A population-based description of familial clustering of pancreatic cancer

Resistance to Gemcitabine in Pancreatic Ductal Adenocarcinoma: A Physiopathologic and Pharmacologic Review

Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive tumor with a poor prognosis and inadequate response to treatment. Many factors contribute to this therapeutic failure: lack of symptoms until the tumor reaches an advanced stage, leading to late diagnosis; early lymphatic and hematic spread; advanced age of patients; important development of a pro-tumoral and hyperfibrotic stroma; high genetic and metabolic heterogeneity; poor vascular supply; a highly acidic matrix; extreme hypoxia; and early development of resistance to the available therapeutic options. In most cases, the disease is silent for a long time, andwhen it does become symptomatic, it is too late for ablative surgery; this is one of the major reasons explaining the short survival associated with the disease. Even when surgery is possible, relapsesare frequent, andthe causes of this devastating picture are the low efficacy ofand early resistance to all known chemotherapeutic treatments. Thus, it is imperative to analyze the roots of this resistance in order to improve the benefits of therapy. PDAC chemoresistance is the final product of different, but to some extent, interconnected factors. Surgery, being the most adequate treatment for pancreatic cancer and the only one that in a few selected cases can achieve longer survival, is only possible in less than 20% of patients. Thus, the treatment burden relies on chemotherapy in mostcases. While the FOLFIRINOX scheme has a slightly longer overall survival, it also produces many more adverse eventsso that gemcitabine is still considered the first choice for treatment, especially in combination with other compounds/agents. This review discusses the multiple causes of gemcitabine resistance in PDAC.

Screening for pancreatic cancer: a review for general clinicians

Pancreatic cancer (PC) is an exceptionally lethal malignancy with increasing incidence and mortality worldwide. One of the principal challenges in the treatment of PC is that the diagnosis is usually made at a late stage when potentially curative surgical resection is no longer an option. General clinicians including internists and family physicians are well positioned to identify high-risk individuals and refer them to centers with expertise in PC screening and treatment where screening modalities can be employed. Here, we provide an up-to-date review of PC precursor lesions, epidemiology, and risk factors to empower the general clinician to recognize high-risk patients and employ risk reduction strategies. We also review current screening guidelines and modalities and preview progress that is being made to improve screening tests and biomarkers. It is our hope that this review article will empower the general clinician to understand which patients need to be screened for PC, strategies that may be used to reduce PC risk, and which screening modalities are available in order to diminish the lethality of PC.

Familial pancreatic cancer risk: a population-based study in Utah

INTRODUCTION

Pancreas adenocarcinoma (PC) has an undefined hereditary component. We quantified the familial risk of PC among relatives of patients diagnosed with PC and stratified it based on anatomic location of PC and age and sex of the proband.

METHODS

This is a retrospective, population-based, case-control study of PC diagnosed in Utah between 1980 and 2011. The Utah population database and cancer registry were used to identify index patients with PC. The risk of PC in first-degree relatives (FDRs), second-degree relatives (SDRs), and first cousins (FCs) of probands was compared with randomly selected sex- and age-matched population controls.

RESULTS

A total of 4,095 patients and 40,933 controls were identified. The relative risk (RR) of PC was 1.76 (95% CI 1.35-2.29) in FDRs, 1.42 (95% CI 1.18-1.7) in SDRs and 1.08 (95% CI 0.95-1.23) in FCs of probands compared to relatives of PC-free controls. The RR were elevated in FDRs (1.96, 95% CI 1.45-2.65), SDRs (1.54, 95% CI 1.19-1.98) and FCs (1.18, 95% CI 1.0-1.64) of female probands. Among probands diagnosed as < 65 years, RR was 2.12 (95% CI 1.37-3.28) in FDRs, 1.94 (95% CI 1.44-2.62) in SDRs, and 1.28 (95% CI 1.0-1.64) in FCs. Overall, the RR for PC was elevated in FDRs regardless of the anatomic location of PC.

DISCUSSION

There is an increased risk of PC in FDR and more distant relatives of patients with PC. Relatives of female patients with PC and patients diagnosed at age < 65 years are at a significantly increased risk of PC.

Pancreatic Adenocarcinoma: Improving Prevention and Survivorship

Pancreatic cancer is a growing problem in oncology, given slowly rising incidence and continued suboptimal outcomes. A concerted effort to reverse this tide will require prevention, early diagnosis, and improved systemic therapy for curable disease. We focus on these aspects in detail in this study. Hereditary pancreatic cancer is an underappreciated area. With the growing use of genomics (both somatic and germline) in cancer care, there is increasing recognition of hereditary pancreatic cancer cases: around 10% of all pancreatic cancer may be related to familial syndromes, such as familial atypical multiple mole and melanoma (FAMMM) syndrome, hereditary breast and ovarian cancer, Lynch syndrome, and Peutz-Jeghers syndrome. Screening and surveillance guidelines by various expert groups are discussed. Management of resectable pancreatic cancer is evolving; the use of multiagent systemic therapies, in the adjuvant and neoadjuvant settings, is discussed. Current and emerging data, along with ongoing clinical trials addressing important questions in this area, are described. Surveillance recommendations based on latest ASCO guidelines are also discussed. Finally, the multimodality management of borderline resectable pancreatic cancer is discussed. The various clinicoanatomic definitions of this entity, followed by consensus definitions, are described. Then, we focus on current opinions and practices around neoadjuvant therapy, discussing chemotherapy and radiation aspects, and the role of surgical resection.

Familial Risk of Biliary Tract Cancers: A Population-Based Study in Utah

BACKGROUND AND OBJECTIVES

Biliary tract cancers (BTC) including, cholangiocarcinoma (CC) and gallbladder cancer (GBC), are rare and highly fatal malignancies. The etiology and inherited susceptibility of both malignancies are poorly understood. We quantified the risk of BTC in first-degree (FDR), second-degree (SDR), and first cousin (FC) relatives of individuals with BTC, stratified by tumor subsite.

METHODS

BTC diagnosed between 1980 and 2011 were identified from the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. Age- and gender-matched BTC-free controls were selected to form the comparison group for determining BTC risk in relatives using Cox regression analysis.

RESULTS

Of the 1302 index patients diagnosed with BTC, 550 (42.2 %) were located in the gallbladder and 752 (57.8 %) were cholangiocarcinomas. There was no elevated risk of BTC (all subsites combined) in FDRs (HR 0.94, 95 % CI 0.29-3.0), SDRs (HR 0.25, 95 % CI 0.06-1.03), and FCs (HR 0.96, 95 % CI 0.61-1.51) of BTC cases compared to cancer-free controls. Similarly, no increased familial risk of GBC or CC was found in relatives of BTC patients stratified by tumor subsite compared to relatives of controls.

CONCLUSIONS

Relatives of BTC patients are not at an increased risk of GBC or CC in a statewide population. This suggests that biliary tract cancer risk is not associated with a familial predisposition and may be mitigated more strongly by environmental modifiers.

Familial pancreatic cancer

Familial pancreatic cancer (FPC) includes those kindreds that contain at least two first-degree relatives with pancreatic ductal adenocarcinoma. At least 12 known hereditary syndromes or genes are associated with increased risk of developing pancreatic cancer, the foremost being BRCA2 and CDKN2A. Research into the identification of mutations in known cancer predisposition genes and through next-generation sequencing has revealed extensive heterogeneity. The development of genetic panel testing has enabled genetic risk assessment and predisposition testing to be routinely offered. Precision oncology has opened the possibility of "incidental" germline mutations that may have implications for family members. However, in both cases, evidence-based recommendations for managing patients and at-risk family members in light of genetic status remain emergent, with current practice based on expert opinion.

Pancreatic Cancer Genetics

Although relatively rare, pancreatic tumors are highly lethal [1]. In the United States, an estimated 48,960 individuals will be diagnosed with pancreatic cancer and 40,560 will die from this disease in 2015 [1]. Globally, 337,872 new pancreatic cancer cases and 330,391 deaths were estimated in 2012 [2]. In contrast to most other cancers, mortality rates for pancreatic cancer are not improving; in the US, it is predicted to become the second leading cause of cancer related deaths by 2030 [3, 4]. The vast majority of tumors arise in the exocrine pancreas, with pancreatic ductal adenocarcinoma (PDAC) accounting for approximately 95% of tumors. Tumors arising in the endocrine pancreas (pancreatic neuroendocrine tumors) represent less than 5% of all pancreatic tumors [5]. Smoking, type 2 diabetes mellitus (T2D), obesity and pancreatitis are the most consistent epidemiological risk factors for pancreatic cancer [5]. Family history is also a risk factor for developing pancreatic cancer with odds ratios (OR) ranging from 1.7-2.3 for first-degree relatives in most studies, indicating that shared genetic factors may play a role in the etiology of this disease [6-9]. This review summarizes the current knowledge of germline pancreatic cancer risk variants with a special emphasis on common susceptibility alleles identified through Genome Wide Association Studies (GWAS).

Risk of associated conditions in relatives of subjects with interstitial cystitis

OBJECTIVES

Urological chronic pelvic pain syndrome includes interstitial cystitis/painful bladder syndrome (IC/PBS), a chronic bladder pain condition of unknown etiology. Interstitial cystitis/painful bladder syndrome can co-occur with a number of associated conditions such as irritable bowel syndrome and fibromyalgia. The purpose of this study was to estimate the heritability of approximately 20 associated conditions in first-degree relatives (and if appropriate, second- and third-degree relatives) of patients with IC/PBS to identify shared genetic contributions for the disease combinations.

METHODS

We used the Utah Population Database, a unique population-based genealogical database that has been linked to electronic health records for the University of Utah Health Sciences Center back in 1994. Interstitial cystitis/painful bladder syndrome probands were identified by the International Classification of Diseases, Ninth Revision code for chronic interstitial cystitis and had genealogy information for 12 of their 14 immediate ancestors. We calculated excess risk of an associated condition in relatives of patients with IC/PBS using relative risk estimates.

RESULTS

We identified 248 IC/PBS probands. We found that 2 associated conditions, myalgia and myositis/unspecified (fibromyalgia) as well as constipation, were in significant excess in the patients with IC/PBS themselves, their first-degree relatives, and their second-degree relatives. The excess risk among relatives between IC/PBS and these associated conditions also held in the converse direction. Excess risk of IC/PBS was observed in the first- and second-degree relatives in probands with myalgia and myositis/unspecified (fibromyalgia) and in probands with constipation.

CONCLUSIONS

These results suggest that myalgia and myositis/unspecified (fibromyalgia) as well as constipation are likely to share underlying genetic factors with IC/PBS.

Racial disparities of pancreatic cancer in Georgia: a county-wide comparison of incidence and mortality across the state, 2000-2011

Understanding the geographic distribution of pancreatic cancer is important in assessing disease burden and identifying high‐risk populations. This study examined the geographic trends of pancreatic cancer incidence, mortality, and mortality‐to‐incidence ratios (MIRs) in Georgia, with a special focus on racial disparities of disease. Directly age‐adjusted pancreatic cancer incidence and mortality rates for Georgia counties (N = 159) were obtained for 2000–2011. Maps of county age‐adjusted disease rates and MIRs were generated separately for African Americans and Caucasians. Cluster analyses were conducted to identify unusual geographic aggregations of cancer cases or deaths. Pearson correlation coefficients were calculated to examine associations between county health factors (e.g., health behaviors, clinical care, and physical environment) and pancreatic cancer incidence or mortality rates. African Americans displayed a significantly higher age‐adjusted incidence (14.6/100,000) and mortality rate (13.3/100,000), compared to Caucasians. Cluster analyses identified five significant incidence clusters and four significant mortality clusters among Caucasians; one significant incidence cluster and two significant mortality clusters were identified among African Americans. Weak but significant correlations were noted between physical environment and pancreatic cancer incidence (ρ = 0.16, P = 0.04) and mortality (ρ = 0.18, P = 0.02) among African Americans. A disproportion burden of pancreatic cancer incidence and mortality was exhibited among African Americans in Georgia. Disease intervention efforts should be implemented in high‐risk areas, such as the southwest and central region of the state. Future studies should assess health behaviors and physical environment in relationship with the spatial distribution of pancreatic cancer.

Familial Pancreatic Adenocarcinoma

Familial pancreatic cancer (FPC) kindreds have at least 2 first-degree relatives with pancreatic ductal adenocarcinoma. Studies of FPC have focused on the discovery of genetic cause and on the management of those at genetically high risk. Research reveals that a half dozen known hereditary syndromes or genes are associated with increased risk of developing pancreatic cancer, the most prominent of which are BRCA2 and CDKN2A. Genetic risk assessment and testing is already available. Owing to limited experience worldwide, guidance is often based on expert opinion, although all agree that research is needed to improve the shaping of options.

Genetic analysis of low BMI phenotype in the Utah Population Database

The low body mass index (BMI) phenotype of less than 18.5 has been linked to medical and psychological morbidity as well as increased mortality risk. Although genetic factors have been shown to influence BMI across the entire BMI, the contribution of genetic factors to the low BMI phenotype is unclear. We hypothesized genetic factors would contribute to risk of a low BMI phenotype. To test this hypothesis, we conducted a genealogy data analysis using height and weight measurements from driver's license data from the Utah Population Data Base. The Genealogical Index of Familiality (GIF) test and relative risk in relatives were used to examine evidence for excess relatedness among individuals with the low BMI phenotype. The overall GIF test for excess relatedness in the low BMI phenotype showed a significant excess over expected (GIF 4.47 for all cases versus 4.10 for controls, overall empirical p-value<0.001). The significant excess relatedness was still observed when close relationships were ignored, supporting a specific genetic contribution rather than only a family environmental effect. This study supports a specific genetic contribution in the risk for the low BMI phenotype. Better understanding of the genetic contribution to low BMI holds promise for weight regulation and potentially for novel strategies in the treatment of leanness and obesity.

Strong evidence for a genetic contribution to late-onset Alzheimer's disease mortality: a population-based study

BACKGROUND

Alzheimer's disease (AD) is an international health concern that has a devastating effect on patients and families. While several genetic risk factors for AD have been identified much of the genetic variance in AD remains unexplained. There are limited published assessments of the familiality of Alzheimer's disease. Here we present the largest genealogy-based analysis of AD to date.

METHODS

We assessed the familiality of AD in The Utah Population Database (UPDB), a population-based resource linking electronic health data repositories for the state with the computerized genealogy of the Utah settlers and their descendants. We searched UPDB for significant familial clustering of AD to evaluate the genetic contribution to disease. We compared the Genealogical Index of Familiality (GIF) between AD individuals and randomly selected controls and estimated the Relative Risk (RR) for a range of family relationships. Finally, we identified pedigrees with a significant excess of AD deaths.

RESULTS

The GIF analysis showed that pairs of individuals dying from AD were significantly more related than expected. This excess of relatedness was observed for both close and distant relationships. RRs for death from AD among relatives of individuals dying from AD were significantly increased for both close and more distant relatives. Multiple pedigrees had a significant excess of AD deaths.

CONCLUSIONS

These data strongly support a genetic contribution to the observed clustering of individuals dying from AD. This report is the first large population-based assessment of the familiality of AD mortality and provides the only reported estimates of relative risk of AD mortality in extended relatives to date. The high-risk pedigrees identified show a true excess of AD mortality (not just multiple cases) and are greater in depth and width than published AD pedigrees. The presence of these high-risk pedigrees strongly supports the possibility of rare predisposition variants not yet identified.

Screening for pancreatic cancer: why, how, and who?

Pancreatic cancer is the fourth most common cause of cancer mortality in the United States, with 5-year survival rates for patients with resectable tumors ranging from 15% to 20%. However, most patients presenting with distant metastases, are not resectable, and have a 5-year survival rate of close to 0%. This demonstrates a need for improved screening to identify pancreatic cancer while the tumor is still localized and amenable to surgical resection. Studies of patients with pancreatic tumors incidentally diagnosed demonstrate longer median survival than tumors discovered only when the patient is symptomatic, suggesting that early detection may improve outcome. Recent evidence from genomic sequencing indicates a 15-year interval for genetic progression of pancreatic cancer from initiation to the metastatic stage, suggesting a sufficient window for early detection. Still, many challenges remain in implementing effective screening. Early diagnosis of pancreatic cancer relies on developing screening methodologies with highly sensitive and specific biomarkers and imaging modalities. It also depends on a better understanding of the risk factors and natural history of the disease to accurately identify high-risk groups that would be best served by screening. This review summarizes our current understanding of the biology of pancreatic cancer relevant to methods available for screening. At this time, given the lack of proven benefit in this disease, screening efforts should probably be undertaken in the context of prospective trials.

Significant evidence for a heritable contribution to cancer predisposition: a review of cancer familiality by site

BACKGROUND/AIMS

Sound and rigorous well-established, and newly extended, methods for genetic epidemiological analysis were used to analyze population evidence for genetic contributions to risk for numerous common cancer sites in Utah. The Utah Population Database (UPDB) has provided important illumination of the familial contribution to cancer risk by cancer site.

METHODS

With over 15 years of new cancer data since the previous comprehensive familial cancer analysis, we tested for excess familial clustering using an expanded Genealogical Index of Familiality (dGIF) methodology that provides for a more informative, but conservative test for the existence of a genetic contribution to familial relatedness in cancer.

RESULTS

Some new cancer sites have been analyzed for the first time, having achieved sufficiently large sample size with additions to the UPDB. This new analysis has identified 6 cancer sites with significant evidence for a heritable contribution to risk, including lip, chronic lymphocytic leukemia, thyroid, lung, prostate, and melanoma.

CONCLUSIONS

Both environmentally and genetically-based familial clustering have clinical significance, and these results support increased surveillance for cancer of the same sites among close relatives of affected individuals for many more cancers than are typically considered.

Screening for pancreatic cancer in a high-risk cohort: an eight-year experience

BACKGROUND

Pancreatic adenocarcinoma is the fourth leading cause of cancer death.

METHODS

A prospective cohort study was undertaken between 2003 and 2011 at a tertiary care centre in Toronto, Canada. Two hundred and sixty-two subjects were enrolled based on an elevated estimated lifetime risk for pancreatic cancer due to known genetic mutations and/or cancer family history. Subjects underwent annual magnetic resonance imaging, followed by additional investigations if abnormal findings were detected. Evidence of malignancy or suspicious macroscopic abnormalities prompted referral for surgical intervention.

RESULTS

Average length of follow-up was 4.2 years, during which 84/262 (32%) subjects demonstrated pancreatic abnormalities. Three participants developed pancreatic adenocarcinoma (one 1.5-cm tumor was resected but recurred, while the other two subjects developed metastatic cancer), and a fourth participant developed a pancreatic neuroendocrine tumor that was resected. Fifteen subjects had radiologic evidence of branch-duct intraductal papillary mucinous neoplasms, of which two underwent surgical resection. Sixty-five subjects had simple pancreatic cysts that have remained stable.

CONCLUSION

Magnetic resonance imaging can detect small pancreatic tumors and cystic lesions, but further improvement in sensitivity is needed. An understanding of the natural history of pre-invasive lesions in members of high-risk families is necessary for developing a more effective screening program.

Molecular characteristics of pancreatic ductal adenocarcinoma

Pancreatic cancer is an almost universally lethal disease and despite extensive research over the last decades, this has not changed significantly. Nevertheless, much progress has been made in understanding the pathogenesis of pancreatic ductal adenocarcinoma (PDAC) suggesting that different therapeutic strategies based on these new insights are forthcoming. Increasing focus exists on designing the so-called targeted treatment strategies in which the genetic characteristics of a tumor guide therapy. In the past, the focus of research was on identifying the most frequently affected genes in PDAC, but with the complete sequencing of the pancreatic cancer genome the focus has shifted to defining the biological function that the altered genes play. In this paper we aimed to put the genetic alterations present in pancreatic cancer in the context of their role in signaling pathways. In addition, this paper provides an update of the recent advances made in the development of the targeted treatment approach in PDAC.