIT kits prior to colonoscopy. Test diagnostic performance of colorectal cancer (CRC), advanced and non-advanced adenoma detection was calculated for single and double FIT strategies. A faecal-Hb of 10 µg Hb/g was considered positive.

RESULTS

In total, 78 patients, with 45 (57.7%) female, median age 52 years (IQR 41-63), completed at least one FIT and colonoscopy. The median time from FIT to colonoscopy was 47 days. A single FIT was positive in 7/30 cases of adenoma (2/3 advanced, 5/27 non-advanced). A total of 64 (82.1% of FIT1T returners) completed a second FIT. Using the greatest of the two FITs (FIT2TMAX) 8/26 (2/3 advanced, 4/23 non-advanced), patients with adenomas were identified. There were no cases of CRC. The sensitivity for adenoma detection was 23.3% and 23.1%, respectively.

CONCLUSIONS

In patients with LS awaiting colonoscopy, FIT has a low sensitivity for detecting adenomas and advanced adenomas. This is not improved by the addition of a second FIT test.

Pediatric Cancer Screening in Hereditary Gastrointestinal Cancer Risk Syndromes: An Update from the AACR Childhood Cancer Predisposition Working Group

Gastrointestinal (GI) polyposis and cancer in pediatric patients is frequently due to an underlying hereditary cancer risk syndrome requiring ongoing cancer screening. Identification of at-risk patients through family history, clinical features of a syndrome, or symptom onset ensures appropriate cancer risk assessment and management in childhood and beyond. In this 2024 perspective, we outline updates to the hereditary GI cancer screening guidelines first published by the American Association of Cancer Research Pediatric Cancer Predisposition Workshop in 2017. These guidelines consider existing recommendations by pediatric and adult gastroenterology consortia to ensure alignment with gastroenterology practices in managing polyposis conditions. We specifically address the recommendations for pediatric screening in familial adenomatous polyposis, Peutz-Jeghers syndrome, and juvenile polyposis syndrome. Further, we emphasize the importance of multidisciplinary care and partnership with gastroenterology, as it is crucial in management of children and families with these conditions.

Analysis of the Application of Professional Society Screening Guidelines for Colorectal Polyposis Syndromes at a Single Institution

Several professional society guidelines suggest germline genetic testing for colorectal polyposis syndromes in patients with ≥10 lifetime adenomatous polyps. This study evaluated the factors associated with genetic testing decisions and outcomes when germline testing was recommended per guidelines. Surgical archives revealed 145 patients with a recommendation for germline genetic polyposis testing based on guidelines. Demographic data and medical history were collected to examine their association with testing decisions and results. Germline genetic testing was ordered in 90 out of 145 patients and was ordered in younger patients with more lifetime adenomas. Pathogenic alterations were detected in 12 out of 53 patients who completed testing. Younger ages and higher numbers of lifetime adenomas were not associated with the detection of germline genetic alterations. In fact, patients with a pathogenic germline alteration had higher median ages and fewer lifetime adenomas than those without an alteration. Half of the 12 patients with a pathogenic germline mutation were not White non-Hispanic, although White non-Hispanic patients comprised 75.5% of those tested. This study supports the 10 adenomatous polyp threshold for recommending germline genetic polyposis testing, as an alteration was detected in a sizable proportion (>20%) of patients tested. Although a younger age and a higher number of lifetime adenomas were associated with an increased likelihood of ordered tests, no evidence was found to support these additional factors in testing decisions.

Enhancing colorectal cancer screening in high-risk population through fecal immunochemical test surveillance: Results from a surveillance program

BACKGROUND

Current guidelines recommend colonoscopy-based surveillance to decrease the risk of colorectal cancer (CRC) among these participants with above-average risk. The fecal immunochemical test (FIT) holds promise as a viable alternative surveillance tool, but the existing evidence regarding the use of settings remains limited. Therefore, our aim is to evaluate the CRC incidence rates in individuals with above-average CRC risk and the relationship between FIT surveillance and CRC incidence.

METHODS

The retrospective cohort study was performed based on the CRC screening program between January 2012 and December 2022, in Tianjin, China. This cohort study included 12,515 participants aged 40-74 years with above-average risk. The primary outcomes were the incidence rates of CRC and advanced colorectal neoplasia which were expressed as the number of events per 100,000 person-years. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models.

RESULTS

We included 12,515 participants aged 40-74 years, of whom 4980 received subsequent FIT surveillance during the study period. Among these participants, 51 CRC cases occurred in the non-FIT surveillance group (incidence rate, 233.88 per 100,000 person-years) and there were 29 cases of CRC in the FIT surveillance group (incidence rate, 184.85 per 100,000 person-years), resulting in an incidence rate ratio (IRR) of 0.58 (95% CI, 0.37-0.91). Meanwhile, 428 advanced colorectal neoplasia cases were reported in the non-FIT surveillance group, while 269 cases occurred in the FIT surveillance group, with significantly lower incidence of advanced colorectal neoplasia in the FIT surveillance group (IRR: 0.64; 95% CI, 0.55-0.74). Compared with the non-FIT surveillance group, the FIT surveillance group had a 54% decreased risk of developing CRC (HR, 0.46; 95% CI, 0.29-0.74) and a 45% decreased risk of developing advanced colorectal neoplasia (HR, 0.55; 95% CI, 0.47-0.64).

CONCLUSIONS

In this retrospective cohort study, above-average risk individuals who received subsequent FIT in the intervals between colonoscopies were associated with a reduction of CRC and advanced colorectal neoplasia incidence, which indicated the value and utility of FIT in the surveillance program.

Single-cell AI-based detection and prognostic and predictive value of DNA mismatch repair deficiency in colorectal cancer

Testing for DNA mismatch repair deficiency (MMRd) is recommended for all colorectal cancers (CRCs). Automating this would enable precision medicine, particularly if providing information on etiology not captured by deep learning (DL) methods. We present AIMMeR, an AI-based method for determination of mismatch repair (MMR) protein expression at a single-cell level in routine pathology samples. AIMMeR shows an area under the receiver-operator curve (AUROC) of 0.98, and specificity of ≥75% at 98% sensitivity against pathologist ground truth in stage II/III in two trial cohorts, with positive predictive value of ≥98% for the commonest pattern of somatic MMRd. Lower agreement with microsatellite instability (MSI) testing (AUROC 0.86) reflects discordance between MMR and MSI PCR rather than AIMMeR misclassification. Analysis of the SCOT trial confirms MMRd prognostic value in oxaliplatin-treated patients; while MMRd does not predict differential benefit of chemotherapy duration, it correlates with difference in relapse by regimen (PInteraction = 0.04). AIMMeR may help reduce pathologist workload and streamline diagnostics in CRC.

Familial adenomatous polyposis: a case report

BACKGROUND

Familial adenomatous polyposis is characterized by the presence of multiple colorectal adenomatous polyps and caused by germline mutations in the tumor suppressor gene and adenomatous polyposis coli, located on chromosome 5q21-q22. Familial adenomatous polyposis occurs in approximately 1/10,000 to 1/30,000 live births, and accounts for less than 1% of all colorectal cancers in the USA. It affects both sexes equally and has a worldwide distribution. The incidence of colon cancer in low- and middle-income countries is rising. In addition to the increasing incidence, lack of early detection and impeded access to optimal multidisciplinary treatment may worsen survival outcomes. Developing quality diagnostic services in the proper health context is crucial for early diagnosis and successful therapy of patients with colorectal cancer, and applying a resource-sensitive approach to prioritize essential treatments on the basis of effectiveness and cost-effectiveness is key to overcoming barriers in low- and middle-income countries. We report a case of familial adenomatous polyposis presenting as adenocarcinoma with multiple colorectal adenomatous polyps. The diagnosis of familial adenomatous polyposis was made by the presence of numerous colorectal adenomatous polyps and family history of colonic adenocarcinoma. Due to its rarity, we decided to report it.

CASE PRESENTATION

A 22-year-old Ethiopian female patient presented to Addis Ababa University College of Health science, Addis Ababa, Ethiopia with rectal bleeding. Abdominopelvic computed tomography scan was done and showed distal rectal asymmetric anterior wall thickening in keeping with rectal tumor. Colonoscopy was done and she was diagnosed to have familial adenomatous polyposis with severe dysplasia. In the meantime, colonoscopy guided biopsy was taken and the diagnosis of adenocarcinoma with familial adenomatous polyposis was rendered. For this, total proctocolectomy was carried out. On laparotomy there was also incidental finding of left ovarian deposition for which left salpingo-oophorectomy was done, and 4 weeks after surgical resection, the patient was started on oxaliplatin, leucovorin, fluorouracil chemotherapy regimen.

CONCLUSION

In the clinical evaluation of a patient with rectal bleeding, familial adenomatous polyposis must be considered as a differential diagnosis in subjects having family history of colonic adenocarcinoma for early diagnostic workup, management, family genetic counseling, and testing.

Chinese national clinical practice guidelines on prevention, diagnosis and treatment of early colorectal cancer

BACKGROUND

The incidence and mortality of colorectal cancer (CRC) in China are increasing in recent years. The clarified pathogenesis and detectable precancerous lesions of CRC make it possible to prevent, screen, and diagnose CRC at an early stage. With the development of endoscopic and surgical techniques, the choice of treatment for early CRC is also worth further discussion, and accordingly, a standard follow-up program after treatment needs to be established.

METHODS

This clinical practice guideline (CPG) was developed following the recommended process of the World Health Organization, adopting Grading of Recommendations Assessment, Development and Evaluation (GRADE) in assessing evidence quality, and using the Evidence to Decision framework to formulate clinical recommendations, thereby minimizing bias and increasing transparency of the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guides to ensure the guideline's completeness and transparency.

RESULTS

This CPG comprises 46 recommendations concerning prevention, screening, diagnosis, treatment, and surveillance of CRC. In these recommendations, we have indicated protective and risk factors for CRC and made recommendations for chemoprevention. We proposed a suitable screening program for CRC based on the Chinese context. We also provided normative statements for the diagnosis, treatment, and surveillance of CRC based on existing clinical evidence and guidelines.

CONCLUSIONS

The 46 recommendations in this CPG are formed with consideration for stakeholders' values and preferences, feasibility, and acceptability. Recommendations are generalizable to resource-limited settings with similar CRC epidemiology pattern as China.

Risk of Gastric and Small Intestinal Cancer in Patients With Lynch Syndrome: Data From a Large, Community-Based US Population

INTRODUCTION

Risk of gastric and small intestinal cancer in Lynch syndrome (LS) remains poorly understood. We investigated the risk of gastric and small intestinal cancer in patients with LS in a large, community-based population.

METHODS

This retrospective cohort study included all patients diagnosed with LS between January 1, 1997, and December 31, 2020, at Kaiser Permanente Northern California. Cumulative incidence of gastric cancer and small intestinal cancer was calculated using competing risk methodology.

RESULTS

Among 1,106 patients with LS with a median follow-up of 19.3 years (interquartile range [IQR] 9.4-24.0 years), 11 developed gastric cancer (8 MSH2 , 2 MLH1 and 1 PMS2 ) with a median diagnosis age of 56 years (IQR 42-63 years) and 11 developed small intestinal cancer (6 MSH2 , 3 MLH1 , 1 MSH6 and 1 PMS2 ) with a median diagnosis age of 57 years (IQR 50-66 years). Cumulative incidence by age 80 years was 7.26% (95% confidence internal [CI], 1.80-18.03%) for men and 3.43% (95% CI, 0.50-11.71%) for women for gastric cancer and 7.28% (95% CI, 3.19-13.63%) for men and 2.21% (95% CI, 0.23-9.19%) for women for small intestinal cancer. Pathogenic variant carriers of MSH2 and MLH1 had the highest risk of gastric and small intestinal cancer. History of Helicobacter pylori infection was associated with increased risk of gastric cancer (adjusted odds ratio 5.52; 95% CI, 1.72-17.75).

DISCUSSION

Patients with LS, particularly MSH2 and MLH1 pathogenic variant carriers, had significantly increased lifetime risk of gastric and small intestinal cancer. Testing and treatment of H. pylori infection should be considered for all patients with LS.

Reproductive decision-making in cancer susceptibility syndromes

Cancer susceptibility syndromes confer an increased lifetime risk of cancer and occur due to germline likely-pathogenic or pathogenic variants in a cancer susceptibility gene. Clinical Genetics services advise patients of ways to manage their future cancer risks, often prefaced with uncertainties due to poor understandings of individualised risk. For individuals/couples whose future offspring are at risk of a cancer susceptibility syndrome, different options are available depending on their preferences and circumstances, including prenatal diagnosis and preimplantation genetic testing. This review provides an overview of the most common cancer susceptibility syndromes, available reproductive options and a genetic counselling framework recommended to support individuals/couples in their decision-making. We describe complexities of decision-making involving moderate penetrance and sex-specific variable penetrance genes and explore associated ethical issues arising in this complex area of medicine.

From Crypts to Cancer: A Holistic Perspective on Colorectal Carcinogenesis and Therapeutic Strategies

Colorectal cancer (CRC) represents a significant global health burden, with high incidence and mortality rates worldwide. Recent progress in research highlights the distinct clinical and molecular characteristics of colon versus rectal cancers, underscoring tumor location's importance in treatment approaches. This article provides a comprehensive review of our current understanding of CRC epidemiology, risk factors, molecular pathogenesis, and management strategies. We also present the intricate cellular architecture of colonic crypts and their roles in intestinal homeostasis. Colorectal carcinogenesis multistep processes are also described, covering the conventional adenoma-carcinoma sequence, alternative serrated pathways, and the influential Vogelstein model, which proposes sequential APC, KRAS, and TP53 alterations as drivers. The consensus molecular CRC subtypes (CMS1-CMS4) are examined, shedding light on disease heterogeneity and personalized therapy implications.

Effect of genetic profiling on surgical decisions at hereditary colorectal cancer syndromes

Hereditary colorectal cancer syndromes, such as Lynch syndrome and familial adenomatous polyposis (FAP), present significant clinical challenges due to the heightened cancer risks associated with these genetic conditions. This review explores genetic profiling impact on surgical decisions for hereditary colorectal cancer (HCRC), assessing options, timing, and outcomes. Genotypes of different HCRCs are discussed, revealing a connection between genetic profiles, disease severity, and outcomes. For Lynch syndrome, mutations in the MLH1, MSH2, MSH6, and PMS2 genes guide the choice of surgery. Subtotal colectomy is recommended for patients with mutations in MLH1 and MSH2, while segmental colectomy is preferred for those with MSH6 and PMS2 mutations. In cases of metachronous colon cancer after segmental colectomy, subtotal colectomy with ileorectal anastomosis is advised for all mutations. Surgical strategies for primary rectal cancer include anterior resection or abdominoperineal resection (APR), irrespective of the specific mutation. For rectal cancer occurring after a previous segmental colectomy, proctocolectomy with ileal pouch-anal anastomosis (IPAA) or APR with a permanent ileostomy is recommended. In FAP, surgical decisions are based on genotype-phenotype correlations. The risk of desmoid tumors post-surgery supports a single-stage approach, particularly for certain APC gene variants. Juvenile Polyposis Syndrome (JPS) surgical decisions involve genetic testing, polyp characteristics with attention to vascular lesions in SMAD4 mutation carriers. However, genetic profiling does not directly dictate the specific surgical approach for JPS. In conclusion this review highlights the critical role of personalized surgical plans based on genetic profiles to optimize patient outcomes and reduce cancer risk. Further research is needed to refine these strategies and enhance clinical guidelines.

Colonoscopy and Upper Endoscopy Surveillance in Lynch Syndrome: A Longitudinal Study From a Large Tertiary Healthcare System

Background and Aims

Lynch syndrome (LS) is caused by pathogenic mutations in mismatch repair (MMR) genes. There are limited data on differences in colorectal cancer (CRC) surveillance by MMR genes, and an international consensus on surveillance based on genes is not established. We aimed to evaluate colonoscopy and esophagogastroduodenoscopy (EGD) surveillance outcomes and compare CRC surveillance findings by the mutated gene.

Methods

One hundred one patients with LS were included and colonoscopy results were compared by MMR mutation. Primary outcomes included the development and recurrence of adenoma, CRC, high-grade dysplasia, advanced adenoma, and sessile serrated lesions. Logistic regressions evaluated the relationship between genes and the development or recurrence of primary outcomes. Survival analysis evaluated primary outcomes in patients with ≥ 2 colonoscopies. EGD results were summarized.

Results

Three hundred twenty seven colonoscopies were reviewed. Compared to PMS2, MLH1 was associated with a higher risk of advanced adenoma/high-grade dysplasia/CRC development (odds ratio [OR] 9.85, 95% confidence interval [CI]: 1.97-77.24) and MSH2 was associated with a higher risk of adenoma development (OR 4.17, 95% CI: 1.11-17.61). Among those with > 2 colonoscopies, MLH1 (hazard ratio 18.98, 95% CI: 1.31-274.51) and MSH6 (hazard ratio 15.03, 95% CI: 1.16-194.65) had a higher risk of sessile serrated lesions compared to MSH2. Among patients who had adenoma detected once, MLH1 had a higher risk of adenoma recurrence compared to MSH6 (OR 14.59, 95% CI: 1.53-244.30) and PMS2 (OR 47.15, 95% CI: 4.26-984.28). MSH2 had a higher risk of adenoma recurrence compared to PMS2 (OR 11.89, 95% CI: 1.38-164.78). Of 170 EGDs, an actionable finding was identified in 16% of patients during their first 3 EGDs.

Conclusion

Surveillance colonoscopy outcomes differed in patients with LS and suggest the need to guide surveillance based on MMR gene mutation.

Research Advances of Lipid Nanoparticles in the Treatment of Colorectal Cancer

Colorectal cancer (CRC) is a common type of gastrointestinal tract (GIT) cancer and poses an enormous threat to human health. Current strategies for metastatic colorectal cancer (mCRC) therapy primarily focus on chemotherapy, targeted therapy, immunotherapy, and radiotherapy; however, their adverse reactions and drug resistance limit their clinical application. Advances in nanotechnology have rendered lipid nanoparticles (LNPs) a promising nanomaterial-based drug delivery system for CRC therapy. LNPs can adapt to the biological characteristics of CRC by modifying their formulation, enabling the selective delivery of drugs to cancer tissues. They overcome the limitations of traditional therapies, such as poor water solubility, nonspecific biodistribution, and limited bioavailability. Herein, we review the composition and targeting strategies of LNPs for CRC therapy. Subsequently, the applications of these nanoparticles in CRC treatment including drug delivery, thermal therapy, and nucleic acid-based gene therapy are summarized with examples provided. The last section provides a glimpse into the advantages, current limitations, and prospects of LNPs in the treatment of CRC.

A novel colorectal cancer test combining microsatellite instability and BRAF/RAS analysis: Clinical validation and impact on Lynch syndrome screening

Background

Lynch syndrome (LS) is under-diagnosed. UK National Institute for Health and Care Excellence guidelines recommend multistep molecular testing of all colorectal cancers (CRCs) to screen for LS. However, the complexity of the pathway has resulted in limited improvement in diagnosis.

Methods

One-step multiplex PCR was used to generate sequencing-ready amplicons from 14 microsatellite instability (MSI) markers and 22 BRAF, KRAS, and NRAS mutation hotspots. MSI and BRAF/RAS variants were detected using amplicon-sequencing and automated analysis. The assay was clinically validated and deployed into service in northern England, followed by regional and local audits to assess its impact.

Results

MSI analysis achieved 99.1% sensitivity and 99.2% specificity and was reproducible (r = 0.995). Mutation hotspot analysis had 100% sensitivity, 99.9% specificity, and was reproducible (r = 0.998). Assay-use in service in 2022-2023 increased CRC testing (97.2% (2466/2536) versus 28.6% (601/2104)), halved turnaround times, and identified more CRC patients at-risk of LS (5.5% (139/2536) versus 2.9% (61/2104)) compared to 2019-2020 when a multi-test pathway was used.

Conclusion

A novel amplicon-sequencing assay of CRCs, including all biomarkers for LS screening and anti-EGFR therapy, achieved >95% testing rate. Adoption of this low cost, scalable, and fully automatable test will complement on-going, national initiatives to improve LS screening.

Hereditary Gastrointestinal Tumor Syndromes: When Risk Comes with Your Genes

Despite recent campaigns for screening and the latest advances in cancer therapy and molecular biology, gastrointestinal (GI) neoplasms remain among the most frequent and lethal human tumors. Most GI neoplasms are sporadic, but there are some well-known familial syndromes associated with a significant risk of developing both benign and malignant GI tumors. Although some of these entities were described more than a century ago based on clinical grounds, the increasing molecular information obtained with high-throughput techniques has shed light on the pathogenesis of several of them. The vast amount of information gained from next-generation sequencing has led to the identification of some high-risk genetic variants, although others remain to be discovered. The opportunity for genetic assessment and counseling in these families has dramatically changed the management of these syndromes, though it has also resulted in significant psychological distress for the affected patients, especially those with indeterminate variants. Herein, we aim to summarize the most relevant hereditary cancer syndromes involving the stomach and colon, with an emphasis on new molecular findings, novel entities, and recent changes in the management of these patients.

Extent of investigation and management of cases of 'unexplained' mismatch repair deficiency (u-dMMR): a UK Cancer Genetics Group consensus

BACKGROUND

Mismatch repair deficiency (dMMR) is a characteristic feature of cancers linked to Lynch syndrome. However, in most cases, it results from sporadic somatic events rather than hereditary factors. The term 'Lynch-like syndrome' (LLS) has been used to guide colorectal cancer surveillance for relatives of individuals with a dMMR tumour when somatic and germline genomic testing is uninformative. As the assessment of mismatch repair through immunohistochemistry and/or microsatellite instability is increasingly applied across various tumour types for treatment planning, dMMR is increasingly detected in tumours where suspicion of hereditary aetiology is low. Our objective was to establish current practices and develop national guidance for investigating, and managing relatives of, patients with cancers demonstrating unexplained dMMR.

METHODS

This was achieved through a virtual consensus meeting involving key stakeholders from the UK, through premeeting surveys, structured discussions and in-meeting polling to formulate best practice guidance.

RESULTS

We identified variability in the availability of diagnostic technologies across specialist centres. It was agreed that equitable access to baseline testing is required, acknowledging the need for a pragmatic approach to investigating dMMR cancers not traditionally associated with Lynch syndrome. Factors such as family history, age, tumour type, protein loss pattern and extent of the investigation were deemed crucial in guiding family management. The term 'unexplained dMMR' was recommended over LLS.

CONCLUSION

Decisions regarding investigations and future cancer risk management in patients and relatives should be nuanced, considering factors like clinical suspicion of hereditary predisposition to allocate limited resources efficiently and avoid unnecessary investigations in low-suspicion families.

Modifiable risk factors for cancer among people with lynch syndrome: an international, cross-sectional survey

BACKGROUND

Lynch syndrome is the most common cause of hereditary colorectal and endometrial cancer. Lifestyle modification may provide an opportunity for adjunctive cancer prevention. In this study, we aimed to characterise modifiable risk factors in people with Lynch syndrome and compare this with international guidelines for cancer prevention.

METHODS

A cross-sectional study was carried out utilizing survey methodology. Following public and patient involvement, the survey was disseminated through patient advocacy groups and by social media. Self-reported demographic and health behaviours were collected in April 2023. Guidelines from the World Cancer Research Fund (WCRF) were used to compare percentage adherence to 9 lifestyle recommendations, including diet, physical activity, weight, and alcohol intake. Median adherence scores, as a surrogate for lifestyle risk, were calculated and compared between groups.

RESULTS

156 individuals with Lynch syndrome participated from 13 countries. The median age was 51, and 54% were cancer survivors. The mean BMI was 26.7 and the mean weekly duration of moderate to vigorous physical activity was 90 min. Median weekly consumption of ethanol was 60 g, and 3% reported current smoking. Adherence to WCRF recommendations for cancer prevention ranged from 9 to 73%, with all but one recommendation having < 50% adherence. The median adherence score was 2.5 out of 7. There was no significant association between median adherence scores and age (p = 0.27), sex (p = 0.31), or cancer history (p = 0.75).

CONCLUSIONS

We have characterised the modifiable risk profile of people living with Lynch syndrome, outlining targets for intervention based on lifestyle guidelines for the general population. As evidence supporting the relevance of modifiable factors in Lynch syndrome emerges, behavioural modification may prove an impactful means of cancer prevention.

The Role of Colon in Isolated Intestinal Transplantation: Description of 4 Cases

Intra-abdominal desmoid tumors are a rare and complex clinical problem. These tumors are locally invasive, and surgical ablation represents the mainstay of treatment. When localized at the root of the mesentery, their resection may require extensive excision of the intestine resulting in intestinal failure and life-long total parenteral nutrition. Intestinal transplantation, either autotransplantation or allotransplantation, has been used as a viable option to treat this group of patients. Herein, we describe a series of 4 patients with unresectable intra-abdominal desmoid tumor who underwent cadaveric isolated intestinal and ascending colon transplantation.

Therapeutic, and pharmacological prospects of nutmeg seed: A comprehensive review for novel drug potential insights

Background and objectives

For centuries, plant seed extracts have been widely used and valued for their benefits. They have been used in food, perfumes, aromatherapy, and traditional medicine. These natural products are renowned for their therapeutic properties and are commonly used in medicinal treatments. Their significant pharmacological profiles provide an excellent hallmark for the prevention or treatment of various diseases. In this study, we comprehensively evaluated the biological and pharmacological properties of nutmeg seeds and explored their efficacy in treating various illnesses.

Method

Published articles in databases including Google Scholar, PubMed, Elsevier, Scopus, ScienceDirect, and Wiley, were analyzed using keywords related to nutmeg seed. The searched keywords were chemical compounds, antioxidants, anti-inflammatory, antibacterial, antifungal, antiviral, antidiabetic, anticancer properties, and their protective mechanisms in cardiovascular and Alzheimer's diseases.

Results & discussion

Nutmeg seeds have been reported to have potent antimicrobial properties against a wide range of various bacteria and fungi, thus showing potential for combating microbial infections and promoting overall health. Furthermore, nutmeg extract effectively reduces oxidative stress and inflammation by improving the body's natural antioxidant defense mechanism. Nutmeg affected lipid peroxidation, reduced lipid oxidation, reduced low-density lipoprotein (LDL), and increased phospholipid and cholesterol excretion. In addition, nutmeg extract improves the modulation of cardiac metabolism, accelerates cardiac conductivity and ventricular contractility, and prevents cell apoptosis. This study elucidated the psychotropic, narcotic, antidepressant, and anxiogenic effects of nutmeg seeds and their potential as a pharmaceutical medicine. Notably, despite its sedative and toxic properties, nutmeg ingestion alone did not cause death or life-threatening effects within the dosage range of 20-80 g powder. However, chemical analysis of nutmeg extracts identified over 50 compounds, including flavonoids, alkaloids, and polyphenolic compounds, which exhibit antioxidant properties and can be used as phytomedicines. Moreover, the exceptional pharmacokinetics and bioavailability of nutmeg have been found different for different administration routes, yet, more clinical trials are still needed.

Conclusion

Understanding the chemical composition and pharmacological properties of nutmeg holds promise for novel drug discovery and therapeutic advancements. Nutmeg seed offers therapeutic and novel drug prospects that can revolutionize medicine. By delving into their pharmacological properties, we can uncover the vast potential possibilities of this natural wonder.

Colorectal cancer screening guidelines for average-risk and high-risk individuals: A systematic review

AIMS

This review aims to summarize the different colorectal cancer guidelines for average-risk and high-risk individuals from various countries.

METHODS

A comprehensive literature search regarding guidelines, consensus recommendations, or position statements about colorectal cancer screening published within the last 10 years (1st January 2012 to 27th August 2022), was performed at EBSCOhost, JSTOR, PubMed, ProQuest, SAGE, and ScienceDirect.

RESULTS

A total of 18 guidelines were included in this review. Most guidelines recommended screening between 45 and 75 years for average-risk individuals. Recommendations regarding colorectal cancer screening in high-risk individuals were more varied and depended on the risk factor. For high-risk individuals with a positive family history of colorectal cancer or advanced colorectal polyp, screening should begin at age 40. Some frequently suggested screening modalities in order of frequency are colonoscopy, FIT, and CTC. Furthermore, several screening intervals were suggested, including colonoscopy every 10 years for average-risk and every 5-10 years for high-risk individuals, FIT annually in average-risk and every 1-2 years in high-risk individuals, and CTC every five years for all individuals.

CONCLUSION

All individuals with average-risk should undergo colorectal cancer screening between 45 and 75. Meanwhile, individuals with higher risks, such as those with a positive family history, should begin screening at age 40. Several recommended screening modalities were suggested, including colonoscopy every 10 years in average-risk and every 5-10 years in high-risk, FIT annually in average-risk and every 1-2 years in high-risk, and CTC every five years.

Endoscopic scoring indices for assessing disease severity in familial adenomatous polyposis: Systematic review

Background and study aims There is limited consensus on the optimal method for measuring disease severity in familial adenomatous polyposis (FAP). We aimed to systematically review the operating properties of existing endoscopic severity indices for FAP. Methods We searched MEDLINE, EMBASE, and the Cochrane Library from inception to February 2023 to identify randomized controlled trials (RCTs) that utilized endoscopic outcomes or studies that evaluated the operating properties of endoscopic disease severity indices in FAP. Results A total of 134 studies were included. We evaluated scoring indices and component items of scoring indices, such as polyp count, polyp size, and histology. Partial validation was observed for polyp count and size. The most commonly reported scoring index was the Spigelman classification system, which was used for assessing the severity of duodenal involvement. A single study reported almost perfect interobserver and intra-observer agreement for this system. The InSIGHT polyposis staging system, which was used for assessing colorectal polyp burden, has been partially validated. It showed substantial interobserver reliability; however, the intra-observer reliability was not assessed. Novel criteria for high-risk gastric polyps have been developed and assessed for interobserver reliability. However, these criteria showed a poor level of agreement. Other scoring indices assessing the anal transition zone, duodenal, and colorectal polyps have not undergone validation. Conclusions There are no fully validated endoscopic disease severity indices for FAP. Development and validation of a reliable and responsive endoscopic disease severity instrument will be informative for clinical care and RCTs of pharmacological therapies for FAP.

An Unusual Case of Lynch Syndrome

Lynch syndrome is the most common cause of hereditary colorectal cancer. It usually develops asymptomatically until symptoms related to colorectal carcinoma appear, such as gastrointestinal bleeding, abdominal pain, and changes in bowel habits and/or stool characteristics. Oftentime, when these clinical signs and symptoms are not present, the diagnosis becomes challenging. We present the clinical case of a 69-year-old woman, adopted, with no known previous history, who presented to the emergency department with low back pain, without irradiation, that had been going on for three days, associated with inflammatory signs in the right hip region. There were no urinary or sensory alterations and no recent trauma. She was initially discharged with antibiotherapy with the diagnosis of hip cellulitis. As the symptoms continued and the inflammation spread to the right lower limb, she returned to the emergency department. A CT scan revealed an abscess (17 cm) in the right buttock, complicated by necrotizing fasciitis due to fistulization from a tumor in the right colon. She underwent an exploratory laparotomy, which identified a neoplasm of the ascending colon, adherent to the abdominal wall, in the right lumbar region. Right hemicolectomy and drainage of the right buttock/thigh abscess were performed. The histology was compatible with invasive adenocarcinoma, with high-grade dysplasia but well differentiated, pT3G1N0. The immunohistochemistry was suggestive of Lynch syndrome.