Role of the intestinal microbiome in colorectal cancer surgery outcomes

Abstract

ObjectivesGrowing evidence supports the role of the intestinal microbiome in the carcinogenesis of colorectal cancers, but its impact on colorectal cancer surgery outcomes is not clearly defined. This systematic review aimed to analyze the association between intestinal microbiome composition and postoperative complication and survival following colorectal cancer surgery.MethodsA systematic review was conducted according to the 2009 PRISMA guidelines. Two independent reviewers searched the literature in a systematic manner through online databases, including Medline, Scopus, Embase, Cochrane Oral Health Group Specialized Register, ProQuest Dissertations and Theses Database, and Google Scholar. Human studies investigating the association between the intestinal microbiome and the short-term (anastomotic leakage, surgical site infection, postoperative ileus) and long-term outcomes (cancer-specific mortality, overall and disease-free survival) of colorectal cancer surgery were selected. Patients with any stage of colorectal cancer were included. The Newcastle-Ottawa scale for case-control and cohort studies was used for the quality assessment of the selected articles.ResultsOverall, 8 studies (7 cohort studies and 1 case-control) published between 2014 and 2018 were included. Only one study focused on short-term surgical outcomes, showing that anastomotic leakage is associated with low microbial diversity and abundance of Lachnospiraceae and Bacteroidaceae families in the non-cancerous resection lines of the stapled anastomoses of colorectal cancer patients. The other 7 studies focused on long-term oncological outcomes, including survival and cancer recurrence. The majority of the studies (5/8) found that a higher level of Fusobacterium nucleatum adherent to the tumor tissue is associated with worse oncological outcomes, in particular, increased cancer-specific mortality, decreased median and overall survival, disease-free and cancer-specific survival rates. Also a high abundance of Bacteroides fragilis was found to be linked to worse outcomes, whereas the relative abundance of the Prevotella-co-abundance group (CAG), the Bacteroides CAG, and the pathogen CAG as well as Faecalibacterium prausnitzii appeared to be associated with better survival.ConclusionsBased on the limited available evidence, microbiome composition may be associated with colorectal cancer surgery outcomes. Further studies are needed to elucidate the role of the intestinal microbiome as a prognostic factor in colorectal cancer surgery and its possible clinical implications.

Dynamic Serosal Perfusion Assessment during Colorectal Resection Using Visible Light Spectroscopy

“…Our findings underline the multifactorial pathogenesis of AL. Low intraoperative blood pressure, liberal perioperative fluid management, and the gut microbiome seem to contribute to its occurrence [21, 22]. Consequently, a trial protocol assessing perfusion as well as multiple other factors, such as mechanic stability and tension, as risk factors for AL was recently published [23].…”

Guild-based analysis for understanding gut microbiome in human health and diseases

“…However, they clustered taxonomic groups instead of unique bacterial genomes and did not explore potential relationships between CAGs and host phenotypes. Since then, the concept of co-abundance group or co-abundance network has been applied in several dozens of microbiota studies [ 51 – 73 ]. Most of these studies [ 51 – 64 ], including Claesson et al [ 50 ], first collapsed unique bacterial genomes into taxonomic units and then clustered taxonomic units into CAGs.…”

“…Most of these studies [ 51 – 64 ], including Claesson et al [ 50 ], first collapsed unique bacterial genomes into taxonomic units and then clustered taxonomic units into CAGs. The remaining publications [ 65 – 73 ] grouped unique genomes, operational taxonomic units (OTUs), or amplicon sequence variants (ASVs) into CAGs. However, these studies [ 65 – 73 ] did not treat CAGs as functional units nor directly investigated potential relationships between CAGs and host phenotypes.…”

“…The remaining publications [ 65 – 73 ] grouped unique genomes, operational taxonomic units (OTUs), or amplicon sequence variants (ASVs) into CAGs. However, these studies [ 65 – 73 ] did not treat CAGs as functional units nor directly investigated potential relationships between CAGs and host phenotypes. Though the concept of co-abundance analysis is not entirely new, our proposed strategy is different from previous work in two important aspects.…”

New Insights Into the Cancer–Microbiome–Immune Axis: Decrypting a Decade of Discoveries

“…Many of the important lifestyle risk factors for cancer like obesity (6), smoking (7), diet (8) and alcohol (9) can cause perturbations in the microbial composition as well. Emerging evidence suggests that host microbial signatures may be able to predict some incipient cancers (10), modulate response to and toxicity of cancer immunotherapy (11)(12)(13) and even correlate with survival in specific cancers (14,15). Extensive exploration of the role of the microbiome in cancer evolution has demonstrated that while the microbiome can affect cancer cells themselves, it can also modulate the cancer immunosurveillance.…”