Microbiological aspects of cancer progression: A systematic review conducted according to the PRISMA 2020 guidelines and the Cochrane Handbook for Systematic Reviews of Interventions.

The complex interplay between the gut microbiota, cancer treatments and patient characteristics has emerged as a significant area of research. This study sought to examine these relationships in the context of colorectal cancer (CRC).A comprehensive search of relevant studies was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The studies included a variety of treatment modalities and microbiological parameters. A data extraction form, designed specifically for this review, was used to assess a range of variables across all studies.The analysis revealed a multifaceted interaction between the gut microbiota, genetic factors and treatment outcomes. Elderly patients with CRC frequently received single-agent chemotherapy, with outcomes that were comparable to those of younger patients. The presence of tumorigenic bacteria, including Escherichia coli and Bacteroides fragilis, was associated with early colon neoplasia. Additionally, an abundance of Fusobacterium spp. was observed in colonic adenomas, contributing to a pro-inflammatory environment. Although the FcγRIIIa-158 V/V genotype was associated with higher cetuximab-mediated antibodydependent cellular cytotoxicity (ADCC), no direct influence of FcγR polymorphisms on treatment response was noted. Furthermore, the combination of programmed cell death protein-1 (PD-1), BRAF and MEK inhibition showed favorable response rates. The gut microbiome, especially the presence of Fusobacterium spp., had a notable influence on the therapeutic response in CRC.These findings underscore the role of the gut microbiota and genetic factors in cancer treatment outcomes, emphasizing the potential of a holistic approach to cancer management. Future research should exploit these findings in order to develop microbiota-modulating strategies and personalized medicine approaches for the purpose of improving the efficacy of cancer treatment.