Genetic and other risk factors for pancreatic ductal adenocarcinoma (PDAC)

Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at an advanced stage, resulting in poor prognosis and low 5-year survival rates. While early evidence suggests increased long-term survival in those with screen-detected resectable cancers, surveillance imaging is currently only recommended for individuals with a lifetime risk of PDAC ≥ 5%. Identification of risk factors for PDAC provides opportunities for early detection, risk reducing interventions, and targeted therapies, thus potentially improving patient outcomes. Here, we summarize modifiable and non-modifiable risk factors for PDAC. We review hereditary cancer syndromes associated with risk for PDAC and their implications for patients and their relatives. In addition, other biologically relevant pathways and environmental and lifestyle risk factors are discussed. Future work may focus on elucidating additional genetic, environmental, and lifestyle risk factors that may modify PDAC risk to continue to identify individuals at increased risk for PDAC who may benefit from surveillance and risk reducing interventions.

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.

Multiple TP53 p.R337H haplotypes and implications for tumor susceptibility

The germline TP53 p.R337H mutation is reported as the most common germline TP53 variant. It exists at a remarkably high frequency in the population of southeast Brazil as founder mutation in two distinct haplotypes with the most frequent co-segregating with the p.E134∗ variant of the XAF1 tumor suppressor and an increased cancer risk. Founder mutations demonstrate linkage disequilibrium with neighboring genetic polymorphic markers that can be used to identify the founder variant in different geographic regions and diverse populations. We report here a shared haplotype among Brazilian, Portuguese, and Spanish families and the existence of three additional distinct TP53 p.R337H alleles. Mitochondrial DNA sequencing and Y-STR profiling of Brazilian carriers of the founder TP53 p.R337H allele reveal an excess of Native American haplogroups in maternal lineages and exclusively European haplogroups in paternal lineages, consistent with communities established through male European settlers with extensive intermarriage with Indigenous women. The identification of founder and independent TP53 p.R337H alleles underlines the importance for considering the haplotype as a functional unit and the additive effects of constitutive polymorphisms and associated variants in modifier genes that can influence the cancer phenotype.

Big advocacy, little recognition: the hidden work of Black patients in precision medicine

As cost-effective next-generation genome sequencing rapidly develops, calls for greater inclusion of Black people in genomic research, policy, and practice are necessary for effective translation of genomic science into precision population health and medicine. Employing a community-based participatory mixed methods research design, we developed a semi-structured survey that was disseminated to three cancer advocacy organizations. Of the 81 survey respondents 49 (60%) self-identified as Black, and 26 (32%) indicated a prior breast cancer diagnosis. Black participants' expressed concerns about genetic testing were evenly distributed between concerns that could be addressed through genetic counseling (24%) and concerns about subsequent use of their genetic data (27%). Patient advocates contributed to contextualization of respondent concerns in terms of community experiences. Although genetic counseling services and policies governing genomic data use are not always accessible to many Black communities, advocates on our research team provided a bridge to discussion of the intersection between respondent concerns and the roles advocates play in filling gaps in access to genetic counseling and data governance. Concerns expressed by Black patients underscore a shared need among all patients for access to education, inclusion in research, and assurances regarding the use and handling of genetic data. Black cancer patients have joined in patient-led efforts to overcome systemic inequities in cancer care to improve their health outcomes through representation. Often their efforts are overshadowed by a relentless burden of continued health disparities. Future research should support their hidden work as a means to reduce barriers and improve representation in genomic databases.

Region-specific Wnt signaling responses promote gastric polyp formation in patients with familial adenomatous polyposis

Germline adenomatous polyposis coli (APC) mutation in patients with familial adenomatous polyposis (FAP) promotes gastrointestinal polyposis, including the formation of frequent gastric fundic gland polyps (FGPs). In this study, we investigated how dysregulated Wnt signaling promotes FGPs and why they localize to the corpus region of the stomach. We developed a biobank of FGP and surrounding nonpolyp corpus biopsies and organoids from patients with FAP for comparative studies. Polyp biopsies and polyp-derived organoids exhibited enhanced Wnt target gene expression. Polyp-derived organoids with intrinsically upregulated Wnt signaling showed poor tolerance to further induction, suggesting that high Wnt restricts growth. Targeted genomic sequencing revealed that most gastric polyps did not arise via APC loss of heterozygosity. Studies in genetic mouse models demonstrated that heterozygous Apc loss increased epithelial cell proliferation in the corpus but not the antrum, while homozygous Apc loss was not maintained in the corpus yet induced hyperproliferation in the antrum. Our findings suggest that heterozygous APC mutation in patients with FAP may be sufficient to drive polyp formation in the corpus region while subsequent loss of heterozygosity to further enhance Wnt signaling is not tolerated. This finding contextualizes the abundant yet benign nature of gastric polyps in FAP patient corpus compared with the rare, yet adenomatous polyps in the antrum.

Implementation of a dedicated cascade testing clinic for patients at risk for hereditary cancer syndromes

Cascade testing, the site-specific genetic testing of relatives within families with an inherited condition, is underutilized. Long wait times for appointments in specialty genetics clinics are a known barrier to genetic testing access. In our cancer genetics, New Patient Clinic (NPC), the long wait time for an appointment (on average 5 months for routine referrals), was identified by both providers and patients as a barrier to uptake of cascade testing. Timely testing of at-risk relatives is essential to maximize the benefits of cascade testing and reduce cancer morbidity and mortality. Our objective was to improve access via implementation of a different clinical model that designated appointments for patients seeking cascade testing. A secondary goal was to improve use of genetic counselor time. We implemented a dedicated Cascade Testing Clinic (CTC) with an expedited triaging and unique scheduling model to decrease patient wait time to appointment and optimize clinician time. We report on the process and outcomes here. Between October 2016 and February 2020, the average wait time between referral date and first scheduled appointment date was 46 days for the CTC compared to 144 days for the NPC (p < 0.0001). No-show/cancelation/rescheduling rate was 11.7% in the CTC compared to 29.7% in the NPC (p < 0.0001). Genetic counselors saw approximately twice as many patients per half-day clinic in the CTC compared to the NPC (p < 0.00001). Modifications to clinic staffing and appointment times were made based on provider feedback. Implementation of a dedicated clinic specifically for patients seeking cascade testing significantly shortened wait times for this population, reduced patient drop-off, and improved clinician efficiency. The relatively straightforward indications and generally uncomplicated medical histories made this an ideal population for expedited appointments.

High-fat diet plus HNF1A variant promotes polyps by activating β-catenin in early-onset colorectal cancer

The incidence of early-onset colorectal cancer (EO-CRC) is rising and is poorly understood. Lifestyle factors and altered genetic background possibly contribute. Here, we performed targeted exon sequencing of archived leukocyte DNA from 158 EO-CRC participants, which identified a missense mutation at p.A98V within the proximal DNA binding domain of Hepatic Nuclear Factor 1 α (HNF1AA98V, rs1800574). The HNF1AA98V exhibited reduced DNA binding. To test function, the HNF1A variant was introduced into the mouse genome by CRISPR/Cas9, and the mice were placed on either a high-fat diet (HFD) or high-sugar diet (HSD). Only 1% of the HNF1A mutant mice developed polyps on normal chow; however, 19% and 3% developed polyps on the HFD and HSD, respectively. RNA-Seq revealed an increase in metabolic, immune, lipid biogenesis genes, and Wnt/β-catenin signaling components in the HNF1A mutant relative to the WT mice. Mouse polyps and colon cancers from participants carrying the HNF1AA98V variant exhibited reduced CDX2 and elevated β-catenin proteins. We further demonstrated decreased occupancy of HNF1AA98V at the Cdx2 locus and reduced Cdx2 promoter activity compared with WT HNF1A. Collectively, our study shows that the HNF1AA98V variant plus a HFD promotes the formation of colonic polyps by activating β-catenin via decreasing Cdx2 expression.

Gut Microbiome Composition in Lynch Syndrome With and Without History of Colorectal Neoplasia and Non-Lynch Controls

BACKGROUND

While Lynch syndrome (LS) is a highly penetrant colorectal cancer (CRC) syndrome, there is considerable variation in penetrance; few studies have investigated the association between microbiome and CRC risk in LS. We analyzed the microbiome composition among individuals with LS with and without personal history of colorectal neoplasia (CRN) and non-LS controls.

METHODS

We sequenced the V4 region of the 16S rRNA gene from the stool of 46 individuals with LS and 53 individuals without LS. We characterized within community and in between community microbiome variation, compared taxon abundance, and built machine learning models to investigate the differences in microbiome.

RESULTS

There was no difference within or between community variations among LS groups, but there was a statistically significant difference in both within and between community variation comparing LS to non-LS. Streptococcus and Actinomyces were differentially enriched in LS-CRC compared to LS-without CRN. There were numerous differences in taxa abundance comparing LS to non-LS; notably, Veillonella was enriched and Faecalibacterium and Romboutsia were depleted in LS. Finally, machine learning models classifying LS from non-LS controls and LS-CRC from LS-without CRN performed moderately well.

CONCLUSIONS

Differences in microbiome composition between LS and non-LS may suggest a microbiome pattern unique to LS formed by underlying differences in epithelial biology and immunology. We found specific taxa differences among LS groups, which may be due to underlying anatomy. Larger prospective studies following for CRN diagnosis and microbiome composition changes are needed to determine if microbiome composition contributes to CRN development in patients with LS.

The role of area-level socioeconomic disadvantage in racial disparities in cancer incidence in metropolitan Detroit

BACKGROUND

Neighborhood deprivation is associated with both race and cancer incidence, but there is a need to better understand the effect of structural inequities on racial cancer disparities. The goal of this analysis was to evaluate the relationship between a comprehensive measure of neighborhood-level social disadvantage and cancer incidence within the racially diverse population of metropolitan Detroit.

METHODS

We estimated breast, colorectal, lung, and prostate cancer incidence rates using Metropolitan Detroit Cancer Surveillance System and US decennial census data. Neighborhood socioeconomic disadvantage was measured by the Area Deprivation Index (ADI) using Census Bureau's American Community Survey data at the Public Use Microdata Areas (PUMA) level. Associations between ADI at time of diagnosis and cancer incidence were estimated using Poisson mixed-effects models adjusting for age and sex. Attenuation of race-incidence associations by ADI was quantified using the "mediation" package in R.

RESULTS

ADI was inversely associated with incidence of breast cancer for both non-Hispanic White (NHW) and non-Hispanic Black (NHB) women (NHW: per-quartile RR = 0.92, 95% CI 0.88-0.96; NHB: per-quartile RR = 0.94, 95% CI 0.91-0.98) and with prostate cancer incidence only for NHW men (per-quartile RR = 0.94, 95% CI 0.90-0.97). ADI was positively associated with incidence of lung cancer for NHWs and NHBs (NHW: per-quartile RR = 1.12, 95% CI 1.04-1.21; NHB: per-quartile RR = 1.37, 95% CI 1.25-1.51) and incidence of colorectal cancer (CRC) only among NHBs (per-quartile RR = 1.11, 95% CI 1.02-1.21). ADI significantly attenuated the relationship between race and hormone receptor positive, HER2-negative breast cancer (proportion attenuated = 8.5%, 95% CI 4.1-16.6%) and CRC cancer (proportion attenuated = 7.3%, 95% CI 3.7 to 12.8%), and there was a significant interaction between race and ADI for lung (interaction RR = 1.22, p < 0.0001) and prostate cancer (interaction RR = 1.09, p = 0.00092).

CONCLUSIONS

Area-level socioeconomic disadvantage is associated with risk of common cancers in a racially diverse population and plays a role in racial differences in cancer incidence.

Psychosocial factors impacting barriers and motivators to cancer genetic testing

BACKGROUND

Only a small proportion of patients who qualify for clinical genetic testing for cancer susceptibility get testing. Many patient-level barriers contribute to low uptake. In this study, we examined self-reported patient barriers and motivators for cancer genetic testing.

METHODS

A survey comprised of both new and existing measures related to barriers and motivators to genetic testing was emailed to patients with a diagnosis of cancer at a large academic medical center. Patients who self-reported receiving a genetic test were included in these analyses (n = 376). Responses about emotions following testing as well as barriers and motivators prior to getting testing were examined. Group differences in barriers and motivators by patient demographic characteristics were examined.

RESULTS

Being assigned female at birth was associated with increased emotional, insurance, and family concerns as well as increased health benefits compared to patients assigned male at birth. Younger respondents had significantly higher emotional and family concerns compared to older respondents. Recently diagnosed respondents expressed fewer concerns about insurance implications and emotional concerns. Those with a BRCA-related cancer had higher scores on social and interpersonal concerns scale than those with other cancers. Participants with higher depression scores indicated increased emotional, social and interpersonal, and family concerns.

CONCLUSIONS

Self-reported depression emerged as the most consistent factor influencing report of barriers to genetic testing. By incorporating mental health resources into clinical practice, oncologists may better identify those patients who might need more assistance following through with a referral for genetic testing and the response afterwards.

Area-level Socioeconomic Disadvantage and Cancer Survival in Metropolitan Detroit

BACKGROUND

Racial segregation is linked to poorer neighborhood quality and adverse health conditions among minorities, including worse cancer outcomes. We evaluated relationships between race, neighborhood social disadvantage, and cancer survival.

METHODS

We calculated overall and cancer-specific survival for 11,367 non-Hispanic Black (NHB) and 29,481 non-Hispanic White (NHW) individuals with breast, colorectal, lung, or prostate cancer using data from the Metropolitan Detroit Cancer Surveillance System. The area deprivation index (ADI) was used to measure social disadvantage at the census block group level, where higher ADI is associated with poorer neighborhood factors. Associations between ADI and survival were estimated using Cox proportional hazards mixed-effects models accounting for geographic grouping and adjusting for demographic and clinical factors.

RESULTS

Increasing ADI quintile was associated with increased overall mortality for all four cancer sites in multivariable-adjusted models. Stratified by race, these associations remained among breast (NHW: HR = 1.16, P < 0.0001; NHB: HR = 1.20, P < 0.0001), colorectal (NHW: HR = 1.11, P < 0.0001; NHB: HR = 1.09, P = 0.00378), prostate (NHW: HR = 1.18, P < 0.0001; NHB: HR = 1.18, P < 0.0001), and lung cancers (NHW: HR = 1.06, P < 0.0001; NHB: HR = 1.07, P = 0.00177). Cancer-specific mortality estimates were similar to overall mortality. Adjustment for ADI substantially attenuated the effects of race on mortality for breast [overall proportion attenuated (OPA) = 47%, P < 0.0001; cancer-specific proportion attenuated (CSPA) = 37%, P < 0.0001] prostate cancer (OPA = 51%, P < 0.0001; CSPA = 56%, P < 0.0001), and colorectal cancer (OPA = 69%, P = 0.032; CSPA = 36%, P = 0.018).

CONCLUSIONS

Area-level socioeconomic disadvantage is related to cancer mortality in a racially diverse population, impacting racial differences in cancer mortality.

IMPACT

Understanding the role of neighborhood quality in cancer survivorship could improve community-based intervention practices.

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.

Pancreatic Cancer: Changing Epidemiology and New Approaches to Risk Assessment, Early Detection, and Prevention

Pancreatic cancer usually results in poor survival with limited options for treatment, as most affected individuals present with advanced disease. Early detection of preinvasive pancreatic neoplasia and identifying molecular therapeutic targets provide opportunities for extending survival. Although screening for pancreatic cancer is currently not recommended for the general population, emerging evidence indicates that pancreatic surveillance can improve outcomes for individuals in certain high-risk groups. Changes in the epidemiology of pancreatic cancer, experience from pancreatic surveillance, and discovery of novel biomarkers provide a roadmap for new strategies for pancreatic cancer risk assessment, early detection, and prevention.

The Michigan Genetic Hereditary Testing (MiGHT) study's innovative approaches to promote uptake of clinical genetic testing among cancer patients: a study protocol for a 3-arm randomized controlled trial

BACKGROUND

Although most cancers are sporadic, germline genetic variants are implicated in 5-10% of cancer cases. Clinical genetic testing identifies pathogenic germline genetic variants for hereditary cancers. The Michigan Genetic Hereditary Testing (MiGHT) study is a three-arm randomized clinical trial that aims to test the efficacy of two patient-level behavioral interventions on uptake of cancer genetic testing.

METHODS

The two interventions being tested are (1) a virtual genetics navigator and (2) motivational interviewing by genetic health coaches. Eligible participants are adults with a diagnosis of breast, prostate, endometrial, ovarian, colorectal, or pancreatic cancer who meet the National Comprehensive Cancer Network (NCCN) criteria for genetic testing. Participants are recruited through community oncology practices affiliated with the Michigan Oncology Quality Consortium (MOQC) and have used the Family Health History Tool (FHHT) to determine testing eligibility. The recruitment goal is 759 participants, who will be randomized to usual care or to either the virtual genetics navigator or the motivational interviewing intervention arms. The primary outcome will be the proportion of individuals who complete germline genetic testing within 6 months.

DISCUSSION

This study addresses patient-level factors which are associated with the uptake of genetic testing. The study will test two different intervention approaches, both of which can help address the shortage of genetic counselors and improve access to care.

TRIAL REGISTRATION

This study has been approved by the Institutional Review Board of the University of Michigan Medical School (HUM00192898) and registered in ClinicalTrials.gov (NCT05162846).

Satisfaction With Clinician-Led Germline Genetic Counseling in Patients With Prostate Cancer

PURPOSE

Indications for germline testing in prostate cancer patients have expanded substantially over the past decade. With a near-universal shortage of genetic counselors and increasing demand, increased access to genetic counseling is crucial. We sought to prospectively implement and assess a clinician-led approach to genetic counseling and testing.

MATERIALS AND METHODS

Patients with metastatic or localized prostate cancer meeting National Comprehensive Cancer Network® criteria for consideration of genetic testing were offered pre-test genetic counseling by their urologist or medical oncologist as part of their routine clinical care and concurrently approached for enrollment in the Germline Genetics in Prostate Cancer Study. Consented patients filled out a post-counseling survey using validated instruments to assess the quality of counseling. For patients who elected to undergo genetic testing, an additional validated questionnaire was completed following disclosure of results. The primary outcome was the proportion of patients undergoing testing, with a target >60% of patients. The secondary outcome was overall satisfaction with counseling, with a target >85% of patients.

RESULTS

A total of 275 patients enrolled, and 203 patients elected to undergo genetic testing. Post-counseling surveys were obtained from 265 patients, and post-genetic testing surveys were obtained from 132 patients. Patient satisfaction was high, with 98% of patients reporting being satisfied with the overall quality of pre-test counseling, and 74% of patients elected to undergo genetic testing.

CONCLUSIONS

These results support the effectiveness of clinician-led genetic counseling in prostate cancer. With clinician training, this approach can be utilized to expand access to appropriate germline genetic testing.

The Multicenter Cancer of Pancreas Screening Study: Impact on Stage and Survival

PURPOSE

To report pancreas surveillance outcomes of high-risk individuals within the multicenter Cancer of Pancreas Screening-5 (CAPS5) study and to update outcomes of patients enrolled in prior CAPS studies.

METHODS

Individuals recommended for pancreas surveillance were prospectively enrolled into one of eight CAPS5 study centers between 2014 and 2021. The primary end point was the stage distribution of pancreatic ductal adenocarcinoma (PDAC) detected (stage I v higher-stage). Overall survival was determined using the Kaplan-Meier method.

RESULTS

Of 1,461 high-risk individuals enrolled into CAPS5, 48.5% had a pathogenic variant in a PDAC-susceptibility gene. Ten patients were diagnosed with PDAC, one of whom was diagnosed with metastatic PDAC 4 years after dropping out of surveillance. Of the remaining nine, seven (77.8%) had a stage I PDAC (by surgical pathology) detected during surveillance; one had stage II, and one had stage III disease. Seven of these nine patients with PDAC were alive after a median follow-up of 2.6 years. Eight additional patients underwent surgical resection for worrisome lesions; three had high-grade and five had low-grade dysplasia in their resected specimens. In the entire CAPS cohort (CAPS1-5 studies, 1,731 patients), 26 PDAC cases have been diagnosed, 19 within surveillance, 57.9% of whom had stage I and 5.2% had stage IV disease. By contrast, six of the seven PDACs (85.7%) detected outside surveillance were stage IV. Five-year survival to date of the patients with a screen-detected PDAC is 73.3%, and median overall survival is 9.8 years, compared with 1.5 years for patients diagnosed with PDAC outside surveillance (hazard ratio [95% CI]; 0.13 [0.03 to 0.50], P = .003).

CONCLUSION

Most pancreatic cancers diagnosed within the CAPS high-risk cohort in the recent years have had stage I disease with long-term survival.

Combination of Sulindac and Eflornithine Delays the Need for Lower Gastrointestinal Surgery in Patients With Familial Adenomatous Polyposis: Post Hoc Analysis of a Randomized Clinical Trial

BACKGROUND

Colectomy and proctocolectomy are the initial standard of care for patients with familial adenomatous polyposis. Pharmacotherapy to prevent the progression of polyposis and surgeries in the lower GI tract would be beneficial to patients with this disease.

OBJECTIVE

This analysis aimed to evaluate the impact of eflornithine-sulindac combination versus monotherapy in delaying time to disease progression in the lower GI tract of patients with familial adenomatous polyposis.

DESIGN

This is a post hoc analysis of a randomized phase 3 trial.

SETTING

This study was conducted in 21 hospitals in 7 countries treating patients with familial adenomatous polyposis.

PATIENTS

Adults with familial adenomatous polyposis were randomly assigned 1:1:1 into 3 arms.

INTERVENTIONS

Patients received either eflornithine (750 mg), sulindac (150 mg), or both once daily for up to 48 months.

MAIN OUTCOME MEASURES

Efficacy was evaluated as the time from randomization to predefined primary disease progression end points.

RESULTS

A total of 158 patients were included in the study. Disease progression was observed in 2 of 54 (3.7%), 9 of 53 (17.0%), and 10 of 51 (19.6%) patients with at least partial lower GI tract in the combination, sulindac, and eflornithine arms, corresponding to risk reductions of 80% (p = 0.02) and 83% (p = 0.01) between combination and sulindac or eflornithine. When endoscopic excision of adenomas ≥10 mm in size was censored, the need for major surgery was observed in 0 of 54, 7 of 53 (13.2%), and 8 of 51 (15.7%) patients in the combination, sulindac, and eflornithine arms, corresponding to risk reductions approaching 100% between combination and sulindac (p = 0.005) or combination and eflornithine (p = 0.003).

LIMITATIONS

This was a post hoc analysis, the sample size was small, and there were fewer than expected events.

CONCLUSIONS

Eflornithine-sulindac combination therapy was superior to either drug alone in delaying or preventing the need for lower GI tract surgery in patients with familial adenomatous polyposis. See Video Abstract at http://links.lww.com/DCR/B658.

REGISTRATION

ClinicalTrials.gov, NCT01483144; EU Clinical Trials Register, EudraCT 2012-000427-41.

LA COMBINACIN DE SULINDAC Y EFLORNITINA RETRASA LA NECESIDAD DE CIRUGA DEL TUBO DIGESTIVO BAJO EN PACIENTES CON PAF ANLISIS POSTHOC DE UN ENSAYO CLNICO ALEATORIZADO

ANTECEDENTES:La colectomía y la proctocolectomía son el estándar inicial de atención para los pacientes con poliposis adenomatosa familiar. La farmacoterapia para prevenir la progresión de la poliposis y las cirugías en el tracto gastrointestinal inferior sería beneficiosa para los pacientes con esta enfermedad.OBJETIVO:Este análisis tuvo como objetivo evaluar el impacto de la combinación de eflornitina-sulindac versus la monoterapia en el retraso del tiempo hasta la progresión de la enfermedad en el tracto gastrointestinal inferior de pacientes con poliposis adenomatosa familiar.DISEÑO:Este es un análisis posthoc de un ensayo de fase 3 aleatorizado.ENTORNO CLINICO:Veintiún hospitales en 7 países que tratan a pacientes con poliposis adenomatosa familiar.PACIENTES:Adultos con poliposis adenomatosa familiar fueron aleatorizados 1: 1: 1 en 3 brazos.INTERVENCIONES:Los pacientes recibieron eflornitina (750 mg), sulindac (150 mg) o ambos una vez al día durante un máximo de 48 meses.PRINCIPALES MEDIDAS DE VALORACION:La eficacia se evaluó como el tiempo desde la aleatorización hasta los criterios de valoración primarios predefinidos de progresión de la enfermedad.RESULTADOS:Los resultados se informan para la población de estudio excluyendo a los pacientes que se habían sometido a ileostomías permanentes (n = 158). Se observó progresión de la enfermedad en 2/54 (3,7%), 9/53 (17,0%) y 10/51 (19,6%) pacientes con al menos tracto gastrointestinal inferior parcial en los brazos de combinación, sulindac y eflornitina, respectivamente, correspondientes al riesgo de reducciones del 80% (p = 0,02) y del 83% (p = 0,01) entre la combinación y el sulindaco o la eflornitina, respectivamente. Cuando se censuró la escisión endoscópica de adenomas ≥10 mm de tamaño, se observó la necesidad de cirugía mayor en 0/54, 7/53 (13,2%) y 8/51 (15,7%) pacientes en la combinación, sulindac y eflornitina, respectivamente, correspondientes a reducciones de riesgo cercanas al 100% entre combinación y sulindac (p = 0,005) o combinación y eflornitina (p = 0,003).LIMITACIONES:Este fue un análisis posthoc, el tamaño de la muestra fue pequeño y hubo menos eventos de los esperados.CONCLUSIONES:La terapia de combinación de eflornitina-sulindac fue superior a cualquier fármaco solo para retrasar o prevenir la necesidad de cirugía del tracto gastrointestinal inferior en pacientes con poliposis adenomatosa familiar. Consulte Video Resumen en http://links.lww.com/DCR/B658.

Timeline of Development of Pancreatic Cancer and Implications for Successful Early Detection in High-Risk Individuals

BACKGROUND & AIMS

To successfully implement imaging-based pancreatic cancer (PC) surveillance, understanding the timeline and morphologic features of neoplastic progression is key. We aimed to investigate the progression to neoplasia from serial prediagnostic pancreatic imaging tests in high-risk individuals and identify factors associated with successful early detection.

METHODS

We retrospectively examined the development of pancreatic abnormalities in high-risk individuals who were diagnosed with PC or underwent pancreatic surgery, or both, in 16 international surveillance programs.

RESULTS

Of 2552 high-risk individuals under surveillance, 28 (1%) developed neoplastic progression to PC or high-grade dysplasia during a median follow-up of 29 months after baseline (interquartile range [IQR], 40 months). Of these, 13 of 28 (46%) presented with a new lesion (median size, 15 mm; range 7-57 mm), a median of 11 months (IQR, 8; range 3-17 months) after a prior examination, by which time 10 of 13 (77%) had progressed beyond the pancreas. The remaining 15 of 28 (54%) had neoplastic progression in a previously detected lesion (12 originally cystic, 2 indeterminate, 1 solid), and 11 (73%) had PC progressed beyond the pancreas. The 12 patients with cysts had been monitored for 21 months (IQR, 15 months) and had a median growth of 5 mm/y (IQR, 8 mm/y). Successful early detection (as high-grade dysplasia or PC confined to the pancreas) was associated with resection of cystic lesions (vs solid or indeterminate lesions (odds ratio, 5.388; 95% confidence interval, 1.525-19.029) and small lesions (odds ratio, 0.890/mm; 95% confidence interval 0.812-0.976/mm).

CONCLUSIONS

In nearly half of high-risk individuals developing high-grade dysplasia or PC, no prior lesions are detected by imaging, yet they present at an advanced stage. Progression can occur before the next scheduled annual examination. More sensitive diagnostic tools or a different management strategy for rapidly growing cysts are needed.

Racial and Ethnic Disparities in Germline Genetic Testing of Patients With Young-Onset Colorectal Cancer

BACKGROUND & AIMS

Up to 20% of younger patients (age <50 years) diagnosed with colorectal cancer (CRC) have germline mutations in cancer susceptibility genes. Germline genetic testing may guide clinical management and facilitate earlier intervention in affected relatives. Few studies have characterized differences in genetic testing by race/ethnicity.

METHODS

We identified young adults (age 18-49 years) diagnosed with CRC between 2009 and 2017 in 2 health systems in Dallas, TX. We evaluated referral to genetic counseling, attendance at genetic counseling appointments, and receipt of germline genetic testing by race/ethnicity.

RESULTS

Of 385 patients with young-onset CRC (median age at diagnosis 44.4 years), 176 (45.7%) were Hispanic, 98 (25.4%) non-Hispanic Black, and 111 (28.8%) non-Hispanic White. Most patients (76.9%) received immunohistochemistry (IHC) for mismatch repair proteins, and there was no difference in receipt of IHC by race/ethnicity. However, a lower proportion of Black patients were referred to genetic counseling (50.0% vs White patients 54.1% vs Hispanic patients 65.9%; P = .02) and attended genetic counseling appointments (61.2% vs 81.7% White patients vs 86.2% Hispanic patients; P < .01). Of 141 patients receiving genetic testing, 38 (27.0%) had a pathogenic or likely pathogenic variant in a cancer susceptibility gene. An additional 33 patients (23.4%) had variants of uncertain significance, of which 84.8% occurred in racial/ethnic minorities.

CONCLUSIONS

In a diverse population of patients diagnosed with young-onset CRC, we observed racial/ethnic differences in referral to and receipt of germline genetic testing. Our findings underscore the importance of universal genetic testing to address racial/ethnic disparities in young-onset CRC.

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.

Outcomes of retesting in patients with previously uninformative cancer genetics evaluations

Advances in cancer genetics have increased germline pathogenic/likely pathogenic variant (PV/LPV) detection rates. More data is needed to inform which patients with previously uninformative results could benefit most from retesting, especially beyond breast/ovarian cancer populations. Here, we describe retesting outcomes and predictors of PV/LPVs in a cohort of patients unselected by cancer diagnosis. Retrospective chart reviews were conducted for patients at a cancer genetics clinic between 1998 and 2019 who underwent genetic testing (GT) on ≥ 2 dates with ≥ 1 year between tests, with no PV/LPVs on first-line GT. Demographics, retesting indications, and GT details were reviewed to evaluate predictive factors of PV/LPV identification. 139 patients underwent retesting, of whom 24 (17.3%) had a PV/LPV, encompassing 15 genes. 14 PV/LPV carriers (58.3%) only returned for retesting after personal or familial history changes (typically new cancer diagnoses), while 10 (41.7%) retested due to updated GT availability. No specific GT method was most likely to identify PV/LPVs and no specific clinical factors were predictive of a PV/LPV. The identified PV/LPVs were consistent with patients' personal or family histories, but were discordant with the initial referral indication for GT. For 16 (66.7%) PV/LPV carriers, the genetic diagnosis changed clinical management. This study adds to the limited body of literature on retesting outcomes beyond first-line BRCA analysis alone and confirms the utility of multigene panel testing. Retesting certain affected individuals when updated GT is available could result in earlier PV/LPV identification, significantly impacting screening recommendations and potentially reducing cancer-related morbidity and mortality.

Initial Findings from a High Genetic Risk Prostate Cancer Clinic

OBJECTIVE

To improve prostate cancer screening for high-risk men, we developed an early detection clinic for patients at high genetic risk of developing prostate cancer. Despite the rapidly growing understanding of germline variants in driving aggressive prostate cancer and the increased availability of genetic testing, there is little evidence surrounding how best to screen these men.

METHODS

We are reporting on the first 45 patients enrolled, men between the ages of 35-75, primarily with known pathogenic germline variants in prostate cancer susceptibility genes. Screening consists of an intake lifestyle survey, PSA, DRE, and SelectMDx urine assay. A biopsy was recommended for any of the following indications: 1) abnormal DRE, 2) PSA above threshold, or 3) SelectMDx above threshold. The primary outcomes were number needed to screen, and number needed to biopsy to diagnose a patient with prostate cancer.

RESULTS

Patients enrolled in the clinic included those with BRCA1 (n=7), BRCA2 (n=16), Lynch Syndrome (n=6), and CHEK2 (n = 4) known pathogenic germline variants. The median age and PSA were 58 (range 35-71) and 1.4 ng/ml (range 0.1-11.4 ng/ml), respectively. 12 patients underwent a prostate needle biopsy and there were 4positive biopsies for prostate cancer.

CONCLUSION

These early data support the feasibility of opening a dedicated clinic for men at high genetic risk of prostate cancer. This early report on the initial enrollment of our long-term study will help optimize early detection protocols and provide evidence for personalized prostate cancer screening in men with key pathogenic germline variants.

COVID-19 related pancreatic cancer surveillance disruptions amongst high-risk individuals

BACKGROUND

COVID-19 pandemic-related disruptions to EUS-based pancreatic cancer surveillance in high-risk individuals remain uncertain.

METHODS

Analysis of enrolled participants in the CAPS5 Study, a prospective multicenter study of pancreatic cancer surveillance in high-risk individuals.

RESULTS

Amongst 693 enrolled high-risk individuals under active surveillance, 108 (16%) had an EUS scheduled during the COVID-19 pandemic-related shutdown (median length of 78 days) in the spring of 2020, with 97% of these procedures being canceled. Of these canceled surveillance EUSs, 83% were rescheduled in a median of 4.1 months, however 17% were not rescheduled after 6 months follow-up. Prior history of cancer was associated with increased likelihood of rescheduling. To date no pancreatic cancer has been diagnosed among those whose surveillance was delayed.

CONCLUSIONS

COVID-19 delayed pancreatic cancer surveillance with no adverse outcomes in efficiently rescheduled individuals. However, 1 in 6 high-risk individuals had not rescheduled surveillance, indicating the need for vigilance to ensure timely surveillance rescheduling.

Colon Cancer, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

This selection from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Colon Cancer focuses on systemic therapy options for the treatment of metastatic colorectal cancer (mCRC), because important updates have recently been made to this section. These updates include recommendations for first-line use of checkpoint inhibitors for mCRC, that is deficient mismatch repair/microsatellite instability-high, recommendations related to the use of biosimilars, and expanded recommendations for biomarker testing. The systemic therapy recommendations now include targeted therapy options for patients with mCRC that is HER2-amplified, or BRAF V600E mutation-positive. Treatment and management of nonmetastatic or resectable/ablatable metastatic disease are discussed in the complete version of the NCCN Guidelines for Colon Cancer available at NCCN.org. Additional topics covered in the complete version include risk assessment, staging, pathology, posttreatment surveillance, and survivorship.

Naproxen chemoprevention promotes immune activation in Lynch syndrome colorectal mucosa

OBJECTIVE

Patients with Lynch syndrome (LS) are at markedly increased risk for colorectal cancer. It is being increasingly recognised that the immune system plays an essential role in LS tumour development, thus making an ideal target for cancer prevention. Our objective was to evaluate the safety, assess the activity and discover novel molecular pathways involved in the activity of naproxen as primary and secondary chemoprevention in patients with LS.

DESIGN

We conducted a Phase Ib, placebo-controlled, randomised clinical trial of two dose levels of naproxen sodium (440 and 220 mg) administered daily for 6 months to 80 participants with LS, and a co-clinical trial using a genetically engineered mouse model of LS and patient-derived organoids (PDOs).

RESULTS

Overall, the total number of adverse events was not different across treatment arms with excellent tolerance of the intervention. The level of prostaglandin E2 in the colorectal mucosa was significantly decreased after treatment with naproxen when compared with placebo. Naproxen activated different resident immune cell types without any increase in lymphoid cellularity, and changed the expression patterns of the intestinal crypt towards epithelial differentiation and stem cell regulation. Naproxen demonstrated robust chemopreventive activity in a mouse co-clinical trial and gene expression profiles induced by naproxen in humans showed perfect discrimination of mice specimens with LS and PDOs treated with naproxen and control.

CONCLUSIONS

Naproxen is a promising strategy for immune interception in LS. We have discovered naproxen-induced gene expression profiles for their potential use as predictive biomarkers of drug activity.

TRIAL REGISTRATION NUMBER

gov Identifier: NCT02052908.

Assessment of Clinical Benefit of Integrative Genomic Profiling in Advanced Solid Tumors

Question

What is the clinical utility of genomic profiling for patients with advanced solid tumors?

Findings

In this cohort study of 1015 patients who underwent integrative genomic profiling, a high rate of pathogenic germline variants and a subset of patients who derive substantial clinical benefit from sequencing information were identified.

Meaning

These findings support (1) directed germline testing for inherited cancer predisposition in all patients with advanced cancer and (2) use of integrative genomic profiling as a component of standard of care for patients with cancer of unknown origin and other rare malignant neoplasms.

Importance

Use of next-generation sequencing (NGS) to identify clinically actionable genomic targets has been incorporated into routine clinical practice in the management of advanced solid tumors; however, the clinical utility of this testing remains uncertain.

Objective

To determine which patients derived the greatest degree of clinical benefit from NGS profiling.

Design, Setting, and Participants

Patients in this cohort study underwent fresh tumor biopsy and blood sample collection for genomic profiling of paired tumor and normal DNA (whole-exome or targeted-exome capture with analysis of 1700 genes) and tumor transcriptome (RNA) sequencing. Somatic and germline genomic alterations were annotated and classified according to degree of clinical actionability. Results were returned to treating oncologists. Data were collected from May 1, 2011, to February 28, 2018, and analyzed from May 1, 2011, to April 30, 2020.

Main Outcomes and Measures

Patients’ subsequent therapy and treatment response were extracted from the medical record to determine clinical benefit rate from NGS-directed therapy at 6 months and exceptional responses lasting 12 months or longer.

Results

During the study period, NGS was attempted on tumors from 1138 patients and was successful in 1015 (89.2%) (MET1000 cohort) (538 men [53.0%]; mean [SD] age, 57.7 [13.3] years). Potentially clinically actionable genomic alterations were discovered in 817 patients (80.5%). Of these, 132 patients (16.2%) received sequencing-directed therapy, and 49 had clinical benefit (37.1%). Exceptional responses were observed in 26 patients (19.7% of treated patients). Pathogenic germline variants (PGVs) were identified in 160 patients (15.8% of cohort), including 49 PGVs (4.8% of cohort) with therapeutic relevance. For 55 patients with carcinoma of unknown primary origin, NGS identified the primary site in 28 (50.9%), and sequencing-directed therapy in 13 patients resulted in clinical benefit in 7 instances (53.8%), including 5 exceptional responses.

Conclusions and Relevance

The high rate of therapeutically relevant PGVs identified across diverse cancer types supports a recommendation for directed germline testing in all patients with advanced cancer. The high frequency of therapeutically relevant somatic and germline findings in patients with carcinoma of unknown primary origin and other rare cancers supports the use of comprehensive NGS profiling as a component of standard of care for these disease entities.

Abstract PO-222: Co-morbid risk factors and NSAID use among white and black Americans that predicts overall survival from diagnosed colon cancer

Black Americans (BA) have higher incidence and higher mortality rates for colorectal cancers (CRC) as compared to White Americans (WA). While there are several identified risk factors associated with the development of CRC and evidence that high levels of adequate screening can reduce differences in incidence for CRC between BA and WA, there remains little data regarding patient co-morbid contributions towards survival once an individual has CRC. Here we set out to identify patient risk factors that influenced overall survival in a cohort of 293 BA and 348 WA with colon cancer, ages 40 to 84 years old, with at least 10 years of follow- up. We utilized the logistic regression test for statistical associations, the Kaplan- Meier method with log rank test for survival analyses, and Cox Proportional Hazards Models for covariate independence. Amid our cohort, we found that patients’ age, tobacco usage, and pre-diagnosed medical conditions such as hypertension and diabetes were associated with shorter overall survival (OS) from colon cancer. We identified pre-diagnosed hypertension (19.6% contribution) and diabetes (12% contribution) among BA were together responsible for nearly one-third of the colon cancer mortality disparity compared with WA. We also identified long-term regular use (&gt;5 years aggregated years of drug use) of non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin, was associated with shorter OS from colon cancer among WA &gt;65 years of age (Hazard Ratio 1.76, 95% confidence interval 1.12-2.77), but not younger WA patients or any aged BA patients. Our results raise the importance of not only treating the colon cancer itself, but also taking into consideration co-morbid medical conditions and NSAID usage to enhance patient OS. Further evaluation regarding adequate treatment of co-morbidities and timing of NSAID continuance after cancer therapy will need to be studied.

Citation Format: Minoru Koi, Yoshiki Okita, Erika Koeppe, Elena M. Stoffel, Joseph A. Galanko, Nikki McCoy, Temitope Keku, John M. Carethers. Co-morbid risk factors and NSAID use among white and black Americans that predicts overall survival from diagnosed colon cancer [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-222.

Co-morbid risk factors and NSAID use among white and black Americans that predicts overall survival from diagnosed colon cancer

Black Americans (BA) have higher incidence and higher mortality rates for colorectal cancers (CRC) as compared to White Americans (WA). While there are several identified risk factors associated with the development of CRC and evidence that high levels of adequate screening can reduce differences in incidence for CRC between BA and WA, there remains little data regarding patient co-morbid contributions towards survival once an individual has CRC. Here we set out to identify patient risk factors that influenced overall survival in a cohort of 293 BA and 348 WA with colon cancer. Amid our cohort, we found that patients’ age, tobacco usage, and pre-diagnosed medical conditions such as hypertension and diabetes were associated with shorter overall survival (OS) from colon cancer. We identified pre-diagnosed hypertension and diabetes among BA were responsible for one-third of the colon cancer mortality disparity compared with WA. We also identified long-term regular use of non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin, was associated with shorter OS from colon cancer among WA >65 years of age, but not younger WA patients or any aged BA patients. Our results raise the importance of not only treating the colon cancer itself, but also taking into consideration co-morbid medical conditions and NSAID usage to enhance patient OS. Further evaluation regarding adequate treatment of co-morbidities and timing of NSAID continuance after cancer therapy will need to be studied.

A Summary of the 2020 Gastric Cancer Summit at Stanford University

There exists no coherent national strategy for the early detection or prevention of gastric cancer in the United States (US), even among identified high-risk groups such as Asian Americans, African Americans, Hispanic Americans, and Alaska Native/American Indian peoples. As a result, patients with gastric cancer in the US are diagnosed at later stages and demonstrate worse overall survival compared to nations of East Asia with established screening programs (Table 1). The under-recognition of gastric cancer risk within minority communities is a significant unaddressed healthcare disparity.

Fusobacterium nucleatum infection correlates with two types of microsatellite alterations in colorectal cancer and triggers DNA damage

Fusobacterium nucleatum (Fn) is frequently found in colorectal cancers (CRCs). High loads of Fn DNA are detected in CRC tissues with microsatellite instability-high (MSI-H), or with the CpG island hypermethylation phenotype (CIMP). Fn infection is also associated with the inflammatory tumor microenvironment of CRC. A subtype of CRC exhibits inflammation-associated microsatellite alterations (IAMA), which are characterized by microsatellite instability-low (MSI-L) and/or an elevated level of microsatellite alterations at selected tetra-nucleotide repeats (EMAST). Here we describe two independent CRC cohorts in which heavy or moderate loads of Fn DNA are associated with MSI-H and L/E CRC respectively. We also show evidence that Fn produces factors that induce γ-H2AX, a hallmark of DNA double strand breaks (DSBs), in the infected cells.

Eflornithine plus Sulindac for Prevention of Progression in Familial Adenomatous Polyposis

BACKGROUND

The efficacy and safety of combination therapy with eflornithine and sulindac, as compared with either drug alone, in delaying disease progression in patients with familial adenomatous polyposis are unknown.

METHODS

We evaluated the efficacy and safety of the combination of eflornithine and sulindac, as compared with either drug alone, in adults with familial adenomatous polyposis. The patients were stratified on the basis of anatomical site with the highest polyp burden and surgical status; the strata were precolectomy (shortest projected time to disease progression), rectal or ileal pouch polyposis after colectomy (longest projected time), and duodenal polyposis (intermediate projected time). The patients were then randomly assigned in a 1:1:1 ratio to receive 750 mg of eflornithine, 150 mg of sulindac, or both once daily for up to 48 months. The primary end point, assessed in a time-to-event analysis, was disease progression, defined as a composite of major surgery, endoscopic excision of advanced adenomas, diagnosis of high-grade dysplasia in the rectum or pouch, or progression of duodenal disease.

RESULTS

A total of 171 patients underwent randomization. Disease progression occurred in 18 of 56 patients (32%) in the eflornithine-sulindac group, 22 of 58 (38%) in the sulindac group, and 23 of 57 (40%) in the eflornithine group, with a hazard ratio of 0.71 (95% confidence interval [CI], 0.39 to 1.32) for eflornithine-sulindac as compared with sulindac (P = 0.29) and 0.66 (95% CI, 0.36 to 1.24) for eflornithine-sulindac as compared with eflornithine. Among 37 precolectomy patients, the corresponding values in the treatment groups were 2 of 12 patients (17%), 6 of 13 (46%), and 5 of 12 (42%) (hazard ratios, 0.30 [95% CI, 0.07 to 1.32] and 0.20 [95% CI, 0.03 to 1.32]); among 34 patients with rectal or ileal pouch polyposis, the values were 4 of 11 patients (36%), 2 of 11 (18%), and 5 of 12 (42%) (hazard ratios, 2.03 [95% CI, 0.43 to 9.62] and 0.84 [95% CI, 0.24 to 2.90]); and among 100 patients with duodenal polyposis, the values were 12 of 33 patients (36%), 14 of 34 (41%), and 13 of 33 (39%) (hazard ratios, 0.73 [95% CI, 0.34 to 1.52] and 0.76 [95% CI, 0.35 to 1.64]). Adverse and serious adverse events were similar across the treatment groups.

CONCLUSIONS

In this trial involving patients with familial adenomatous polyposis, the incidence of disease progression was not significantly lower with the combination of eflornithine and sulindac than with either drug alone. (Funded by Cancer Prevention Pharmaceuticals; ClinicalTrials.gov number, NCT01483144; EudraCT number, 2012-000427-41.).

Small Bowel Adenocarcinoma, Version 1.2020, NCCN Clinical Practice Guidelines in Oncology

Small bowel adenocarcinoma (SBA) is a rare malignancy of the gastrointestinal tract that has increased in incidence across recent years. Often diagnosed at an advanced stage, outcomes for SBA are worse on average than for other related malignancies, including colorectal cancer. Due to the rarity of this disease, few studies have been done to direct optimal treatment, although recent data have shown that SBA responds to treatment differently than colorectal cancer, necessitating a separate approach to treatment. The NCCN Guidelines for Small Bowel Adenocarcinoma were created to establish an evidence-based standard of care for patients with SBA. These guidelines provide recommendations on the workup of suspected SBA, primary treatment options, adjuvant treatment, surveillance, and systemic therapy for metastatic disease. Additionally, principles of imaging and endoscopy, pathologic review, surgery, radiation therapy, and survivorship are described.

NCCN Guidelines Insights: Rectal Cancer, Version 6.2020

The NCCN Guidelines for Rectal Cancer provide recommendations for the diagnosis, evaluation, treatment, and follow-up of patients with rectal cancer. These NCCN Guidelines Insights summarize the panel discussion behind recent important updates to the guidelines. These updates include clarifying the definition of rectum and differentiating the rectum from the sigmoid colon; the total neoadjuvant therapy approach for localized rectal cancer; and biomarker-targeted therapy for metastatic colorectal cancer, with a focus on new treatment options for patients with BRAF V600E- or HER2 amplification-positive disease.

XAF1 as a modifier of p53 function and cancer susceptibility

Cancer risk is highly variable in carriers of the common TP53-R337H founder allele, possibly due to the influence of modifier genes. Whole-genome sequencing identified a variant in the tumor suppressor XAF1 (E134*/Glu134Ter/rs146752602) in a subset of R337H carriers. Haplotype-defining variants were verified in 203 patients with cancer, 582 relatives, and 42,438 newborns. The compound mutant haplotype was enriched in patients with cancer, conferring risk for sarcoma (P = 0.003) and subsequent malignancies (P = 0.006). Functional analyses demonstrated that wild-type XAF1 enhances transactivation of wild-type and hypomorphic TP53 variants, whereas XAF1-E134* is markedly attenuated in this activity. We propose that cosegregation of XAF1-E134* and TP53-R337H mutations leads to a more aggressive cancer phenotype than TP53-R337H alone, with implications for genetic counseling and clinical management of hypomorphic TP53 mutant carriers.

Current Approaches to Germline Cancer Genetic Testing

The prevalence of genetic predisposition to cancer is greater than initially appreciated, yet most affected individuals remain undiagnosed. Deleterious germline variants in cancer predisposition genes are implicated in 1 in 10 cases of advanced cancer. Next-generation sequencing technologies have made germline and tumor DNA sequencing more accessible and less expensive. Expanded access to clinical genetic testing will improve identification of individuals with genetic predisposition to cancer and provide opportunities to effectively reduce morbidity through precision cancer therapies and surveillance. Cross-disciplinary clinical education in genomic medicine is needed to translate advances in genomic medicine into improved health outcomes.

Epidemiology and Mechanisms of the Increasing Incidence of Colon and Rectal Cancers in Young Adults

In contrast to the decreasing incidence of colorectal cancer (CRC) in older populations, the incidence has nearly doubled in younger adults since the early 1990s. Approximately 1 in 10 new diagnoses of CRC are now made in individuals 50 years or younger. Patients' risk of CRC has been calculated largely by age and family history, yet 3 of 4 patients with early-onset CRC have no family history of the disease. Rapidly increasing incidence rates in younger people could result from generational differences in diet, environmental exposures, and lifestyle factors. We review epidemiologic trends in CRC, data on genetic and nongenetic risk factors, and new approaches for determining CRC risk. These may identify individuals likely to benefit from early screening and specialized surveillance.

Rectal Cancer, Version 2.2018, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Rectal Cancer address diagnosis, staging, surgical management, perioperative treatment, management of recurrent and metastatic disease, disease surveillance, and survivorship in patients with rectal cancer. This portion of the guidelines focuses on the management of localized disease, which involves careful patient selection for curative-intent treatment options that sequence multimodality therapy usually comprised of chemotherapy, radiation, and surgical resection.

Anal Carcinoma, Version 2.2018, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Anal Carcinoma provide recommendations for the management of patients with squamous cell carcinoma of the anal canal or perianal region. Primary treatment of anal cancer usually includes chemoradiation, although certain lesions can be treated with margin-negative local excision alone. Disease surveillance is recommended for all patients with anal carcinoma because additional curative-intent treatment is possible. A multidisciplinary approach including physicians from gastroenterology, medical oncology, surgical oncology, radiation oncology, and radiology is essential for optimal patient care.

NCCN Guidelines Insights: Colon Cancer, Version 2.2018

The NCCN Guidelines for Colon Cancer provide recommendations regarding diagnosis, pathologic staging, surgical management, perioperative treatment, surveillance, management of recurrent and metastatic disease, and survivorship. These NCCN Guidelines Insights summarize the NCCN Colon Cancer Panel discussions for the 2018 update of the guidelines regarding risk stratification and adjuvant treatment for patients with stage III colon cancer, and treatment of BRAF V600E mutation-positive metastatic colorectal cancer with regimens containing vemurafenib.

Surveillance for pancreatic cancer in high-risk individuals

Background

Surveillance of individuals at high risk of pancreatic ductal adenocarcinoma (PDAC) and its precursors might lead to better outcomes. The aim of this study was to determine the prevalence and outcomes of PDAC and high-risk neoplastic precursor lesions among such patients participating in surveillance programmes.

Methods

A multicentre study was conducted through the International CAncer of the Pancreas Screening (CAPS) Consortium Registry to identify high-risk individuals who had undergone pancreatic resection or progressed to advanced PDAC while under surveillance. High-risk neoplastic precursor lesions were defined as: pancreatic intraepithelial neoplasia (PanIN) 3, intraductal papillary mucinous neoplasia (IPMN) with high-grade dysplasia, and pancreatic neuroendocrine tumours at least 2 cm in diameter.

Results

Of 76 high-risk individuals identified in 11 surveillance programmes, 71 had undergone surgery and five had been diagnosed with inoperable PDAC. Of the 71 patients who underwent resection, 32 (45 per cent) had PDAC or a high-risk precursor (19 PDAC, 4 main-duct IPMN, 4 branch-duct IPMN, 5 PanIN-3); the other 39 patients had lesions thought to be associated with a lower risk of neoplastic progression. Age at least 65 years, female sex, carriage of a gene mutation and location of a lesion in the head/uncinate region were associated with high-risk precursor lesions or PDAC. The survival of high-risk individuals with low-risk neoplastic lesions did not differ from that in those with high-risk precursor lesions. Survival was worse among patients with PDAC. There was no surgery-related mortality.

Conclusion

A high proportion of high-risk individuals who had surgical resection for screening- or surveillance-detected pancreatic lesions had a high-risk neoplastic precursor lesion or PDAC at the time of surgery. Survival was better in high-risk individuals who had either low- or high-risk neoplastic precursor lesions compared with that in patients who developed PDAC.

Outcomes of Endoscopic Surveillance in Individuals With Genetic Predisposition to Hereditary Diffuse Gastric Cancer

BACKGROUND & AIMS

Pathogenic germline variants in CDH1 are associated with risk for diffuse gastric cancer (DGC) and lobular breast cancer. The reported high incidence of DGC and limited sensitivity of endoscopy in detection have prompted recommendation for total prophylactic gastrectomy for carriers of pathogenic or likely pathogenic (PLP) germline variants of CDH1. Multigene panel tests have identified increasing numbers of carriers of PLP variants in CDH1 who lack a family history of DGC. We evaluated outcomes of endoscopic surveillance for carriers of PLP variants of CDH1 with and without family history of DGC.

METHODS

Individuals from 13 families with germline PLP variants of CDH1 were evaluated at the Michigan Medicine Cancer Genetics Clinic from January 1998 through May 2018. Outcomes of esophagogastroduodenoscopy examinations, histopathology analyses, and surgery were compared between individuals with and without a family history of DGC.

RESULTS

We identified 20 carriers of germline CDH1 PLP variants; they underwent endoscopic examinations and/or gastrectomy. None had abnormal findings visible during endoscopy. Signet ring cell carcinoma (SRCC) was detected in 12 of 20 subjects. All but 1 of the carcinomas were tiny and confined to the lamina propria, and 1 was transmural. Seven of 12 subjects who had SRCC reported no diagnoses of DGC in first-degree relatives and did not meet established criteria for CDH1 analysis based on a 3-generation family pedigree.

CONCLUSIONS

More than half of individuals with germlines variants of CDH1 that are PLP had histopathologic evidence for DGC on endoscopy and/or gastrectomy. Family history of DGC and endoscopic findings therefore do not appear to be reliable determinants of risk of SRCC in individuals with genetic predisposition to DGC.

Genetic predisposition to colorectal cancer: syndromes, genes, classification of genetic variants and implications for precision medicine

This article reviews genes and syndromes associated with predisposition to colorectal cancer (CRC), with an overview of gene variant classification. We include updates on the application of preventive and therapeutic measures, focusing on the use of non-steroidal anti-inflammatory drugs (NSAIDs) and immunotherapy. Germline pathogenic variants in genes conferring high or moderate risk to cancer are detected in 6-10% of all CRCs and 20% of those diagnosed before age 50. CRC syndromes can be subdivided into nonpolyposis and polyposis entities, the most common of which are Lynch syndrome and familial adenomatous polyposis, respectively. In addition to known and novel genes associated with highly penetrant CRC risk, identification of pathogenic germline variants in genes associated with moderate-penetrance cancer risk and/or hereditary cancer syndromes not traditionally linked to CRC may have an impact on genetic testing, counseling, and surveillance. The use of multigene panels in genetic testing has exposed challenges in the classification of variants of uncertain significance. We provide an overview of the main classification systems and strategies for improving these. Finally, we highlight approaches for integrating chemoprevention in the care of individuals with genetic predisposition to CRC and use of targeted agents and immunotherapy for treatment of mismatch repair-deficient and hypermutant tumors. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.