Familial Pancreatic Cancer

Familial pancreatic cancer accounts for 10% of all patients with pancreatic cancer. Because the 5-year survival rate of pancreatic cancer is only 7%, screening programs for high-risk individuals are essential and might be advantageous. Pancreatic ductal adenocarcinoma mostly shows symptoms at an advanced state and treatment is not efficient enough to cure most patients. People with hereditary tumor syndromes or their affected relatives can also be included in such screening programs. Besides the collection of data to investigate the background of the disease, these screening programs aim to diagnose and treat precursor lesions so that more dangerous, invasive lesions are prevented. These precursor lesions can be pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm. This review summarizes the latest knowledge of pancreatic screening programs, shows the procedure of pancreatic cancer screening, and gives an overview of current guidelines.

Pathological and prognostic role of mdig in pancreatic cancer

Pancreatic cancer is a highly aggressive malignant disease having very limited therapeutic options that ultimately results in its poor prognosis. It is still elusive on the etiology and tumorigenic mechanisms of pancreatic cancer. In the present report, we provide evidence showing involvement of the mineral dust-induced gene (mdig) in the pathogenesis and prognosis of the pancreatic cancer. Using immunohistochemistry approach on human pancreatic cancer tissue microarray, we found differential expression of mdig in pancreatic adenocarcinoma and normal pancreas. Based on the staining intensities of mdig in these tissue samples, we found that 12% of the cancer tissues were strongly positive for mdig, 39% and 31% were moderately and weakly positive respectively. Several alternatively spliced mdig mRNAs were detected in the selected pancreatic cancer cell lines. Through R2 platform for the patient survival analysis (http://r2.amc.nl), we found that enrichment of some specific exon of mdig predicates different survival rate of the pancreatic cancer patients. In summary, our findings may help in assessing the role of mdig in the pathogenesis of the pancreatic cancer and the prognosis of the pancreatic cancer patients.

Recent progress on liver kinase B1 (LKB1): expression, regulation, downstream signaling and cancer suppressive function

Liver kinase B1 (LKB1), known as a serine/threonine kinase, has been identified as a critical cancer suppressor in many cancer cells. It is a master upstream kinase of 13 AMP-activated protein kinase (AMPK)-related protein kinases, and possesses versatile biological functions. LKB1 gene is mutated in many cancers, and its protein can form different protein complexes with different cellular localizations in various cell types. The expression of LKB1 can be regulated through epigenetic modification, transcriptional regulation and post-translational modification. LKB1 dowcnstream pathways mainly include AMPK, microtubule affinity regulating kinase (MARK), salt-inducible kinase (SIK), sucrose non-fermenting protein-related kinase (SNRK) and brain selective kinase (BRSK) signalings, etc. This review, therefore, mainly discusses recent studies about the expression, regulation, downstream signaling and cancer suppressive function of LKB1, which can be helpful for better understanding of this molecular and its significance in cancers.

Familial pancreatic cancer--status quo

INTRODUCTION

Familial pancreatic cancer (FPC) is defined by families with at least two first-degree relatives with confirmed pancreatic ductal adenocarcinoma (PDAC) that do not fulfill the criteria of other inherited tumor syndromes with an increased risk for the development of PDAC, such as hereditary pancreatitis or hereditary breast and ovarian cancer. FPC is mostly autosomal dominant inherited and presents with a heterogeneous phenotype. Although the major gene defect has not yet been identified, some important germline mutations in the BRCA2-, PALB2-, and ATM-genes are causative in some FPC families.

FPC SCREENING

It is suggested by experts to include high-risk individuals in a screening program with a multidisciplinary approach under research protocol conditions. However, neither biomarkers nor reliable imaging modalities for the detection of high-grade precursor lesions are yet available. Most screening programs are currently based on endoscopic ultrasound and magnetic resonance imaging, and first data demonstrated that precursor lesions (pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasm) of PDAC can be identified. Timing and extent of surgery are still a matter of debate.

SCOPE OF THE REVIEW

The present review focuses on the clinical phenotype of FPC, its histopathological characteristics, known underlying genetic changes, genetic counseling, and screening.

Challenges and advances in mouse modeling for human pancreatic tumorigenesis and metastasis

Pancreatic cancer is critical for developed countries, where its rate of diagnosis has been increasing steadily annually. In the past decade, the advances of pancreatic cancer research have not contributed to the decline in mortality rates from pancreatic cancer-the overall 5-year survival rate remains about 5% low. This number only underscores an obvious urgency for us to better understand the biological features of pancreatic carcinogenesis, to develop early detection methods, and to improve novel therapeutic treatments. To achieve these goals, animal modeling that faithfully recapitulates the whole process of human pancreatic cancer is central to making the advancements. In this review, we summarize the currently available animal models for pancreatic cancer and the advances in pancreatic cancer animal modeling. We compare and contrast the advantages and disadvantages of three major categories of these models: (1) carcinogen-induced; (2) xenograft and allograft; and (3) genetically engineered mouse models. We focus more on the genetically engineered mouse models, a category which has been rapidly expanded recently for their capacities to mimic human pancreatic cancer and metastasis, and highlight the combinations of these models with various newly developed strategies and cell-lineage labeling systems.

Familial pancreatic cancer: current status

The term 'familial pancreatic cancer (FPC) defines families with at least two first-degree relatives with confirmed pancreatic cancer that do not fulfill the criteria of other inherited cancer syndromes with an increased risk for the development of PC, such as Peutz-Jeghers syndrome, hereditary pancreatitis and hereditary breast and ovarian cancer. FPC is a mostly autosomal dominant inherited tumor syndrome with a heterogeneous phenotype. The major genetic defect has not been identified yet, although mutations, for example in the BRCA2 gene, could be identified in some FPC families. Nevertheless, most experts recommend participation in screening and surveillance programs to high-risk individuals. Most board-approved screening programs are based on endoscopic ultrasound. The first data on the prospective screening of high-risk individuals have demonstrated that precursor lesions of PC can be identified, but false-positive findings do occur.

Familial pancreatic cancer--current knowledge

Familial pancreatic cancer (FPC) describes families with at least two first-degree relatives with confirmed exocrine pancreatic cancer that do not fulfil the criteria of other inherited tumour syndromes with increased risks of pancreatic cancer, such as Peutz-Jeghers syndrome, hereditary pancreatitis, and hereditary breast and ovarian cancer. The inheritance of FPC is mostly autosomal dominant and with a heterogeneous phenotype. The major gene defect is yet to be identified, although germline mutations in BRCA2, PALB2 and ATM are causative in some FPC families. Expert consensus conferences considered it appropriate to screen for pancreatic cancer in high-risk individuals using a multidisciplinary approach under research protocol conditions. However, neither biomarkers nor reliable imaging modalities for the detection of high-grade precursor lesions are yet available. Most screening programmes are currently based on findings from endoscopic ultrasonography and MRI, and data has demonstrated that precursor lesions of pancreatic cancer can be identified. No consensus exists regarding the age to initiate or stop screening and the optimal intervals for follow-up. Timing and extent of surgery as a treatment for FPC are debated. This Review focuses on the clinical phenotype of FPC, its histopathological characteristics, known underlying genetic changes and associated genetic counselling and screening.

German national case collection for familial pancreatic cancer (FaPaCa): ten years experience

Familial pancreatic cancer (FPC) is a rare hereditary tumor syndrome. The 10-years experience of the national case collection for familial pancreatic cancer of Germany (FaPaCa) is reported. Since 1999 FaPaCa has collected families with at least two first-degree relatives with confirmed pancreatic cancer (PC), who did not fulfill the criteria of other hereditary tumor syndromes. Histopathological verification of tumor diagnoses, and genetic counseling were prerequisites for enrollment of families in FaPaCa. 94 of 452 evaluated families fulfilled the criteria for partaking in FaPaCa. PC represented the sole tumor entity in 38 (40%) families. In 56 families additional tumor types occurred, including breast cancer (n = 28), colon cancer (n = 20) and lung cancer (n = 11). In 70 (74%) families the pattern of inheritance was consistent with an autosomal dominant trait. Compared to the preceding generation, a younger age of onset was observed in the offspring of PC patients (median: 57 vs. 69 years), indicating anticipation. Mutation analyses of BRCA2, PALB2, CDKN2a, RNASEL, STK11, NOD2, CHEK2 and PALLD, revealed deleterious causative germline mutations of BRCA2 and PALB2 in 2 of 70 (3%) and 2 of 41 (4.9%) German FPC families, respectively. Prospective PC screening with EUS, MRI and MRCP detected precancerous lesions (IPMN, multifocal PanIN2/3) or carcinoma in 5.5% (4 of 72) to 12.5% (9 of 72) of individuals at risk, depending on histological verification. Appropriate inclusion of families at high risk for PC in registries, such as FaPaCa, provides a unique and excellent tool to gain clinical and genetic knowledge of FPC. Focused research projects can be conducted most efficiently, when data of different FPC registries are combined.

Magnetic resonance imaging surveillance detects early-stage pancreatic cancer in carriers of a p16-Leiden mutation

BACKGROUND & AIMS

Surveillance of high-risk groups for pancreatic cancer might increase early detection and treatment outcomes. Individuals with germline mutations in p16-Leiden have a lifetime risk of 15% to 20% of developing pancreatic cancer. We assessed the feasibility of detecting pancreatic cancer at an early stage and investigated the outcomes of patients with neoplastic lesions.

METHODS

Individuals with germline mutations in p16-Leiden (N = 79; 31 male; mean age, 56 years; range, 39-72 years) were offered annual surveillance by magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP). Those found to have neoplastic lesions were offered options for surgery or intensive follow-up. Individuals found to have possible neoplastic lesions were examined again by MRI/MRCP within 2 to 4 months.

RESULTS

After a median follow-up period of 4 years (range, 0-10 years), pancreatic cancer was diagnosed in 7 patients (9%). The mean age at diagnosis was 59 years (range, 49-72 years). Three of the tumors were present at the first examination, and 4 were detected after a negative result in the initial examination. All 7 patients had a resectable lesion; 5 underwent surgery, 3 had an R0 resection, and 2 had lymph node metastases. Possible precursor lesions (ie, duct ectasias, based on MRCP) were found in 9 individuals (11%).

CONCLUSIONS

MRI/MRCP detects small, solid pancreatic tumors and small duct ectasias. Although surveillance increases the rate of resectability, carriers of a p16-Leiden mutation develop aggressive tumors.

Upper gastrointestinal cancer predisposition syndromes

Malignancies of the upper gastrointestinal tract form a heterogeneous group of cancers characterized by unique epidemiology and biology. Despite these differences, survival for advanced disease remains poor across the panel of diseases, from cancers of the esophagus, stomach, pancreas, and, until recently, even gastrointestinal stromal tumors. Genetic predisposition syndromes associated with these diseases comprise an emerging subset of these diseases that may provide valuable information on cause and etiology. They may provide insight into molecular drivers for the disease, or disease subtypes, and also insights into novel gene/environment interactions. This review summarizes the current understanding of genetic predisposition syndromes of cancers of the upper gastrointestinal tract.

[Pancreatic cancer]

About 7200 new cases of pancreatic adenocarcinomas are diagnosed each year in France. At the time of diagnosis, an efficient carcinologic surgery will not be possible for nearly 80% of patients, in relation to loco-regional extension or metastatic dissemination. After surgical resection, the median survival of resected patients ranges from 12 to 20 months, with a high rate of relapses. Currently, the use of radiotherapy for patients with pancreatic cancer is controversial. In adjuvant setting, the standard treatment is six months of chemotherapy with FUFOL or gemcitabine. Chemoradiation (CRT) may improve the survival of patients with incompletely resected tumors (R1). This must be validated in a prospective trial. Neoadjuvant CRT is a promising treatment but always under evaluation. For the treatment of patients with locally advanced tumors, there is not a standart treatment. A strategy of initial chemotherapy followed by CRT for non progressive patients is under evaluation. Whereas in the first trials of CRT large fields were used, the current trend is to reduce the treated volumes to improve tolerance. The delineation of target volumes has been improved by the use of simulation CT. The aims of this work are to precise the radio-anatomical particularities, the pattern of spread of pancreatic cancer and the principles of 3D conformal radiotherapy illustrated with a clinical case.

Prevalence of BRCA2 and CDKN2a mutations in German familial pancreatic cancer families

Previous small scale studies reported that deleterious BRCA2 and CDKN2a germline mutations contribute to a subset of families with inherited pancreatic cancer. As the prevalence of those mutations in the setting of familial pancreatic cancer is still not well defined for the German population, we evaluated the presence of BRCA2 and CDKN2a germline mutations in a large cohort of familial pancreatic cancer (FPC) families from the German National Case Collection for Familial Pancreatic Cancer (FaPaCa). Fifty-six FPC families with at least two-first-degree relatives with confirmed pancreatic cancer that did not fulfill the criteria of other tumor predisposition syndromes, were analyzed for BRCA2 and CDKN2a germline mutations by DHPLC and/or direct sequencing. No deleterious CDKN2a mutations were identified in our families suggesting that CDKN2a mutations are unlikely to predispose PC in FPC families without melanoma. No deleterious BRCA2 mutations, but 6 unclassified variants, were detected in our FPC collection. Combining the prevalence of deleterious BRCA2 germline mutations from our previous separate study with the data from this study we were able to much more accurately estimate the BRCA2 carrier frequency for FPC families in the German population. A total of two mutations and 6 unclassified variants (mutation range: 2.8-11.4%) were thus identified in 70 German FPC families, indicating that the prevalence of BRCA2 mutations in the German FPC population is less frequent than previously reported.

LKB1 catalytic activity contributes to estrogen receptor alpha signaling

The tumor suppressor serine-threonine kinase LKB1 is mutated in Peutz-Jeghers syndrome (PJS) and in epithelial cancers, including hormone-sensitive organs such as breast, ovaries, testes, and prostate. Clinical studies in breast cancer patients show low LKB1 expression is related to poor prognosis, whereas in PJS, the risk of breast cancer is similar to the risk from germline mutations in breast cancer (BRCA) 1/BRCA2. In this study, we investigate the role of LKB1 in estrogen receptor alpha (ERalpha) signaling. We demonstrate for the first time that LKB1 binds to ERalpha in the cell nucleus in which it is recruited to the promoter of ERalpha-responsive genes. Furthermore, LKB1 catalytic activity enhances ERalpha transactivation compared with LKB1 catalytically deficient mutants. The significance of our discovery is that we demonstrate for the first time a novel functional link between LKB1 and ERalpha. Our discovery places LKB1 in a coactivator role for ERalpha signaling, broadening the scientific scope of this tumor suppressor kinase and laying the groundwork for the use of LKB1 as a target for the development of new therapies against breast cancer.

Resectability of presymptomatic pancreatic cancer and its relationship to onset of diabetes: a retrospective review of CT scans and fasting glucose values prior to diagnosis

BACKGROUND

The timeline of progression of pancreatic cancer from resectable to unresectable disease is unknown. New-onset diabetes often occurs in pancreatic cancer. It is unclear if the cancer is resectable at the onset of diabetes. We (a) determined the resectability of pancreatic cancer on abdominal CT scans done prior to clinical diagnosis and (b) correlated resectability with onset of diabetes.

METHODS

All CT scans done at diagnosis or before pancreatic cancer diagnosis were reviewed and pancreatic changes classified as normal, potentially resectable, or unresectable pancreatic cancer. Fasting blood glucose values obtained at and prior to diagnosis were available in 18 patients. The date of onset of diabetes and the interval between onset of diabetes and diagnosis of cancer were noted.

RESULTS

Thirty patients fulfilled inclusion criteria. Prior to diagnosis, 28 patients had 38 CT scans done at a median of 18 months (range 1-41) before cancer diagnosis. At cancer diagnosis, only 7/30 patients could undergo margin-negative surgical resection. CT scans done >/=6 months prior to diagnosis showed either a normal pancreas (N = 20) or a resectable mass (N = 6); none had unresectable cancer. The mean interval between onset of diabetes and diagnosis of pancreatic cancer was 10 months (range 5-29 months). At the onset of diabetes, 3 patients had normal pancreas, 6 had resectable, and 4 had unresectable pancreatic cancer.

CONCLUSIONS

Pancreatic cancer is frequently undetectable or resectable on CT scans done >/=6 months prior to clinical diagnosis. At onset of diabetes, pancreatic cancers are generally resectable.

Assessment of celecoxib pharmacodynamics in pancreatic cancer

Cyclooxygenase-2 (COX-2) inhibitors are being developed as chemopreventive and anticancer agents. This study aimed to determine the biological effect of the COX-2 inhibitor celecoxib in pancreatic cancer as an early step to the further development of the agent in this disease. Eight patients scheduled for resection of an infiltrating adenocarcinoma of the pancreas were randomized to receive celecoxib at a dose of 400 mg twice daily or placebo for 5 to 15 days before the surgery. In addition, carcinomas from nine additional patients were xenografted in nude mice, expanded, and treated with vehicle or celecoxib for 28 days. Celecoxib markedly decreased the intra-tumor levels of prostaglandin E2 in patient carcinomas and in the heterotransplanted xenografts. However, this effect did not result in inhibition of cell proliferation or microvessel density (as assessed by Ki67 and CD31 staining). In addition, a panel of markers, including bcl-2, COX-1, COX-2, and VEGF, did not change with treatment in a significant manner. Furthermore, there was no evidence of antitumor effects in the xenografted carcinomas. In summary, celecoxib efficiently inhibited the synthesis of prostaglandin E2 both in pancreatic cancer surgical specimens and in xenografted carcinomas but did not exert evident antitumor, antiproliferative, or antiangiogenic effect as a single agent. The direct pancreatic cancer xenograft model proved to be a valuable tool for drug evaluation and biological studies and showed similar results to those observed in resected pancreatic cancer specimens.

Screening for early pancreatic neoplasia in high-risk individuals: a prospective controlled study

BACKGROUND & AIMS

Individuals with a strong family history of pancreatic cancer and persons with Peutz-Jeghers syndrome (PJS) have an increased risk for pancreatic cancer. This study screened for early pancreatic neoplasia and compared the pancreatic abnormalities in high-risk individuals and control subjects.

METHODS

High-risk individuals with PJS or a strong family history of pancreatic cancer were prospectively evaluated with baseline and 12-month computed tomography (CT) scan and endoscopic ultrasonography (EUS). If EUS was abnormal, EUS-fine-needle aspiration and endoscopic retrograde cholangiopancreatography (ERCP) were performed. Surgery was offered to patients with potentially neoplastic lesions. Radiologic findings and pathologic diagnoses were compared. Patients undergoing EUS and/or ERCP for benign non-pancreatic indications were concurrently enrolled as control subjects.

RESULTS

Seventy-eight high-risk patients (72 from familial pancreatic cancer kindreds, 6 PJS) and 149 control patients were studied. To date, 8 patients with pancreatic neoplasia have been confirmed by surgery or fine-needle aspiration (10% yield of screening); 6 patients had 8 benign intraductal papillary mucinous neoplasms (IPMNs), 1 had an IPMN that progressed to invasive ductal adenocarcinoma, and 1 had pancreatic intraepithelial neoplasia. EUS and CT also diagnosed 3 patients with 5 extrapancreatic neoplasms. At EUS and ERCP abnormalities suggestive of chronic pancreatitis were more common in high-risk patients than in control subjects.

CONCLUSIONS

Screening EUS and CT diagnosed significant asymptomatic pancreatic and extrapancreatic neoplasms in high-risk individuals. IPMN should be considered a part of the phenotype of familial pancreatic cancer. Abnormalities suggestive of chronic pancreatitis are identified more commonly at EUS and ERCP in high-risk individuals.

Analysis of co-aggregation of cancer based on registry data

OBJECTIVE

An exploratory analysis of co-aggregation of cancers using registry-based data.

METHODS

We utilized sibships from over 18,000 families who had been recruited to the NCI-sponsored multi-institutional Cancer Genetics Network. The analysis assesses co-aggregation at the individual and family level and adjusts for ascertainment.

RESULTS

We found statistically significant familial co-aggregation of lung cancer with pancreatic (adjusted p < 0.001), prostate (adjusted p < 0.003), and colorectal cancers (adjusted p = 0.004). In addition, we found significant familial co-aggregation of pancreatic and colorectal cancers (adjusted p = 0.018), and co-aggregation of hematopoietic and (non-ovarian) gynecologic cancers (adjusted p = 0.01).

CONCLUSION

This analysis identified familial aggregation of cancers for which a genetic component has yet to be established.

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.

Genetics of hereditary pancreatic carcinoma

Several tumor syndromes are known to have an increased incidence of pancreatic carcinoma. Unfortunately, the incidence of pancreatic carcinoma almost equals its mortality. Because of intense research activities in the past decade, several genetic alterations have been identified that are responsible for the so-called sporadic pancreatic carcinoma development. National and international research activities only recently have begun focusing on the molecular pathogenesis of hereditary risk factors for pancreatic carcinoma. It is hoped that these genetic studies will aid the development of clinical management strategies for pancreatic carcinoma prevention.

Hereditary cancer predisposition syndromes

Cancer genetics is increasingly becoming integrated into the practice of modern medical oncology. The ability to distinguish a growing proportion of the 5% to 10% of all cancers that develop in individuals who have inherited a genetic mutation conferring heightened susceptibility to specific cancers may permit targeted efforts in cancer surveillance and prevention. While these individuals comprise a small proportion of the overall burden of cancer, strategies successful in reducing their remarkable cancer risks may be generalizable to the broader population. In this review, we highlight the most common hereditary cancer syndromes, most attributable to genes inherited in an autosomal dominant manner with incomplete penetrance, and a number of rare syndromes in which particular progress has been made. The prevalence, penetrance, tumor spectrum, and underlying genetic defects are discussed and summarized in a large table in which a more comprehensive enumeration of syndromes is provided.

Overexpression of the nuclear receptor coactivator AIB1 (SRC-3) during progression of pancreatic adenocarcinoma

PURPOSE

The nuclear receptor coactivator amplified in breast cancer 1 (AIB1) was found to be amplified and overexpressed in breast and some other epithelial tumors. We have reported that expression of AIB1 is rate limiting for growth factor, as well as hormone signaling. Here, we assess the involvement of AIB1 in the development of pancreatic adenocarcinoma.

EXPERIMENTAL DESIGN

We investigated expression levels of AIB1 protein and mRNA in pancreatic cancer cell lines and in a series of archival pancreatic adenocarcinoma (n=78), pancreatic intraepithelial neoplasia (n=93), pancreatitis (n=28), and normal pancreas tissues (n=52). We also determined AIB1 gene copy numbers by fluorescence in situ hybridization in a subset of cases.

RESULTS

In normal pancreas ducts, we rarely found detectable levels of AIB1 mRNA or protein (<6% of the samples). In pancreatitis and low-grade intraepithelial neoplasia, we found an increased frequency of AIB1 expression (>14 and >23%, respectively) relative to normal tissues (P < 0.01). Adenocarcinoma, as well as high-grade intraepithelial neoplasia, showed increased levels as well as the highest frequency of AIB1 expression with >65% of samples positive for mRNA and protein (P < 0.0001 relative to the other groups). An increased copy number of the AIB1 gene, observed in 37% of cancers, may account for a portion of the increase in expression.

CONCLUSIONS

AIB1 overexpression is frequent in pancreatic adenocarcinoma and its precursor lesions. On the basis of its rate-limiting role for the modulation of growth factor signals, we propose a major role of AIB1 in the multistage progression of pancreatic cancer.

Genetics of hereditary pancreatic carcinoma

Several tumor syndromes are known to have an increased incidence of pancreatic carcinoma. Unfortunately, the incidence of pancreatic carcinoma almost equals its mortality. Because of intense research activities in the past decade, several genetic alterations have been identified that are responsible for the so-called sporadic pancreatic carcinoma development. National and international research activities only recently have begun focusing on the molecular pathogenesis of hereditary risk factors for pancreatic carcinoma. It is hoped that these genetic studies will aid the development of clinical management strategies for pancreatic carcinoma prevention.

A new indication for pancreas transplantation: high grade pancreatic dysplasia

A 42-yr-old male presented with a family history of pancreatic carcinoma inherited an autosomal dominant pattern. The development of endocrine and exocrine pancreatic insufficiency served as early markers for neoplastic transformation. Screening endoscopic ultrasound and ERCP showed abnormalities suggestive of pancreatic dysplasia. Total pancreatectomy was performed and pathology confirmed carcinoma in situ, also known as high-grade pancreatic ductal dysplasia or Pan IN-3. The patient's post-operative course was complicated by life threatening, brittle diabetes. Pancreas transplantation was successfully performed. One year following transplantation, the patient has excellent pancreas graft function. He remains insulin free and has no signs of malignancy. Total pancreatectomy followed by pancreas transplantation is a viable therapeutic option for patients in the dysplastic but still pre-malignant phase of familial pancreatic adenocarcinoma who develop hypoglycemic unawareness following total pancreatectomy.

CDKN2A germline mutations in familial pancreatic cancer

OBJECTIVE

To evaluate the prevalence of mutations in the CDKN2A gene encoding p16 and p14 in familial pancreatic cancer (FPC).

SUMMARY BACKGROUND DATA

The genetic basis of FPC is still widely unknown. Recently, it has been shown that germline mutations in the p16 tumor suppressor gene can predispose to pancreatic cancer. The presence of p14 germline mutations has yet not been determined in this setting.

METHODS

Eighteen families with at least two first-degree relatives with histologically confirmed pancreatic cancer and five families with at least one patient with pancreatic cancer and another first-degree relative with malignant melanoma of the German National Case Collection for Familial Pancreatic Cancer were analyzed for CDKN2A germline mutations including p16 and p14 by direct DNA sequencing. All participating family members were genetically counseled and evaluated by a three-generation pedigree.

RESULTS

None of 18 FPC families without malignant melanoma revealed p16 mutations, compared to 2 of 5 families with pancreatic cancer and melanoma. Truncating p16 germline mutations Q50X and E119X were identified in the affected patients of pancreatic cancer plus melanoma families. None of the 23 families revealed p14 germline mutations.

CONCLUSIONS

CDKN2A germline mutations are rare in FPC families. However, these data provide further evidence for a pancreatic cancer-melanoma syndrome associated with CDKN2A germline mutations affecting p16. Thus, all members of families with combined occurrence of pancreatic cancer and melanoma should be counseled and offered screening for p16 mutations to identify high-risk family members who should be enrolled in a clinical screening program.

Hereditary cancer syndromes of the gastrointestinal system

Gastrointestinal (GI) malignancies account for a large percentage of the cancer burden in the United States. Although the majority of cancer cases are sporadic, approximately 5% to 10% of cancer results from inherited genetic mutations. There are several hereditary cancer syndromes of the GI tract that have been identified. To date, the genetics of colorectal cancer and its associated hereditary cancer syndromes have been characterized in detail, and effective screening modalities and recommendations have been incorporated into standards of care. Today, scientists are beginning to understand the genetic basis of pancreatic and gastric cancer, and in some cases have identified a number of their associated inherited cancer syndromes. Information about cancer genetics and hereditary cancer syndromes not only will provide advanced practice nurses with knowledge of these diseases but also, more importantly, will provide opportunities to improve patient care by providing patients with treatment options and opportunities for the early detection and prevention of cancer.

Cyclooxygenase 2 expression in pancreatic adenocarcinoma and pancreatic intraepithelial neoplasia: an immunohistochemical analysis with automated cellular imaging

We immunohistochemically examined material from 36 pancreata (adenocarcinomas, 30 lesions; pancreatic intraepithelial neoplasia [PanIN], 65; normal pancreatic ducts, 30) for cyclooxygenase 2 (COX-2) with an automated platform. We analyzed 7 to 10 discrete foci and generated an average percentage of positive cells and average staining intensity for each lesion. These 2 values were then multiplied to create an overall "HistoScore" for each lesion. COX-2 demonstrated considerable heterogeneity of expression between and within cases. The overall average percentage of positive cells in adenocarcinomas was 47.3%; in PanINs, 36.3%; and in normal ducts, 19.2%. COX-2 was expressed in more than 20% of cells in 23 adenocarcinomas (77%), 42 PanINs (65%), and 12 normal ducts (40%). The overall average HistoScore for adenocarcinomas was 6.1; for PanINs, 5.4; and for normal ducts, 3.5. Significant differences in COX-2 expression were demonstrable in adenocarcinomas vs normal ducts, PanINs vs normal ducts, and PanIN 2/3 vs PanIN 1a/1b. In general, the pattern of COX-2 expression increased from normal to PanIN to adenocarcinoma. The up-regulation of COX-2 in a subset of noninvasive precursor lesions makes it a potential target for chemoprevention with selective COX-2 inhibitors.

Evidence for a major gene influencing risk of pancreatic cancer

Family history of pancreatic cancer, the fifth leading cause of cancer death in the United States, confers a 1.5-13-fold higher risk of developing pancreatic cancer. Pancreatic cancer is associated with several genetic syndromes, including hereditary breast cancer (BRCA2), familial atypical multiple mole melanoma (FAMMM) syndrome, Peutz-Jeghers syndrome, hereditary pancreatitis, and hereditary nonpolyposis colorectal cancer (HNPCC). However, these syndromes explain little of the observed familial aggregation of pancreatic cancer. We performed complex segregation analysis on 287 families ascertained through an index case diagnosed with pancreatic cancer at the Johns Hopkins Medical Institutions between January 1, 1994 and December 31, 1999. We tested for the presence of a major gene controlling either the "age-at-onset of pancreatic cancer" of "susceptibility to pancreatic cancer," and incorporated smoking data on kindred members as a covariate. We found evidence for involvement of a major gene in the etiology of pancreatic cancer. Whether inheritance was modeled as "age-at-onset" or "susceptibility," nongenetic transmission models were strongly rejected. However, modeling "age-at-onset" provided a better fit to the observed data than did modeling "susceptibility." The most parsimonious models included autosomal-dominant inheritance of a rare allele. Under the age-at-onset model, approximately 0.7% of the population appears to be at high risk of developing pancreatic cancer due to this putative gene, whereas 0.4% of the population is at high risk under the susceptibility model. Inclusion of smoking as a covariate did not significantly improve the fit of these models. This hospital-based segregation analysis of pancreatic cancer found evidence supporting the role of a rare major gene influencing risk of pancreatic cancer.

Pancreatitis as a risk for pancreatic cancer

Chronic pancreatitis clearly predisposes to pancreatic cancer, with early onset-long duration chronic pancreatitis from cystic fibrosis, TP, and HP conferring the highest risk. Chronic pancreatitis is not a critical step, however, but rather one of several conditions that accelerate the accumulation of critical genetic mutations and chromosomal losses necessary for carcinogenesis. Indeed, other germline mutations, environmental factors such as tobacco smoking and alcohol consumption, or dietary factors may also accelerate the pathway to carcinogenesis, and may be synergistic with the conditions created by chronic pancreatitis. Because patients with chronic pancreatitis are at high risk of pancreatic cancer, the physician is faced with decisions on how to manage this risk. Discontinuing smoking and alcohol consumption, and perhaps dietary modification are obvious recommendations for risk reduction. If, however, the patient is older and already in a very high-risk category (e.g., long-standing HP), then screening for cancers must be considered. Inclusion in multicenter trials is recommended, and information on ongoing studies can be obtained through the office of Dr. Whitcomb, or as posted on www.pancreas.org.

Risk of pancreatic cancer among individuals with a family history of cancer of the pancreas

In a hospital based case-control study of pancreatic cancer in Ontario and Quebec, a total of 174 incident pancreatic cancer cases and 136 healthy controls were compared for their family history of cancer. Information regarding the ages and sites of cancer was taken for 966 first-degree relatives of the cancer cases and for 903 first-degree relatives of the controls. A total of 150 cancer cases were reported among the relatives of the cases, compared to 122 cases among the relatives of the controls (relative risk 1.15; p = 0.23). Pancreatic cancer was the only site statistically in excess in the case relatives, compared to the control relatives (relative risk = 5.0; p = 0.01). The lifetime risk of pancreatic cancer was 4.7% for the first-degree relatives of the pancreatic cancer cases. The risk was 7.2% for relatives of cases diagnosed before age 60, and was 12.3% for relatives of patients with multiple primary cancers (all ages). These individuals comprise a high-risk group for pancreatic cancer and might benefit from enhanced surveillance or chemoprevention. Familial site-specific pancreatic cancer appears to be a distinct genetic entity, but contributes only modestly to the total burden of pancreatic cancer.

Cancer surveillance of patients from familial pancreatic cancer kindreds

The family history can be used to determine which family members warrant surveillance and when to start it. Surveillance should be started at least 1 decade before the earliest age of pancreatic cancer in the family. EUS is the basic, least-invasive surveillance tool; however, findings are similar to those seen in chronic pancreatitis. All patients who have a positive EUS or who have symptoms warrant ERCP. Changes on ERCP of ductal stricturing and clubbed or saccular side branches are suggestive of patients who may need pancreatectomy in the setting of hereditary pancreatic cancer. The goal for surveillance of familial pancreatic cancer patients is to diagnose them before the development of cancer, when they have dysplasia or carcinoma in situ, and to perform a complete pancreatectomy. Timing is crucial for determining when a patient warrants surgery; if performed too early, the patient is put at risk for the morbidity and mortality of a total pancreatectomy, which is not inconsequential. If the patient survives the operation, he or she is often left a brittle diabetic. The alternative of diagnosing too late is more worrisome because the patient dies of pancreatic cancer. An essential ingredient to a good patient outcome is a team approach to these patients, using gastroenterologists, surgeons, and pathologists who have expertise and interest in pancreatic disease.