DEPEND study protocol: early detection of patients with pancreatic cancer - a pilot study to evaluate the utility of faecal elastase-1 and 13C-mixed triglyceride breath test as screening tools in high-risk individuals

Determining the feasibility of calculating pancreatic cancer risk scores for people with new-onset diabetes in primary care (DEFEND PRIME): study protocol

INTRODUCTION

Worldwide, pancreatic cancer has a poor prognosis. Early diagnosis may improve survival by enabling curative treatment. Statistical and machine learning diagnostic prediction models using risk factors such as patient demographics and blood tests are being developed for clinical use to improve early diagnosis. One example is the Enriching New-onset Diabetes for Pancreatic Cancer (ENDPAC) model, which employs patients' age, blood glucose and weight changes to provide pancreatic cancer risk scores. These values are routinely collected in primary care in the UK. Primary care's central role in cancer diagnosis makes it an ideal setting to implement ENDPAC but it has yet to be used in clinical settings. This study aims to determine the feasibility of applying ENDPAC to data held by UK primary care practices.

METHODS AND ANALYSIS

This will be a multicentre observational study with a cohort design, determining the feasibility of applying ENDPAC in UK primary care. We will develop software to search, extract and process anonymised data from 20 primary care providers' electronic patient record management systems on participants aged 50+ years, with a glycated haemoglobin (HbA1c) test result of ≥48 mmol/mol (6.5%) and no previous abnormal HbA1c results. Software to calculate ENDPAC scores will be developed, and descriptive statistics used to summarise the cohort's demographics and assess data quality. Findings will inform the development of a future UK clinical trial to test ENDPAC's effectiveness for the early detection of pancreatic cancer.

ETHICS AND DISSEMINATION

This project has been reviewed by the University of Surrey University Ethics Committee and received a favourable ethical opinion (FHMS 22-23151 EGA). Study findings will be presented at scientific meetings and published in international peer-reviewed journals. Participating primary care practices, clinical leads and policy makers will be provided with summaries of the findings.

Utilising Pancreatic Exocrine Insufficiency in the Detection of Resectable Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is usually diagnosed late, leading to a high mortality rate. Early detection facilitates better treatment options. The aim of this UK-based case-control study was to determine whether two validated tests for pancreatic exocrine insufficiency (PEI), namely, the 13C-mixed triglyceride breath test (13C-MTGBT) and a faecal elastase (FE-1) test, can discriminate between patients with resectable PDAC versus healthy volunteers (HVs) along with a comparison group with chronic pancreatitis (CP). Discrimination between disease states and HVs was tested with receiver operator characteristic (ROC) curves. In total, 59 participants (23 PDAC (16 men), 24 HVs (13 men) and 12 CP (10 men)) were recruited, with a similar age in each population, and a combined median (IQR) age of 66 (57-71). The areas under the ROC curve for discriminating between PDAC and HVs were 0.83 (95% CI: 0.70-0.96) for the 13C-MTGBT, and 0.85 (95% CI: 0.75-0.95) for the FE-1 test. These were similar to CP vs. HV. In conclusion, PEI occurs in resectable PDAC to a similar extent as in CP; further large-scale, prospective studies using these tests in the primary care setting on high-risk groups are warranted.

A systematic review and meta-analysis of the accuracy and methodology of the 13C mixed triglyceride breath test for the evaluation of pancreatic function

INTRODUCTION

The diagnosis of pancreatic exocrine insufficiency (PEI) is challenging. The ¹³C mixed triglyceride breath test (¹³C MTGT) has emerged as a promising diagnostic method. However, there is need to assimilate high quality evidence to understand its accuracy and address variation in the conduct of the test. This systematic review aims to appraise the existing literature on the methodology and accuracy of the ¹³C MTGT.

METHODS

A systematic literature search of PUBMED, MEDLINE, and EMBASE databases identified articles describing the use of the ¹³C MTGT in the analysis of pancreatic function in adults. Data extraction addressed each methodological step in detail. These were combined in a narrative synthesis. For quantitative analysis, those studies within this search that assessed the accuracy of the ¹³C MTGT were selected.

RESULTS

37 studies were included for qualitative review, 6 assessed sensitivity and specificity of the ¹³C MTGT against another measure of PEI and were included in quantitative synthesis. Areas with a majority consensus were pre-test overnight fasting, a test meal with a lipid load of at least 10 g, within-test control of exercise and dietary intake, breath sampling every 30 min and the preference of isotope ratio mass spectrometry (IRMS) for analysis. Good evidence suggests there is no benefit to extend the total timeframe of breath sampling beyond 6 h. Areas of uncertainty are a) Duration of PERT cessation b) the addition of metoclopramide, c) the ideal test meal and d) if the time frame can be shortened. Quantitative analysis among 6 studies demonstrated a pooled sensitivity and specificity of the ¹³C MTGT for diagnosing PEI of 0.84 (95% CI: 0.73-0.91) and 0.87 (95% CI: 0.79-0.93) respectively.

CONCLUSION

There is yet to emerge a clear standard of breath test methodology that is validated for all causes of PEI and suitable for routine use. The accuracy of the ¹³C MTGT for diagnosing PEI is encouraging when compared to other measures. We present a suggested set protocol based on the current literature and identify areas that need further, high quality evidence. With refinement, the ¹³C MTGT could become a valuable, non-invasive PEI diagnostic tool that could be used outside of specialist centres.