
==== Front
Clin Transl Gastroenterol
Clin Transl Gastroenterol
CLTG
CT9
Clinical and Translational Gastroenterology
2155-384X
Wolters Kluwer Philadelphia, PA

38147532
CTG-23-0175
10.14309/ctg.0000000000000668
00009
3
Article
Pancreas
Surveillance Outcome and Genetic Findings in Individuals at High Risk of Pancreatic Cancer
https://orcid.org/0000-0003-1044-4935
Rosner Guy MD 12
Scapa Erez MD 12erezs@tlvmc.gov.il

Ziv Tomer PhD 2ziv.bar.cons@gmail.com

Gluck Nathan MD, PhD 12nathang@tlvmc.gov.il

Ben-Yehoyada Merav PhD 12meravby@tlvmc.gov.il

1 Department of Gastroenterology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel;
2 Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Correspondence: Guy Rosner, MD. E-mail: guyr@tlvmc.gov.il.
2 2024
27 12 2023
15 2 e0066803 6 2023
08 12 2023
© 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

INTRODUCTION:

Pancreatic ductal adenocarcinoma (PDAC) has a poor 5-year survival rate. PDAC surveillance is recommended in high-risk individuals (HRIs) with strong PDAC family history or a pathogenic germline variant (PGV) in a PDAC susceptibility gene. We aimed to explore a potential correlation between genetic status, extent of family history, pancreatic findings, and surveillance implications in heterogeneous PDAC HRIs.

METHODS:

A total of 239 HRIs from 202 families were tested genetically and underwent prospective pancreatic surveillance for 6 years.

RESULTS:

The cohort was divided into 3 groups: familial pancreatic cancer (FPC; 70 individuals, 54 families), familial non-FPC (81 individuals, 73 families), and hereditary pancreatic cancer (PC) (88 individuals, 75 families). PGVs were detected in 37.6% of all families, including 11.1% of FPC families and 9.6% of familial non-FPC families. The hereditary PC group had earlier onset of PDAC compared with the other 2 groups. BRCA2 PGV carriers showed earlier onset of PDAC and pancreatic cysts. Of the 239 HRIs, PDAC was detected in 11 individuals (4.6%), with 73% diagnosed at an early stage; 4 (1.67%) had pancreatic neuroendocrine tumor; 6 (2.5%) had main-duct intraductal papillary neoplasm (IPMN); and 41 (17.15%) had side-branch IPMN. Seventeen individuals were referred to surgery, and 12 were alive at the end of the study.

DISCUSSION:

The percentage of PDAC was similar in the 3 groups studied. The hereditary PC group, and particularly BRCA2 PGV carriers, had an earlier age of PDAC onset. PGVs were detected in a significant percentage of HRIs with PC. Surveillance seems effective for detection of early-stage PDAC and precursor lesions.

KEYWORDS:

pancreatic cancer surveillance
familial pancreatic cancer
BRCA1/2
genetics
OPEN-ACCESSTRUE
SDCT
==== Body
pmcINTRODUCTION

Pancreatic cancer (PC) is the seventh leading cause of cancer death worldwide (1) and is predicted to be the second leading cause of cancer death in the United States by 2026 (2). The overall 5-year survival rate of PC is approximately 12% (3). While surgical resection and adjuvant therapy may increase 5-year survival to around 20% (4), more than 80% of patients with PC have advanced stage disease at diagnosis and are not candidates for resection (5). Approximately 90% of pancreatic cancers are pancreatic ductal adenocarcinoma (PDAC) (6). PDAC screening and surveillance may improve prognosis by detecting resectable early-stage PDAC or precursor lesions. Because of its relatively low incidence, PDAC screening is not feasible in the general population. The International Cancer of the Pancreas Screening Consortium guidelines (2013 and 2020) recommend pancreatic screening and surveillance at experienced academic pancreatic centers for PC high-risk individuals (HRIs) with a lifetime risk greater than 5% (7,8). High-risk conditions for PC include familial pancreatic cancer (FPC) and genetic causes. FPC is defined in families where 2 or more first-degree relatives (FDRs) have been diagnosed with PC. Genetic causes associated with PC risk include genes that predispose to inherited syndromes: BRCA1 and BRCA2 (BRCA1/2), STK11, Lynch syndrome (MLH1, MSH2, PMS2, MSH6 genes), CDKN2A, PALB2, ATM, APC, and PRSS1 (9–15). PDAC surveillance programs have shown increased 5-year survival rates to 25% in Europe (16) and 60% in the United States (17) in asymptomatic HRIs with screen-detected neoplasms. We followed a heterogeneous group of PC HRIs for 6 years. We aimed to identify pathogenic germline variants (PGVs) and explore a potential correlation between genetic status, extent of family history, and clinical findings.

METHODS

During a period of 6 years (recruitment during 2014 and 2015, follow-up for 6 years, until 2020–2021, respectively), 239 Jewish HRIs with PC from 202 families were prospectively followed in a tertiary academic pancreatic referral center located in Tel Aviv, Israel. This cohort study was performed after obtaining institutional review board approval and written consent from each of the individuals included in the study.

All participants were scheduled for annual clinic visits that included evaluation by 2 senior gastroenterologists and a medical geneticist. Participants completed a questionnaire that included personal and familial medical history, dietary habits, daily activities with emphasis on smoking habits, alcohol use, and physical activity. Annual laboratory testing included complete blood count, chemistry profile, HbA1C level, and cancer markers CEA and CA19-9. All participants were scheduled for annual pancreatic imaging by endoscopic ultrasound (EUS) and/or abdominal magnetic resonance imaging (MRI) + magnetic resonance cholangiopancreatography (MRCP). Timing of first imaging was planned to be from age 40 years or 10 years before the youngest PC age occurrence in the family. EUS was performed in the first 2 years, and from the third year onward, MRI + MRCP or EUS was performed. Individuals had an average of 4 clinic visits and 4 imaging procedures.

Genetic evaluation was performed in all individuals. Genomic DNA was extracted from whole blood using a dedicated kit (ArchivePure; 5 PRIME, Gaithersburg, MD) as instructed by manufacturer guidelines. The genetic analysis was performed in 2 stages. First, the entire cohort was screened for a panel of 30 BRCA1/2 founder and predominant PGVs in different Israeli ethnic groups (see Supplementary Table 1, Supplementary Digital Content 3, http://links.lww.com/CTG/B59). Individuals with a normal BRCA1/2 PGV panel result were offered more comprehensive genetic evaluation by either whole-exome sequencing (WES) or a multigene cancer panel. Multigene cancer panel testing was performed by Pronto Diagnostics in Israel. WES was performed by Centogene in Germany.

Seventy individuals were tested by multigene cancer panel, and 43 individuals were tested by WES. Multigene cancer panel and WES were performed mainly in individuals with a family history of familial PC (group 1 as described below in the results section) or familial non-FPC (group 2 as described below in the results section), in similar numbers in both groups. Only few individuals from the hereditary PC group (group 3 as described below in the results section) were tested by multigene cancer panel or WES.

Multigene cancer panel testing performed by Pronto Diagnostics is based on testing the sequence of DNA bases using next-generation technology sequencing of the coding region and its boundaries in the tested genes. The test is performed in a kit developed by Pronto Diagnostics. This kit allows simultaneous sequencing of 44 genes known to be associated with various types of hereditary cancers. The test allows the identification of point changes in the DNA sequence, including small deletion changes. In addition, large deletion and duplication changes are also tested. The run is performed on an Illumina sequencing device. The bioinformatic analysis is performed using the DDM SOPHiA software. The clinical interpretation is performed using database incidences, medical literature, and bioinformatic tools available at the time of the test. Pathogenic and suspected pathogenic changes are not verified by another method as long as they meet the defined quality standards. If findings are found deep in the intron, they are reported if they are unequivocally classified in the literature as pathogenic or suspected to be pathogenic. No polymorphic changes known to be clinically insignificant are reported. Changes defined as variants of unknown significance (VUSs) are not validated in any case; if their level of certainty is less than high, a note is added to that effect. No changes are reported with low confidence. Genomic locations are reported as hg19. The list of the genes tested includes ABRAXAS1, APC, ATM, AXIN2, BAP1, BARD1, BMPR1A, BRCA1, BRCA2, BRIP1, CDH1, CDK4, CDKN2A, CHEK2, CTNNA1, EPCAM, GALNT12, GREM1, HOXB13, MLH1, MRE11, MSH2, MSH3, MSH6, MUTYH, NBN, NF1, NTHL1, PALB2, PIK3CA, PMS2, POLD1, POLE, PTEN, RAD50, RAD51C, RAD51D, RNF43, RPS20, SMAD4, SMARCA4, STK11, P53, and XRCC2.

WES at Centogene: Genomic DNA is enzymatically fragmented, and libraries are generated by PCR-mediated addition of Illumina compatible adapters. The libraries are paired-end sequenced on an Illumina platform to yield an average coverage depth of ∼30×. Centogene's bioinformatics pipeline including read alignment to GRCh37/hg19 genome assembly, variant calling, and annotation is used. Structural variant calling is based on the DRAGEN pipeline from Illumina. All variants with minor allele frequency less than 1% in the gnomAD database and disease-causing variants reported in HGMD, in ClinVar, or in CentoMD are considered. The evaluation is focused on coding exons and flanking ±20 intronic bases; the complete gene region is interrogated for candidate variants with plausible association to the phenotype. All potential modes of inheritance patterns are considered. In addition, provided family history and clinical information are used to evaluate identified variants for their pathogenicity and causality. Variants are categorized into 5 classes (pathogenic, likely pathogenic, VUS, likely benign, benign). All variants related to the phenotype of the patient were reported. Variants of unknown significance are not reported. A specificity of >99.9% for all reported variants is warranted.

The statistical review of the study was performed by a biomedical statistician. Categorical variables were described as frequency and percentage. Continuous variables were evaluated for normal distribution using histogram and reported as mean and SD. χ2 test was used to compare categorical variables, and analysis of variance and independent samples t test were applied to compare continuous variables. All statistical tests were 2-sided, and P < 0.05 was considered as statistically significant. Statistical analysis was performed using SPSS statistical software (IBM SPSS Statistics for Windows, version 24, IBM, Armonk, NY, 2016).

RESULTS

Study groups

A total of 239 individuals from 202 families were recruited and followed. Based on family history and results from the initial BRCA1/2 PGV panel analysis, participants were divided into 3 groups. Group 1: FPC (family with 2 or more FDR with PDAC) included 70 individuals from 54 families (26.7%); group 2: familial non-FPC (family with at least 2 biological relatives with PDAC and not meeting FPC criteria, e.g., 1 FDR and at least 1 additional blood relative with PDAC or 2 second-degree relatives with PDAC) included 81 individuals from 73 families (36.1%); and group 3: hereditary PC (individuals with PGV in a PC susceptibility gene and a family member with PDAC carrying the same PGV) included 88 individuals from 75 families (37.1%). Demographic data are presented in Tables 1 and 2.

Table 1. Demographic data

	Total cohort	FPC	Familial non-FPC	Hereditary PC	
No. of patients	239	70	81	88	
Male	105	35	32	38	
Female	134	35	49	50	
Mean age (SEM)		61.3 ± 1.38	55.7 ± 1.3	53.6 ± 1.27	
Median age (SD)		62 ± 11.5	53.7 ± 11.5	52.7 ± 11.8	
Age at first visit		58 ± 1.38	52.6 ± 1.28	50.2 ± 1.24	
Positive smoking history (past or current), n (%)		25 (35.7)	30 (37)	29 (32.95)	
Type 2 diabetes mellitus, n (%)		10 (14.3)	6 (7.4)	7 (7.95)	
FPC, familial pancreatic cancer; PC, pancreatic cancer; SEM, standard error of mean.

Table 2. Study groups

Category	Definition	No. of participants (no. of families)	Percentage of the entire cohort (percentage of families)	
Group 1: FPC	Family with 2 or more FDR with PDAC	70 (54)	29.29 (26.74)	
Group 2: Familial non-FPC	Family with at least 2 biological relatives with PDAC and not meeting FPC criteria	81 (73)	33.9 (36.135)	
Group 3: Hereditary PC	BRCA2 + PDAC
BRCA1 + PDAC	50 (45)
18 (17)	28.45 (30.69)	
PJS	3 (2)	1.255 (0.99)	
HNPCC + PDAC	3 (3)	1.255 (1.485)	
ATM + PDAC	11 (5)	4.6 (2.475)	
Other pathogenic variant carriers + PDAC	3 (3)	1.255 (1.485)	
Total		239	202	
FDR, first-degree relative; FPC, familial pancreatic cancer; PC, pancreatic cancer; PDAC, pancreatic ductal adenocarcinoma.

Genetic findings

In addition to BRCA1/2 PGV panel analysis that was performed in the entire cohort, multigene cancer panel was performed in 70 individuals and WES was performed in 43 individuals. Genetic variants were found in 88 of the 202 families in our cohort (43.5%). Of these, PGVs were detected in 76 families (37.6%) while in 12 families, genetic variants were defined as VUSs or likely benign changes. We refer to the number of families and not to the number of individual carriers because in each family, there might have been more than 1 affected family member that would have falsely increased the percentage of positive genetic findings. PGVs detected are defined as either pathogenic or likely pathogenic according to American College of Medical Genetics and Genomics classification. Figure 1 shows the number of families with genetic variants that were detected. Table 3 summarizes each coding variant alongside its protein variant and interpretation of pathogenicity according to ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/), Franklin Genoox (https://www.genoox.com), and Varsome (https://varsome.com/variant/hg38) resources (last accessed on Oct 1, 2023).

Figure 1. Genetic variants. Genes with genetic variants detected in the cohort are presented on the X axis. Bars (Y axis) represent the number of families carrying variants in these genes.

Table 3. Variants detected and their interpretation

Gene variant	No. of families	Study group	ClinVar	Franklin Geenox	Varsome	Method of variant detection	
BRCA2 c.6174delT, p.Phe2058fs (rs80359550, chr13:32,340,529)	39	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	BRCA1/2 mutation panel	
BRCA2 c.8537_8538del AG (8765delAG), p.Glu2846GlyfsX22 (rs80359714, chr13:32,371,001)	1	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	BRCA1/2 mutation panel	
BRCA2 c.3847_3848del GT (4075delGT), p.Val1283Lysfs*2 (rs80359405, chr13:32,338,202-32,338,203)	1	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	BRCA1/2 mutation panel	
BRCA2 c.3187C>T, p.Gln1063fs (rs1555289789, chr13:32,337,542)	1	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	Whole-exome sequencing	
BRCA2 c.1813_1814insA, p.Ile605fs (rs80359306, chr13: 32333283–32333284)	1	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	BRCA1/2 mutation panel	
BRCA2 c. 3751dupA, p.Thr1251fs (rs397507683, chr13: 32338103–32338104)	1	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	BRCA1/2 mutation panel	
BRCA2 c.4829_4830delTG, p.Val1610fs (rs80359468, chr13: 32339182–32339183)	1	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	BRCA1/2 mutation panel	
BRCA1 c.68_69delAG (185delAG), p.Glu23fs (rs80357914, chr17: 43124028–43124029)	15	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	BRCA1/2 mutation panel	
BRCA1 c.5381_5382insC (5266dup), p.Glu1756fs (rs80357906, chr 17: 43057062–43057063)	2	Hereditary PC	Not reported	Pathogenic	Pathogenic	BRCA1/2 mutation panel	
ATM c.6228delT (6227delT), p.Leu2077fs (rs786203008, chr11: 108317401)	2	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	Whole-exome sequencing	
ATM c.6315G>C, p.Arg2105Ser (rs587780632, chr11:108,317,489)	2	Hereditary PC	Conflicting interpretations of pathogenicity	VUS	VUS	Whole-exome sequencing	
ATM c.1703G>T, p.Arg568Ile, (rs200381392, chr11:108251932)	1	Hereditary PC	Conflicting interpretations of pathogenicity	Likely benign	Likely benign	Multigene panel	
PALLD c.2285T>C, p.Ile762Thr (rs757164572, chr4:168898527)	2	Familial non-FPC	VUS	VUS	Likely benign	Whole-exome sequencing	
PALLD c.368C>T, p.Ala123Val (rs751116198, chr4: 168511872)	1	FPC	VUS	VUS	Likely benign	Whole-exome sequencing	
CDKN2A c.176T>G, p.Val59Gly (rs104894099, chr9: 21971183)	3	FPC	Pathogenic	Likely pathogenic	Likely pathogenic	Multigene panel	
MUTYH c.1187G>A, p.Gly368Asp (rs36053993, chr1: 45331556)	1	Familial non-FPC	Pathogenic	Pathogenic	Pathogenic	Whole-exome sequencing	
MUTYH c.1227_1228dupGC (1143_1144dup), p.His410fs (rs2275602, chr1: 45331431)	1	Familial non-FPC	Pathogenic	Likely pathogenic	Likely pathogenic	Multigene panel	
STK11 c.992G>A, p.Arg331Gly (rs371264852, chr19:1223056)	1	Hereditary PC	Conflicting interpretations of pathogenicity	VUS	Benign	Multigene panel	
STK11 c.290+1G>A (rs1131690950, chr 19:1207204)	1	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	Multigene panel	
MSH2 c.2634+1G>A (rs267608019, chr 2:4748087)	1	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	Multigene panel	
MSH2 c.970_971delCA, p.Gln324fs (rs63751044, chr2: 47416323)	1	Hereditary PC	Pathogenic	Pathogenic	Pathogenic	Multigene panel	
CDH1 c.1849G>A, p.Ala617Thr (rs33935154, chr16:68822138)	1	Hereditary PC	Benign	Benign	Benign	Multigene panel	
CDH1 c.2440-6C>G (rs139757930, chr16:68833284)	1	Familial non-FPC	Benign	Benign	Benign	Whole-exome sequencing	
MSR1 c.877C>T, p.Arg293fs (rs41341748, chr8:16,155,085)	1	FPC	Conflicting interpretations of pathogenicity	Pathogenic	VUS	Whole-exome sequencing	
GATA5 c.616G>C, p.Gly206Arg (rs141050743, chr20:62473486)	1	FPC	Conflicting interpretations of pathogenicity	Likely pathogenic	Likely benign	Whole-exome sequencing	
PMS2 c.1243G>A, p.Val415Met (rs138387687, chr7:5987522)	1	Hereditary PC	Conflicting interpretations of pathogenicity	VUS	Likely benign	Multigene panel	
RAD51 c.166C>T, p.Pro56Ser (rs45623838, chr15:40701142)	1	Familial non-FPC	Benign	VUS	Benign	Multigene panel	
KLLN c.197G>A, p.Arg66His (rs780478359, chr10:87862291)	1	Familial non-FPC	Not reported	VUS	VUS	Whole-exome sequencing	
PRSS1 c.292C>A, p.Gln98Lys (rs750348889, chr7:142751865)	1	Hereditary PC	Likely benign	VUS	Likely benign	Multigene panel	
CHEK2 c.1412C>T, p.Pro471Leu (rs28909981, chr22:28694081)	1	Hereditary PC	VUS	VUS	Likely benign	Whole-exome sequencing	
PC, pancreatic cancer; VUS, variant of unknown significance.

Most PGVs were found in BRCA2 (45 families) and BRCA1 (17 families), correlating with 30.7% of all families (62/202). Other genes with PGVs included ATM (5 families), PALLD (3 families), and CDKN2A (3 families). Three families had a variant in a Lynch syndrome-associated gene (2 in MSH2 and 1 in PMS2), 2 families had MUTYH variants, and 2 families had STK11 variants. Four families had a variant in breast cancer-associated genes (2 in CDH1, 1 in RAD51, and 1 in CHEK2). Four families had variants in other genes: MSR1 (1 family), GATA5 (1 family), KLLN (1 family), and PRSS1 (1 family). Most PGVs were detected in genes known as pancreatic cancer risk genes while only few PGVs were detected in genes not considered to be directly related to pancreatic cancer risk (MUTYH, CDH1, RAD51, KLLN, CHEK2).

In group 1 (FPC), 6 of the 54 families (11.1%) were found to carry a PGV. Mutated genes were MSR1, PALLD, CDKN2A, and GATA5. In group 2 (familial non-FPC), 7 of the 73 families (9.6%) were found to carry a PGV. Genetic changes were found in PALLD, MUTYH, KLLN, RAD51, and CDH1. In group 3 (hereditary PC), genetic variants were found in BRCA1, BRCA2, ATM, STK11, MSH2, CDH1, PMS2, PRSS1, and CHEK2. No correlation was detected between genetic status (PGV carriers vs non-carriers) and findings on pancreatic surveillance imaging in groups 1 and 2.

We explored whether WES enhances the genetic evaluation of HRIs with PC by detecting PGVs in genes that are not included in the multigene cancer panels. WES was performed in 43 individuals from 35 families. PGVs were detected in 11 of the 35 families (31.4%), VUS were detected in 12 families (34.3%), and 12 families (34.3%) had normal exome analysis. Genetic variants were detected in BRCA2, PALLD, and ATM and in other genes including MSR1 and GATA5 that are not included in the multigene cancer panels.

Clinical characteristics

When comparing the age of PDAC occurrence in the 3 groups (see Supplementary Figure 1, Supplementary Digital Content 1, http://links.lww.com/CTG/B57), group 3 (hereditary PC group) was found to have earlier PDAC detection compared with the other 2 groups (P = 0.07, overall interquartile range [IQR] 25%–75%, 54–84). The mean and median ages of individuals with PDAC were 69.1 and 67.4 years in group 1 (SE 2.437, IQR 25%–75%, 64–89), 60.3 and 62.3 years in group 2 (SE 1.52, IQR 25%–75%, 54–71), and 59.8 and 53.7 years in group 3 (SE 2.596, IQR 25%–75%, 52–84), respectively. In 2 individuals in the cohort, PDAC was detected at younger than 50 years, 1 in group 2 (not a PGV carrier) and 1 in group 3 (carrier of BRCA2 c.4829_4830delTG PGV). The age of PDAC diagnosis was not affected by sex (P = 0.53, female: mean 64.33, median 61.25, SE 2.09, IQR 25%–75%, 54–84; male: mean 63.98, median 64.86, SE 1.96, IQR 25%–75%, 55–78).

The mean age of pancreatic cyst detection was similar in the 3 groups: 67.8 (SE 1.741), 66.0 (SE 1.652), and 67.7 (SE 3.137) years in groups 1, 2, and 3, respectively (P = 0.965, IQR 25%–75%, 64.97–79.89). Analysis of group 3 showed that in BRCA2 PGV carriers, pancreatic cysts were detected at an earlier age (mean and median age 52.8 and 49.8 years, respectively, SE 2.021, IQR 25%–75%, 48.9–62.8), compared with individuals who were not BRCA2 carriers (mean and median age 60.0 and 60.7 years, respectively, SE 1.212, IQR 25%–75%, 53.6–70.7). These results were statistically significant (P = 0.034) (see Supplementary Figure 2, Supplementary Digital Content 2, http://links.lww.com/CTG/B58).

Table 4 presents pancreatic imaging findings (EUS and MRI + MRCP) during the 6 years of follow-up. Clinically significant imaging findings were detected in 25.9% (62/239) of HRIs: 15 cases of cancer (11 PDAC and 4 pancreatic neuroendocrine tumor [PNET]), 6 main-duct IPMN, and 41 side-branch IPMN (SB-IPMN). The percentage of significant pancreatic findings was similar in all 3 groups (P = 0.859). Seventeen individuals with clinically significant pancreatic findings were referred for surgical resection. These included 11 cases of PDAC, of which 73% were diagnosed at a localized stage (stages I and II), 4 cases of PNET, and 2 cases of main-duct IPMN with dysplastic changes (Table 5). Twelve of the 17 individuals were alive at the end of the study (6 years of follow-up). Five individuals, all with PDAC, died during follow-up. Notably, 4 of these 5 individuals were already symptomatic at their first visit and had advanced disease at the time of diagnosis (stage IIB or III, Table 5).

Table 4. Pancreatic imaging (EUS and MRI/MRCP findings)

Study group	Total no. of individuals	Side-branch IPMN	Main-duct IPMN	Chronic pancreatitis like changes	Fatty infiltration	Cancer	Total no. of findings	No. of significant findings (IPMN and cancer)	PC percentage	
Group 1: FPC	70	12	4	3	2	5 (3 PDAC, 2 PNET)	26/70 = 37.1%	21/70 = 30%	3/70 = 4.3%	
Group 2: Familial non-FPC	81	15	1	11	0	5 (5 PDAC)	32/81 = 39.5%	21/81 = 26%	5/81 = 6.2%	
Group 3: Hereditary PC	BRCA1,2 + PDAC (68)	12	1	9	1	5 (3 PDAC, 2 PNET)	28/68 = 41.2%	18/68 = 26.5%	3/68 = 4.4%	
	PJS (3)	1	0	0	0	0	1/3 = 33.3%	1/3 = 33.3%	0	
	HNPCC + PDAC (3)	1	0	1	0	0	2/3 = 66.6%	1/3 = 33.3%	0	
	Other PGV (14)	0	0	1	0	0	1/14 = 7%	0/14 = 0%	0	
EUS, endoscopic ultrasound; FPC, familial pancreatic cancer; HNPCC, hereditary nonpolyposis colon cancer; IPMN, intraductal papillary mucinous neoplasm; MRCP, magnetic resonance cholangiopancreatography; MRI, magnetic resonance imaging; PC, pancreatic cancer; PDAC, pancreatic ductal adenocarcinoma; PGV, pathogenic germline variant; PJS, Peutz-Jeghers syndrome; PNET, pancreatic neuroendocrine tumor.

Table 5. Pancreatic imaging and genetic findings of the 17 individuals referred for surgical resection

Study group	Sex	Age of PC/IPMN occurrence	No. of follow-up years before PC/IPMN	Age of death	Last EUS before PC diagnosis (yr)	Cyst detection on prior EUS	Diagnosis	Treatment	Genetic findings	
Group 1: FPC	Female	64	3	67	NA (detected on first EUS)	NA	PDAC (stage III, T3N2MO)	Whipple + folfirinox	Not found	
Female	68	<1	72	NA (detected on first EUS)	NA	PDAC (stage IB, T2N0M0)	Whipple + folfirinox	Not found	
Female	51	<1	53	NA (detected on first EUS)	NA	PDAC (stage III, T3N2MO)	Whipple + folfirinox	Not found	
Female	70	4	NA	1	NA	PNET (grade 1)	Whipple	Not found	
Female	68	2	NA	1	NA	PNET (grade 1)	Whipple	Not found	
Group 2: Familial non-FPC	Male	53	<1	56	NA (detected on first EUS)	NA	PDAC (stage IIB, T2N1M0)	Distal pancreatectomy + folfirinox	Not found	
Female	59	2	NA	1	1 cm SB-IPMN	Main duct IPMN with high grade dysplasia	Whipple	Not found	
Male	78	<1	NA	NA (detected on first EUS)	NA	PDAC (stage IB, T2N0M0)	Whipple + gemzar	Not found	
Male	71	<1	75	NA (detected on first EUS)	NA	PDAC (stage III, T3N1MO)	Whipple + gemzar	Not found	
Female	49	<1	NA	NA (detected on first EUS)	NA	PDAC (stage IIB, T1N1M0)	Whipple + folfirinox	Not found	
Group 3: Hereditary PC	Female	56	2	NA	NA (detected on first EUS)	NA	PDAC (stage IIA, T3N0M0)	Whipple + folfirinox	BRCA2 c.6174delT	
Female	64	4	NA	NA (detected on first EUS)	NA	PDAC (stage IB, T2N0M0)	Whipple + folfirinox	BRCA1 c.185delAG	
Male	55	4	NA	1	15 mm SB-IPMN	Main duct IPMN with low grade dysplasia	Whipple	BRCA2 c.6174delT	
Female	43	<1	NA	NA (detected on first EUS)	NA	PDAC (stage IB, T2N0M0)	Whipple + folfirinox	BRCA2 c.4829_4830del	
Male	53	<1	NA	NA (detected on first EUS)	NA	PNET (grade 1)	Whipple	BRCA2 c.6174delT	
Female	63	8	NA	1	NA	PNET (grade 1)	Distal pancreatectomy	BRCA2 c.6174delT	
Female	52	<1	NA	NA (detected on first EUS)	NA	PDAC (stage IIA, T3N0M0)	Whipple + folfirinox	BRCA2 c.3187C>T	
FPC, familial pancreatic cancer; IPMN, intraductal papillary mucinous neoplasm; NA, not applicable; PC, pancreatic cancer; PDAC, pancreatic ductal adenocarcinoma; PNET, pancreatic neuroendocrine tumor; SB-IPMN, side-branch intraductal papillary mucinous neoplasm.

DISCUSSION

Screening and surveillance are recommended for high-risk individuals with PC-associated genetic predisposition syndromes or a strong family PC history defined as 2 or more affected FDRs and no known germline deleterious variants in a cancer susceptibility gene. In this prospective study, heterogeneous HRIs under surveillance were divided into 3 groups to explore potential clinical differences related to genetic status and extent of family history. Individuals with FPC were enrolled to group 1, individuals with familial non-FPC (2 affected blood relatives who did not meet criteria for FPC) were enrolled to group 2, and individuals with a hereditary genetic PC syndrome were enrolled to group 3. Genetic evaluation in our cohort detected PGVs or likely PGVs in 76 of the 202 families (37.6%). Despite stronger family history in the FPC group, no major difference in PGV detection rates was found between FPC and familial non-FPC groups (11.1% and 9.6%, respectively).

Germline genetic testing using multigene cancer panels in various PDAC cohorts has identified PGVs in cancer susceptibility genes in 5%–20% of patients not selected for family history (18–22). In a cohort of 302 PDAC patients with a positive family history (FPC and familial non-FPC), Chaffee et al (15) reported 11.9% PGV carriers, with a greater prevalence of PGVs in patients with FPC compared with patients with familial non-FPC (13.5% vs 9.4%), similar to the percentages identified in the familial groups in our cohort of mainly healthy HRIs.

BRCA1 and BRCA2 (BRCA1/2) founder and predominant variants have been described in Jews (23), with an estimated prevalence of 1 in 44 for Ashkenazi Jewish individuals, compared with 1 in 286 in the general population (6). BRCA1/2 PGVs are among the most common variants identified in patients with PDAC, with prevalence as high as 7% in unselected patients and up to 17% in patients with FPC (6,24). In the Ashkenazi Jewish population, up to 20% of patients with PDAC may harbor BRCA1 or BRCA2 PGVs (25). BRCA1/2 PGVs were the most prevalent genetic finding in our cohort of HRIs and were identified in 62 of the 76 families with PGVs (81.6%). In 60 of these 62 families, BRCA1/2 PGVs were in founder and previously described predominant variants and contributed to the disproportionately high percentage of genetic variants found in our study cohort compared with other reports. A private BRCA2 genetic variant was detected in only 1 family: c.3187C>T PGV. When analyzing genetic findings without the 62 BRCA1/2 cases, a total of 14 PGVs were detected in the remaining 140 families (10%).

Comprehensive genetic testing by WES was performed in 43 individuals from 35 families and detected PGVs in 31.4% of the families tested. In addition to PGVs detected in PC susceptibility genes, PGVs were identified in genes not considered PC susceptibility genes such as CHEK2 and MUTYH and in potential susceptibility genes such as MSR1, KLLN, and GATA5 that are not usually included in the multigene cancer panels. It is unclear whether CHEK2, MUTYH, MSR1, KLLN, and GATA5 confer susceptibility to pancreatic cancer predisposition in our cohort or were bystander variants. WES, including the current platforms, does not sufficiently capture the whole exome, especially in GC-rich first exons, and it has been suggested that whole-genome sequencing, which forgoes capturing and is less sensitive to GC content, will be more likely than WES to provide complete coverage of the entire coding region of the genome and should be considered as the most comprehensive second-tier test after normal results in the multigene cancer panel test (26).

We used a stepwise genetic testing approach beginning with a panel testing for 30 BRCA1/2 pathogenic variants. Individuals having normal BRCA1/2 pathogenic variants panel results were offered additional evaluation by either multigene cancer panel testing or by WES. Although numbers are small, comparison of the 3 genetic testing approaches used in this study showed that the BRCA1/2 pathogenic variants panel had a 25.5% detection rate (61/239), the multigene cancer panel had a 18.6% detection rate (13/70), and WES had a 32.5% detection rate (14/43). In our study, WES was the most efficient approach for HRI-PDAC genetic testing, but has the limitation of being more costly than BRCA1/2 pathogenic variants panel and multigene cancer panel testing. Based on our findings, which detected PGVs in one-third of the HRIs, comprehensive genetic testing should be offered to this population.

Clinically significant findings were detected by pancreatic imaging (EUS and MRI + MRCP) in a quarter of our high-risk cohort (62/239; 25.9%), including 11 PDAC, 4 PNET, 6 main-duct IPMN, and 41 SB-IPMN. Interestingly, the hereditary PC group (group 3) had PDAC detected at a significantly earlier age than groups 1 and 2. In addition, carriers of BRCA2 PGVs had earlier onset of PDAC detection and pancreatic cyst detection compared with individuals in groups 1 and 2 and non-BRCA2 carriers in group 3. In a large PDAC surveillance study in the Netherlands, none of the BRCA2 carriers developed PDAC, which was possibly attributed to less stringent inclusion criteria (27). Power et al (28) reported that BRCA2 PGV carriers are associated with earlier onset PDAC with a mean age of 55 years at diagnosis compared with 71 years in non-BRCA1/2 PGV carrier PDAC patients. The International Cancer of the Pancreas Screening guidelines recommend initiating PC surveillance for BRCA1/2 PGV carriers between age 45 and 50 years or 10 years before the age of occurrence in the youngest affected blood relative (8) while the American Society for Gastrointestinal Endoscopy recommends initiating surveillance for BRCA1/2 PGV carriers from age 50 years or 10 years earlier than the youngest relative with pancreatic cancer (5). Based on the earlier onset of pancreatic cyst and PDAC detected in BRCA2 PGV carriers in our cohort, we recommend considering PC surveillance from age 40 years. Surveillance from this earlier age will increase the burden on resources such as EUS and MRI units, and should be considered.

During follow-up of our cohort, 4 cases of PNET were detected, 2 of them in BRCA2 carriers. Although not typically considered in the tumor spectrum of BRCA2, PGVs in BRCA2 have been described in PNET (29,30). The possible association between BRCA2 and PNET further supports the American Society for Gastrointestinal Endoscopy guidelines for PC screening in BRCA1/2 carriers, regardless of family history (5).

In this study, 17 individuals were referred for surgical resection of a malignant or premalignant pancreatic lesion (Table 5). Of these, 11 had PDACs and 4 had PNETs. The majority did not have genetic findings, emphasizing the fact that even in HRIs, other factors contribute to PDAC risk and the absence of genetics findings does not diminish the importance of surveillance. From the genetic point of view, 6 individuals (4 of the 11 PDAC, 2 of the 4 PNET) were found to be BRCA1/2 PGV carriers, providing evidence of the correlation between BRCA1/2 PGVs and the increased risk of developing pancreatic neoplasm. However, this is not in agreement with the observation made by Overbeek et al (27).

Pancreatic cysts (IPMN) were detected in 19.6% of our cohort. Data on the prevalence of pancreatic cysts in asymptomatic patient cohorts range from as low as 0.21% up to 50% depending on the methods of detection (31). Canto et al (32) reported that IPMN can be visualized in approximately 40% of FPC families while Kromrey et al (33) reported a 49.1% prevalence of pancreatic cysts in the general population, but with minimal risk of malignant transformation. In our cohort, only 2 individuals had SB-IPMN that transformed within a year to a more advanced lesion (1 main-duct IPMN and 1 PDAC). A longer follow-up period is needed to draw conclusions regarding cyst growth rate and their malignant potential in this high-risk cohort. In a long-term follow-up study of individuals at high risk of PDAC, Canto et al found PDAC and its high-grade precursor neoplasms in 7% of the cohort, which develops at a rate of 1.6% per year. Most PDAC detected during surveillance were found to be of resection potential, and 85% of these patients survived for at least 3 years (34). In our cohort, 12 of the 17 individuals who underwent resection (70.5%) survived until the end of the study.

Strengths of this study include the relatively large cohort including a substantial number of BRCA1/2 PGV carriers, genetic testing in the entire cohort including different methods of identifying germline variants, and thorough clinical follow-up. Limitations include the absence of a control group, potential selection bias associated with patients from a single academic center in a geographic region known to have a relatively high number of BRCA1/2 PGV carriers, and lack of uniformity of genetic testing where all study individuals were tested for BRCA1/2 but only 47% had more comprehensive testing by either WES or multigene cancer panel, possibly leading to variability in variant detection. Another limitation is the real-world nature of a PC high-risk center, where inclusion criteria were based on family history alone, with no formal screening period or pancreatic imaging before study entry. In a few cases, PDAC was detected at the first imaging performed, suggesting that these individuals already had PDAC at the time of enrollment. Finally, the relatively short surveillance period of 6 years might have limited the number of progressors to PDAC.

In conclusion, a significant number of HRIs were shown to have premalignant or early-stage PDAC during surveillance. The percentage of PDAC and precursor lesions was similar in all 3 high-risk groups in 6 years of follow-up. PGVs were found in one-third of the study cohort, with BRCA1/2 being the most prevalent affected genes. BRCA2 PGV carriers showed an earlier onset of PDAC and premalignant lesions, suggesting that re-evaluation of the surveillance protocol in these individuals should be considered, to include earlier onset (from age 40 years) and closer surveillance. Large multicenter studies of BRCA2 PGV carriers of different ethnicities and from different geographic locations are necessary to determine the recommended age of pancreatic surveillance onset. The addition of noninvasive surveillance modalities, such as chromatin-based liquid biopsy, is encouraged.

CONFLICTS OF INTEREST

Guarantor of the article: Guy Rosner, MD.

Specific author contributions: G.R.: planned the study, acquired, analyzed, and interpreted study data; performed clinical follow-up of the study cohort; prepared the original manuscript and the final manuscript. E.S.: acquired study data and performed clinical follow-up of the study cohort. T.Z.: analyzed and interpreted study data. N.G.: interpreted study data and prepared the original manuscript. M.B.-Y.: planned the study, acquired, analyzed, and interpreted study data. All authors reviewed the manuscript and approved the final version.

Financial support: None to report.

Competing interests: None to report.

Ethics approval: The study was approved by the Institutional Review Board of the Tel Aviv Sourasky Medical Center (IRB protocol code 0436-14-TLV approved in 2015). All participants provided informed consent for the performed genetic studies. All the procedures were performed under the Declaration of Helsinki and relevant policies.

Data availability statement: All data analyzed during this study are included in this published article.Study Highlights

WHAT IS KNOWN

✓ Pancreatic ductal adenocarcinoma (PDAC) has a poor 5-year survival rate.

✓ Screening and surveillance at experienced academic pancreatic centers is recommended for high-risk individuals with a lifetime risk of more than 5%.

✓ Surveillance programs have shown increased 5-year survival rates.

WHAT IS NEW HERE

✓ Pathogenic germline variants (PGV) were detected in 37.6% of the families tested.

✓ 25.9% of the cohort had abnormal pancreatic findings, with most cases of PDAC detected at an early stage.

✓ This is one of the largest studies of pancreatic cancer high-risk individuals carrying BRCA1/2 pathogenic germline variants.

✓ BRCA2 PGV carriers had an earlier age of onset of pancreatic precursor lesions and pancreatic cancer.

Supplementary Material

ACKNOWLEDGMENT

We thank Serena Wolchock Rosner for her contribution in the preparation and review of this manuscript.

SUPPLEMENTARY MATERIAL accompanies this paper at http://links.lww.com/CTG/B57; http://links.lww.com/CTG/B58; http://links.lww.com/CTG/B59
==== Refs
REFERENCES

1. Sung H Ferlay J Siegel RL . Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2021;71 (3 ):209–49.33538338
2. Rahib L Wehner MR Matrisian LM . Estimated projection of US cancer incidence and death to 2040. JAMA Netw Open 2021;4 :e214708.33825840
3. Siegel RL Miller KD Wagle NS . Cancer statistics, 2023. CA Cancer J Clin 2023;73 (1 ):17–48.36633525
4. Blackford AL Canto MI Klein AP . Recent trends in the incidence and survival of stage 1A pancreatic cancer: A surveillance, epidemiology, and end results analysis. J Natl Cancer Inst 2020;112 (11 ):1162–9.31958122
5. Sawhney MS Calderwood AH Thosani NC . ASGE guideline on screening for pancreatic cancer in individuals with genetic susceptibility: Summary and recommendations. Gastrointest Endosc 2022;95 (5 ):817–26.35183358
6. Stoffel EM Brand RE Goggins M . Pancreatic cancer: Changing epidemiology and new approaches to risk assessment, early detection, and prevention. Gastroenterology 2023;164 (5 ):752–65.36804602
7. Canto MI Harinck F Hruban RH . International Cancer of the Pancreas Screening (CAPS) Consortium summit on the management of patients with increased risk for familial pancreatic cancer. Gut 2013;62 (3 ):339–47.23135763
8. Goggins M Overbeek KA Brand R . Management of patients with increased risk for familial pancreatic cancer: Updated recommendations from the International Cancer of the Pancreas Screening (CAPS) Consortium. Gut 2020;69 (1 ):7–17.31672839
9. Zhen DB Rabe KG Gallinger S . BRCA1, BRCA2, PALB2, and CDKN2A mutations in familial pancreatic cancer: A PACGENE study. Genet Med 2015;17 (7 ):569–77.25356972
10. Grant RC Selander I Connor AA . Prevalence of germline mutations in cancer predisposition genes in patients with pancreatic cancer. Gastroenterology 2015;148 (3 ):556–64.25479140
11. Lin KM Shashidharan M Thorson AG . Cumulative incidence of colorectal and extracolonic cancers in MLH1 and MSH2 mutation carriers of hereditary nonpolyposis colorectal cancer. J Gastrointest Surg 1998;2 (1 ):67–71.9841970
12. Kastrinos F Mukherjee B Tayob N . Risk of pancreatic cancer in families with Lynch syndrome. JAMA 2009;302 (16 ):1790–5.19861671
13. Roberts NJ Jiao Y Yu J . ATM mutations in patients with hereditary pancreatic cancer. Cancer Discov 2012;2 (1 ):41–6.22585167
14. Roberts NJ Norris AL Petersen GM . Whole genome sequencing defines the genetic heterogeneity of familial pancreatic cancer. Cancer Discov 2016;6 (2 ):166–75.26658419
15. Chaffee KG Oberg AL McWilliams RR . Prevalence of germ-line mutations in cancer genes among pancreatic cancer patients with a positive family history. Genet Med 2018;20 (1 ):119–27.28726808
16. Vasen H Ibrahim I Ponce CG . Benefit of surveillance for pancreatic cancer in high-risk individuals: Outcome of long-term prospective follow-up studies from three European expert centers. J Clin Oncol 2016;34 (17 ):2010–9.27114589
17. Canto MI Kerdsirichairat T Yeo CJ . Surgical outcomes after pancreatic resection of screening-detected lesions in individuals at high risk for developing pancreatic cancer. J Gastrointest Surg 2020;24 (5 ):1101–10.31197699
18. Shindo K Yu J Suenaga M . Deleterious germline mutations in patients with apparently sporadic pancreatic adenocarcinoma. J Clin Oncol 2017;35 (30 ):3382–90.28767289
19. Hu C Hart SN Polley EC . Association between inherited germline mutations in cancer predisposition genes and risk of pancreatic cancer. JAMA 2018;319 (23 ):2401–9.29922827
20. Yurgelun MB Chittenden AB Morales-Oyarvide V . Germline cancer susceptibility gene variants, somatic second hits, and survival outcomes in patients with resected pancreatic cancer. Genet Med 2019;21 (1 ):213–23.29961768
21. Lowery MA Wong W Jordan EJ . Prospective evaluation of germline alterations in patients with exocrine pancreatic neoplasms. J Natl Cancer Inst 2018;110 (10 ):1067–74.29506128
22. Brand R Borazanci E Speare V . Prospective study of germline genetic testing in incident cases of pancreatic adenocarcinoma. Cancer 2018;124 (17 ):3520–7.30067863
23. Barnes-Kedar I Bernstein-Molho R Ginzach N . The yield of full BRCA1/2 genotyping in Israeli high-risk breast/ovarian cancer patients who do not carry the predominant mutations. Breast Cancer Res Treat 2018;172 (1 ):151–7.30014164
24. Wong W Raufi AG Safyan RA . BRCA mutations in pancreas cancer: Spectrum, current management, challenges and future prospects. Cancer Manag Res 2020;12 :2731–42.32368150
25. Daly MB Pal T Berry MP . Genetic/familial high-risk assessment: Breast, ovarian, and pancreatic, version 2.2021, NCCN clinical practice guidelines in oncology. J Natl Compr Canc Netw 2021;19 (1 ):77–102.33406487
26. Meienberg J Bruggmann R Oexle K . Clinical sequencing: Is WGS the better WES? Hum Genet 2016;135 (3 ):359–62.26742503
27. Overbeek KA Levink IJM Koopmann BDM . Long-term yield of pancreatic cancer surveillance in high-risk individuals. Gut 2022;71 (6 ):1152–60.33820756
28. Power R Leavy C Nolan C . Prevalence of pancreaticobiliary cancers in Irish families with pathogenic BRCA1 and BRCA2 variants. Fam Cancer 2021;20 (2 ):97–101.32918181
29. Scarpa A Chang DK Nones K . Whole-genome landscape of pancreatic neuroendocrine tumours. Nature 2017;543 (7643 ):65–71.28199314
30. Pipinikas CP Berner AM Sposito T . The evolving (epi)genetic landscape of pancreatic neuroendocrine tumours. Endocr Relat Cancer 2019;26 (9 ):R519–44.31252410
31. Zaheer A Pokharel SS Wolfgang C . Incidentally detected cystic lesions of the pancreas on CT: Review of literature and management suggestions. Abdom Imaging 2013;38 (2 ):331–41.22534872
32. Canto MI Hruban RH Fishman EK . Frequent detection of pancreatic lesions in asymptomatic high-risk individuals. Gastroenterology 2012;142 (4 ):796–804; quiz e14–5.22245846
33. Kromrey ML Bulow R Hubner J . Prospective study on the incidence, prevalence and 5-year pancreatic-related mortality of pancreatic cysts in a population-based study. Gut 2018;67 (1 ):138–45.28877981
34. Canto MI Almario JA Schulick RD . Risk of neoplastic progression in individuals at high risk for pancreatic cancer undergoing long-term surveillance. Gastroenterology 2018;155 (3 ):740–51.e2.29803839
