Biomarkers in Fecal Microbiota May Offer Early Detection of PDAC

Recent research indicates that fecal and salivary microbiota may have a role as potential diagnostic biomarkers that could help in the early detection of pancreatic ductal adenocarcinoma (PDAC).

The investigators wrote, “We applied shotgun metagenomic and 16S rRNA amplicon sequencing to samples from a Spanish case-control study (n=136), including 57 cases, 50 controls, and 29 patients with chronic pancreatitis in the discovery phase, and from a German case-control study (n=76), in the validation phase.”

They found that fecal metagenomic classifiers “performed much better than saliva-based classifiers and identified patients with PDAC with an accuracy of up to 0.84 area under the receiver operating characteristic curve (AUROC) based on a set of 27 microbial species, with consistent accuracy across early and late disease stages.”

Biomarker performance improved to up to 0.94 AUROC when the researchers combined predictions based on the microbiome with serum levels of carbohydrate antigen (CA) 19-9. CA 19-9 is the only noninvasive, low specificity diagnostic biomarker for PDAC that has been approved by the US Food and Drug Administration. In addition, the investigators found that the classification model based on microbiota and confined to PDAC-enriched species “was highly disease-specific when validated against 25 publicly available metagenomic study populations for various health conditions (n=5792).”

They added, “Both microbiome-based models had a high prediction accuracy on a German validation population (n=76). Several fecal PDAC marker species were detectable in pancreatic tumor and nontumor tissue using 16S rRNA sequencing and fluorescence in situ hybridization.”

These results indicate that early detection of PDAC is feasible when using noninvasive screening based on specific fecal microbiota, the authors concluded.

—Rebecca Mashaw

Reference:

Kartal E, Schmidt TSB, Molina-Montes E, et al. A faecal microbiota signature with high specificity for pancreatic cancer. Gut. Published online March 8, 2022. http://dx.doi.org/10.1136/gutjnl-2021-324755