Targeted screening of individuals at high risk for pancreatic cancer: results of a simulation model

A Review on Calibration Methods of Cancer Simulation Models

Calibration, a critical step in the development of simulation models, involves adjusting unobservable parameters to ensure that the outcomes of the model closely align with observed target data. This process is particularly vital in cancer simulation models with a natural history component where direct data to inform natural history parameters are rarely available. This work reviews the literature of cancer simulation models with a natural history component and identifies the calibration approaches used in these models with respect to the following attributes: calibration target, goodness-of-fit (GOF) measure, parameter search algorithm, acceptance criteria, and stopping rules. After a comprehensive search of the PubMed database from 1981 to June 2023, 68 studies were included in the review. Nearly all (n=66) articles specified the calibration targets, and most articles (n=56) specified the parameter search algorithms they used, whereas goodness-of-fit metric (n=51) and acceptance criteria/stopping rule (n=45) were reported for fewer times. The most frequently used calibration targets were incidence, mortality, and prevalence, whose data sources primarily come from cancer registries and observational studies. The most used goodness-of-fit measure was weighted mean squared error. Random search has been the predominant method for parameter search, followed by grid search and Nelder-mead method. Machine learning-based algorithms, despite their fast advancement in the recent decade, has been underutilized in the cancer simulation models. More research is needed to compare different parameter search algorithms used for calibration.

Key points

This work reviewed the literature of cancer simulation models with a natural history component and identified the calibration approaches used in these models with respect to the following attributes: calibration target, goodness-of-fit (GOF) measure, parameter search algorithm, acceptance criteria, and stopping rules.Random search has been the predominant method for parameter search, followed by grid search and Nelder-mead method.Machine learning-based algorithms, despite their fast advancement in the recent decade, has been underutilized in the cancer simulation models. Furthermore, more research is needed to compare different parameter search algorithms used for calibration.

Cost-Effectiveness Analysis of Screening for Pancreatic Cancer Among High-Risk Populations

PURPOSE

We evaluated the potential cost-effectiveness of combined magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS) screening for pancreatic ductal adenocarcinoma (PDAC) among populations at high risk for the disease.

METHODS

We used a microsimulation model of the natural history of PDAC to estimate the lifetime health benefits, costs, and cost-effectiveness of PDAC screening among populations with specific genetic risk factors for PDAC, including BRCA1 and BRCA2, PALB2, ATM, Lynch syndrome, TP53, CDKN2A, and STK11. For each high-risk population, we simulated 29 screening strategies, defined by starting age and frequency. Screening included MRI with follow-up EUS in a subset of patients. Costs of tests were based on Medicare reimbursement for MRI, EUS, fine-needle aspiration biopsy, and pancreatectomy. Cancer-related cost by stage of disease and phase of treatment was based on the literature. For each high-risk population, we performed an incremental cost-effectiveness analysis, assuming a willingness-to-pay (WTP) threshold of $100,000 US dollars (USD) per quality-adjusted life year (QALY) gained.

RESULTS

For men with relative risk (RR) 12.33 (CDKN2A) and RR 28 (STK11), annual screening was cost-effective, starting at age 55 and 40 years, respectively. For women, screening was only cost-effective for those with RR 28 (STK11), with annual screening starting at age 45 years.

CONCLUSION

Combined MRI/EUS screening may be a cost-effective approach for the highest-risk populations (among mutations considered, those with RR >12). However, for those with moderate risk (RR, 5-12), screening would only be cost-effective at higher WTP thresholds (eg, $200K USD/QALY) or with once-only screening.

The impact of pancreatic cancer screening on life expectancy: A systematic review of modeling studies

Evidence supporting the effectiveness of pancreatic cancer (PC) screening is scant. Most clinical studies concern small populations with short follow-up durations. Mathematical models are useful to estimate long-term effects of PC screening using short-term indicators. This systematic review aims to evaluate the impact of PC screening on life expectancy (LE) in model-based studies. Therefore, we searched four databases (Embase, Medline, Web-of-science, Cochrane) until 30 May 2022 to identify model-based studies evaluating the impact of PC screening on LE in different risk populations. Two authors independently screened identified papers, extracted data and assessed the methodological quality of studies. A descriptive analysis was performed and the impact of screening strategies on LE of different risk groups was reported. Our search resulted in 419 studies, of which eight met the eligibility criteria (mathematical model, PC screening, LE). Reported relative risks (RR) for PC varied from 1 to 70. In higher risk individuals (RR > 5), annual screening (by imaging with 56% sensitivity for HGD/early stage PC) predicted to increase LE of screened individuals by 20 to 260 days. In the general population, one-time PC screening was estimated to decrease LE (2-110 days), depending on the test characteristics and treatment mortality risk. In conclusion, although the models use different and sometimes outdated or unrealistic assumptions, it seems that PC screening in high-risk populations improves LE, and that this gain increases with a higher PC risk. Updated model studies, with data from large clinical trials are necessary to predict the long-term effect of PC screening more accurately.

Cost-effectiveness of pancreas surveillance: The CDKN2A-p16-Leiden cohort

BACKGROUND

CDKN2A-p16-Leiden mutation carriers have a high lifetime risk of developing pancreatic ductal adenocarcinoma (PDAC), with very poor survival. Surveillance may improve prognosis.

OBJECTIVE

To assess the cost-effectiveness of surveillance, as compared to no surveillance.

METHODS

In 2000, a surveillance program was initiated at Leiden University Medical Center with annual MRI and optional endoscopic ultrasound. Data were collected on the resection rate of screen-detected tumors and on survival. The Kaplan-Meier method and a parametric cure model were used to analyze and compare survival. Based on the surveillance and survival data from the screening program, a state-transition model was constructed to estimate lifelong outcomes.

RESULTS

A total of 347 mutation carriers participated in the surveillance program. PDAC was detected in 31 patients (8.9%) and the tumor could be resected in 22 patients (71.0%). Long-term cure among patients with resected PDAC was estimated at 47.1% (p < 0.001). The surveillance program was estimated to reduce mortality from PDAC by 12.1% and increase average life expectancy by 2.10 years. Lifelong costs increased by €13,900 per patient, with a cost-utility ratio of €14,000 per quality-adjusted life year gained. For annual surveillance to have an acceptable cost-effectiveness in other settings, lifetime PDAC risk needs to be 10% or higher.

CONCLUSION

The tumor could be resected in most patients with a screen-detected PDAC. These patients had considerably better survival and as a result annual surveillance was found to be cost-effective.

Pancreatic Tumorigenesis: Precursors, Genetic Risk Factors and Screening

Pancreatic cancer (PC) is a highly malignant and aggressive tumor. Despite medical advancement, the silent nature of PC results in only 20% of all cases considered resectable at the time of diagnosis. It is projected to become the second leading cause in 2030. Most pancreatic cancer cases are diagnosed in the advanced stages. Such cases are typically unresectable and are associated with a 5-year survival of less than 10%. Although there is no guideline consensus regarding recommendations for screening for pancreatic cancer, early detection has been associated with better outcomes. In addition to continued utilization of imaging and conventional tumor markers, clinicians should be aware of novel testing modalities that may be effective for early detection of pancreatic cancer in individuals with high-risk factors. The pathogenesis of PC is not well understood; however, various modifiable and non-modifiable factors have been implicated in pancreatic oncogenesis. PC detection in the earlier stages is associated with better outcomes; nevertheless, most oncological societies do not recommend universal screening as it may result in a high false-positive rate. Therefore, targeted screening for high-risk individuals represents a reasonable option. In this review, we aimed to summarize the pathogenesis, genetic risk factors, high-risk population, and screening modalities for PC.

Genetic testing to guide screening for pancreatic ductal adenocarcinoma: Results of a microsimulation model

BACKGROUND

First-degree relatives (FDRs) of patients with pancreatic ductal adenocarcinoma (PDAC) have elevated PDAC risk, partially due to germline genetic variants. We evaluated the potential effectiveness of genetic testing to target MRI-based screening among FDRs.

METHODS

We used a microsimulation model of PDAC, calibrated to Surveillance, Epidemiology, and End Results (SEER) data, to estimate the potential life expectancy (LE) gain of screening for each of the following groups of FDRs: individuals who test positive for each of eight variants associated with elevated PDAC risk (e.g., BRCA2, CDKN2A); individuals who test negative; and individuals who do not test. Screening was assumed to take place if LE gains were achievable. We simulated multiple screening approaches, defined by starting age and frequency. Sensitivity analysis evaluated changes in results given varying model assumptions.

RESULTS

For women, 92% of mutation carriers had projected LE gains from screening for PDAC, if screening strategies (start age, frequency) were optimized. Among carriers, LE gains ranged from 0.1 days (ATM+ women screened once at age 70) to 510 days (STK11+ women screened annually from age 40). For men, LE gains were projected for all mutation carriers, ranging from 0.2 days (BRCA1+ men screened once at age 70) to 620 days (STK11+ men screened annually from age 40). For men and women who did not undergo genetic testing, or for whom testing showed no variant, screening yielded small LE benefit (0-2.1 days).

CONCLUSIONS

Genetic testing of FDRs can inform targeted PDAC screening by identifying which FDRs may benefit.

Deep learning on time series laboratory test results from electronic health records for early detection of pancreatic cancer

The multi-modal and unstructured nature of observational data in Electronic Health Records (EHR) is currently a significant obstacle for the application of machine learning towards risk stratification. In this study, we develop a deep learning framework for incorporating longitudinal clinical data from EHR to infer risk for pancreatic cancer (PC). This framework includes a novel training protocol, which enforces an emphasis on early detection by applying an independent Poisson-random mask on proximal-time measurements for each variable. Data fusion for irregular multivariate time-series features is enabled by a "grouped" neural network (GrpNN) architecture, which uses representation learning to generate a dimensionally reduced vector for each measurement set before making a final prediction. These models were evaluated using EHR data from Columbia University Irving Medical Center-New York Presbyterian Hospital. Our framework demonstrated better performance on early detection (AUROC 0.671, CI 95% 0.667 - 0.675, p < 0.001) at 12 months prior to diagnosis compared to a logistic regression, xgboost, and a feedforward neural network baseline. We demonstrate that our masking strategy results greater improvements at distal times prior to diagnosis, and that our GrpNN model improves generalizability by reducing overfitting relative to the feedforward baseline. The results were consistent across reported race. Our proposed algorithm is potentially generalizable to other diseases including but not limited to cancer where early detection can improve survival.

Multicancer Early Detection Technologies: A Review Informed by Past Cancer Screening Studies

More than 75% of cancer-related deaths occur from cancers for which we do not screen. New screening liquid biopsies may help fill these clinical gaps, although evidence of benefit still needs to be assessed. Which lessons can we learn from previous efforts to guide those of the future? Screening trials for ovarian, prostate, pancreatic, and esophageal cancers are revisited to assess the evidence, which has been limited by small effect sizes, short duration of early-stage disease relative to screening frequency, study design, and confounding factors. Randomized controlled trials (RCT) to show mortality reduction have required millions of screening-years, two-decade durations, and been susceptible to external confounding. Future RCTs with late-stage incidence as a surrogate endpoint could substantially reduce these challenges, and clinical studies demonstrating safety and effectiveness of screening in high-risk populations may enable extrapolation to broader average-risk populations. Multicancer early detection tests provide an opportunity to advance these practical study designs. Conditional approvals based on RCTs with surrogate endpoints, contingent upon real world evidence generation and continuation of trials to definitive endpoints, may lower practical barriers to innovation in cancer screening and enable greater progress.

Identifying key factors for the effectiveness of pancreatic cancer screening: A model-based analysis

Pancreatic cancer (PC) survival is poor, as detection usually occurs late, when treatment options are limited. Screening of high‐risk individuals may enable early detection and a more favorable prognosis. Knowledge gaps prohibit establishing the effectiveness of screening. We developed a Microsimulation Screening Analysis model to analyze the impact of relevant uncertainties on the effect of PC screening in high‐risk individuals. The model simulates two base cases: one in which lesions always progress to PC and one in which indolent and faster progressive lesions coexist. For each base case, the effect of annual and 5‐yearly screening with endoscopic ultrasonography/magnetic resonance imaging was evaluated. The impact of variance in PC risk, screening test characteristics and surgery‐related mortality was evaluated using sensitivity analyses. Screening resulted in a reduction of PC mortality by at least 16% in all simulated scenarios. This reduction depended strongly on the natural disease course (annual screening: −57% for “Progressive‐only” vs −41% for “Indolent Included”). The number of screen and surveillance tests needed to prevent one cancer death was impacted most by PC risk. A 10% increase in test sensitivity reduced mortality by 1.9% at most. Test specificity is important for the number of surveillance tests. In conclusion, screening reduces PC mortality in all modeled scenarios. The natural disease course and PC risk strongly determines the effectiveness of screening. Test sensitivity seems of lesser influence than specificity. Future research should gain more insight in PC pathobiology to establish the true value of PC screening in high‐risk individuals.

What's new?

About 10 percent of pancreatic cancers occur in individuals with inherited risk factors. While screening such high‐risk individuals can facilitate the detection of precursor lesions and early‐stage cancer, the extent to which benefits outweigh harms, including overdiagnosis, remains unknown. Here, using a microsimulation model, the authors explored uncertainties concerning the early detection of pancreatic cancer and analyzed the impact of these uncertainties on the effect of screening. In all simulated scenarios, screening was associated with reduced pancreatic cancer mortality. The effectiveness of screening was most strongly impacted by characteristics of natural disease course and level of pancreatic cancer risk

A unique urinary metabolomic signature for the detection of pancreatic ductal adenocarcinoma

Our study aimed to identify a urinary metabolite panel for the detection/diagnosis of pancreatic ductal adenocarcinoma (PDAC). PDAC continues to have poor survival outcomes. One of the major reasons for poor prognosis is the advanced stage of the disease at diagnosis. Hence, identification of a novel and cost-effective biomarker signature for early detection/diagnosis of PDAC could lead to better survival outcomes. Untargeted metabolomics was employed to identify a novel metabolite-based biomarker signature for PDAC diagnosis. Urinary metabolites from 92 PDAC patients (56 discovery cohort and 36 validation cohort) were compared with 56 healthy volunteers using ¹ H nuclear magnetic resonance spectroscopy. Multivariate (partial-least squares discriminate analysis) and univariate (Mann-Whitney's U-test) analyses were performed to identify a metabolite panel which can be used to detect PDAC. The selected metabolites were further validated for their diagnostic potential using the area under the receiver operating characteristic (AUROC) curve. Statistical analysis identified a six-metabolite panel (trigonelline, glycolate, hippurate, creatine, myoinositol and hydroxyacetone), which demonstrated high potential to diagnose PDAC, with AUROC of 0.933 and 0.864 in the discovery and validation cohort, respectively. Notably, the identified panel also demonstrated very high potential to diagnose early-stage (I and II) PDAC patients with AUROC of 0.897. These results demonstrate that the selected metabolite signature could be used to detect PDAC and will pave the way for the development of a urinary test for detection/diagnosis of PDAC.

Toward the Clinical Development and Validation of a Thy1-Targeted Ultrasound Contrast Agent for the Early Detection of Pancreatic Ductal Adenocarcinoma

Early detection of pancreatic ductal adenocarcinoma (PDAC) represents the most significant step toward the treatment of this aggressive lethal disease. Previously, we engineered a preclinical Thy1-targeted microbubble (MBThy1) contrast agent that specifically recognizes Thy1 antigen overexpressed in the vasculature of murine PDAC tissues by ultrasound (US) imaging. In this study, we adopted a single-chain variable fragment (scFv) site-specific bioconjugation approach to construct clinically translatable MBThy1-scFv and test for its efficacy in vivo in murine PDAC imaging, and functionally evaluated the binding specificity of scFv ligand to human Thy1 in patient PDAC tissues ex vivo.

MATERIALS AND METHODS

We recombinantly expressed the Thy1-scFv with a carboxy-terminus cysteine residue to facilitate its thioether conjugation to the PEGylated MBs presenting with maleimide functional groups. After the scFv-MB conjugations, we tested binding activity of the MBThy1-scFv to MS1 cells overexpressing human Thy1 (MS1Thy1) under liquid shear stress conditions in vitro using a flow chamber setup at 0.6 mL/min flow rate, corresponding to a wall shear stress rate of 100 seconds, similar to that in tumor capillaries. For in vivo Thy1 US molecular imaging, MBThy1-scFv was tested in the transgenic mouse model (C57BL/6J - Pdx1-Cre; KRas; Ink4a/Arf) of PDAC and in control mice (C57BL/6J) with L-arginine-induced pancreatitis or normal pancreas. To facilitate its clinical feasibility, we further produced Thy1-scFv without the bacterial fusion tags and confirmed its recognition of human Thy1 in cell lines by flow cytometry and in patient PDAC frozen tissue sections of different clinical grades by immunofluorescence staining.

RESULTS

Under shear stress flow conditions in vitro, MBThy1-scFv bound to MS1Thy1 cells at significantly higher numbers (3.0 ± 0.8 MB/cell; P < 0.01) compared with MBNontargeted (0.5 ± 0.5 MB/cell). In vivo, MBThy1-scFv (5.3 ± 1.9 arbitrary units [a.u.]) but not the MBNontargeted (1.2 ± 1.0 a.u.) produced high US molecular imaging signal (4.4-fold vs MBNontargeted; n = 8; P < 0.01) in the transgenic mice with spontaneous PDAC tumors (2-6 mm). Imaging signal from mice with L-arginine-induced pancreatitis (n = 8) or normal pancreas (n = 3) were not significantly different between the two MB constructs and were significantly lower than PDAC Thy1 molecular signal. Clinical-grade scFv conjugated to Alexa Fluor 647 dye recognized MS1Thy1 cells but not the parental wild-type cells as evaluated by flow cytometry. More importantly, scFv showed highly specific binding to VEGFR2-positive vasculature and fibroblast-like stromal components surrounding the ducts of human PDAC tissues as evaluated by confocal microscopy.

CONCLUSIONS

Our findings summarize the development and validation of a clinically relevant Thy1-targeted US contrast agent for the early detection of human PDAC by US molecular imaging.

CA19-9 and apolipoprotein-A2 isoforms as detection markers for pancreatic cancer: a prospective evaluation

Recently, we identified unique processing patterns of apolipoprotein A2 (ApoA2) in patients with pancreatic cancer. Our study provides a first prospective evaluation of an ApoA2 isoform ("ApoA2-ATQ/AT"), alone and in combination with carbohydrate antigen 19-9 (CA19-9), as an early detection biomarker for pancreatic cancer. We performed ELISA measurements of CA19-9 and ApoA2-ATQ/AT in 156 patients with pancreatic cancer and 217 matched controls within the European EPIC cohort, using plasma samples collected up to 60 months prior to diagnosis. The detection discrimination statistics were calculated for risk scores by strata of lag-time. For CA19-9, in univariate marker analyses, C-statistics to distinguish future pancreatic cancer patients from cancer-free individuals were 0.80 for plasma taken ≤6 months before diagnosis, and 0.71 for >6-18 months; for ApoA2-ATQ/AT, C-statistics were 0.62, and 0.65, respectively. Joint models based on ApoA2-ATQ/AT plus CA19-9 significantly improved discrimination within >6-18 months (C = 0.74 vs. 0.71 for CA19-9 alone, p = 0.022) and ≤ 18 months (C = 0.75 vs. 0.74, p = 0.022). At 98% specificity, and for lag times of ≤6, >6-18 or ≤ 18 months, sensitivities were 57%, 36% and 43% for CA19-9 combined with ApoA2-ATQ/AT, respectively, vs. 50%, 29% and 36% for CA19-9 alone. Compared to CA19-9 alone, the combination of CA19-9 and ApoA2-ATQ/AT may improve detection of pancreatic cancer up to 18 months prior to diagnosis under usual care, and may provide a useful first measure for pancreatic cancer detection prior to imaging.

Chronic pancreatitis changes in high-risk individuals for pancreatic ductal adenocarcinoma

BACKGROUND AND AIMS

Pancreatic intraepithelial neoplasia is associated with chronic pancreatitis (CP) changes on EUS. The objective of this study was to determine whether CP changes were more common in high-risk individuals (HRIs) than in control subjects and whether these changes differed among higher-risk subsets of HRIs.

METHODS

HRIs and control subjects were identified from an endoscopy database. HRIs were defined as having predisposing mutations or a family history (FH) of pancreatic ductal adenocarcinoma. HRIs were classified as vHRIs who met Cancer of the Pancreas Screening (CAPS) criteria for high risk and mHRIs who did not. Multivariable logistic regression was used to adjust for confounders and CP risk factors.

RESULTS

Sixty-five HRIs (44 vHRIs, 21 mHRIs) and 118 control subjects were included. HRIs were included for FH (25), Lynch syndrome (5), Peutz-Jeghers syndrome (2), and mutations in BRCA1/2 (26), PALB2 (3), ATM (3), and CDKN2A (1). After adjustment for relevant variables, HRIs were 16 times more likely to exhibit 3 or more CP changes than control subjects (95% confidence interval, 2.6-97.0; P = .003). HRIs were also more likely to have hypoechoic foci (odds ratio, 8.0; 95% confidence interval, 1.9-32.9; P = .004). vHRIs and mHRIs did not differ in frequency of 3 or more CP changes on EUS.

CONCLUSIONS

HRIs were more likely to exhibit CP changes and hypoechoic foci on EUS compared with control subjects. HRIs with these findings may require closer surveillance. HRIs who did or did not meet CAPS criteria did not differ with regard to CP findings, supporting a more inclusive approach to screening.

Cost-effectiveness of Pancreatic Cancer Surveillance in High-Risk Individuals: An Economic Analysis

OBJECTIVE

The aim of the study was to perform an economic analysis to identify the clinical and cost determinants of pancreatic cancer (PC) surveillance in high-risk individuals (HRIs).

METHODS

A Markov model was created to compare the following 3 strategies: no screening, endoscopic ultrasound (EUS), and magnetic resonance imaging (MRI) screening. Patients were considered HRIs according to the Cancer of the Pancreas Screening consortium recommendations. Risk for developing PC, survival, and costs data were obtained from the Surveillance, Epidemiology, and End Results and Medicare databases. Surveillance effectiveness was obtained from a recent meta-analysis.

RESULTS

Analysis of a cohort with fivefold relative risk of PC higher than the US population showed that MRI is the most cost-effective strategy. For those with the highest risk (>×20 relative risk), EUS became the dominant strategy. Our model was impacted by cost and imaging performance, but still cost-effective within the range reported in literature. Threshold analysis showed that if MRI increases greater than US $1600, EUS becomes more cost-effective. Once patients reached the age of 76 years, "no screening" was favored. Both surveillance strategies were cost-effective over a wide range of willingness to pay.

CONCLUSIONS

Abdominal imaging followed by pancreatectomy is cost-effective to prevent PC in HRIs, favoring MRI in moderate risk cases but EUS in those with highest risk.

Progression to pancreatic ductal adenocarcinoma from pancreatic intraepithelial neoplasia: Results of a simulation model

OBJECTIVES

To gain insight into the natural history and carcinogenesis pathway of Pancreatic Intraepithelial Neoplasia (PanIN) lesions by building a calibrated simulation model of PanIN progression to pancreatic ductal adenocarcinoma (PDAC) METHODS: We revised a previously validated simulation model of solid PDAC, calibrating the model to fit data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program and published literature on PanIN prevalence by age. We estimated the likelihood of progression from PanIN states (1, 2, and 3) to PDAC and the time between PanIN onset and PDAC (dwell time). We evaluated a hypothetical intervention to test for and treat PanIN 3 lesions to estimate the potential benefits from PanIN detection.

RESULTS

We estimated the lifetime probability of progressing from PanIN 1 to PDAC to be 1.5% (men), 1.3% (women). Progression from PanIN 1 to PDAC took 33.6 years and 35.3 years, respectively, and from PanIN 3 to PDAC took 11.3 years and 12.3 years. A hypothetical test for PanIN 3 detection and treatment could provide a maximum, average life expectancy gain of 40 days.

CONCLUSIONS

Our modeling analysis estimates PanINs have a relatively indolent course to PDAC, supporting the feasibility of potential future early detection strategies.

Universal cancer screening: revolutionary, rational, and realizable

Cancer remains the second leading cause of mortality worldwide, and overall cancer-related deaths are increasing. Despite the survival benefit from early detection, screening has to date targeted only those few organs that harbor tumors of sufficient prevalence to show cost-effectiveness at population levels, leaving most cancer types unscreened. In this perspective overview, a case is made for universal cancer screening as a logical and more inclusive approach with potentially high impact. The centrally important conceptual drivers to universal screening are biological and epidemiological. The shared biology of tumor marker release into a common distant medium, like blood, can be exploited for multi-cancer detection from a single test. And, by aggregating prevalence rates, universal screening allows all cancers (including less common ones) to be included as targets, increases screening efficiency and integration across tumor types, and potentially improves cost-effectiveness over single-organ approaches. The identification of new tumor marker classes with both broad expression across tumor types and site-prediction, remarkable advances in assay technologies, and compelling early clinical data increase the likelihood of actualizing this new paradigm. Multi-organ screening could be achieved by targeting markers within or stemming from the circulation (including blood, urine, saliva, and expired breath) or those exfoliated into common excretory pathways (including the gastrointestinal and female reproductive tracts). Rigorous clinical studies in intended use populations and collaborations between academia, industry, professional societies, and government will be required to bring this lofty vision to a population application.

Genetics of Pancreatic Neoplasms and Role of Screening

There is a wide spectrum of pancreatic neoplasms with characteristic genetic abnormalities, tumor pathways, and histopathology that primarily determine tumor biology, treatment response, and prognosis. Although most pancreatic tumors are sporadic, 10% of neoplasms occur in the setting of distinct hereditary syndromes. Detailed studies of these rare syndromes have allowed researchers to identify a myriad of specific genetic signatures of pancreatic tumors. A better understanding of tumor genomics may have significant clinical implications in the diagnosis and management of patients with pancreatic tumors. Evolving knowledge has paved the way to screening paradigms and protocols in individuals at higher risk of developing pancreatic tumors.

Screening/surveillance programs for pancreatic cancer in familial high-risk individuals: A systematic review and proportion meta-analysis of screening results

BACKGROUND/OBJECTIVES

Screening/surveillance programs for pancreatic cancer (PC) in familial high-risk individuals (FPC-HRI) have been widely reported, but their merits remain unclear. The data reported so far are heterogeneous-especially in terms of screening yield. We performed a systematic review and meta-analysis of currently available data coming from screening/surveillance programs to evaluate the proportion of screening goal achievement (SGA), overall surgery and unnecessary surgery.

METHODS

We searched MEDLINE, Embase, PubMed and the Cochrane Library database from January 2000 to December 2016to identify studies reporting results of screening/surveillance programs including cohorts of FPC-HRI. The main outcome measures were weighted proportion of SGA, overall surgery, and unnecessary surgery among the FPC-HRI cohort, using a random effects model. SGA was defined as any diagnosis of resectable PC, PanIN3, or high-grade dysplasia intraductal papillary mucinous neoplasm (HGD-IPMN). Unnecessary surgery was defined as any other final pathology.

RESULTS

In a meta-analysis of 16 studies reporting on 1551 FPC-HRI cases, 30 subjects (1.82%), received a diagnosis of PC, PanIN3 or HGD-IPMNs. The pooled proportion of SGA was 1.4%(95% CI 0.8-2, p < 0.001, I² = 0%). The pooled proportion of overall surgery was 6%(95% CI 4.1-7.9, p < 0.001, I² = 60.91%). The pooled proportion of unnecessary surgery was 68.1%(95% CI 59.5-76.7, p < 0.001, I² = 4.05%); 105 subjects (6.3%) received surgery, and the overall number of diagnoses from non-malignant specimens was 156 (1.5 lesion/subject).

CONCLUSIONS

The weighted proportion of SGA of screening/surveillance programs published thus far is excellent. However, the probability of receiving surgery during the screening/surveillance program is non-negligible, and unnecessary surgery is a potential negative outcome.

Pancreatic cancer screening in high-risk individuals with germline genetic mutations

BACKGROUND AND AIMS

Pancreatic cancer (PC) is a deadly disease that is most commonly diagnosed at an incurable stage. Different high-risk genetic variants and cancer syndromes increase the lifetime risk of developing PC. This study aims to assess the yield of initial PC screening in patients with high-risk germline mutations.

METHODS

Asymptomatic adults underwent PC screening by EUS, magnetic resonance imaging, or CT during a 10-year period and were retrospectively identified. High-risk individuals were defined as carrying germline mutations in BRCA1, BRCA2, p53 (Li-Fraumeni), STK11 (Peutz-Jeghers), MSH2 (Lynch), ATM (ataxia-telangiectasia), or APC (familial adenomatous polyposis). Patients without germline mutations were excluded.

RESULTS

In total, 86 patients met the study criteria. The median age was 48.5 years (interquartile range, 40-58), 79.1% (68) were women, and 43.0% (37) had a family history of PC. The genetic mutations were BRCA2 (50, 58.1%), BRCA1 (14, 16.3%), p53 (12, 14.0%), STK11 (5, 5.8%), MSH2 (3, 3.5%), ATM (1, 1.2%), and APC (1, 1.2%). Screening detected a pancreatic abnormality (PA) in 26.7% (23/86), including cysts (11, 47.8%), hyperechoic strands and foci (10, 43.5%), and mild pancreatic duct dilation (2, 8.7%). Patients older than 60 years were more likely to have a PA detected (P = .043). EUS detected more PAs than magnetic resonance imaging or CT. No cases of PC were diagnosed by screening or during follow-up (median, 29.8 months; interquartile range, 21.7-43.5).

CONCLUSIONS

Unless indicated otherwise by family or personal history, PC screening under the age of 50 is low yield. Linear EUS may be the preferred modality for initial PC screening.

Imaging and Screening of Pancreatic Cancer

Given the low disease prevalence of both exocrine and endocrine cancers in the general population, screening is not recommended. However, in as many as 25% of cases there is a precursor lesion or an identifiable genetic predisposition. For these patients at increased risk, screening with imaging is recommended. Multidetector computed tomography, MR imaging or magnetic resonance cholangiopancreatography, and endoscopic ultrasound examination can be used as screening modalities. Recent advances in dual energy CT and total body MR imaging have increased the suitability of these noninvasive modalities as first-line imaging screening options.

Self-Reported Questionnaire Detects Family History of Cancer in a Pancreatic Cancer Screening Program

Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer death; approximately 5-10% of PDAC is hereditary. Self-administered health history questionnaires (HHQs) may provide a low-cost method to detail family history (FH) of malignancy. Pancreas Center patients were asked to enroll in a registry; 149 with PDAC completed a HHQ which included FH data. Patients with FH of PDAC, or concern for inherited PDAC syndrome, were separately evaluated in a Prevention Program and additionally met with a genetic counselor (GC) to assess PDAC risk (n = 61). FH obtained through GC and HHQ were compared using Wilcoxon signed-rank sum and generalized linear mixed models with Poisson distribution. Agreement between GC and HHQ risk-assessment was assessed using kappa (κ) statistic. In the Prevention Program, HHQ was as precise in detecting FH of cancer as the GC (all p > 0.05). GC and HHQ demonstrated substantial agreement in risk-stratification of the Prevention Program cohort (κ = 0.73, 95% CI 0.59-0.87.) The sensitivity of the HHQ to detect a patient at elevated risk (i.e., moderate- or high-risk) of PDAC, compared to GC, was 82.9% (95% CI 67.3-92.3%) with a specificity of 95% (95% CI 73.1-99.7%). However, seven patients who were classified as average-risk by the HHQ were found to be at an elevated-risk of PDAC by the GC. In the PDAC cohort, 30/149 (20.1%) reported at least one first-degree relative (FDR) with PDAC. The limited sensitivity of the HHQ to detect patients at elevated risk of PDAC in the Prevention Program cohort suggests that a GC adds value in risk-assessment in this population. The HHQ may offer an opportunity to identify high-risk patients in a PDAC population.

Prevention of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) accounts for 95% of all pancreatic cancers. About 230,000 PDA cases are diagnosed worldwide each year. PDA has the lowest five-year survival rate as compared to others cancers. PDA in Poland is the fifth leading cause of death after lung, stomach, colon and breast cancer. In our paper we have analysed the newest epidemiological research, some of it controversial, to establish the best practical solution for pancreatic cancer prevention in the healthy population as well as treatment for patients already diagnosed with pancreatic cancer. We found that PDA occurs quite frequently but is usually diagnosed too late, at its advanced stage. Screening for PDA is not very well defined except in subgroups of high-risk individuals with genetic disorders or with chronic pancreatitis. We present convincing, probable, and suggestive risk factors associated with pancreatic cancer, many of which are modifiable and should be introduced and implemented in our society.

Early Pancreatic Ductal Adenocarcinoma Survival Is Dependent on Size: Positive Implications for Future Targeted Screening

OBJECTIVES

Pancreatic ductal adenocarcinoma (PDAC) has not experienced a meaningful mortality improvement for the past few decades. Successful screening is difficult to accomplish because most PDACs present late in their natural history, and current interventions have not provided significant benefit. Our goal was to identify determinants of survival for early PDAC to help inform future screening strategies.

METHODS

Early PDACs from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program database (2000-2010) were analyzed. We stratified by size and included carcinomas in situ (Tis). Overall cancer-specific survival was calculated. A Cox proportional hazards model was developed and the significance of key covariates for survival prediction was evaluated.

RESULTS

A Kaplan-Meier plot demonstrated significant differences in survival by size at diagnosis; these survival benefits persisted after adjustment for key covariates in the Cox proportional hazards analysis. In addition, relatively weaker predictors of worse survival included older age, male sex, black race, nodal involvement, tumor location within the head of the pancreas, and no surgery or radiotherapy.

CONCLUSIONS

For early PDAC, we found tumor size to be the strongest predictor of survival, even after adjustment for other patient characteristics. Our findings suggest that early PDAC detection can have clinical benefit, which has positive implications for future screening strategies.

Pancreatic cancer

Pancreatic cancer is a major cause of cancer-associated mortality, with a dismal overall prognosis that has remained virtually unchanged for many decades. Currently, prevention or early diagnosis at a curable stage is exceedingly difficult; patients rarely exhibit symptoms and tumours do not display sensitive and specific markers to aid detection. Pancreatic cancers also have few prevalent genetic mutations; the most commonly mutated genes are KRAS, CDKN2A (encoding p16), TP53 and SMAD4 - none of which are currently druggable. Indeed, therapeutic options are limited and progress in drug development is impeded because most pancreatic cancers are complex at the genomic, epigenetic and metabolic levels, with multiple activated pathways and crosstalk evident. Furthermore, the multilayered interplay between neoplastic and stromal cells in the tumour microenvironment challenges medical treatment. Fewer than 20% of patients have surgically resectable disease; however, neoadjuvant therapies might shift tumours towards resectability. Although newer drug combinations and multimodal regimens in this setting, as well as the adjuvant setting, appreciably extend survival, ∼80% of patients will relapse after surgery and ultimately die of their disease. Thus, consideration of quality of life and overall survival is important. In this Primer, we summarize the current understanding of the salient pathophysiological, molecular, translational and clinical aspects of this disease. In addition, we present an outline of potential future directions for pancreatic cancer research and patient management.

Combining in Vitro Diagnostics with in Vivo Imaging for Earlier Detection of Pancreatic Ductal Adenocarcinoma: Challenges and Solutions

Pancreatic ductal adenocarcinoma (PDAC) is the fourth-leading cause of cancer-related death in the United States and is associated with a dismal prognosis, particularly when diagnosed at an advanced stage. Overall survival is significantly improved if PDAC is detected at an early stage prior to the onset of symptoms. At present, there is no suitable screening strategy for the general population. Available diagnostic serum markers are not sensitive or specific enough, and clinically available imaging modalities are inadequate for visualizing early-stage lesions. In this article, the role of currently available blood biomarkers and imaging tests for the early detection of PDAC will be reviewed. Also, the emerging biomarkers and molecularly targeted imaging agents being developed to improve the specificity of current imaging modalities for PDAC will be discussed. A strategy incorporating blood biomarkers and molecularly targeted imaging agents could lead to improved screening and earlier detection of PDAC in the future. (©) RSNA, 2015.

Screening for Pancreatic Cancer in High-risk Populations

Pancreatic adenocarcinoma is a leading cause of cancer death. Few patients are candidates for curative resection due to the late stage at diagnosis. While most pancreatic adenocarcinomas are sporadic, approximately 10% have an underlying hereditary basis. Known genetic syndromes account for only 20% of the familial clustering of pancreatic cancer cases. The majority are due to non-syndromic aggregation of pancreatic cancer cases or familial pancreatic cancer. Screening aims to identify high-risk lesions amenable to surgical resection. However, the optimal interval for screening and the management of pancreatic cancer precursor lesions detected on imaging are controversial.

Screening for Pancreatic Adenocarcinoma in BRCA2 Mutation Carriers: Results of a Disease Simulation Model

BACKGROUND

BRCA2 mutation carriers are at increased risk for multiple cancers including pancreatic adenocarcinoma (PAC). Our goal was to compare the effectiveness of different PAC screening strategies in BRCA2 mutation carriers, from the standpoint of life expectancy.

METHODS

A previously published Markov model of PAC was updated and extended to incorporate key aspects of BRCA2 mutation carrier status, including competing risks of breast- and ovarian-cancer specific mortality. BRCA2 mutation carriers were modeled and analyzed as the primary cohort for the analysis. Additional higher risk BRCA2 cohorts that were stratified according to the number of first-degree relatives (FDRs) with PAC were also analyzed. For each cohort, one-time screening and annual screening were evaluated, with screening starting at age 50 in both strategies. The primary outcome was net gain in life expectancy (LE) compared to no screening. Sensitivity analysis was performed on key model parameters, including surgical mortality and MRI test performance.

FINDINGS

One-time screening at age 50 resulted in a LE gain of 3.9 days for the primary BRCA2 cohort, and a gain of 5.8 days for those with BRCA2 and one FDR. Annual screening resulted in LE loss of 12.9 days for the primary cohort and 1.3 days for BRCA2 carriers with 1 FDR, but resulted in 20.6 days gained for carriers with 2 FDRs and 260 days gained for those with 3 FDRs. For patients with ≥ 3 FDRs, annual screening starting at an earlier age (i.e. 35-40) was optimal.

INTERPRETATION

Among BRCA2 mutation carriers, aggressive screening regimens may be ineffective unless additional indicators of elevated risk (e.g., 2 or more FDRs) are present. More clinical studies are needed to confirm these findings.

FUNDING

American Cancer Society - New England Division - Ellison Foundation Research Scholar Grant (RSG-15-129-01-CPHPS).