Biomarkers of Chronic Pancreatitis: A systematic literature review.

BACKGROUND: Chronic pancreatitis (CP) does not have diagnostic or prognostic biomarkers. CP is the end stage of a progressive inflammatory syndrome that is diagnosed at late stages by morphologic features. To diagnose earlier stages of the disease, a new mechanistic definition was established based on identifying underlying pathogenic processes and biomarker evidence of disease activity and stage. Although multiple risk factors are known, the corresponding biomarkers needed to make a highly accurate diagnosis of earlier disease stages have not been established. The goal of this study is to systematically analyze the literature to identify the most likely candidates for development into biomarkers of CP. METHODS: We conducted a systematic review of candidate analytes from easily accessible biological fluids and identified 67 studies that compared CP to nonpancreatic-disease controls. We then ranked candidate biomarkers for sensitivity and specificity by area under the receiver operator curves (AUROCs). RESULTS: Five biomarkers had a large effect size (an AUROC > 0.96), whereas 30 biomarkers had a moderate effect size (an AUROC between 0.96 and 0.83) for distinguishing CP cases from controls or other diseases. However, the studies reviewed had marked variability in design, enrollment criteria, and biospecimen sample handling and collection. CONCLUSIONS: Several biomarkers have the potential for evaluation in prospective cohort studies and should be correlated with risk factors, clinical features, imaging studies and outcomes. The Consortium for the Study of Chronic Pancreatitis, Diabetes and Pancreas Cancer provides recommendations for avoiding design biases and heterogeneity in sample collection and handling in future studies.

Phases of Metabolic and Soft Tissue Changes in Months Preceding a Diagnosis of Pancreatic Ductal Adenocarcinoma.

BACKGROUND & AIMS: Identifying metabolic abnormalities that occur before pancreatic ductal adenocarcinoma (PDAC) diagnosis could increase chances for early detection. We collected data on changes in metabolic parameters (glucose, serum lipids, triglycerides; total, low-density, and high-density cholesterol; and total body weight) and soft tissues (abdominal subcutaneous fat [SAT], adipose tissue, visceral adipose tissue [VAT], and muscle) from patients 5 years before the received a diagnosis of PDAC. METHODS: We collected data from 219 patients with a diagnosis of PDAC (patients) and 657 healthy individuals (controls) from the Rochester Epidemiology Project, from 2000 through 2015. We compared metabolic profiles of patients with those of age- and sex-matched controls, constructing temporal profiles of fasting blood glucose, serum lipids including triglycerides, cholesterol profiles, and body weight and temperature for 60 months before the diagnosis of PDAC (index date). To construct the temporal profile of soft tissue changes, we collected computed tomography scans from 68 patients, comparing baseline (>18 months before diagnosis) areas of SAT, VAT, and muscle at L2/L3 vertebra with those of later scans until time of diagnosis. SAT and VAT, isolated from healthy individuals, were exposed to exosomes isolated from PDAC cell lines and analyzed by RNA sequencing. SAT was collected from KRAS+/LSLG12D P53flox/flox mice with PDACs, C57/BL6 (control) mice, and 5 patients and analyzed by histology and immunohistochemistry. RESULTS: There were no significant differences in metabolic or soft tissue features of patients vs controls until 30 months before PDAC diagnosis. In the 30 to 18 months before PDAC diagnosis (phase 1, hyperglycemia), a significant proportion of patients developed hyperglycemia, compared with controls, without soft tissue changes. In the 18 to 6 months before PDAC diagnosis (phase 2, pre-cachexia), patients had significant increases in hyperglycemia and decreases in serum lipids, body weight, and SAT, with preserved VAT and muscle. In the 6 to 0 months before PDAC diagnosis (phase 3, cachexia), a significant proportion of patients had hyperglycemia compared with controls, and patients had significant reductions in all serum lipids, SAT, VAT, and muscle. We believe the patients had browning of SAT, based on increases in body temperature, starting 18 months before PDAC diagnosis. We observed expression of uncoupling protein 1 (UCP1) in SAT exposed to PDAC exosomes, SAT from mice with PDACs, and SAT from all 5 patients but only 1 of 4 controls. CONCLUSIONS: We identified 3 phases of metabolic and soft tissue changes that precede a diagnosis of PDAC. Loss of SAT starts 18 months before PDAC identification, and is likely due to browning. Overexpression of UCP1 in SAT might be a biomarker of early-stage PDAC, but further studies are needed.

Risk of Pancreatic Cancer in Patients With Pancreatic Cysts and Family History of Pancreatic Cancer.

BACKGROUND & AIMS: A diagnosis of pancreatic cancer in a first-degree relative increases an individuals' risk of this cancer. However, it is not clear whether this cancer risk increases in individuals with pancreatic cystic lesions who have a first-degree relative with pancreatic cancer. The Fukuoka criteria are used to estimate risk of pancreatic cancer for patients with pancreatic cystic lesions: individuals with cysts with high risk or worrisome features (Fukuoka positive) have a higher risk of pancreatic cancer than individuals without these features (Fukuoka negative). We aimed to compare the risk of pancreatic cancer and surgery based on presence or absence of pancreatic cystic lesions and a first-degree relative with pancreatic cancer. METHODS: We performed a retrospective study of patients seen at the Mayo Clinic in Rochester, Minnesota, from January 1, 2000, through December 31, 2012. We identified individuals with: pancreatic cystic lesions and first-degree relative with pancreatic cancer (group 1, n = 269), individuals with pancreatic cystic lesions but no first-degree relative with pancreatic cancer (group 2, n = 1195), and individuals without pancreatic cystic lesions but with a first-degree relative with pancreatic cancer (group 3, n = 720). We compared, among groups, as well among patients with cysts classified according to Fukuoka criteria, proportions of individuals who developed pancreatic cancer or underwent pancreatic surgery within a 5-year period. RESULTS: A significantly higher proportion of individuals in group 1 developed pancreatic cancer during the 5-year period than in group 3 (6.64% vs 1.69%; P = .03); there was no significant difference between the percentage of individuals in group 1 vs group 2 who developed pancreatic cancer (6.64% vs 4.05%; P = .41). There was no significant difference in pancreatic cancer development among individuals with Fukuoka-positive cysts with vs without a family history of pancreatic cancer (P = .39). There was no significant difference in the proportion of patients in group 1 vs group 2 who underwent pancreatic surgery for their pancreatic cyst over the 5-year period (14.37% vs 11.80%; P = .59). Among patients with Fukuoka-negative cysts, a significantly higher proportion underwent surgery in group 1 than in group 2 (10.90% vs 5.90%; P = .03). However, among patients with Fukuoka-positive cysts, there was no difference in proportions of patients who underwent surgery between groups 1 and 2 (P = .66). CONCLUSIONS: In a retrospective study of patients with pancreatic cysts and/or cancer, we found that a family history of pancreatic cancer does not affect 5-year risk of pancreatic cancer in patients with pancreatic cystic lesions. Despite this, among patients with Fukuoka-negative cysts, a higher proportion of those with a family history of pancreatic cancer undergo surgery than patients without family history of pancreatic cancer.

Salivary Biomarker Evaluation of Chronic Pancreatitis Patients Reveals Alterations in Human Proteins, Cytokines, Prostaglandin E2 Levels, and Bacterial Diversity.

OBJECTIVES: Chronic pancreatitis (CP) is a chronic fibroinflammatory condition of the pancreas difficult to diagnose in early stages. Novel biomarkers useful to facilitate early diagnosis or treatment responses may be found in biofluids. Although saliva can be easily and noninvasively collected from patients, useful salivary biomarkers from CP patients have not yet been identified. METHODS: Here, we analyzed the proteome by quantitative proteomics, cytokine/chemokine levels by Luminex analysis, prostaglandin E2 (PGE2) levels by a mass spectrometry-based assay, and bacterial species diversity by 16S ribosomal ribonucleic acid sequencing in saliva samples from confirmed CP patients and healthy controls. RESULTS: Our results indicate the presence of various differentially expressed proteins, cytokines/chemokines, and a loss of oral bacterial diversity in the saliva of CP patients. The PGE2 levels trend toward elevation in CP patients. Area under the receiver operating characteristic curve models for proteomic, cytokine, and PGE2 assays ranged from 0.59 to 0.90. CONCLUSIONS: Collectively, our studies identify a range of putative CP biomarkers and alterations in human saliva requiring further validation. The biomarker discovery approaches we used might lead to identification of biomarkers useful for CP diagnosis and monitoring.