Background
Anastomotic leaks post oesophagectomy for cancer, are a feared post-operative complication and often cause significant morbidity.
In patients undergoing colorectal cancer surgery, the local microbiome has been shown to contribute to anastomotic leaks. Little is known on its effect on oesophagectomy patients.
We aimed to Assess the feasibility of testing archived histological specimens (FFPE) against fresh frozen (FF) specimen and Identify differences between microbiome of patients who suffered anastomotic leak and those who did not.
Methods
28 oesophagectomy patients had both FFPE and FF samples available. These samples were compared by performing shotgun metagenomic sequencing. Sequences were assigned Operational Taxonomic Units using both k-mer analysis as well further in-house alignment-based profiler analysis (mIHoP).
FF tissue samples of 8 patients who suffered leaks were then matched with 6 patients who did not. These were compared using the same methods described.
Results
Analysis of FFPE and FF specimens showed statistically significant differences in microbial composition of the FF samples for microbial abundancy and diversity (p = 0.04). The FF samples of the anastomotic leak patients revealed increased variance within local microbiota (p=0.44). Overall sample sizes were low due to subset analysis.
Conclusion
FF tissue samples show a statistically significant difference in microbial composition, when compared to matched FFPE samples. Patients with anastomotic leak showed variations in their local microbiome compared to patients with no leak. This variation may represent a potential avenue for targeted therapy and may help identify those who are at an increased risk of anastomotic leak.