Pancreatic cancer: any prospects for prevention?

Earlier Diagnosis of Pancreatic Cancer: Is It Possible?

Pancreatic ductal adenocarcinoma has a very high mortality rate which has been only minimally improved in the last 30 years. This high mortality is closely related to late diagnosis, which is usually made when the tumor is large and has extensively infiltrated neighboring tissues or distant metastases are already present. This is a paradoxical situation for a tumor that requires nearly 15 years to develop since the first founding mutation. Response to chemotherapy under such late circumstances is poor, resistance is frequent, and prolongation of survival is almost negligible. Early surgery has been, and still is, the only approach with a slightly better outcome. Unfortunately, the relapse percentage after surgery is still very high. In fact, early surgery clearly requires early diagnosis. Despite all the advances in diagnostic methods, the available tools for improving these results are scarce. Serum tumor markers permit a late diagnosis, but their contribution to an improved therapeutic result is very limited. On the other hand, effective screening methods for high-risk populations have not been fully developed as yet. This paper discusses the difficulties of early diagnosis, evaluates whether the available diagnostic tools are adequate, and proposes some simple and not-so-simple measures to improve it.

Phenotype risk scores (PheRS) for pancreatic cancer using time-stamped electronic health record data: Discovery and validation in two large biobanks

BACKGROUND

Traditional methods for disease risk prediction and assessment, such as diagnostic tests using serum, urine, blood, saliva or imaging biomarkers, have been important for identifying high-risk individuals for many diseases, leading to early detection and improved survival. For pancreatic cancer, traditional methods for screening have been largely unsuccessful in identifying high-risk individuals in advance of disease progression leading to high mortality and poor survival. Electronic health records (EHR) linked to genetic profiles provide an opportunity to integrate multiple sources of patient information for risk prediction and stratification. We leverage a constellation of temporally associated diagnoses available in the EHR to construct a summary risk score, called a phenotype risk score (PheRS), for identifying individuals at high-risk for having pancreatic cancer. The proposed PheRS approach incorporates the time with respect to disease onset into the prediction framework. We combine and contrast the PheRS with more well-known measures of inherited susceptibility, namely, the polygenic risk scores (PRS) for prediction of pancreatic cancer.

METHODOLOGY

We first calculated pairwise, unadjusted associations between pancreatic cancer diagnosis and all possible other diagnoses across the medical phenome. We call these pairwise associations co-occurrences. After accounting for cross-phenotype correlations, the multivariable association estimates from a subset of relatively independent diagnoses were used to create a weighted sum PheRS. We constructed time-restricted risk scores using data from 38,359 participants in the Michigan Genomics Initiative (MGI) based on the diagnoses contained in the EHR at 0, 1, 2, and 5 years prior to the target pancreatic cancer diagnosis. The PheRS was assessed for predictability in the UK Biobank (UKB). We tested the relative contribution of PheRS when added to a model containing a summary measure of inherited genetic susceptibility (PRS) plus other covariates like age, sex, smoking status, drinking status, and body mass index (BMI).

RESULTS

Our exploration of co-occurrence patterns identified expected associations while also revealing unexpected relationships that may warrant closer attention. Solely using the pancreatic cancer PheRS at 5 years before the target diagnoses yielded an AUC of 0.60 (95% CI = [0.58, 0.62]) in UKB. A larger predictive model including PheRS, PRS, and the covariates at the 5-year threshold achieved an AUC of 0.74 (95% CI = [0.72, 0.76]) in UKB. We note that PheRS does contribute independently in the joint model. Finally, scores at the top percentiles of the PheRS distribution demonstrated promise in terms of risk stratification. Scores in the top 2% were 10.20 (95% CI = [9.34, 12.99]) times more likely to identify cases than those in the bottom 98% in UKB at the 5-year threshold prior to pancreatic cancer diagnosis.

CONCLUSIONS

We developed a framework for creating a time-restricted PheRS from EHR data for pancreatic cancer using the rich information content of a medical phenome. In addition to identifying hypothesis-generating associations for future research, this PheRS demonstrates a potentially important contribution in identifying high-risk individuals, even after adjusting for PRS for pancreatic cancer and other traditional epidemiologic covariates. The methods are generalizable to other phenotypic traits.

Influence of diet and tobacco smoking on pancreatic cancer incidence in poland in 1960-2008

The aim of the study was to investigate the relationship between pancreatic cancer incidence and selected dietary factors, alcohol consumption, and tobacco smoking in Poland in 1960–2008. Data on pancreatic cancer morbidity were derived from the National Cancer Registry and on food consumption from the national food balance sheets. In 1960–1989 correlations were found between pancreatic cancer incidence rates and energy (0.60 for males and 0.57 for females), cholesterol (0.87 and 0.80), fibre (−0.84 and −0.89) and folate (−0.45 and −0.49) intake, the consumption of total fats (0.94 and 0.91), animal fats (0,90 and 0,82), sugar (0.88 and 0.87), cereals (−0.93 and −0.91), and alcohol (0.86 and 0.82). In 1990–2008 morbidity correlated with the consumption of red meat (0.67 and 0.48), poultry (−0.88 and −0.57), and fruit (−0.62 and −0.50). Correlation with tobacco smoking was observed in the whole studied period (0.55 and 0.44). Increased incidence of pancreatic cancer in 1960–1995 was probably related to adverse dietary patterns up to 1989, especially high consumption of fats, sugar, and alcohol. Further positive changes in the diet such as lowering red meat consumption and increasing fruit consumption could influence incidence reduction in recent years. Also changes in tobacco smoking could affect the morbidity.

Mortality predictions for esophageal, stomach, and pancreatic cancer, Ireland, up to 2015

BACKGROUND AND AIM OF THE STUDY

An analysis was undertaken to predict numbers of esophageal, stomach, and pancreatic cancer deaths and their World age standardized mortality rates (WASMRs) per 100,000 person years (100,000 PY-1) in Ireland for the years 2005, 2010 and 2015.

METHODS

Linear and log-linear Poisson regression models were applied to 1950-2002 Irish cancer mortality data.

RESULTS

By 2015, esophageal cancer WASMR for males is expected to rise to 9.1 100,000 PY-1, but for females to fall to 2.3 100,000 PY-1. In women under 65 yr, the WASMR is expected to decline to 0.8 100,000 PY-1 but to increase to 3.6 100,000 PY-1 in men. The stomach cancer WASMR for males is predicted to decrease to 5.3 100,000 PY-1 and for females to 2.9 100,000 PY-1. In males under 65 yr, the WASMR is predicted to fall to 1.7 100,000 PY-1 and to 1.0 100,000 PY-1 in women. The male WASMR for pancreatic cancer is predicted to decrease to 5.9 100,000 PY-1 and to 4.7 100,000 PY-1 in women. In men under 65 yr, the WASMR is predicted to drop to 1.7 100,000 PY-1 and to fall in women to 1.2 100,000 PY-1.

CONCLUSIONS

Apart from male esophageal cancer, the findings would indicate that declines in Irish WASMRs for these three cancer types are expected to occur by 2015.

Exocrine pancreatic cancer: symptoms at presentation and their relation to tumour site and stage

INTRODUCTION

The need to detect pancreatic cancer at earlier stages is undisputed. We recorded the signs and symptoms of patients presenting with exocrine pancreatic cancer and evaluated their association with clinical characteristics such as tumour site and disease stage.

PATIENTS AND METHODS

All patients (n = 185) with exocrine pancreatic cancer newly diagnosed at five general hospitals in Eastern Spain were prospectively recruited over 5 years. Symptoms were elicited through personal interviews and signs were recorded by the attending physician on admission.

RESULTS

At diagnosis, one third of tumours of the pancreas head were in stage I and another third in stage IV. None of the tumours of the body and tail were in stage I, and over 80% were in stage IV (p < 0.001) . At presentation, the most frequent symptoms were asthenia (86%), anorexia (85%), weight-loss (85%), abdominal pain (79%), and choluria (59%). Cholestatic symptoms were more common in tumours affecting only the pancreatic head (p < 0.001) . There was a clear trend toward more localized tumours with increasing numbers of cholestatic signs (p < 0.001) . Asthenia, anorexia and weight-loss were unrelated to stage. An increased symptom-to-diagnosis interval was associated with more advanced stage (p = 0.048).

CONCLUSIONS

Proper attention to signs and symptoms, especially cholestasis, may help identify patients with pancreatic cancer at an earlier stage. Results also provide a current picture of the semiology of pancreatic cancer which could be of use in studies on the potential of proteomic tests in the early detection of this neoplasm.

Nutrition and diet in the development of gastrointestinal cancer

Diet plays a role in the prevention and development of gastrointestinal cancers. The majority of available research consists of case-control studies, but the number of clinical trials is growing. The dietary recommendations to reduce gastrointestinal cancer risk include lowering total energy, fat, and saturated fat intake; avoidance of grilled and smoked foods; avoidance of alcohol; and increasing intake of fruits, vegetables, and fiber. Studies of esophageal cancer support these dietary approaches, with the exception of dietary fat reduction and increased green tea intake. For gastric cancer, consuming additional fruits and vegetables, including those high in ascorbic acid, may reduce risk, and the capacity for diet to alter Helicobacter pylori infection should be explored. Recent interventional trials do not support a role for high-fiber or low-fat diets in reducing development of colon adenomas, although the evidence does not rule out efficacy at earlier stages of disease. Finally, the evidence for a relationship between pancreatic cancer and diet remains sparse and warrants additional investigation.

DNA methylation as a cancer-specific biomarker: from molecules to populations

Cancer contributes to a large proportion of the mortality and morbidity in the United States and worldwide. Despite advances in diagnosis and treatment of various cancers, early detection and treatment of cancer remain a challenge. Diagnosis of cancer often occurs once the disease has progressed to a point where currently available intervention options provide limited success. Therefore, techniques that enable early detection followed by targeted interventions would influence stage at diagnosis and, in turn, mortality associated with cancer. Identification of molecular biomarkers, especially those that are associated with cancer initiation and progression, shows promise as an effective strategy in this regard. One potential early detection biomarker is DNA methylation of the promoter region of certain cancer-associated genes, which results in gene inactivation. Examination of serum for circulating tumor DNA with abnormal methylation patterns offers a possible method for early detection of several cancers and serves as a point for early intervention and prevention strategies. Additionally, it is imperative to consider how such a screening mechanism can be implemented in populations at risk, especially in resource-poor settings. Thus, the challenge is to validate DNA methylation as a cancer-specific biomarker, with the ultimate goal of designing a research plan that integrates the current knowledge base regarding cancer detection and diagnosis into specific prevention and intervention strategies that can be applied at a population level.