Inherited pancreatic cancer: improvements in our understanding of genetics and screening

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pancreatic Cancer Surveillance and Novel Strategies for Screening

Individuals with a genetic susceptibility to pancreatic ductal adenocarcinoma (PDAC) may benefit from surveillance to increase the likelihood of early detection. Currently, candidates for surveillance are identified based on genetic test results and family history of PDAC, and surveillance is accomplished through imaging of the pancreas (endoscopic ultrasound or MRI). Novel methods that incorporate personalized risk, biomarkers, and radiomics are being investigated in an attempt to improve identification of at-risk individuals and to increase detection of precursor and early-stage lesions.

Spatial distribution and clusters of pancreatic cancer mortality in Shandong Province, China

This study aimed to explore the geographic distribution and risk clusters of pancreatic cancer mortality from 2011 to 2013 in Shandong, China, and to detect the differences between urban and rural areas. Our data were obtained from the Shandong Death Registration System (SDRS) and were adjusted according to the underreporting level. The distribution of mortality was displayed with GIS-based maps at the county level. The results showed an increasing trend in pancreatic cancer mortality from the western region to the eastern region of Shandong. Additionally, four significant risk clusters were detected, and the most likely cluster was focused in the northeastern and northern regions. Urban-rural differences in the mortality distribution and risk clusters were also detected. In conclusion, our study identified pancreatic cancer mortality clusters in Shandong in urban and rural areas; these results can contribute to the development of effective and targeted strategies to control pancreatic cancer in different areas.

The impact of a history of cancer on pancreatic ductal adenocarcinoma survival

BACKGROUND AND OBJECTIVE

Previous studies indicated cancer survivors had a higher risk of developing subsequent pancreatic ductal adenocarcinoma. However, the influence of prior cancer on survival outcomes of current pancreatic cancer remains unclear.

METHODS

Eligible populations were selected from the Surveillance, Epidemiology, and End Results programs from 2000 to 2012. We adopted Kaplan-Meier curves and Cox analysis to compare survival differences between patients with and without prior cancer.

RESULTS

Overall, 67,555 pancreatic cancer patients, including 5582 (8.26%) with and 61,973 (91.74%) without prior cancer, were included. The most common types of prior cancers were prostate, breast, and colorectal cancers. The median time from diagnosis of an initial malignancy to subsequent pancreatic cancer was 59.8 months. Patients with a prior cancer had higher overall one-year and three-year survival rates compared with those without a prior cancer. Multivariable Cox analysis demonstrated that a history of prior malignancy could independently predict the better overall survival outcome of pancreatic cancer (HR = 0.92, 95% CI, 0.89-0.94, p < 0.001), especially for colorectal, breast, corpus uteri and prostate cancer survivors.

CONCLUSIONS

A history of cancer did not contribute to a poor survival outcome for patients with pancreatic cancer. More prospective trials might be warranted to validate our findings.

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.

Incidence of post-ERCP pancreatitis from direct pancreatic juice collection in hereditary pancreatitis and familial pancreatic cancer before and after the introduction of prophylactic pancreatic stents and rectal diclofenac

OBJECTIVES

Individuals from hereditary pancreatitis (HP) and familial pancreatic cancer (FPC) kindreds are at increased risk of developing pancreatic cancer. Premalignant molecular changes may be detected in pancreatic juice collected by endoscopic retrograde cholangiopancreatography (ERCP). The objective was to determine the risk of post-ERCP pancreatitis (PEP).

METHODS

A prospective study (1999-2013) was undertaken of 80 ERCPs (24 in HP and 56 in FPC) from 60 individuals and the impact of PEP prophylaxis using a self-expelling pancreatic stent and 50 mg diclofenac per rectum from 2008.

RESULTS

There was no PEP in the HP cohort and 13 (23.2%) PEP from 56 procedures in the FPC cohort (P = 0.0077). Up to 2008 PEP had occurred in 7 (43.8%) of 16 procedures in FPC individuals versus none of 18 procedures in HP individuals (P = 0.0021). After the introduction of prophylaxis, the incidence of PEP fell to 6 (15.0%) of 40 procedures in FPC individuals (P = 0.0347).The odds ratio (95% confidence interval) was 0.23 (0.06-0.84) in favor of prophylaxis (0.035).

CONCLUSIONS

Individuals with HP are at minimal risk for PEP. Although the risk of PEP in individuals with FPC can be reduced by using prophylactic self-expelling stents and diclofenac, it remains too high for routine screening.

Pancreatic cancer incidence and mortality patterns in china, 2009

OBJECTIVE

To estimate the incidence and mortality rates for pancreatic cancer in China.

METHODS

After checking and reviewing the cancer registry data in 2009 from 72 cancer registry centers, we divided cancer registry areas into urban and rural areas. Incidence/mortality rates, age-specific incidence/mortality rates, age- standardized incidence/mortality rates, proportions, and cumulative incidence/mortality rates for pancreatic cancer were calculated.

RESULTS

The total number of newly diagnosed pancreatic cancer cases and deaths in 2009 were 6,220 and 5,650, respectively. The crude incidence rate in all cancer registry areas was 7.28/100,000 (males 8.24, females 6.29). The age-standardized incidence rate by Chinese standard population (ASR) was 3.35/100,000, with ranking at 7th among all cancers. Pancreatic cancer incidence rate was 8.19/100,000 in urban areas whereas it was 5.41/100 000 in rural areas. Cancer mortality rate in all cancer registry areas was 6.61/100,000 (males 7.45; females 5.75), with ranking at 6th among all cancers, and 7.42/100 000 in urban but 4.94/100000 in rural areas.

CONCLUSIONS

Pancreatic cancer incidence and mortality rates have shown a gradual increase in China. Owing to the difficulty of early diagnosis, identification of high-risk population and modification of risk factors are important to reduce the burden of pancreatic cancer.

Molecular analysis of precursor lesions in familial pancreatic cancer

BACKGROUND

With less than a 5% survival rate pancreatic adenocarcinoma (PDAC) is almost uniformly lethal. In order to make a significant impact on survival of patients with this malignancy, it is necessary to diagnose the disease early, when curative surgery is still possible. Detailed knowledge of the natural history of the disease and molecular events leading to its progression is therefore critical.

METHODS AND FINDINGS

We have analysed the precursor lesions, PanINs, from prophylactic pancreatectomy specimens of patients from four different kindreds with high risk of familial pancreatic cancer who were treated for histologically proven PanIN-2/3. Thus, the material was procured before pancreatic cancer has developed, rather than from PanINs in a tissue field that already contains cancer. Genome-wide transcriptional profiling using such unique specimens was performed. Bulk frozen sections displaying the most extensive but not microdissected PanIN-2/3 lesions were used in order to obtain the holistic view of both the precursor lesions and their microenvironment. A panel of 76 commonly dysregulated genes that underlie neoplastic progression from normal pancreas to PanINs and PDAC were identified. In addition to shared genes some differences between the PanINs of individual families as well as between the PanINs and PDACs were also seen. This was particularly pronounced in the stromal and immune responses.

CONCLUSIONS

Our comprehensive analysis of precursor lesions without the invasive component provides the definitive molecular proof that PanIN lesions beget cancer from a molecular standpoint. We demonstrate the need for accumulation of transcriptomic changes during the progression of PanIN to PDAC, both in the epithelium and in the surrounding stroma. An identified 76-gene signature of PDAC progression presents a rich candidate pool for the development of early diagnostic and/or surveillance markers as well as potential novel preventive/therapeutic targets for both familial and sporadic pancreatic adenocarcinoma.

Incidence of subsequent pancreatic adenocarcinoma in patients with a history of nonpancreatic primary cancers

BACKGROUND

Several environmental risk factors are known to predispose individuals to pancreatic cancer, and up to 15% of pancreatic cancers have an inherited component. Understanding metachronous cancer associations can modify pancreas cancer risk. The objective of this study was to investigate the association of nonpancreatic cancers with subsequent pancreatic adenocarcinoma.

METHODS

The authors used data from the US Surveillance, Epidemiology, and End Results (SEER) registries to identify 1,618,834 individuals who had a primary malignancy and subsequent pancreatic adenocarcinoma (n = 4013). Standardized incidence ratios were calculated as an approximation of relative risk (RR) for the occurrence of pancreatic adenocarcinoma after another primary malignancy.

RESULTS

Among patients who were diagnosed with a first primary malignancy at ages 20 to 49 years, the risk of subsequent pancreatic adenocarcinoma was increased among patients who had cancers of the ascending colon (relative risk [RR], 4.62; 95% confidence interval [CI], 1.86-9.52), hepatic flexure (RR, 5.42; 95% CI, 1.12-15.84), biliary system (RR, 13.14; 95% CI, 4.27-30.66), breast (RR, 1.32; 95% CI, 1.09-1.59), uterine cervix (RR, 1.61; 95% CI, 1.02-2.41), testes (RR, 2.78; 95% CI, 1.83-4.05), and hematopoietic system (RR, 1.83; 95% CI, 1.28-2.53). Among patients who had a first malignancy at ages 50 to 64 years, the risk was increased after cancers of the stomach (RR, 1.88; 95% CI, 1.13-2.93), hepatic flexure (RR, 2.25; 95% CI, 1.08-4.13), lung and bronchus (RR, 1.46; 95% CI, 1.16-1.82), pharynx (RR, 2.26; 95% CI, 1.13-4.04), and bladder (RR, 1.24; 95% CI, 1.03-1.48). Among patients who had a primary cancer after age 65 years, the risk was increased after cancers of the stomach (RR, 1.79; 95% CI, 1.23-2.53), hepatic flexure (RR, 1.76; 95% CI, 1.06-2.75), biliary system (RR, 2.35; 95% CI, 1.17-4.20), and uterus (RR, 1.23; 95% CI, 1.03-1.47).

CONCLUSIONS

The results from the current population-based data set suggested that pancreatic adenocarcinoma is associated with certain primary cancers. Genetic predisposition and common environmental and behavioral risk factors all may contribute to this observation. Specific tumor associations will guide future risk-stratification efforts.

Individuals at high-risk for pancreatic cancer development: management options and the role of surgery

Pancreatic cancer (PC) is a highly lethal disease. Despite advances regarding the safety and long-term results of pancreatectomies, early diagnosis remains the only hope for cure. This necessitates the implementation of an intensive screening program (based mainly on modern imaging), which - given the incidence of PC - is not cost effective for the general population. However, this screening program is recommended for individuals at high-risk for PC development. Indications for screening include the following three clinical settings: hereditary cancer predisposition syndromes associated with PC, hereditary pancreatitis and familial pancreatic cancer syndrome. The aim of this strategy is to identify pre-invasive (precursor) lesions, which are curable. Surgery is recommended in the presence of recognizable lesion on imaging lesions. Partial (anatomic) pancreatectomy - depending on the location of the suspicious lesion - is the most widely accepted type of surgical intervention in this setting; occasionally, however, total pancreatectomy may be required, in carefully selected patients. Despite that experience still remains limited, there is evidence that this aggressive strategy allows early detection of neoplastic lesions, thereby improving the effectiveness of surgery and prognosis.

Imaging in staging and management of pancreatic ductal adenocarcinoma

Pancreatic cancer is a relatively common malignancy of the gastrointestinal tract for which complete surgical excision remains the only curative option. Being infiltrative in nature and bearing a complex anatomical relationship with various organs, peritoneal ligaments and vascular structures, accurate anatomical staging is key in treatment of these patients. In this article, we will discuss and provide a brief overview of anatomy and use of imaging in staging pancreatic cancer.

[Chronic pancreatitis as a risk factor for the development of pancreatic cancer--diagnostic challenges]

Patients with chronic pancreatitis are burdened with an increased risk of developing pancreatic cancer. Strategies or guidelines for the surveillance and early detection of pancreatic adenocarcinoma in patients with chronic pancreatitis are not established, because available clinical, serologic or imaging techniques are still of limited sensitivity and specificity. Despite these limitations do patients with chronic pancreatitis and suspected pancreatic cancer need a careful and sometimes repeated diagnostic work-up. A clear benefit of surveillance programs outside of clinical trials for the early detection of pancreatic cancer has not been demonstrated. A 51-year-old patient with chronic pancreatitis is reported who developed cancer of the pancreatic head while undergoing repeated imaging studies.

[Risk factors and early diagnosis of pancreatic cancer]

Pancreatic cancer (PC) is usually incurable. Identifying people at risk for developing PC may improve the prognosis of this entity. The main risk factors for PC are Peutz-Jeghers syndrome, hereditary pancreatitis and a history family of PC. Other factors, such as advanced age and smoking, should also be taken into account. PC screening is only useful in very high risk individuals. Tools that allow tumors to be identified in the early stages are required in order to apply appropriate curative treatments. In this scenario, only endoscopic ultrasound with cytological analysis of suspicious pancreatic lesions has proved to be useful.

Familial association of pancreatic cancer with other malignancies in Swedish families

Background:

The aim of this study was to characterise the familial association of pancreatic cancer with other malignancies.

Methods:

Relative risks (RRs) of pancreatic cancer according to family history of cancer were calculated using the updated Swedish Family-Cancer Database, which includes over 11.5 million individuals. Estimates were based on Poisson regression. RRs of tumours for individuals with a parental history of pancreatic cancer were also estimated.

Results:

The risk of pancreatic cancer was elevated in individuals with a parental history of cancers of the liver (RR 1.41; 95% CI 1.10–1.81), kidney (RR 1.37; 95% CI 1.06–1.76), lung (RR 1.50; 95% CI 1.27–1.79) and larynx (RR 1.98; 95% CI 1.19–3.28). Associations were also found between parental history of pancreatic cancer and cancers of the small intestine, colon, breast, lung, testis and cervix in offspring. There was an increased risk of pancreatic cancer associated with early-onset breast cancer in siblings.

Conclusion:

Pancreatic cancer aggregates in families with several types of cancer. Smoking may contribute to the familial aggregation of pancreatic and lung tumours, and the familial clustering of pancreatic and breast cancer could be partially explained by inherited mutations in the BRCA2 gene.

Atypical familial presentation of FAMMM syndrome with a high incidence of pancreatic cancer: case finding of asymptomatic individuals by EUS surveillance

BACKGROUND

Pancreatic cancer (PC) is one of the leading causes of cancer death in Western countries. An increased risk for PC is known in a number of hereditary tumor syndromes. In selected individuals at high risk of developing PC, surveillance of the pancreas might be able to detect premalignant lesions and early invasive cancers, and probably improve survival.

METHODS

In a Dutch family with atypical phenotypic presentation of the familial atypical multiple mole melanoma syndrome with high incidence of PC related to a mutation in the CDKN2A gene, pancreatic surveillance was offered to asymptomatic gene mutation carriers.

RESULTS

Three individuals underwent their first screening with endoscopic ultrasound (EUS) and magnetic resonance imaging at an age of 76, 58, and 51 years. In a mother and a daughter, mass lesions were found by EUS in the tail and body of the pancreas. The smallest lesion was not visualized on subsequent computed tomography and magnetic resonance imaging. After surgical resection histologic examination revealed adenocarcinomas in both cases. The patient with the larger lesion was found to have N1 disease. Side branch intraductal papillary mucinous neoplasias were found in the third patient.

CONCLUSIONS

These findings illustrate the potential of the surveillance of high-risk individuals for PC by EUS. Awareness of clinicians of the existence of hereditary syndromes with increased risk for PC may improve identification of high-risk individuals who could benefit from surveillance. Whether screening improves survival remains to be investigated, as is the optimal interval for screening. Side branch intraductal papillary mucinous neoplasias in these patients may serve as a precancerous marker lesion for early intervention to improve survival.

Identification of a novel kindred with familial pancreatitis and pancreatic cancer

BACKGROUND/AIMS

Hereditary pancreatic cancer comprises about 10% of pancreatic cancer cases. Multiple causative mutations have been identified. Here we describe a pancreatitis/pancreatic cancer (P/PC) family, which demonstrates pancreatitis and pancreatic cancer resulting from an uncharacterized mutation.

METHODS

Family members completed evaluations to determine signs of mutation status. Select patients were screened for mutations associated with hereditary pancreatic diseases.

RESULTS

In generation II, 12 siblings exhibit 6 cases of pancreatitis, 3 pancreatic cancer, and 2 obligate carrier status. The average age at pancreatitis diagnosis of enrolled members is 32.5 years; average age at pancreatic cancer diagnosis is 59 years. There is no association with known cancer syndromes. Those affected generally present with mild epigastric pain, and CT scans demonstrate characteristic fatty infiltration of the pancreatic body and tail with sparing of the head and neck. Full sequence analysis of genes associated with hereditary pancreatic disease failed to demonstrate known mutations or polymorphisms.

CONCLUSION

Based upon pedigree evaluation and preliminary DNA analysis, we believe that the family members with P/PC carry a novel genetic mutation resulting in hereditary pancreatitis. This mutation is autosomal dominant, expressed with high penetrance, and is part of a unique hereditary syndrome that significantly increases pancreatic cancer risk.

Pancreatic cancer surveillance among high-risk populations: knowledge and intent

Pancreatic cancer is the fourth most common cancer in both men and women in the United States. It has the lowest survival rate of all cancers, largely due to the presence of non-specific symptoms, leading to diagnosis at advanced stages. While the majority of cases of pancreatic cancer are sporadic, up to 10% may be associated with an inherited predisposition. Currently, there is no standard screening protocol for pancreatic cancer, although this will change in the future as technology improves. Additionally, there is little information regarding the perceptions and intent to screen for pancreatic cancer among those with an increased risk due to a hereditary cancer predisposition syndrome, which was the objective of this study. Focus groups and individual telephone interviews were conducted, with questions focused on knowledge about pancreatic cancer and screening, perceived motivators, and perceived barriers related to each of the screening techniques currently available. Participants were recruited from the High Risk Breast Cancer and Pancreatic Cancer Registries at Huntsman Cancer Institute. The findings of this study indicated that individuals from these high-risk groups have low knowledge levels of pancreatic cancer screening, despite their desire for this information. Motivation to undergo a particular screening technique is related to whether the test is recommended by a physician, cost, degree of invasiveness, and comfort level. This information is useful to genetics professionals who counsel at-risk individuals, physicians who formulate patient care plans, and translational researchers who are developing pancreatic screening methods.

Genetic susceptibility in pancreatic ductal adenocarcinoma

BACKGROUND

The strongest risk factors for pancreatic adenocarcinoma are tobacco smoking and increasing age. However, only a few smokers or elderly individuals develop the disease and genetic factors are also likely to be important.

METHODS

The literature on genetic factors modifying susceptibility to cancer was reviewed, with particular regard to the interindividual variation that exists in the development of pancreatic adenocarcinoma.

RESULTS

Tobacco-derived carcinogen-metabolizing enzyme gene variants have been the main area of study in stratifying the risk of sporadic pancreatic cancer. Inconsistent results have emerged from the few molecular epidemiological studies performed.

CONCLUSION

There is great scope for further investigation of critical pathways and unidentified genetic influences may be revealed. This may eventually allow the identification of individuals at high risk who might be targeted for screening.

A clinical and economic evaluation of endoscopic ultrasound for patients at risk for familial pancreatic adenocarcinoma

BACKGROUND AND AIMS

Approximately 10% of pancreatic adenocarcinoma is familial. Approximately 50% of 1st-degree relatives (FDRs) have endoscopic ultrasound (EUS) findings of chronic pancreatitis. We modeled the natural history of these patients to compare 4 management strategies.

METHODS

We performed a systematic review, and created a Markov model for 45-year-old male FDRs, with findings of chronic pancreatitis on screening EUS. We compared 4 strategies: doing nothing, prophylactic total pancreatectomy (PTP), annual surveillance by EUS, and annual surveillance with EUS and fine needle aspiration (EUS/FNA). Outcomes incorporated mortality, quality of life, procedural complications, and costs.

RESULTS

In the Do Nothing strategy, the lifetime risk of cancer was 20%. Doing nothing provided the greatest remaining years of life, the lowest cost, and the greatest remaining quality-adjusted life years (QALYs). PTP provided the fewest remaining years of life, and the fewest remaining QALYs. Screening with EUS provided nearly identical results to PTP, and screening with EUS/FNA provided intermediate results between PTP and doing nothing. PTP provided the longest life expectancy if the lifetime risk of pancreatic cancer was at least 46%, and provided the most QALYs if the risk was at least 68%.

CONCLUSIONS

FDRs from familial pancreatic cancer kindreds, who have EUS findings of chronic pancreatitis, have increased risk for cancer, but their precise risk is unknown. Without the ability to further quantify that risk, the most effective strategy is to do nothing.

Early prediction of severity in acute pancreatitis using infrared spectroscopy of serum

BACKGROUND

One of the main problems in the management of acute pancreatitis (AP) is the scarcity of accurate predictors of disease severity.

METHODS

In a prospective design, we compared APACHE II score, C-reactive protein (CRP) level, and infrared (IR) spectral absorption of serum (wavelength 940 nm) in 167 consecutive patients with AP, 34 with predicted severe and 133 with mild form.

RESULTS

The IR spectral absorption levels on admission and at 24 h after admission were significantly (p < 0.05) lower in patients with severe AP. On admission, the sensitivity was 74, 56, and 44%; the specificity was 82, 83, and 81%; the positive predictive value was 51, 45, and 37%, and the negative predictive value was 92, 88, and 85%, for IR spectroscopy, APACHE II, and CRP, respectively. At 24 h, the sensitivity, specificity, positive predictive value, and negative predictive value was 82, 74, 44, and 94%; 65, 72, 37, and 89%; 68, 73, 39, and 90%, for IR spectroscopy, CRP, and APACHE II, respectively.

CONCLUSIONS

IR spectroscopy seems to be useful for early detection of severe AP and, in turn, for identifying patients requiring treatment in the intensive care unit and who can benefit from novel therapies.

An update on familial pancreatic cancer and the management of asymptomatic relatives

Families of patients with pancreatic adenocarcinoma (PC) often ask about their own risk of developing this disease. There is now a sufficient body of evidence to inform relatives of their relative risk of developing PC. The purpose of this review is to provide practical advice for the clinician when confronted with questions about the risk of PC in relatives, and the role of genetic testing and screening in high-risk individuals.

Palladin mutation causes familial pancreatic cancer and suggests a new cancer mechanism

BACKGROUND

Pancreatic cancer is a deadly disease. Discovery of the mutated genes that cause the inherited form(s) of the disease may shed light on the mechanism(s) of oncogenesis. Previously we isolated a susceptibility locus for familial pancreatic cancer to chromosome location 4q32-34. In this study, our goal was to discover the identity of the familial pancreatic cancer gene on 4q32 and determine the function of that gene.

METHODS AND FINDINGS

A customized microarray of the candidate chromosomal region affecting pancreatic cancer susceptibility revealed the greatest expression change in palladin (PALLD), a gene that encodes a component of the cytoskeleton that controls cell shape and motility. A mutation causing a proline (hydrophobic) to serine (hydrophilic) amino acid change (P239S) in a highly conserved region tracked with all affected family members and was absent in the non-affected members. The mutational change is not a known single nucleotide polymorphism. Palladin RNA, measured by quantitative RT-PCR, was overexpressed in the tissues from precancerous dysplasia and pancreatic adenocarcinoma in both familial and sporadic disease. Transfection of wild-type and P239S mutant palladin gene constructs into HeLa cells revealed a clear phenotypic effect: cells expressing P239S palladin exhibited cytoskeletal changes, abnormal actin bundle assembly, and an increased ability to migrate.

CONCLUSIONS

These observations suggest that the presence of an abnormal palladin gene in familial pancreatic cancer and the overexpression of palladin protein in sporadic pancreatic cancer cause cytoskeletal changes in pancreatic cancer and may be responsible for or contribute to the tumor's strong invasive and migratory abilities.

A family history of pancreatic cancer

BACKGROUND

A 65-year-old white male with a family history of pancreatic cancer and a personal history of two episodes of acute pancreatitis was referred to our department in January 2005 by his primary-care physician for an assessment of his pancreatic cancer risk.

INVESTIGATIONS

Physical exam, laboratory investigations, CT scan, endoscopic ultrasonography, endoscopic retrograde cholangiopancreatography.

DIAGNOSIS

Familial pancreatic cancer.

MANAGEMENT

Subtotal pancreatectomy, referral to genetic counselor, and continued surveillance.

The inherited genetics of pancreatic cancer and prospects for secondary screening

It is estimated that pancreatic cancer has a familial component in approximately 5-10% of cases. Some of these cases are part of a defined cancer syndrome with a known gene mutation but in the remaining the causative gene remains unknown. In recent years, a better understanding of the molecular events that occur in the progression model of pancreatic cancer has lead to the development of secondary screening programmes with the aim of identifying early precursor lesions or pre-invasive cancer at a stage amenable to curative resection. High-risk groups who have an inherited predisposition for pancreatic cancer form the ideal group to study in developing a robust screening programme. Multimodality screening using computed tomography and endoluminal ultrasound in combination with molecular analysis of pancreatic juice are proving promising as diagnostics tools or at least serving as predictors of risk over a defined period.

Management strategies for patients with hereditary pancreatic cancer

It is likely that hereditary factors play a role in 17% or more of pancreatic cancers. Ten percent of patients have a familial history that causes disease. Another 7% have a history of apparently "sporadic" pancreatic cancer patients carry a genetic mutation that causes the disease. Kindreds, with two or more family members who have been diagnosed with pancreatic cancer and who are first-degree relatives, are considered to have familial pancreatic cancer (FPC). The inheritance pattern for FPC is usually autosomal dominant; however, the penetrance (whether a gene carrier gets the disease) is variable. The lifetime cancer risk for a gene-carrying individual from a FPC kindred can range from 5% to 100%, depending upon the gene inherited and environment-gene interactions. Smoking is the chief environmental risk factor that influences penetrance of pancreatic cancer in these kindreds. Smoking increases the risk of cancer by more than threefold and decreases the age of onset by approximately 10 years. The precursor lesion to pancreatic cancer is pancreatic intraepithelial neoplasia (PanIN), which is graded I to III depending upon the severity of the neoplastic change. Surveillance for the early detection of cancer or intraepithelial neoplasia is possible in high-risk individuals and should be performed in centers with expertise. Endoscopic ultrasound and endoscopic retrograde cholangiopancreatography can help identify those patients who have intraepithelial neoplasia and thus may warrant a tissue diagnosis. Patients who have PanIN III (carcinoma in situ) can consider the option of pancreatectomy. The widespread and multifocal nature of PanIN changes throughout the entire pancreas in high-risk patients would make a total pancreatectomy preferable over a partial surgery. Careful selection of patients, the timing of the operation, and an experienced team of gastroenterologists, pancreatic surgeons, pathologists, and diabetologists are the keys to a good surveillance program and good outcomes for the patient.

Electro-deposit polyaniline on carbon electrode for voltammetric detection of lipase

Normally, the pancreatic digestive enzymes are created and carried into the duodenum in an inactive form. During pancreatitis attacks, these enzymes are inhibited from reaching the duodenum, become activated while still in the pancreas, and begin to autodigest and destroy the pancreas. In order to accurately detect lipase within seconds, a square wave technique was explored without immobilizing enzyme and any other biomolecules over the electrode surface. The cyclic voltammetric (CV) technique was used to coat a carbon electrode with a thin layer of polyaniline. This modified electrode proved to be highly sensitive and specific to detect lipase between 0 and 225 IU/L, which is well within the normal physiological range. The consistency and reliability of this technique proved to be a very formidable detector of lipase present in abnormal quantities due to pancreatitis and other pathological disorders. The interference test has been performed to detect the lipase in the presence of amylase 50, 100, and 150 IU/L to understand the interference phenomenon with lipase detection. There is no significant effect of the amylase concentration over lipase detection resulting from using a modified carbon electrode. The response time of the modified carbon electrode is approximately 5s and the electrode has shown to be stable for 4 weeks at room temperature without special storage condition.

Pancreatic cancer epidemiology

Carcinoma of the exocrine pancreas remains a challenging disease mainly due to advanced stage diagnosis, the early systemic dissemination, aggressive local tumor progression, and subsequent short patient survival. Thus, assessment of incidence markers instead of prevalence indicators is recommended because the time between diagnosis and death is usually very short. Investigations to date have led to the discovery of many rare genes and environmental factors that contribute to pancreatic cancer. However, common genes involved in genetic polymorphisms, and specific risk factors have not been identified. Furthermore, the role of gene-environment interactions on the tumorogenesis and progression of pancreatic cancer need to be further investigated. Given current therapeutic modalities, only early detection of cancer of the pancreas, followed by surgical resection, offers the possibility of lengthening survival time.