BRCA2 germline mutations in familial pancreatic carcinoma

Dramatic response of FOLFIRINOX regimen in a collision pancreatic adenocarcinoma patient with a germline BRCA2 mutation: a case report

Germline BRCA1 and BRCA2 mutations are the most common gene mutations in familial pancreatic adenocarcinoma. Several reports have demonstrated the utility of platinum-based chemotherapy for treating cancer patients who harbour a BRCA mutation. Here we discuss a 47-year-old Japanese female with no relevant past history who presented with epigastralgia and fever in September 2016. A computed tomography scan revealed a low-density, low-enhanced tumour 15 mm in diameter in the head of the pancreas. The pathological diagnosis was a ductal pancreatic carcinoma. A 6 mm low-enhanced metastatic tumour was also detected in segment 4 of the liver. Because she had early onset of the disease and a family history-her mother died of pancreatic adenocarcinoma at age 48-we considered a diagnosis of familial pancreatic adenocarcinoma. She received modified FOLFIRINOX. Two months after starting chemotherapy, she was diagnosed with an invasive ductal carcinoma in the right breast. FOLFIRINOX was continued for 8 cycles (4 months); the primary pancreatic adenocarcinoma shrank and the liver metastatic foci disappeared, but the size of the breast tumour increased. Total right breast excision and sentinel lymph node dissection were performed. FOLFIRINOX was continued and after 12 cycles (6 months), both her pancreatic adenocarcinoma and liver metastasis were no longer visible using imaging. Pancreatoduodenectomy was performed and the primary tumour had shrunk to 2.5 mm. Genetic testing revealed a germline BRCA2 mutation. The FOLFIRINOX regimen showed dramatic effects on the collision pancreatic but not on the breast cancer.

Murine models for familial pancreatic cancer: Histopathology, latency and drug sensitivity among cancers of Palb2, Brca1 and Brca2 mutant mouse strains

Alterations of the PALB2 tumor suppressor gene have been identified in familial breast, ovarian and pancreatic cancer cases. PALB2 cooperates with BRCA1/2 proteins through physical interaction in initiation of homologous recombination, in maintenance of genome integrity following DNA double-strand breaks. To determine if the role of PALB2 as a linker between BRCA1 and BRCA2 is critical for BRCA1/2-mediated tumor suppression, we generated Palb2 mouse pancreatic cancer models and compared tumor latencies, phenotypes and drug responses with previously generated Brca1/2 pancreatic cancer models. For development of Palb2 pancreatic cancer, we crossed conditional Palb2 null mouse with mice carrying the Kras^G12D; p53^R270H; Pdx1-Cre (KPC) constructs, and these animals were observed for pancreatic tumor development. Individual deletion of Palb2, Brca1 or Brca2 genes in pancreas per se using Pdx1-Cre was insufficient to cause tumors, but it reduced pancreata size. Concurrent expression of mutant Kras^G12D and p53^R270H, with tumor suppressor inactivated strains in Palb2-KPC, Brca1-KPC or Brca2-KPC, accelerated pancreatic ductal adenocarcinoma (PDAC) development. Moreover, most Brca1-KPC and some Palb2-KPC animals developed mucinous cystic neoplasms with PDAC, while Brca2-KPC and KPC animals did not. 26% of Palb2-KPC mice developed MCNs in pancreata, which resemble closely the Brca1 deficient tumors. However, the remaining 74% of Palb2-KPC animals developed PDACs without any cysts like Brca2 deficient tumors. In addition, the number of ADM lesions and immune cells infiltrations (CD3⁺ and F/480⁺) were significantly increased in Brca1-KPC tumors, but not in Brca2-KPC tumors. Interestingly, the level of ADM lesions and infiltration of CD3⁺ or F/480⁺ cells in Palb2-KPC tumors were intermediate between Brca1-KPC and Brca2-KPC tumors. As expected, disruption of Palb2 and Brca1/2 sensitized tumor cells to DNA damaging agents in vitro and in vivo. Altogether, Palb2-KPC PDAC exhibited features observed in both Brca1-KPC and Brca2-KPC tumors, which could be due to its role, as a linker between Brca1 and Brca2.

Eastern Canadian Gastrointestinal Cancer Consensus Conference 2018

The annual Eastern Canadian Gastrointestinal Cancer Consensus Conference was held in Halifax, Nova Scotia, 20-22 September 2018. Experts in radiation oncology, medical oncology, surgical oncology, and pathology who are involved in the management of patients with gastrointestinal malignancies participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses multiple topics in the management of pancreatic cancer, pancreatic neuroendocrine tumours, hepatocellular cancer, and rectal and colon cancer, including ■ surgical management of pancreatic adenocarcinoma,■ adjuvant and metastatic systemic therapy options in pancreatic adenocarcinoma,■ the role of radiotherapy in the management of pancreatic adenocarcinoma,■ systemic therapy in pancreatic neuroendocrine tumours,■ updates in systemic therapy for patients with advanced hepatocellular carcinoma,■ optimum duration of adjuvant systemic therapy for colorectal cancer, and■ sequence of therapy in oligometastatic colorectal cancer.

Pharmacogenetic and pharmacogenomic discovery strategies

Genetic/genomic profiling at a single-patient level is expected to provide critical information for determining inter-individual drug toxicity and potential efficacy in cancer therapy. A better definition of cancer subtypes at a molecular level, may correspondingly complement such pharmacogenetic and pharmacogenomic approaches, for more effective personalized treatments. Current pharmacogenetic/pharmacogenomic strategies are largely based on the identification of known polymorphisms, thus limiting the discovery of novel or rarer genetic variants. Recent improvements in cost and throughput of next generation sequencing (NGS) are now making whole-genome profiling a plausible alternative for clinical procedures. Beyond classical pharmacogenetic/pharmacogenomic traits for drug metabolism, NGS screening programs of cancer genomes may lead to the identification of novel cancer-driving mutations. These may not only constitute novel therapeutic targets, but also effector determinants for metabolic pathways linked to drug metabolism. An additional advantage is that cancer NGS profiling is now leading to discovering targetable mutations, e.g., in glioblastomas and pancreatic cancers, which were originally discovered in other tumor types, thus allowing for effective repurposing of active drugs already on the market.

The Role of BRCA Testing in Hereditary Pancreatic and Prostate Cancer Families

Beyond breast and ovarian cancers, mutations in the BRCA1 and BRCA2 genes increase risks for pancreatic and prostate cancers and contribute to the prevalence of these cancers. Mutations in a number of other genes have also been shown to increase the risk for these cancers as well. Genetic testing is playing an increasingly important role in the treatment of patients with pancreatic and prostate cancer and is now recommended for all patients with pancreatic or metastatic prostate cancer, as well as patients with high Gleason grade prostate cancer and a remarkable family history. Identification of an inherited mutation can direct evaluation of the patient for other cancer risks as well as identification and management of disease in at-risk relatives. Growing evidence suggests improved responses to PARP inhibitors and other therapies in patients with mutations in the BRCA and other DNA repair genes. Although more work must be done to clarify the prevalence and penetrance of mutations in genes other than BRCA1 and BRCA2 in patients with pancreatic and prostate cancer, in most cases, testing is now being done with a panel of multiple genes. Because of the complexities in panel testing and the increased likelihood of finding variants of uncertain significance, pre- and post-test genetic counseling are essential.

Epidemiology of Pancreatic Cancer: Global Trends, Etiology and Risk Factors

Pancreatic cancer is the seventh leading cause of cancer-related deaths worldwide. However, its toll is higher in more developed countries. Reasons for vast differences in mortality rates of pancreatic cancer are not completely clear yet, but it may be due to lack of appropriate diagnosis, treatment and cataloging of cancer cases. Because patients seldom exhibit symptoms until an advanced stage of the disease, pancreatic cancer remains one of the most lethal malignant neoplasms that caused 432,242 new deaths in 2018 (GLOBOCAN 2018 estimates). Globally, 458,918 new cases of pancreatic cancer have been reported in 2018, and 355,317 new cases are estimated to occur until 2040. Despite advancements in the detection and management of pancreatic cancer, the 5-year survival rate still stands at 9% only. To date, the causes of pancreatic carcinoma are still insufficiently known, although certain risk factors have been identified, such as tobacco smoking, diabetes mellitus, obesity, dietary factors, alcohol abuse, age, ethnicity, family history and genetic factors, Helicobacter pylori infection, non-O blood group and chronic pancreatitis. In general population, screening of large groups is not considered useful to detect the disease at its early stage, although newer techniques and the screening of tightly targeted groups (especially of those with family history), are being evaluated. Primary prevention is considered of utmost importance. Up-to-date statistics on pancreatic cancer occurrence and outcome along with a better understanding of the etiology and identifying the causative risk factors are essential for the primary prevention of this disease.

Genomic Features and Clinical Management of Patients with Hereditary Pancreatic Cancer Syndromes and Familial Pancreatic Cancer

Pancreatic cancer (PC) is one of the most devastating malignancies; it has a 5-year survival rate of only 9%, and novel treatment strategies are urgently needed. While most PC cases occur sporadically, PC associated with hereditary syndromes or familial PC (FPC; defined as an individual having two or more first-degree relatives diagnosed with PC) accounts for about 10% of cases. Hereditary cancer syndromes associated with increased risk for PC include Peutz-Jeghers syndrome, hereditary pancreatitis, familial atypical multiple mole melanoma, familial adenomatous polyposis, Lynch syndrome and hereditary breast and ovarian cancer syndrome. Next-generation sequencing of FPC patients has uncovered new susceptibility genes such as PALB2 and ATM, which participate in homologous recombination repair, and further investigations are in progress. Previous studies have demonstrated that some sporadic cases that do not fulfil FPC criteria also harbor similar mutations, and so genomic testing based on family history might overlook some susceptibility gene carriers. There are no established screening procedures for high-risk unaffected cases, and it is not clear whether surveillance programs would have clinical benefits. In terms of treatment, poly (ADP-ribose) polymerase inhibitors for BRCA-mutated cases or immune checkpoint inhibitors for mismatch repair deficient cases are promising, and clinical trials of these agents are underway.

Are BRCA1 and BRCA2 gene mutation patients underscreened for pancreatic adenocarcinoma?

BACKGROUND

Breast cancer (BRCA) mutations account for the highest proportion of hereditary causes of pancreatic ductal adenocarcinoma (PDAC). Screening is currently recommended only for patients with one first-degree relative or two family members with PDAC. We hypothesized that screening all BRCA1/2 patients would identify a higher rate of pancreatic abnormalities.

METHODS

All BRCA1/2 patients at a single academic center were retrospectively reviewed (2005-2015). Pancreatic abnormalities were defined on cross-sectional imaging as pancreatic neoplasm (cystic/solid) or main-duct dilation.

RESULTS

Two hundred and four patients were identified with BRCA mutations. Forty-seven (40%) had abdominal imaging (20 computerized tomography and 27 magnetic resonance imaging). Twenty-one percent had pancreatic abnormalities (PDAC [n = 2] and intraductal papillary mucinous neoplasm [IPMN; n = 8]). The prevalence of pancreatic abnormalities and IPMN was higher in BRCA2 patients than in the general population (21% vs 8% and 17% vs 1%; P = 0.0007 and P < 0.0001, respectively), with no influence of family history. Similarly, BRCA1 patients had an increased prevalence of IPMN (8.3% vs 1%; P < 0.0001).

CONCLUSIONS

In this series, 4% and 17% of BRCA2 patients developed PDAC and IPMN, respectively. Eight percent of BRCA1 patients developed IPMN. Under current recommended screening, 60% of BRCA1/2 patients had incompletely pancreatic assessment. With no influence of family history, this study suggests all BRCA1/2 patients should undergo a high-risk screening protocol that will identify a higher rate of precancerous pancreatic neoplasms amenable to curative resection.

Evaluating Susceptibility to Pancreatic Cancer: ASCO Provisional Clinical Opinion

Purpose

An ASCO provisional clinical opinion (PCO) offers timely clinical direction to ASCO’s membership and other health care providers. This PCO addresses identification and management of patients and family members with possible predisposition to pancreatic adenocarcinoma.

Methods

ASCO convened an Expert Panel and conducted a systematic review of the literature published from January 1998 to June 2018. Results of the databases searched were supplemented with hand searching of the bibliographies of systematic reviews and selected seminal articles and contributions from Expert Panel members’ curated files.

Provisional Clinical Opinion

All patients diagnosed with pancreatic adenocarcinoma should undergo assessment of risk for hereditary syndromes known to be associated with an increased risk for pancreatic adenocarcinoma. Assessment of risk should include a comprehensive review of family history of cancer. Individuals with a family history of pancreatic cancer affecting two first-degree relatives meet criteria for familial pancreatic cancer (FPC). Individuals (cancer affected or unaffected) with a family history of pancreatic cancer meeting criteria for FPC, those with three or more diagnoses of pancreatic cancer in same side of the family, and individuals meeting criteria for other genetic syndromes associated with increased risk for pancreatic cancer have an increased risk for pancreatic cancer and are candidates for genetic testing. Germline genetic testing for cancer susceptibility may be discussed with individuals diagnosed with pancreatic cancer, even if family history is unremarkable. Benefits and limitations of pancreatic cancer screening should be discussed with individuals whose family history meets criteria for FPC and/or genetic susceptibility to pancreatic cancer. Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines .

The association between non-breast and ovary cancers and BRCA mutation in first- and second-degree relatives of high-risk breast cancer patients: a large-scale study of Koreans

Background

As a large-scale study of Koreans, we evaluated the association between BRCA mutation and the prevalence of non-breast and ovary cancers in first- and second-degree relatives of high-risk breast cancer patients.

Methods

We organized familial pedigrees of 2555 patients with breast cancer who underwent genetic screening for BRCA1/2 in Samsung Medical Center between January 2002 and May 2018. Families with a member that had a history of cancer other than of the breast or ovary were regarded positive for other primary cancer.

Results

The median age of the population was 40 years (range, 19 to 82 years). BRCA mutation was detected in 377 (14.8%) of the patients. The BRCA-positive group had a higher frequency of family history of breast or ovarian cancer (p <  0.001), bilateral breast cancer (p = 0.021), and the male gender (p = 0.038). There were 103 (27.3%) patients who had multiple risk factors in the BRCA-positive group, while there were 165 (7.6%) patients who had multiple risk factors in the BRCA-negative group (p <  0.001). BRCA mutation was detected in 215 (11.7%) of the 1841 families without history of other primary cancers. Among the 714 families with histories of other primary cancers, 162 (22.7%) had BRCA mutation, and this was significantly more frequent (p < 0.001) than in those without a history. The occurrence of other primary cancers in families of high-risk patients was associated with a younger age at diagnosis (p = 0.044), bilateral breast cancer (p = 0.006), and BRCA mutations (p < 0.001). The most common site for the occurrence of another type of primary cancer was the stomach. In the BRCA-positive group, the proportional incidences of stomach, pancreas, colorectal, lung, and uterine cancer were 13.8, 4.0, 7.7, 8.8, and 5.0%, respectively; these were all relatively higher than those in the BRCA-negative group.

Conclusions

We confirmed that BRCA mutation was associated with having multiple risk factors and an increased prevalence of non-breast and ovary cancers in first- and second-degree relatives of high-risk breast cancer patients. Due to the possibility of inherited cancer risk, genetic counseling with options for risk assessment and management should be provided to both patients and families of BRCA mutation carriers.

Talking Genes in Breast and Pancreatic Malignancies

Introduction:

Both breast and pancreatic cancers have high mortality rates. Breast cancer is the second leading cause of cancer death in females, while pancreatic ductal adenocarcinoma (PDAC) is the fourth most common cause of cancer death. Almost 4-16 % of individuals with pancreatic cancer have a family history of the disease. Intra-ductal papillary mucinous neoplasms (IPMNs) are cystic lesions that received more attention lately due to their associations with PDAC and other solid organ tumors, such as breast cancer.

Aim:

The purpose of this article is to discuss the association of the familiar pancreatic cancer (FPC), sporadic pancreatic cancer, and IPMNs with the breast cancer.

Results:

Mutations in BRCA2, BRCA1, p16 and PALB2 play a major role in the genetic etiologies of familial pancreatic cancer. In familial and sporadic pancreatic cancers, mutations in BRCA2 are associated with a high incidence of PDAC, while mutations in BRCA1have shown inconsistent results. Data is insufficient to prove an association between IPMNs and breast cancer.

Conclusion:

The familial clustering of PDAC is not well understood. Further studies are required for greater comprehension of the genetic basis of PDAC and the association between IPMNs and breast cancer.

Screening and surveillance in hereditary gastrointestinal cancers: Recommendations from the European Society of Digestive Oncology (ESDO) expert discussion at the 20th European Society for Medical Oncology (ESMO)/World Congress on Gastrointestinal Cancer, Barcelona, June 2018

Patients with hereditary gastrointestinal (GI) cancers represent a substantial fraction of the overall affected population. Although awareness for hereditary GI cancer syndromes is on the rise, identification of patients and measures of surveillance are often unclear in everyday clinical routine. Therefore, the European Society of Digestive Oncology expert discussion 2018 at the World Congress on Gastrointestinal Cancer focussed on screening and surveillance of hereditary colorectal, gastric and pancreatic cancers. An international panel of experts and opinion leaders developed the here presented recommendations based on published evidence and on profound clinical expertise to facilitate clinical routine in identification and caretaking of patients with familial GI cancers.

Germline Variants and Risk for Pancreatic Cancer: A Systematic Review and Emerging Concepts

Pancreatic cancer requires many genetic mutations. Combinations of underlying germline variants and environmental factors may increase the risk of cancer and accelerate the oncogenic process. We systematically reviewed, annotated, and classified previously reported pancreatic cancer-associated germline variants in established risk genes. Variants were scored using multiple criteria and binned by evidence for pathogenicity, then annotated with published functional studies and associated biological systems/pathways. Twenty-two previously identified pancreatic cancer risk genes and 337 germline variants were identified from 97 informative studies that met our inclusion criteria. Fifteen of these genes contained 66 variants predicted to be pathogenic (APC, ATM, BRCA1, BRCA2, CDKN2A, CFTR, CHEK2, MLH1, MSH2, NBN, PALB2, PALLD, PRSS1, SPINK1, TP53). Pancreatic cancer risk genes were organized into key biological mechanisms that promote pancreatic oncogenesis within an oncogenic model. Development of precision medicine approaches requires updated variant information within the framework of an oncogenic progression model. Complex risk modeling may improve interpretation of early biomarkers and guide pathway-specific treatment for pancreatic cancer in the future. Precision medicine is within reach.

Genetic Alterations of Periampullary and Pancreatic Ductal Adenocarcinoma: An Overview

Pancreatic Ductal AdenoCarcinoma (PDAC) is one of the most lethal malignancies of all solid cancers. Precancerous lesions for PDAC include PanIN, IPMNs and MCNs. PDAC has a poor prognosis with a 5-year survival of approximately 6%. Whereas Periampulary AdenoCarcinoma (PAC) having four anatomic subtypes, pancreatic, Common Bile Duct (CBD), ampullary and duodenum shows relative better prognosis. The highest incidence of PDAC has been reported with black with respect to white population. Similarly, incidence rate of PAC also differs with different ethnic populations. Several lifestyle, environmental and occupational exposures including long-term diabetes, obesity, and smoking, have been linked to PDAC, however, for PAC the causal risk factors were poorly described. It is now clear that PDAC and PAC are a multi-stage process resulting from the accumulation of genomic alterations in the somatic DNA of normal cells as well as inherited mutations. Approximately 10% of PDAC have a familial inheritance. Germline mutations in CDKN2A, BRCA2, STK11, PALB2, PRSS1, etc., as well as certain syndromes have been well associated with predisposition to PDAC. KRAS, CDKN2A, TP53 and SMAD4 are the 4 "mountains" (high-frequency driver genes) which have been known to earliest somatic alterations for PDAC while relatively less frequent in PAC. Our understanding of the molecular carcinogenesis has improved in the last few years due to extensive research on PDAC which was not well explored in case of PAC. The genetic alterations that have been identified in PDAC and different subgroups of PAC are important implications for the development of genetic screening test, early diagnosis, and prognostic genetic markers. The present review will provide a brief overview of the incidence and prevalence of PDAC and PAC, mainly, increased risk in India, the several kinds of risk factors associated with the diseases as well as required genetic alterations for disease initiation and progression.

Pancreatic cancer as a sentinel for hereditary cancer predisposition

BACKGROUND

Genes associated with hereditary breast and ovarian cancer (HBOC) and colorectal cancer (CRC) predisposition have been shown to play a role in pancreatic cancer susceptibility. Growing evidence suggests that pancreatic cancer may be useful as a sentinel cancer to identify families that could benefit from HBOC or CRC surveillance, but to date pancreatic cancer is only considered an indication for genetic testing in the context of additional family history.

METHODS

Preliminary data generated at the Huntsman Cancer Hospital (HCH) included variants identified on a custom 34-gene panel or 59-gene panel including both known HBOC and CRC genes for respective sets of 66 and 147 pancreatic cancer cases, unselected for family history. Given the strength of preliminary data and corresponding literature, 61 sequential pancreatic cancer cases underwent a custom 14-gene clinical panel. Sequencing data from HCH pancreatic cancer cases, pancreatic cancer cases of the Cancer Genome Atlas (TCGA), and an unselected pancreatic cancer screen from the Mayo Clinic were combined in a meta-analysis to estimate the proportion of carriers with pathogenic and high probability of pathogenic variants of uncertain significance (HiP-VUS).

RESULTS

Approximately 8.6% of unselected pancreatic cancer cases at the HCH carried a variant with potential HBOC or CRC screening recommendations. A meta-analysis of unselected pancreatic cancer cases revealed that approximately 11.5% carry a pathogenic variant or HiP-VUS.

CONCLUSION

With the inclusion of both HBOC and CRC susceptibility genes in a panel test, unselected pancreatic cancer cases act as a useful sentinel cancer to identify asymptomatic at-risk relatives who could benefit from relevant HBOC and CRC surveillance measures.

Defects in homologous recombination repair genes are associated with good prognosis and clinical sensitivity to DNA-damaging agents in pancreatic cancer: A case report

Tumor genome sequencing is important for increasing our understanding of the development of cancer, which may be affected by different therapies. In the present study, genomic evolution was investigated in a patient with stage IV pancreatic cancer bearing a germline breast cancer 2 (BRCA2) mutation. The patient received cisplatin, a DNA cross-linking agent, which led to a long-lasting complete response. Eventually the patient developed brain metastasis, suggesting the acquisition of resistance to cisplatin. He subsequently underwent brain lesion resection, radiofrequency ablation and chemotherapy, again resulting in long-lasting response. Samples of blood, pancreatic tumor tissue and brain metastases were collected and the extracted DNA was sequenced. The pancreatic and brain lesions, when compared with the blood samples, exhibited mutations in the BRCA1 and checkpoint kinase 2 genes, in addition to the germline BRCA2 mutation. The brain lesion, when compared with the primary tumor, harbored no additional mutations or copy-number variations. These findings suggest that the isolated relapse in the brain was due to pharmacological sanctuary rather than genomic alterations. It may be suggested that the presence of defects in the homologous recombination repair pathways are associated with a good prognosis and clinical sensitivity to agents that damage the DNA in pancreatic cancer.

Endoscopic Ultrasound-Based Pancreatic Cancer Screening of High-Risk Individuals: A Prospective Observational Trial

OBJECTIVES

Pancreatic cancer (PC), a common cause of cancer death, is rarely diagnosed at an early stage. Early detection of PC may improve outcomes in affected patients. This study evaluated the utility of screening of high-risk individuals (HRIs) using an endoscopic ultrasound (EUS)-only approach to detect early malignant changes.

METHODS

A prospective PC screening program for HRIs was opened in 2007. Fifty-eight patients have enrolled to date. Patients with normal EUS examinations underwent repeat EUS annually for 5 years. Patients with abnormal EUS underwent fine-needle aspiration (FNA) if a mass/cyst 1 cm or longer was found. Those with cysts/mass shorter than 1 cm or benign FNA underwent repeat EUS in 3 months. If unchanged, patients were followed with magnetic resonance imaging.

RESULTS

Thirty-nine patients (67%) had initial normal EUS examinations, and 16 patients completed the 5-year trial. Five patients who initially had a normal EUS developed cysts on subsequent examinations. Of the 24 subjects (41%) with abnormal findings, 3 underwent FNA: 2 consistent with intraductal papillary mucinous neoplasm, 1 with benign cytology. The 21 remaining patients had 1 subcentimeter cyst or more followed by magnetic resonance imaging. No PCs have been detected.

CONCLUSIONS

Precancerous cysts are frequently detected with EUS in HRI. Whether screening impacts survival in HRIs remains unclear and requires further evaluation in larger multicenter trials.

Antimicrobial Peptide Human Neutrophil Peptide 1 as a Potential Link Between Chronic Inflammation and Ductal Adenocarcinoma of the Pancreas

OBJECTIVES

Defensins are antimicrobial peptides playing a role in innate immunity, in epithelial cell regeneration, and in carcinogenesis of inflammation-triggered malignancies. We analyzed this role in pancreatic ductal adenocarcinoma (PDAC) in the context of its association with chronic pancreatitis (CP).

METHODS

Human tissue of healthy pancreas, CP, and PDAC was screened for defensins by immunohistochemistry. Defensin α 1 (human neutrophil peptide 1 [HNP-1]) expression was validated using mass spectrometry and microarray analysis. Human neutrophil peptide 1 expression and influences of proinflammatory cytokines (tumor necrosis factor α, interleukin 1β, and interferon γ) were studied in human pancreatic cancer cells (Colo 357, T3M4, PANC-1) and normal human pancreatic duct epithelial cells (HPDE).

RESULTS

Accumulation of HNP-1 in malignant pancreatic ductal epithelia was seen. Spectrometry showed increased expression of HNP-1 in CP and even more in PDAC. At RNA level, no significant regulation was found. In cancer cells, HNP-1 expression was significantly higher than in HPDE. Proinflammatory cytokines significantly led to increased HNP-1 levels in culture supernatants and decreased levels in lysates of cancer cells. In HPDE cytokines significantly decreased HNP-1 levels.

CONCLUSIONS

Inflammatory regulation of HNP-1 in PDAC tissue and cells indicates that HNP-1 may be a link between chronic inflammation and malignant transformation in the pancreas.

Germline mutation prevalence in individuals with pancreatic cancer and a history of previous malignancy

BACKGROUND

Approximately 10% of pancreatic adenocarcinoma (PC) cases are attributed to hereditary causes. Individuals with PC and a personal history of another cancer associated with hereditary breast and ovarian cancer (HBOC) or Lynch syndrome (LS) may be more likely to carry germline mutations.

METHODS

Participants with PC and a history of cancer were selected from a pancreatic disease registry. Of 1296 individuals with PC, 149 had a relevant history of cancer. If banked DNA was available, a multigene panel was performed for individuals who had not 1) previously had a mutation identified through clinical testing or 2) undergone clinical multigene panel testing with no mutations detected.

RESULTS

Twenty-two of 124 individuals with PC and another HBOC- or LS-related cancer who underwent genetic testing had a mutation identified in a PC susceptibility gene (18%). If prostate cancer is excluded, the mutation prevalence increased to 23% (21/93). Mutation carriers were more likely to have more than 1 previous cancer diagnosis (P = .001), to have had clinical genetic testing (P = .001), and to meet National Comprehensive Cancer Network (NCCN) genetic testing criteria (P < .001). Approximately 23% of mutation carriers did not meet NCCN HBOC or LS testing guidelines based on their personal cancer history and reported cancer history in first-degree relatives.

CONCLUSION

At least 18% of individuals with PC and a personal history of other HBOC- or LS-related cancers carry mutations in a PC susceptibility gene based on our data, suggesting that criteria for genetic testing in individuals with PC should include consideration of previous cancer history. Cancer 2018;124:1691-700. © 2018 American Cancer Society.

Germline mutations in Japanese familial pancreatic cancer patients

Clinicopathologic and genetic features of familial pancreatic cancer (FPC) in Asian countries remain largely unknown. The main purpose of this study was to determine the prevalence of FPC and to define causative FPC-predisposition genes in a Japanese cohort with pancreatic ductal adenocarcinoma (PDAC).We reviewed 1,197 patients with a pathologically proven PDAC and found that 88 (7.3%) were FPC patients who had at least one first-degree relative with PDAC. There were no significant differences between the FPC cases and sporadic cases in terms of gender, age, tumor location, stage, family history of any cancer except PDAC, and personal history of smoking, other cancers, diabetes mellitus and chronic pancreatitis. In the FPC patients, we then investigated the prevalence of germline mutations in 21 genes associated with hereditary predispositions for pancreatic, breast and ovarian cancers by means of the next-generation sequencing using a custom multiple-gene panel. We found that eight (14.5%) of the 54 FPC patients with available germline DNA carried deleterious mutations in BRCA2, PALB2, ATM, or MLH1. These results indicate that a significant fraction of patients with PDAC in Japan have a family history of pancreatic cancer, and some of them harbor deleterious causative mutations in known FPC predisposition genes.

Cardiovascular Concerns in BRCA1 and BRCA2 Mutation Carriers

PURPOSE OF REVIEW

BRCA1 and BRCA2 mutation carriers can be at increased cardiovascular risk. The goal of this review is to provide information about factors associated with increased cardiovascular risk, methods to prevent cardiovascular toxicities, and recommended screening guidelines.

RECENT FINDINGS

BRCA1/2 mutation carriers who are diagnosed with cancer are often exposed to chemotherapy, chest radiotherapy, and/or HER2 directed therapies, all of which can be cardiotoxic. In addition, BRCA1/2 carriers often undergo prophylactic salpingoopherectomies, which may also increase cardiovascular risks. Understanding the potential for increased cardiovascular risk in individuals with a BRCA1 or BRCA2 mutation, as well as gold standard practices for prevention, detection, and treatment of cardiac concerns in this population, is important.

BRCA1/BRCA2 Germline Mutation Carriers and Sporadic Pancreatic Ductal Adenocarcinoma

BACKGROUND

The outcomes of sporadic pancreatic ductal adenocarcinoma (PDAC) patients with germline mutations of BRCA1/BRCA2 remains unclear. The prognostic significance of BRCA1/BRCA2 mutations on survival is not well established.

STUDY DESIGN

We performed targeted next-generation sequencing (NGS) to identify BRCA1/BRCA2 germline mutations in resected sporadic PDAC cases from 2000 to 2015. Germline BRCA mutation carriers were matched by age and tumor location to those with BRCA1/BRCA2 wild-type genes from our institutional database. Demographics, clinicopathologic features, overall survival (OS), and disease-free survival (DFS) were abstracted from medical records and compared between the 2 cohorts.

RESULTS

Twenty-two patients with sporadic cancer and BRCA1 (n = 4) or BRCA2 (n = 18) germline mutations and 105 wild-type patients were identified for this case-control study. The BRCA1/BRCA2 mutations were associated with inferior median OS (20.2 vs 27.8 months, p = 0.034) and DFS (8.4 vs 16.7 months, p < 0.001) when compared with the matched wild-type controls. On multivariable analyses, a BRCA1/BRCA2 mutation (hazard ratio [HR] 2.10, p < 0.001), positive margin status (HR 1.72, p = 0.021), and lack of adjuvant therapy (HR 2.38, p < 0.001), were all independently associated with worse survival. Within the BRCA1/BRCA2 mutated group, having had platinum-based adjuvant chemotherapy (n = 10) was associated with better survival than alternative chemotherapy (n = 8) or no adjuvant therapy (n = 4) (31.0 vs 17.8 vs 9.3 months, respectively, p < 0.001).

CONCLUSIONS

Carriers of BRCA1/BRCA2 mutation with sporadic PDAC had a worse survival after pancreatectomy than their BRCA wild-type counterparts. However, platinum-based chemotherapy regimens were associated with markedly improved survival in patients with BRCA1/BRCA2 mutations, with survival differences no longer appreciated with wild-type patients.

Inherited pancreatic cancer

Pancreatic cancers arise through a series of genetic events both inherited and acquired. Inherited genetic changes, both high penetrance and low penetrance, are an important component of pancreatic cancer risk, and may be used to characterize populations who will benefit from early detection. Furthermore, pancreatic cancer patients with inherited mutations may be particularly sensitive to certain targeted agents, providing an opportunity to personalized treatment. Family history of pancreatic cancer is one of the strongest risk factors for the disease, and is associated with an increased risk of caners at other sites, including but not limited to breast, ovarian and colorectal cancer. The goal of this chapter is to discuss the importance of family history of pancreatic cancer, and the known genes that account for a portion of the familial clustering of pancreatic cancer.

Integrating surgery and genetic testing for the modern surgeon

The field of cancer genetics is rapidly evolving and several genetic mutations have been identified in hereditary cancer syndromes. These mutations can be diagnosed via routine genetic testing allowing prompt intervention. This is especially true for certain variants of colorectal, breast, and thyroid cancers where genetic testing may guide surgical therapy. Ultimately, surgical intervention may drastically diminish disease manifestation or progression in individuals deemed as high-risk based on their genetic makeup. Understanding the concepts of gene-based testing and integrating into current surgical practice is crucial. This review addresses common genetic syndromes, tests, and interventions salient to the current surgeon.

Germline mutations in pancreatic cancer and potential new therapeutic options

Due to short-lived treatment responses in unresectable disease, pancreatic ductal adenocarcinoma (PDAC) continues to be one of the deadliest cancers. There is availability of new information about germline and sporadic mutations in the deoxyribonucleic acid (DNA) damage repair pathway in PDAC in recent decades and the expectation is that novel targeted therapies will thus be developed. A variety of germline mutations (BRCA2, BRCA1, PALB2, CDKN2A, ATM, TP53 and mismatch repair genes MLH1, MSH2, MSH6) have been reported in these patients with the highest prevalence being BRCA1/2. Positive results have been reported with the use of targeted therapies, particularly poly (ADP-ribose) polymerase inhibitors in BRCA-mutated ovarian and breast cancers, and their use is currently being investigated in germline-mutated pancreatic cancer. The aim of this review is to provide an outline of germline DNA damage repair mutations in pancreatic cancer and their effect on the incidence, outcomes and responses to different therapeutic options.

Overlooked FANCD2 variant encodes a promising, portent tumor suppressor, and alternative polyadenylation contributes to its expression

Fanconi Anemia (FA) complementation group D2 protein (FANCD2) is the center of the FA tumor suppressor pathway, which has become an important field of investigation in human aging and cancer. Here we report an overlooked central player in the FA pathway, FANCD2 variant 2 (FANCD2-V2), which appears to perform more potent tumor suppressor-function compared to the known variant of FANCD2, namely, FANCD2-V1. Detailed analysis of the FANCD2 gene structure indicated a proximal and distal polyadenylation site (PAS), associated with V2 and V1 transcripts accordingly. RNA polymerase II Chromatin immunoprecipitation (ChIP) targeting the two PAS-regions determined lesser binding of RNA pol II to DNA fragments in the distal PAS region in non-malignant cells compared to malignant cells. Conversely, the opposite occurred in the proximal PAS region. Moreover, RNA immunoprecipitation (RIP) identified that U2 snRNP, a major component of RNA splicing complex that interacts with the 3′end of an intron, showed greater binding to the last intron of the FANCD2-V1 transcript in malignant cells compared to the non-malignant cells. Importantly, our data showed that in human tissue samples, the ratio of V2 /V1 expression in lung, bladder, or ovarian cancer correlates inversely with the tumor stages/grades. Therefore, these findings provide a previously unrecognized central player FANCD2-V2 and thus novel insights into human tumorigenesis, and indicate that V2/V1 can act as an effective biomarker in assisting the recognition of tumor malignance.

FANCD2 and DNA Damage

Investigators have dedicated considerable effort to understanding the molecular basis underlying Fanconi Anemia (FA), a rare human genetic disease featuring an extremely high incidence of cancer and many congenital defects. Among those studies, FA group D2 protein (FANCD2) has emerged as the focal point of FA signaling and plays crucial roles in multiple aspects of cellular life, especially in the cellular responses to DNA damage. Here, we discuss the recent and relevant studies to provide an updated review on the roles of FANCD2 in the DNA damage response.

Germline BRCA mutations in Asian patients with pancreatic adenocarcinoma: a prospective study evaluating risk category for genetic testing

Introduction Germline BRCA mutations may have therapeutic implications as surrogate markers of DNA-damage repair status in pancreatic ductal adenocarcinoma (PDAC). We performed a prospective study to evaluate the efficiency of risk criteria based on personal or family history of breast and ovarian cancer for determining germline BRCA mutations in PDAC patients with Asian ethnicity. Methods Between November 2015 and May 2016, we screened consecutive PDAC patients with locally advanced unresectable or metastatic disease who were referred for systemic chemotherapy. Analyses for germline BRCA mutations were performed if patients had one or more first-degree or second-degree relatives with breast or ovarian cancers or had a personal medical history of these diseases. DNA was extracted from whole blood, and all coding exons and their flanking intron regions of BRCA1 and BRCA2 were sequenced. Results A total of 175 patients were screened for personal and family history and 10 (5.7%) met the inclusion criteria for genetic sequencing. Pathogenic germline BRCA2 mutation [c.7480C>T (p.Arg2494*)] was identified in one male patient, resulting in a frequency of 10% for the risk-stratified patients and 0.6% for the unselected PDAC population. Two patients had germline BRCA2 variants of uncertain significance [c.1744A>C (p.Thr582Pro) and c.68-7T>A]. Conclusion Personal or family history of breast or ovarian cancers is a feasible, cost-effective risk categorization for screening germline BRCA mutations in Asian PDAC patients as 10% of this population had the pathogenic mutation herein. Future validation from a large, prospective cohort is needed.

Impact of germline and somatic BRCA1/2 mutations: tumor spectrum and detection platforms

The BRCA1/2 genes are long and complex and mutation carriers are at risk of developing malignancies, mainly of gynecological origin. Various mutations arise in these genes and their characterization is a time-consuming, cost intensive, complicated process. Tumors of BRCA1/2 origin have distinct molecular and histological features that can impact responses to therapy. Therefore, detection of these mutations constitutes an important step in the risk assessment, prevention strategy and treatment of subjects. Although Sanger sequencing is the gold standard for the detection of genetic mutations, several next generation sequencing-based high throughput platforms have been developed and adapted for the detection of BRCA1/2 mutations. This review provides a comprehensive overview of the sequencing platforms available for the screening and identification of these mutations. We also summarize what is known about the different types of mutations that arise in these genes and the tumor spectra they result in. Finally, we present a short discussion on existing clinical guidelines which assist physicians in the decision-making process. These parameters have important consequences for the management of patients and an urgent need exists for the development of detection platforms that are cost effective and can provide clinicians with conclusive results within a significantly shorter time.

Deleterious Germline Mutations in Patients With Apparently Sporadic Pancreatic Adenocarcinoma

Purpose Deleterious germline mutations contribute to pancreatic cancer susceptibility and are well documented in families in which multiple members have had pancreatic cancer. Methods To define the prevalence of these germline mutations in patients with apparently sporadic pancreatic cancer, we sequenced 32 genes, including known pancreatic cancer susceptibility genes, in DNA prepared from normal tissue obtained from 854 patients with pancreatic ductal adenocarcinoma, 288 patients with other pancreatic and periampullary neoplasms, and 51 patients with non-neoplastic diseases who underwent pancreatic resection at Johns Hopkins Hospital between 2000 and 2015. Results Thirty-three (3.9%; 95% CI, 3.0% to 5.8%) of 854 patients with pancreatic cancer had a deleterious germline mutation, 31 (3.5%) of which affected known familial pancreatic cancer susceptibility genes: BRCA2 (12 patients), ATM (10 patients), BRCA1 (3 patients), PALB2 (2 patients), MLH1 (2 patients), CDKN2A (1 patient), and TP53 (1 patient). Patients with these germline mutations were younger than those without (mean ± SD, 60.8 ± 10.6 v 65.1 ± 10.5 years; P = .03). Deleterious germline mutations were also found in BUB1B (1) and BUB3 (1). Only three of these 33 patients had reported a family history of pancreatic cancer, and most did not have a cancer family history to suggest an inherited cancer syndrome. Five (1.7%) of 288 patients with other periampullary neoplasms also had a deleterious germline mutation. Conclusion Germline mutations in pancreatic cancer susceptibility genes are commonly identified in patients with pancreatic cancer without a significant family history of cancer. These deleterious pancreatic cancer susceptibility gene mutations, some of which are therapeutically targetable, will be missed if current family history guidelines are the main criteria used to determine the appropriateness of gene testing.

Involvement of FANCD2 in Energy Metabolism via ATP5α

Growing evidence supports a general hypothesis that aging and cancer are diseases related to energy metabolism. However, the involvement of Fanconi Anemia (FA) signaling, a unique genetic model system for studying human aging or cancer, in energy metabolism remains elusive. Here, we report that FA complementation group D2 protein (FANCD2) functionally impacts mitochondrial ATP production through its interaction with ATP5α, whereas this relationship was not observed in the mutant FANCD2 (K561R)-carrying cells. Moreover, while ATP5α is present within the mitochondria in wild-type cells, it is instead located mostly outside in cells that carry the non-monoubiquitinated FANCD2. In addition, mitochondrial ATP production is significantly reduced in these cells, compared to those cells carrying wtFANCD2. We identified one region (AA42-72) of ATP5α, contributing to the interaction between ATP5α and FANCD2, which was confirmed by protein docking analysis. Further, we demonstrated that mtATP5α (∆AA42-72) showed an aberrant localization, and resulted in a decreased ATP production, similar to what was observed in non-monoubiquitinated FANCD2-carrying cells. Collectively, our study demonstrates a novel role of FANCD2 in governing cellular ATP production, and advances our understanding of how defective FA signaling contributes to aging and cancer at the energy metabolism level.

Targeting reactive nitrogen species suppresses hereditary pancreatic cancer

Germline mutation of BRCA2 induces hereditary pancreatic cancer. However, how BRCA2 mutation specifically induces pancreatic tumorigenesis remains elusive. Here, we have examined a mouse model of Brca2-deficiency-induced pancreatic tumors and found that excessive reactive nitrogen species (RNS), such as nitrite, are generated in precancerous pancreases, which induce massive DNA damage, including DNA double-strand breaks. RNS-induced DNA lesions cause genomic instability in the absence of Brca2. Moreover, with the treatment of antioxidant tempol to suppress RNS, not only are DNA lesions significantly reduced, but also the onset of pancreatic cancer is delayed. Thus, this study demonstrates that excess RNS are a nongenetic driving force for Brca2-deficiency-induced pancreatic tumors. Suppression of RNS could be an important strategy for pancreatic cancer prevention.

Early diagnosis of pancreatic cancer: Current trends and concerns

Early detection of pancreatic cancer (PC) is essential for a better prognosis. Some recent studies have demonstrated that a slight dilatation of the main pancreatic duct (MPD) and small cystic lesions were detected initially in most cases diagnosed at an early stage. Detecting these abnormal findings in cases with high risk factors through an effective screening system including image diagnosis, some biological markers, or familial cancer registrations should contribute to early diagnosis of PC. It has been reported that endoscopic ultrasonography (EUS) is essential for detecting tumors <10 mm with a favorable prognosis. Additionally, EUS‐guided fine‐needle aspiration biopsy is useful for confirming final histological diagnosis. For the diagnosis of stage 0 PC, local irregular stenosis of MPD should be an important initial abnormal sign detected by EUS or magnetic resonance cholangiopancreatography. Cytodiagnosis multiple times using pancreatic juice obtained by endoscopic nasopancreatic drainage should be essential for the final diagnosis. Recently, activities of regional networks between specialist doctors in medical centers and general practitioners for early diagnosis of PC have been reported in Japan. In the future, these activities may play an important role in the early diagnosis of PC.

Screening for Pancreatic Cancer

Pancreatic cancer (PC) is a highly fatal disease that can only be cured by complete surgical resection. However, most patients with PC have unresectable disease at the time of diagnosis, highlighting the need to detect PC and its precursor lesions earlier in asymptomatic patients. Screening is not cost-effective for population-based screening of PC. Individuals with genetic risk factors for PC based on family history or known PC-associated genetic syndromes, however, can be a potential target for PC screening programs. This article provides an overview of the epidemiology and genetic background of familial PC and discusses diagnostic and management approaches.

The Role of BRCA2 Mutation Status as Diagnostic, Predictive, and Prognosis Biomarker for Pancreatic Cancer

Pancreatic cancer is one of the deadliest cancers worldwide, and life expectancy after diagnosis is often short. Most pancreatic tumours appear sporadically and have been highly related to habits such as cigarette smoking, high alcohol intake, high carbohydrate, and sugar consumption. Other observational studies have suggested the association between pancreatic cancer and exposure to arsenic, lead, or cadmium. Aside from these factors, chronic pancreatitis and diabetes have also come to be considered as risk factors for these kinds of tumours. Studies have found that 10% of pancreatic cancer cases arise from an inherited syndrome related to some genetic alterations. One of these alterations includes mutation in BRCA2 gene. BRCA2 mutations impair DNA damage response and homologous recombination by direct regulation of RAD51. In light of these findings that link genetic factors to tumour development, DNA damage agents have been proposed as target therapies for pancreatic cancer patients carrying BRCA2 mutations. Some of these drugs include platinum-based agents and PARP inhibitors. However, the acquired resistance to PARP inhibitors has created a need for new chemotherapeutic strategies to target BRCA2. The present systematic review collects and analyses the role of BRCA2 alterations to be used in early diagnosis of an inherited syndrome associated with familiar cancer and as a prognostic and predictive biomarker for the management of pancreatic cancer patients.

Genetic Syndromes with Pancreatic Manifestations

Although the pancreas is affected by only a small fraction of known inherited disorders, several of these syndromes predispose patients to pancreatic adenocarcinoma, a cancer that has a consistently dismal prognosis. Still other syndromes are associated with neuroendocrine tumors, benign cysts, or recurrent pancreatitis. Because of the variability of pancreatic manifestations and outcomes, it is important for clinicians to be familiar with several well-described genetic disorders to ensure that patients are followed appropriately. The purpose of this review was to briefly describe the hereditary syndromes that are associated with pancreatic disorders and neoplasia.

Pancreatic ductal adenocarcinoma in BRCA2 mutation carriers

Germline BRCA2 mutations are the first known cause of inherited (familial) pancreatic ductal adenocarcinoma (PDAC). This tumor is the third most frequent cancer in carriers of germline BRCA2 mutations, as it occurs in around 10% of BRCA2 families. PDAC is known as one of the most highly lethal cancers, mainly because of its chemoresistance and frequently late diagnosis. Based on recent developments in molecular biology, a subgroup of BRCA2-associated PDAC has been created, allowing screening, early surgical treatment and personalized systemic treatment. BRCA2 germline mutation carriers who have ≥1 first-degree relative, or ≥2 blood relatives with PDAC, should undergo screening and regular follow-up based on magnetic resonance imaging and endoscopic ultrasound. The goal of screening is to detect early invasive PDAC and advanced precancerous lesions suitable for a stepwise surgical complete (R0) resection. Increasing evidence on the molecular role of the BRCA2 protein in the homologous recombination of DNA damages suggest that BRCA2-related PDAC are sensitive to agents causing DNA cross-linking damage, such as platinum salts, and treatments targeting rescue DNA repair pathways, such as poly(ADP-ribose) polymerase inhibitors that are currently under investigation.

SF3A1 and pancreatic cancer: new evidence for the association of the spliceosome and cancer

A two-stage case-control study was conducted to examine the association between six candidate U2-depedent spliceosome genes (SRSF1, SRSF2, SF3A1, SF3B1, SF1 and PRPF40B) and pancreatic cancer (PC). Subjects with one or two T alleles at rs2074733 in SF3A1 had a lower risk of PC compared to those with two C alleles in combined two populations (OR: 0.59, 95% confidence interval: 0.48–0.73, False discovery rate (FDR)-P = 1.5E-05). Moreover, the presence of the higher-risk genotype at rs2074733 plus smoking or drinking had synergic effects on PC risk. These findings illustrate that RNA splicing-related genes appear to be associated with the occurrence of PC, and show synergic interactions with smoking and drinking in the additive model. In the future, our novel findings should be further confirmed by functional studies and independent large-scale population studies.

WEE1 inhibition in pancreatic cancer cells is dependent on DNA repair status in a context dependent manner

Pancreatic ductal adenocarcinoma (PDA) is a lethal disease, in part, because of the lack of effective targeted therapeutic options. MK-1775 (also known as AZD1775), a mitotic inhibitor, has been demonstrated to enhance the anti-tumor effects of DNA damaging agents such as gemcitabine. We evaluated the efficacy of MK-1775 alone or in combination with DNA damaging agents (MMC or oxaliplatin) in PDA cell lines that are either DNA repair proficient (DDR-P) or deficient (DDR-D). PDA cell lines PL11, Hs 766T and Capan-1 harboring naturally selected mutations in DNA repair genes FANCC, FANCG and BRCA2 respectively, were less sensitive to MK-1775 as compared to two out of four representative DDR-P (MIA PaCa2 and PANC-1) cell lines. Accordingly, DDR-P cells exhibit reduced sensitivity to MK-1775 upon siRNA silencing of DNA repair genes, BRCA2 or FANCD2, compared to control cells. Only DDR-P cells showed increased apoptosis as a result of early mitotic entry and catastrophe compared to DDR-D cells. Taken together with other recently published reports, our results add another level of evidence that the efficacy of WEE1 inhibition is influenced by the DNA repair status of a cell and may also be dependent on the tumor type and model evaluated.

Can Molecular Biomarkers Change the Paradigm of Pancreatic Cancer Prognosis?

Pancreatic ductal adenocarcinoma is one of the most lethal types of tumour, and its incidence is rising worldwide. Although survival can be improved when these tumours are detected at an early stage, this cancer is usually asymptomatic, and the disease only becomes apparent after metastasis. The only prognostic biomarker approved by the FDA to date is carbohydrate antigen 19-9 (CA19-9); however, the specificity of this biomarker has been called into question, and diagnosis is usually based on clinical parameters. Tumour size, degree of differentiation, lymph node status, presence of distant metastasis at diagnosis, protein levels of KI-67 or C-reactive protein, and mutational status of P53, KRAS, or BRCA2 are the most useful biomarkers in clinical practice. In addition to these, recent translational research has provided evidence of new biomarkers based on different molecules involved in endoplasmic reticulum stress, epithelial-to-mesenchymal transition, and noncoding RNA panels, especially microRNAs and long noncoding RNAs. These new prospects open new paths to tumour detection using minimally or noninvasive techniques such as liquid biopsies. To find sensitive and specific biomarkers to manage these patients constitutes a challenge for the research community and for public health policies.

Post-transcriptional Regulation of BRCA2 through Interactions with miR-19a and miR-19b

Breast cancer type 2, early onset susceptibility gene (BRCA2) is a major component of the homologous recombination DNA repair pathway. It acts as a tumor suppressor whose function is often lost in cancers. Patients with specific mutations in the BRCA2 gene often display discrete clinical, histopathological, and molecular features. However, a subset of sporadic cancers has wild type BRCA2 and display defects in the homology-directed repair pathway, which is the hallmark of ‘BRCAness.’ The mechanisms by which BRCAness arises are not well understood but post-transcriptional regulation of BRCA2 gene expression by microRNAs (miRNAs) may contribute to this phenotype. Here, we examine the post-transcriptional effects that some members of the six-miRNA cluster known as the miR-17/92 cluster have on the abundance of BRCA2’s messenger RNA (mRNA) and protein. We discuss two interactions involving the miR-19a and miR-19b members of the cluster and the 3′UTR of BRCA2’s mRNA. We investigated these miRNA:mRNA interactions in 15 cell lines derived from pancreatic, breast, colon, and kidney tissue. We show that over-expression of these two miRNAs results in a concomitant decrease of BRCA2’s mRNA and protein expression in a subset of the tested cell lines. Additionally, using luciferase reporter assays we identified direct interactions between miR-19a/miR-19b and a miRNA response element (MRE) in BRCA2’s 3′UTR. Our results suggest that BRCA2 is subject to a complex post-transcriptional regulatory program that has specific dependencies on the genetic and phenotypic background of cell types.

Familial prostate cancer

Prostate cancer is the most commonly diagnosed cancer among men in the United States as well as most Western countries. A significant proportion of men report having a positive family history of prostate cancer in a first-degree relative (father, brother, son), which is important in that family history is one of the only established risk factors for the disease and plays a role in decision-making for prostate cancer screening. Familial aggregation of prostate cancer is considered a surrogate marker of genetic susceptibility to developing the disease, but shared environment cannot be excluded as an explanation for clustering of cases among family members. Prostate cancer is both a clinically and genetically heterogeneous disease with inherited factors predicted to account for 40%-50% of cases, comprised of both rare highly to moderately penetrant gene variants, as well as common genetic variants of low penetrance. Most notably, HOXB13 and BRCA2 mutations have been consistently shown to increase prostate cancer risk, and are more commonly observed among patients diagnosed with early-onset disease. A recurrent mutation in HOXB13 has been shown to predispose to hereditary prostate cancer (HPC), and BRCA2 mutations to hereditary breast and ovarian cancer (HBOC). Genome-wide association studies (GWAS) have also identified approximately 100 loci that associate with modest (odds ratios <2.0) increases in prostate cancer risk, only some of which have been replicated in subsequent studies. Despite these efforts, genetic testing in prostate cancer lags behind other common tumors like breast and colorectal cancer. To date, National Comprehensive Cancer Network (NCCN) guidelines have highly selective criteria for BRCA1/2 testing for men with prostate cancer based on personal history and/or specific family cancer history. Tumor sequencing is also leading to the identification of germline mutations in prostate cancer patients, informing the scope of inheritance. Advances in genetic testing for inherited and familial prostate cancer (FPC) are needed to inform personalized cancer risk screening and treatment approaches.

Analysis of Founder Mutations in Rare Tumors Associated With Hereditary Breast/Ovarian Cancer Reveals a Novel Association of BRCA2 Mutations with Ampulla of Vater Carcinomas

BRCA1 and BRCA2 mutations are responsible for hereditary breast and ovarian cancer, but they also confer an increased risk for the development of rarer cancers associated with this syndrome, namely, cancer of the pancreas, male breast, peritoneum, and fallopian tube. The objective of this work was to quantify the contribution of the founder mutations BRCA2 c.156_157insAlu and BRCA1 c.3331_3334del for cancer etiology in unselected hospital-based cohorts of Portuguese patients diagnosed with these rarer cancers, by using a strategy that included testing of archival tumor tissue. A total of 102 male breast, 68 pancreatic and 33 peritoneal/fallopian tube carcinoma cases were included in the study. The BRCA2 c.156_157insAlu mutation was observed with a frequency of 7.8% in male breast cancers, 3.0% in peritoneal/fallopian tube cancers, and 1.6% in pancreatic cancers, with estimated total contributions of germline BRCA2 mutations of 14.3%, 5.5%, and 2.8%, respectively. No carriers of the BRCA1 c.3331_3334del mutation were identified. During our study, a patient with an ampulla of Vater carcinoma was incidentally found to carry the BRCA2 c.156_157insAlu mutation, so we decided to test a consecutive series of additional 15 ampullary carcinomas for BRCA1/BRCA2 mutations using a combination of direct founder mutation testing and full gene analysis with next generation sequencing. BRCA2 mutations were observed with a frequency of 14.3% in ampulla of Vater carcinomas. In conclusion, taking into account the implications for both the individuals and their family members, we recommend that patients with these neoplasias should be offered BRCA1/BRCA2 genetic testing and we here show that it is feasible to test for founder mutations in archival tumor tissue. Furthermore, we identified for the first time a high frequency of germline BRCA2 mutations in ampullary cancers.

Genomic instability in pancreatic adenocarcinoma: a new step towards precision medicine and novel therapeutic approaches

Pancreatic cancer is one of the most challenging cancers. Whole genome sequencing studies have been conducted to elucidate the underlying fundamentals underscoring disease behavior. Studies have identified a subgroup of pancreatic cancer patients with distinct molecular and clinical features. Genetic fingerprinting of these tumors is consistent with an unstable genome and defective DNA repair pathways, which creates unique susceptibility to agents inducing DNA damage. BRCA1/2 mutations, both germline and somatic, which lead to impaired DNA repair, are found to be important biomarkers of genomic instability as well as of response to DNA damaging agents. Recent studies have elucidated that PARP inhibitors and platinum agents may be effective to induce tumor regression in solid tumors bearing an unstable genome including pancreatic cancer. In this review we discuss the characteristics of genomic instability in pancreatic cancer along with its clinical implications and the utility of DNA targeting agents particularly PARP inhibitors as a novel treatment approach.

Drug metabolism and pancreatic cancer

Pancreatic cancer remains a fatal disease in the majority of patients. The era of personalized medicine is upon us: customizing therapy according to each patient's individual cancer. Potentially, therapy can be targeted at individuals who would most likely have a favorable response, making it more efficacious and cost effective. This is particularly relevant for pancreatic cancer, which currently portends a very poor prognosis. However, there is much to be done in this field, and more studies are needed to bring this concept to reality.

Genetic factors affecting patient responses to pancreatic cancer treatment

Cancer of the exocrine pancreas is a malignancy with a high lethal rate. Surgical resection is the only possible curative mode of treatment. Metastatic pancreatic cancer is incurable with modest results from the current treatment options. New genomic information could prove treatment efficacy. An independent review of PubMed and ScienceDirect databases was performed up to March 2016, using combinations of terms such pancreatic exocrine cancer, chemotherapy, genomic profile, pancreatic cancer pharmacogenomics, genomics, molecular pancreatic pathogenesis, and targeted therapy. Recent genetic studies have identified new markers and therapeutic targets. Our current knowledge of pancreatic cancer genetics must be further advanced to elucidate the molecular basis and pathogenesis of the disease, improve the accuracy of diagnosis, and guide tailor-made therapies.