The role of family history in predicting germline pathogenic variant carriers who develop pancreatic cancer: Results of a multicenter collaboration

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) surveillance is recommended for some individuals with a pathogenic or likely pathogenic variant (PV/LPV) in a PDAC susceptibility gene; the recommendation is often dependent on family history of PDAC. This study aimed to describe PDAC family history in individuals with PDAC who underwent genetic testing to determine the appropriateness of including a family history requirement in these recommendations.

METHODS

Individuals with PDAC with a germline heterozygous PV/LPV in ATM, BRCA1, BRCA2, EPCAM, MLH1, MSH2, MSH6, PALB2, or PMS2 (PV/LPV carriers) were assessed for family history of PDAC in first-degree relatives (FDRs) or second-degree relatives (SDRs) from nine institutions. A control group of individuals with PDAC without a germline PV/LPV was also assessed.

RESULTS

The study included 196 PV/LPV carriers and 1184 controls. In the PV/LPV carriers, 25.5% had an affected FDR and/or SDR compared to 16.9% in the control group (p = .004). PV/LPV carriers were more likely to have an affected FDR compared to the controls (p = .003) but there was no statistical difference when assessing only affected SDRs (p = .344).

CONCLUSIONS

Most PV/LPV carriers who developed PDAC did not have a close family history of PDAC and would not have met most current professional societies' recommendations for consideration of PDAC surveillance before diagnosis. However, PV/LPV carriers were significantly more likely to have a family history of PDAC, particularly an affected FDR. These findings support family history as a risk modifier in PV/LPV carriers, and highlight the need to identify other risk factors.

Germline CDH1 Variants and Lifetime Cancer Risk

Importance

Approximately 1% to 3% of gastric cancers and 5% of lobular breast cancers are hereditary. Loss of function CDH1 gene variants are the most common gene variants associated with hereditary diffuse gastric cancer and lobular breast cancer. Previously, the lifetime risk of gastric cancer was estimated to be approximately 25% to 83% and for breast cancer it was estimated to be approximately 39% to 55% in individuals with loss of function CDH1 gene variants.

Objective

To describe gastric and breast cancer risk estimates for individuals with CDH1 variants.

Design, Setting, and Participants

Multicenter, retrospective cohort and modeling study of 213 families from North America with a CDH1 pathogenic or likely pathogenic (P/LP) variant in 1 or more family members conducted between January 2021 and August 2022.

Main Outcomes and Measures

Hazard ratios (HRs), defined as risk in variant carriers relative to noncarriers, were estimated for each cancer type and used to calculate cumulative risks and risks per decade of life up to age 80 years.

Results

A total of 7323 individuals from 213 families were studied, including 883 with a CDH1 P/LP variant (median proband age, 53 years [IQR, 42-62]; 4% Asian; 4% Hispanic; 85% non-Hispanic White; 50% female). In individuals with a CDH1 P/LP variant, the prevalence of gastric cancer was 13.9% (123/883) and the prevalence of breast cancer among female carriers was 26.3% (144/547). The estimated HR for advanced gastric cancer was 33.5 (95% CI, 9.8-112) at age 30 years and 3.5 (95% CI, 0.4-30.3) at age 70 years. The lifetime cumulative risk of advanced gastric cancer in male and female carriers was 10.3% (95% CI, 6%-23.6%) and 6.5% (95% CI, 3.8%-15.1%), respectively. Gastric cancer risk estimates based on family history indicated that a carrier with 3 affected first-degree relatives had a penetrance of approximately 38% (95% CI, 25%-64%). The HR for breast cancer among female carriers was 5.7 (95% CI, 2.5-13.2) at age 30 years and 3.9 (95% CI, 1.1-13.7) at age 70 years. The lifetime cumulative risk of breast cancer among female carriers was 36.8% (95% CI, 25.7%-62.9%).

Conclusions and Relevance

Among families from North America with germline CDH1 P/LP variants, the cumulative risk of gastric cancer was 7% to 10%, which was lower than previously described, and the cumulative risk of breast cancer among female carriers was 37%, which was similar to prior estimates. These findings inform current management of individuals with germline CDH1 variants.

Creation of a Quality Payment Program Measure for Mismatch Repair or Microsatellite Instability Biomarker Testing Status in Colorectal, Endometrial, Gastroesophageal, or Small Bowel Carcinoma

CONTEXT.—

Quality measures that are supported by evidence-based clinical practice guidelines are preferred for assessing the quality of pathologists' practices. Careful testing of a measure ensures that scores obtained by that measure reflect the quality of a pathologist's practice.

OBJECTIVE.—

To specify a new quality measure and to demonstrate through testing that it is suitable for measuring pathologists' appropriate incorporation of information regarding microsatellite instability (MSI) and/or mismatch repair (MMR) status in pathology reports for colorectal, endometrial, gastroesophageal, and small bowel carcinoma.

DESIGN.—

The College of American Pathologists collaborated with the American Gastroenterological Association to specify and test the new measure. Face validity testing was used to investigate the validity of the measure. Feasibility testing was conducted to understand if data elements required by the measure specification were readily accessible. Signal-to-noise analysis was used to characterize the measure's reliability.

RESULTS.—

Guideline recommendations for MSI and/or MMR testing supported specifications for the measure. Face validity testing indicated that the measure could distinguish the quality of care provided. Data elements required by the measure specification were found to be accessible, which supported the measure's feasibility. Reliability testing showed that differences in measure score were attributable to real differences in performance rather than random variation in scoring.

CONCLUSIONS.—

The Mismatch Repair or Microsatellite Instability Biomarker Testing Status in Colorectal Carcinoma, Endometrial, Gastroesophageal, or Small Bowel Carcinoma measure was appropriately specified, and testing demonstrated that it is well suited for characterizing the quality of pathologists' communication of MMR and/or MSI status.

Chemoprevention in Inherited Colorectal Cancer Syndromes

Cancer prevention in hereditary gastrointestinal predisposition syndromes relies primarily on intensive screening (e.g., colonoscopy) or prophylactic surgery (e.g., colectomy). The use of chemopreventive agents as an adjunct to these measures has long been studied both in the general population and in hereditary cancer patients, in whom the risk of malignancy, and therefore the potential risk reduction, is considerably greater. However, to date only few compounds have been found to be effective, safe, and tolerable for widespread use. Furthermore, many of the studies involving these rare syndromes suffer from small sample sizes, heterogeneous patient cohorts, short follow-up duration, and lack of standardized endpoints, creating challenges to draw generalizable conclusion regarding efficacy. The following review summarizes the current data on various chemopreventive compounds used in Lynch syndrome and familial adenomatous polyposis in addition to several agents that are currently being investigated.

The Pancreatic Cancer Early Detection (PRECEDE) Study is a Global Effort to Drive Early Detection: Baseline Imaging Findings in High-Risk Individuals

BACKGROUND

Pancreatic adenocarcinoma (PC) is a highly lethal malignancy with a survival rate of only 12%. Surveillance is recommended for high-risk individuals (HRIs), but it is not widely adopted. To address this unmet clinical need and drive early diagnosis research, we established the Pancreatic Cancer Early Detection (PRECEDE) Consortium.

METHODS

PRECEDE is a multi-institutional international collaboration that has undertaken an observational prospective cohort study. Individuals (aged 18-90 years) are enrolled into 1 of 7 cohorts based on family history and pathogenic germline variant (PGV) status. From April 1, 2020, to November 21, 2022, a total of 3,402 participants were enrolled in 1 of 7 study cohorts, with 1,759 (51.7%) meeting criteria for the highest-risk cohort (Cohort 1). Cohort 1 HRIs underwent germline testing and pancreas imaging by MRI/MR-cholangiopancreatography or endoscopic ultrasound.

RESULTS

A total of 1,400 participants in Cohort 1 (79.6%) had completed baseline imaging and were subclassified into 3 groups based on familial PC (FPC; n=670), a PGV and FPC (PGV+/FPC+; n=115), and a PGV with a pedigree that does not meet FPC criteria (PGV+/FPC-; n=615). One HRI was diagnosed with stage IIB PC on study entry, and 35.1% of HRIs harbored pancreatic cysts. Increasing age (odds ratio, 1.05; P<.001) and FPC group assignment (odds ratio, 1.57; P<.001; relative to PGV+/FPC-) were independent predictors of harboring a pancreatic cyst.

CONCLUSIONS

PRECEDE provides infrastructure support to increase access to clinical surveillance for HRIs worldwide, while aiming to drive early PC detection advancements through longitudinal standardized clinical data, imaging, and biospecimen captures. Increased cyst prevalence in HRIs with FPC suggests that FPC may infer distinct biological processes. To enable the development of PC surveillance approaches better tailored to risk category, we recommend adoption of subclassification of HRIs into FPC, PGV+/FPC+, and PGV+/FPC- risk groups by surveillance protocols.

Birth Cohort Colorectal Cancer (CRC): Implications for Research and Practice

Colorectal cancer (CRC) epidemiology is changing due to a birth cohort effect, first recognized by increasing incidence of early onset CRC (EOCRC, age <50 years). In this paper, we define "birth cohort CRC" as the observed phenomenon, among individuals born 1960 and later, of increasing CRC risk across successive birth cohorts, rising EOCRC incidence, increasing incidence among individuals aged 50 to 54 years, and flattening of prior decreasing incidence among individuals aged 55 to 74 years. We demonstrate birth cohort CRC is associated with unique features, including increasing rectal cancer (greater than colon) and distant (greater than local) stage CRC diagnosis, and increasing EOCRC across all racial/ethnic groups. We review potential risk factors, etiologies, and mechanisms for birth cohort CRC, using EOCRC as a starting point and describing importance of viewing these through the lens of birth cohort. We also outline implications of birth cohort CRC for epidemiologic and translational research, as well as current clinical practice. We postulate that recognition of birth cohort CRC as an entity-including and extending beyond rising EOCRC-can advance understanding of risk factors, etiologies, and mechanisms, and address the public health consequences of changing CRC epidemiology.

Risk perception and surveillance uptake in individuals at increased risk for pancreatic ductal adenocarcinoma

BACKGROUND

Surveillance for pancreatic ductal adenocarcinoma (PDAC) is recommended for high-risk individuals with genetic variants in PDAC-associated genes and/or family history. Surveillance uptake and adherence may depend on the perception of PDAC risk and cancer worry. We aimed to determine PDAC risk perception in at-risk individuals and assess factors associated with PDAC surveillance uptake.

METHODS

At-risk individuals identified from a prospective academic registry were sent a survey electronically. PDAC risk perception, cancer worry and surveillance uptake were surveyed. Factors associated with increased risk perception and surveillance were assessed. Five-year PDAC risk was calculated using the PancPRO risk assessment model, and correlation with subjective risk assessment was assessed.

RESULTS

The overall survey response rate was 34% (279/816). The median perceived PDAC risk was twofold (IQR 1-4) above respondents' estimates of general population risk. Factors significantly associated with higher perceived PDAC risk included non-Hispanic white race, post-graduate education level, PDAC-affected first-degree relative, genetic variants and lack of personal cancer history. Cancer worry had a very weak correlation across PDAC risk estimates (r=0.16). No correlation between perceived PDAC risk and 5-year calculated PDAC risk was found. Older age, having a first-degree relative with PDAC, meeting with a medical provider about PDAC cancer risk and awareness of surveillance modalities were significant predictors of undergoing PDAC surveillance.

CONCLUSIONS

Individuals at risk for PDAC do not report risk perception that correlates with calculated risk. This presents an opportunity for counselling of at-risk patients to individualise management and improve surveillance uptake for eligible individuals.

Racial, Ethnic, and Sex-based Disparities among High-risk Individuals Undergoing Pancreatic Cancer Surveillance

Since its inception two years ago, the international, multicenter Pancreatic Cancer Early Detection (PRECEDE) Consortium has enrolled high-risk individuals (HRI) undergoing pancreatic ductal adenocarcinoma (PDAC) surveillance. Herein we aim to evaluate enrollment disparities in PRECEDE. Data on HRIs enrolled between May 2020 and March 2022 were collected, with HRIs defined as participants enrolled in PRECEDE meeting guideline-based criteria for PDAC surveillance. Of 1,273 HRIs enrolled, 1,113 were eligible for inclusion, with 47.2% meeting familial pancreatic cancer criteria without a known pathogenic variant (PV) and the remainder having a pathogenic variant in a PDAC-risk gene (CDKN2A, STK11, PRSS1, BRCA1, BRCA2, PALB2, ATM, MLH1, MSH2, MSH6, PMS2, or EPCAM). Study participants were predominantly from the United States (82.7%), the most common age range at enrollment was 60-69 years (37.4%), and a non-PDAC cancer was present in 32.4%. There were racial/ethnic- and sex-based disparities among enrolled subjects, as the majority of participants were female (65.9%) and self-reported white (87.7%), with only 2.9% having Hispanic ethnicity. While more than 97% of participants consented to utilize imaging data and biosamples for research, there was no difference in rate of consent based on race/ethnicity, sex, or age, thereby demonstrating uniform participation in research activities among all subgroups after enrollment. Ensuring that diversity of HRIs in PDAC surveillance programs mirrors the communities served by participating centers is important. Substantial racial/ethnic- and sex-based disparities persist among recently enrolled HRIs undergoing PDAC surveillance, and therefore reducing these disparities will be a major focus of the PRECEDE Consortium moving forward.

PREVENTION RELEVANCE

Pancreatic cancer surveillance is critical to decreasing pancreatic cancer mortality; therefore, it is important that pancreatic cancer surveillance studies enroll diverse patients. We demonstrate that substantial racial/ethnic- and sex-based disparities exist amongst enrollment in the international PRECEDE consortium, highlighting the dire need for future efforts to reduce these disparities. See related Spotlight, p. 305.

Colorectal Cancer Risk Assessment and Precision Approaches to Screening: Brave New World or Worlds Apart?

Current colorectal cancer (CRC) screening recommendations take a "one-size-fits-all" approach using age as the major criterion to initiate screening. Precision screening that incorporates factors beyond age to risk stratify individuals could improve on current approaches and optimally use available resources with benefits for patients, providers, and health care systems. Prediction models could identify high-risk groups who would benefit from more intensive screening, while low-risk groups could be recommended less intensive screening incorporating noninvasive screening modalities. In addition to age, prediction models incorporate well-established risk factors such as genetics (eg, family CRC history, germline, and polygenic risk scores), lifestyle (eg, smoking, alcohol, diet, and physical inactivity), sex, and race and ethnicity among others. Although several risk prediction models have been validated, few have been systematically studied for risk-adapted population CRC screening. In order to envisage clinical implementation of precision screening in the future, it will be critical to develop reliable and accurate prediction models that apply to all individuals in a population; prospectively study risk-adapted CRC screening on the population level; garner acceptance from patients and providers; and assess feasibility, resources, cost, and cost-effectiveness of these new paradigms. This review evaluates the current state of risk prediction modeling and provides a roadmap for future implementation of precision CRC screening.

Delphi Initiative for Early-Onset Colorectal Cancer (DIRECt) International Management Guidelines

BACKGROUND & AIMS

Patients with early-onset colorectal cancer (eoCRC) are managed according to guidelines that are not age-specific. A multidisciplinary international group (DIRECt), composed of 69 experts, was convened to develop the first evidence-based consensus recommendations for eoCRC.

METHODS

After reviewing the published literature, a Delphi methodology was used to draft and respond to clinically relevant questions. Each statement underwent 3 rounds of voting and reached a consensus level of agreement of ≥80%.

RESULTS

The DIRECt group produced 31 statements in 7 areas of interest: diagnosis, risk factors, genetics, pathology-oncology, endoscopy, therapy, and supportive care. There was strong consensus that all individuals younger than 50 should undergo CRC risk stratification and prompt symptom assessment. All newly diagnosed eoCRC patients should receive germline genetic testing, ideally before surgery. On the basis of current evidence, endoscopic, surgical, and oncologic treatment of eoCRC should not differ from later-onset CRC, except for individuals with pathogenic or likely pathogenic germline variants. The evidence on chemotherapy is not sufficient to recommend changes to established therapeutic protocols. Fertility preservation and sexual health are important to address in eoCRC survivors. The DIRECt group highlighted areas with knowledge gaps that should be prioritized in future research efforts, including age at first screening for the general population, use of fecal immunochemical tests, chemotherapy, endoscopic therapy, and post-treatment surveillance for eoCRC patients.

CONCLUSIONS

The DIRECt group produced the first consensus recommendations on eoCRC. All statements should be considered together with the accompanying comments and literature reviews. We highlighted areas where research should be prioritized. These guidelines represent a useful tool for clinicians caring for patients with eoCRC.

Genomic and epigenomic responses to aspirin in human colonic organoids

Aspirin (ASA) is a proven chemoprotective agent for colorectal cancer, though mechanisms underlying these effects are incompletely understood. Human organoids are an ideal system to study genomic and epigenomic host-environment interactions. We use human colonic organoids to profile ASA responses on genome-wide gene expression and chromatin accessibility. Human colonic organoids from one individual were cultured and treated in triplicate with 3 mM ASA or vehicle control (DMSO) for 24 h. Gene expression and chromatin accessibility were measured using RNA- and ATAC-sequencing, respectively. Differentially expressed genes were analyzed using DESeq2. Top genes were validated by qPCR. Gene set enrichment was performed by SetRank. Differentially accessible peaks were analyzed using DiffBind and edgeR. Peak annotation and differential transcription factor motifs were determined by HOMER and diffTF. The results showed robust transcriptional responses to ASA with significant enrichment for fatty acid oxidation and peroxisome proliferator-activated receptor (PPAR) signaling that were validated in independent organoid lines. A large number of differentially accessible chromatin regions were found in response to ASA with significant enrichment for Fos, Jun, and Hnf transcription factor motifs. Integrated analysis of epigenomic and genomic treatment responses highlighted gene regions that could mediate ASA's specific effects in the colon including those involved in chemoprotection and/or toxicity. Assessment of chromatin accessibility and transcriptional responses to ASA yielded new observations about genome-wide effects in the colon facilitated by application of human colonic organoids. This framework can be applied to study colonic ASA responses between individuals and populations in future studies.

Racial, ethnic, and sex-based disparities among high-risk individuals undergoing pancreatic cancer surveillance

687

Background: The international, multi-center Pancreatic Cancer Early Detection (PRECEDE) Consortium enrolls high-risk individuals (HRIs) undergoing pancreatic ductal adenocarcinoma (PDAC) surveillance. Enrollment began in 2020, and despite challenges related to the COVID-19 pandemic, the PRECEDE Consortium rapidly accrued a large cohort of HRIs. The purpose of this study is to describe the characteristics of this cohort and assess racial, ethnic, and sex-based disparities. Methods: The PRECEDE Consortium (NCT04970056) is a prospective, multicenter study focused on improving survival from PDAC through early detection. Data from all HRIs who met criteria for PDAC surveillance and enrolled between May 2020 - March 2022 were collected and included in the analysis. Results: During the study period, 1299 HRIs enrolled in PRECEDE at 32 centers. HRIs were excluded if enrollment data was incomplete or criteria for PDAC surveillance were not met. Of 1113 who were included, 47.2% met criteria for familial pancreatic cancer (FPC) and 45.4% had a family history of PDAC along with a PV in a PDAC-risk gene (BRCA1, BRCA2, PALB2, ATM, MLH1, MSH2, MSH6, PMS2, or EPCAM). The remainder had familial atypical mole melanoma syndrome (5.7%), Peutz-Jeghers syndrome (1.6%), or hereditary pancreatitis (0.2%). More females than males enrolled (65.9% vs. 33.5%). The distribution of HRIs by race and ethnicity is depicted; the majority identified as white (87.7%). Study participants were primarily from the US (82.7%), the median age was 61 (27-85) and 18.5% had Ashkenazi Jewish ancestry. Nearly all HRIs consented to allow access to imaging data (99.6%), collection of germline DNA (97.7%), and biosample collection (99.5%). There were no race, ethnicity, or sex-based differences in rates of consent for collection of imaging, DNA, or biosamples. Conclusions: Enrollment of HRIs in prospective studies of PDAC surveillance is essential for advancing early detection research in PDAC. A distinct advantage of the PRECEDE Consortium for examining enrollment disparities is that recruitment began in 2020, providing a unique and current snapshot of the international PDAC surveillance landscape. Despite the recent attention on addressing disparities in healthcare delivery, significant racial, ethnic, and sex-based disparities persisted in the cohort of HRIs enrolled in the PRECEDE Consortium. Ensuring that the diversity of participants in the PRECEDE Consortium mirrors the communities served by participating centers is crucial. Further examining and addressing the reasons for these disparities is a major focus of the PRECEDE Consortium moving forward. [Table: see text]

Pancreatic imaging findings from the PRECEDE study: A large high-risk heritable cohort for pancreatic cancer

689

Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer typically discovered at incurable stages. The PRECEDE Consortium was established to accelerate early detection by using a large-scale, collaborative, innovative model, predicated on standardized collection of demographic, clinical, and imaging data from high-risk individuals (HRI). Here we report the initial pancreas imaging findings in Cohort 1, representing HRI with familial pancreatic cancer (FPC) or pathogenic germline variants (PGV) in PDAC susceptibility genes with a 1st or 2nd degree relative with PDAC. Methods: The PRECEDE Consortium (NCT04970056) began enrollment in 5/2020. HRI enrolled prospectively at centers worldwide into one of 7 cohorts based on personal and/or family history of PDAC and PGV status. PRECEDE’s planned enrollment is 10,000 patients. Data sharing is required to join PRECEDE, facilitated by a standardized data collection system and central database (PRECEDELink). Imaging (MRI/MRCP and EUS) is performed using standardized image acquisition and reporting templates. Imaging and clinical sequencing data are stored and analyzed in the PRECEDE data cloud. Results: By 9/16/2022, 26 sites enrolled 3156 patients in 7 cohorts, with 1716 in Cohort 1. Cohort 1 was 60% female, 80% white; 48% met FPC criteria, and 52% were PGV carriers. Within Cohort 1, 658 FPC and 965 PGV (1353 total, 79%) underwent imaging (68% MRI; 32% EUS). Overall, 573/1353 (42%) had pancreas abnormalities: 320/573 (49%) FPC, and 253/573 (36%) PGV (OR [95% CI] 1.65 [1.32–2.06], P < 0.001). Cysts were the most common abnormality, present in 549/1353 (41%) and accounting for 310/320 (97%) FPC and 239/253 (94%) PGV HRI abnormalities. Of 549 HRI with cysts, 262 (48%) had 1 cyst, including 137/310 (44%) FPC and 125/239 (52%) PGV HRI (OR 1.43 [1.07–1.92], P = .012) The remaining 287/549 (52%) had ≥2 cysts, including 173/310 (56%) FPC and 114/239 (48%) PGV HRI (OR 1.98 [1.49–2.64], P < 0.001). Worrisome features occurred in 83/1353 (6.1%) including: 14 (1%) cyst > 2 cm, 7 (0.5%) cyst ≥3 cm, 35 (2.6%) main pancreatic duct (MPD) diameter ≥5 mm; 2 (0.15%) duct strictures; and 25 (1.8%) solid masses. Solid masses included 1 (0.07%) PDAC, 9 (0.7%) neuroendocrine tumors, and 15 (1.1%) benign lesions (e.g. lipoma, splenule). Conclusions: Pancreatic abnormalities are common in a cohort of 1353 HRI enrolled in PRECEDE; 6.1% of HRI had findings with worrisome features and clinical implications. Multiple cysts were significantly more common in FPC HRI (OR 1.98); worrisome findings did not differ between FPC and PGV groups. The longitudinal study of this growing HRI cohort with standardized imaging and matched comprehensive epidemiological, clinical, and laboratory data, along with germline testing, will provide critical information and understanding of PDAC risk, and augment existing clinical decision-making models governing surveillance and treatment.

Outcomes of Universal Point-of-Care Genetic Testing in Diverse Patients With Pancreatic Ductal Adenocarcinoma

PURPOSE

Guidelines recommend all patients with pancreatic ductal adenocarcinoma (PDAC) undergo germline genetic testing (GT). Rates of recommendation and completion of GT among diverse patients with PDAC are not known. The aim was to determine rates of recommendation and completion of point-of-care GT in diverse patients with PDAC.

METHODS

A retrospective review of patients with PDAC seen at an academic center between April 2019 and December 2020 was performed. Recommendation, completion and results of point-of-care GT, and demographic and clinical factors were recorded. Univariate and multivariate analyses of GT were performed using the chi-square test and logistic regression.

RESULTS

In total, 579 patients with PDAC were included. The median age at diagnosis was 67 years; 52% were male; 63% were non-Hispanic White (NHW) patients, and 20% were African American (AA) patients. GT was performed in 216 (37%) patients. Of those tested, 47 (22%) had a pathogenic/likely pathogenic variant identified of which 25 (12%) were in PDAC-associated genes. On multivariate analysis, age, NHW race, personal and family cancer history, medical oncology visit, and number of visits were independent predictors of GT completion. AA patients had significantly lower rates of recommendation and completion of GT compared with NHW patients.

CONCLUSION

Point-of-care GT in patients with PDAC is unacceptably low, especially among AA patients. Testing disparity might be due to lack of provider recommendation more than patient uptake. Lack of testing leads to missed opportunities for potential targeted therapies, improved outcomes, and identification of at-risk family members who could potentially benefit from surveillance.

OrganoID: A versatile deep learning platform for tracking and analysis of single-organoid dynamics

Organoids have immense potential as ex vivo disease models for drug discovery and personalized drug screening. Dynamic changes in individual organoid morphology, number, and size can indicate important drug responses. However, these metrics are difficult and labor-intensive to obtain for high-throughput image datasets. Here, we present OrganoID, a robust image analysis platform that automatically recognizes, labels, and tracks single organoids, pixel-by-pixel, in brightfield and phase-contrast microscopy experiments. The platform was trained on images of pancreatic cancer organoids and validated on separate images of pancreatic, lung, colon, and adenoid cystic carcinoma organoids, which showed excellent agreement with manual measurements of organoid count (95%) and size (97%) without any parameter adjustments. Single-organoid tracking accuracy remained above 89% over a four-day time-lapse microscopy study. Automated single-organoid morphology analysis of a chemotherapy dose-response experiment identified strong dose effect sizes on organoid circularity, solidity, and eccentricity. OrganoID enables straightforward, detailed, and accurate image analysis to accelerate the use of organoids in high-throughput, data-intensive biomedical applications.

N6-adenomethylation of GsdmC is essential for Lgr5+ stem cell survival to maintain normal colonic epithelial morphogenesis

Gut epithelial morphogenesis is maintained by intestinal stem cells. Here, we report that depletion of N6-adenosine methyltransferase subunit Mettl14 from gut epithelial cells in mice impaired colon mucosal morphogenesis, leading to increased mucosal permeability, severe inflammation, growth retardation, and premature death. Mettl14 ablation triggered apoptosis that depleted Lgr5+ stem cells and disrupted colonic organoid growth and differentiation, whereas the inhibition of apoptosis rescued Mettl14-deleted mice and organoids. Mettl14 depletion disrupted N6-adenomethylation on GsdmC transcripts and abolished GsdmC expression. Reconstitution of Mettl14-deleted organoids or mice with GSDMC rescued Lgr5 expression and prevented apoptosis and mouse premature death, whereas GSDMC silence eliminated LGR5 and triggered apoptosis in human colonic organoids and epithelial cells. Mechanistically, Mettl14 depletion eliminated mitochondrial GsdmC, disrupted mitochondrial membrane potential, and triggered cytochrome c release that activates the pro-apoptotic pathway. In conclusion, GsdmC N6-adenomethylation protects mitochondrial homeostasis and is essential for Lgr5+ cell survival to maintain normal colonic epithelial regeneration.

Yield of upper gastrointestinal screening in colonic adenomatous polyposis of unknown etiology: a multicenter study

Background and study aims  The majority of patients with 10 or more cumulative colorectal adenomas have uninformative genetic testing and meet criteria for colonic adenomatous polyposis of unknown etiology (CPUE). The yield of upper gastrointestinal screening in patients with CPUE after multi-gene panel testing is unknown and our objective was to characterize this. Patient and methods  A multicenter, retrospective analysis of screening upper endoscopies in adults with CPUE after multi-gene panel testing was performed. Those with a history of gastroduodenal neoplasia prior to CPUE diagnosis were excluded. Demographic and clinical variables were collected and compared. Results  One hundred and twenty-eight patients with CPUE were included from five participating centers. Nine (7.0 %) had gastroduodenal neoplasia on initial screening upper endoscopy. Those with over 100 colorectal adenomas had a significantly higher rate of gastroduodenal neoplasia than those with 20-99 or 10-19 colorectal adenomas (44.4 % vs 4.1 % vs 4.4 %, P  = 0.002). Similar results were seen when the analysis was restricted to only duodenal or ampullary adenomas. The only malignancy was a gastric cancer in a patient with 20 to 99 colorectal adenomas. When comparing patients with gastroduodenal neoplasia to those without, the only significantly different characteristic was the cumulative number of colorectal adenomas. Conclusions  We found a 7 % rate of gastroduodenal neoplasia in patients with CPUE after multi-gene panel testing. Although patients with ≥ 100 colorectal adenomas had a significantly higher risk, over 4 % of patients with 10 to 99 colorectal adenomas had gastroduodenal neoplasia. Given this, we recommend a screening upper endoscopy at the time of a colonoscopy after CPUE diagnosis.

Risk assessment and genetic counseling for Lynch syndrome - Practice resource of the National Society of Genetic Counselors and the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer

Identifying individuals who have Lynch syndrome involves a complex diagnostic workup that includes taking a detailed family history and a combination of various tests such as immunohistochemistry and/or molecular which may be germline and/or somatic. The National Society of Genetic Counselors and the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer have come together to publish this practice resource for the evaluation of Lynch syndrome. The purpose of this practice resource was to provide guidance and a testing algorithm for Lynch syndrome as well as recommendations on when to offer testing. This practice resource does not replace a consultation with a genetics professional. This practice resource includes explanations in support of this and a summary of background data. While this practice resource is not intended to serve as a review of Lynch syndrome, it includes a discussion of background information and cites a number of key publications which should be reviewed for a more in-depth understanding. This practice resource is intended for genetic counselors, geneticists, gastroenterologists, surgeons, medical oncologists, obstetricians and gynecologists, nurses, and other healthcare providers who evaluate patients for Lynch syndrome.

How many is too many? Polyposis syndromes and what to do next

PURPOSE OF REVIEW

The goal of this review is to help providers recognize, diagnose and manage gastrointestinal (GI) polyposis syndromes.

RECENT FINDINGS

Intestinal polyps include a number of histological sub-types such as adenomas, serrated, hamartomas among others. Over a quarter of individuals undergoing screening colonoscopy are expected to have colonic adenomas. Although it is not uncommon for adults to have a few GI polyps in their lifetime, some individuals are found to have multiple polyps of varying histology throughout the GI tract. In these individuals, depending on polyp histology, number, location and size as well as extra-intestinal features and/or family history, a polyposis syndrome should be considered with appropriate testing and management.

SUMMARY

Diagnosis and management of polyposis syndromes has evolved with advent of multigene panel testing and new data on optimal surveillance strategies. Evidence-based recommendations and current practice guidelines for polyposis syndromes are reviewed here. Areas of uncertainty and future research are also highlighted.

Colorectal Cancer Screening Recommendations and Outcomes in Lynch Syndrome

Screening for colorectal cancer (CRC) in Lynch syndrome enables early detection and likely cancer prevention. CRC screening guidelines have evolved from universal to gene-specific recommendations based on lifetime neoplasia risks. Regular screening for Lynch syndrome reduces CRC-related mortality; however, high CRC incidence during regular colonoscopy screening suggests the possibility of nonpolypoid carcinogenesis. Colonoscopy is the primary modality for screening for Lynch syndrome with mixed and emerging data on quality metrics, chromoendoscopy, artificial intelligence, and nonendoscopic modalities. Screening adherence varies across studies. In this review, we present the current state of CRC screening recommendations, outcomes, and modalities in Lynch syndrome.

Upregulation of polycistronic microRNA-143 and microRNA-145 in colonocytes suppresses colitis and inflammation-associated colon cancer

Because ADAM17 promotes colonic tumorigenesis, we investigated potential miRNAs regulating ADAM17; and examined effects of diet and tumorigenesis on these miRNAs. We also examined pre-miRNA processing and tumour suppressor roles of several of these miRNAs in experimental colon cancer. Using TargetScan, miR-145, miR-148a, and miR-152 were predicted to regulate ADAM17. miR-143 was also investigated as miR-143 and miR-145 are co-transcribed and associated with decreased tumour growth. HCT116 colon cancer cells (CCC) were co-transfected with predicted ADAM17-regulating miRNAs and luciferase reporters controlled by ADAM17-3'UTR. Separately, pre-miR-143 processing by colonic cells was measured. miRNAs were quantified by RT-PCR. Tumours were induced with AOM/DSS in WT and transgenic mice (Tg) expressing pre-miR-143/miR-145 under villin promoter. HCT116 transfection with miR-145, -148a or -152, but not scrambled miRNA inhibited ADAM17 expression and luciferase activity. The latter was suppressed by mutations in ADAM17-3'UTR. Lysates from colonocytes, but not CCC, processed pre-miR-143 and mixing experiments suggested CCC lacked a competency factor. Colonic miR-143, miR-145, miR-148a, and miR-152 were downregulated in tumours and more moderately by feeding mice a Western diet. Tg mice were resistant to DSS colitis and had significantly lower cancer incidence and tumour multiplicity. Tg expression blocked up-regulation of putative targets of miR-143 and miR-145, including ADAM17, K-Ras, XPO5, and SET. miR-145, miR-148a, and miR-152 directly suppress colonocyte ADAM17 and are down-regulated in colon cancer. This is the first direct demonstration of tumour suppressor roles for miR-143 and miR-145 in an in vivo model of colonic tumorigenesis.