Abbreviated 13C-mixed triglyceride breath test for detection of pancreatic exocrine insufficiency performs equally as standard 5-hour test in patients after gastrectomy performed for gastric cancer

Abstract

Background: ¹³C-mixed triglyceride breath test (¹³C-MTGT) is a non-invasive test for the detection of moderate and severe pancreatic exocrine insufficiency (PEI), but it requires prolonged breath sampling. The aim of this study was to determine the diagnostic power of abbreviated ¹³C-MTGT in detecting PEI in patients after subtotal and total gastrectomy performed due to gastric cancer.

Subjects and methods: This cross-sectional observational study included 3 groups of subjects; healthy controls, patients with subtotal and patients with total gastrectomy. Demographic and clinical data of patients were collected. Stool samples to determine faecal elastase (Fe-1) and chymotrypsin were collected and measured by ELISA. All subjects performed 5-hour ¹³C-MTGT breath test. The concentration and relative content of ¹³C in exhaled air was measured by isotope ratio mass spectrometer (IRMS). PEI was confirmed as values of ¹³C-exhalation < 26.8% after 5 hours.

Results: Overall, 65 participants were included into analysis, 22 having PEI (n = 11 after subtotal and n = 11 after total gastrectomy, both performed for gastric cancer). ¹³C-MTGT breath test showed difference in percent of exhaled ¹³C between PEI and non-PEI patients already after 60 minutes (p = 0.034). Receiver operating characteristic (ROC) curve analysis showed that cut-off value of 13.74% after 150 minutes is showing equivalent diagnostic power to the longer test with sensitivity and specificity both above 90% for the exclusion of PEI in patients after subtotal and/or total gastrectomy.

Conclusions: In this study abbreviated ¹³C-MTGT test could be shortened from 5 to 2.5 hours without decrease in its diagnostic accuracy for detection of PEI in patients with subtotal or total gastrectomy performed for gastric cancer. This allows significant time savings in the diagnostics of PEI in this subgroup of patients.

Keywords: abbreviated 13C-mixed triglyceride breath test; faecal elastase; gastrectomy; gastric cancer; pancreatic exocrine insufficiency.