Exploring Gut Microbiome Composition and Circulating Microbial DNA Fragments in Patients with Stage II/III Colorectal Cancer: A Comprehensive Analysis

BACKGROUND

Colorectal cancer (CRC) significantly contributes to cancer-related mortality, necessitating the exploration of prognostic factors beyond TNM staging. This study investigates the composition of the gut microbiome and microbial DNA fragments in stage II/III CRC.

METHODS

A cohort of 142 patients with stage II/III CRC and 91 healthy controls underwent comprehensive microbiome analysis. Fecal samples were collected for 16S rRNA sequencing, and blood samples were tested for the presence of microbial DNA fragments. De novo clustering analysis categorized individuals based on their microbial profiles. Alpha and beta diversity metrics were calculated, and taxonomic profiling was conducted.

RESULTS

Patients with CRC exhibited distinct microbial composition compared to controls. Beta diversity analysis confirmed CRC-specific microbial profiles. Taxonomic profiling revealed unique taxonomies in the patient cohort. De novo clustering separated individuals into distinct groups, with specific microbial DNA fragment detection associated with certain patient clusters.

CONCLUSIONS

The gut microbiota can differentiate patients with CRC from healthy individuals. Detecting microbial DNA fragments in the bloodstream may be linked to CRC prognosis. These findings suggest that the gut microbiome could serve as a prognostic factor in stage II/III CRC. Identifying specific microbial markers associated with CRC prognosis has potential clinical implications, including personalized treatment strategies and reduced healthcare costs. Further research is needed to validate these findings and uncover underlying mechanisms.

Unraveling the Role of Molecular Profiling in Predicting Treatment Response in Stage III Colorectal Cancer Patients: Insights from the IDEA International Study

BACKGROUND

This study aimed to investigate the molecular profiles of 237 stage III CRC patients from the international IDEA study. It also sought to correlate these profiles with Toll-like and vitamin D receptor polymorphisms, clinicopathological and epidemiological characteristics, and patient outcomes.

METHODS

Whole Exome Sequencing and PCR-RFLP on surgical specimens and blood samples, respectively, were performed to identify molecular profiling and the presence of Toll-like and vitamin D polymorphisms. Bioinformatic analysis revealed mutational status.

RESULTS

Among the enrolled patients, 63.7% were male, 66.7% had left-sided tumors, and 55.7% received CAPOX as adjuvant chemotherapy. Whole exome sequencing identified 59 mutated genes in 11 different signaling pathways from the Kyoto Encyclopedia of Genes and Genomes (KEGG) CRC panel. On average, patients had 8 mutated genes (range, 2-21 genes). Mutations in ARAF and MAPK10 emerged as independent prognostic factors for reduced DFS (p = 0.027 and p < 0.001, respectively), while RAC3 and RHOA genes emerged as independent prognostic factors for reduced OS (p = 0.029 and p = 0.006, respectively). Right-sided tumors were also identified as independent prognostic factors for reduced DFS (p = 0.019) and OS (p = 0.043). Additionally, patients with tumors in the transverse colon had mutations in genes related to apoptosis, PIK3-Akt, Wnt, and MAPK signaling pathways.

CONCLUSIONS

Molecular characterization of tumor cells can enhance our understanding of the disease course. Mutations may serve as promising prognostic biomarkers, offering improved treatment options. Confirming these findings will require larger patient cohorts and international collaborations to establish correlations between molecular profiling, clinicopathological and epidemiological characteristics and clinical outcomes.

Investigation of Microbial Translocation, TLR and VDR Gene Polymorphisms, and Recurrence Risk in Stage III Colorectal Cancer Patients

Gut microbial dysbiosis and microbial passage into the peripheral blood leads to colorectal cancer (CRC) and disease progression. Toll-like (TLR) and vitamin D (VDR) receptors play important role in the immune modulation and polymorphisms that may increase CRC risk and death rates. The aim of the current study was to demonstrate the prognostic value of microbial DNA fragments in the blood of stage III CRC patients and correlate such microbial detection to TLR/VDR polymorphisms. Peripheral blood was collected from 132 patients for the detection of microbial DNA fragments, and TLR/VDR gene polymorphisms. In the detection of various microbial DNA fragments, TLR and VDR polymorphisms was significantly higher compared to healthy group. Homozygous individuals of either TLR or VDR polymorphisms had significantly higher detection rates of microbial DNA fragments. Mutational and MSI status were significantly correlated with TLR9 and VDR polymorphisms. Significantly shorter disease-free survival was associated with patients with BRAF mutated tumors and ApaI polymorphisms, whereas shorter overall survival was associated with the detection of C. albicans. The detection of B. fragilis, as demonstrated by the multivariate analysis, is an independent poor prognostic factor for shorter disease-free survival. TLR/VDR genetic variants were significantly correlated with the detection of microbial fragments in the blood, and this in turn is significantly associated with tumorigenesis and disease progression.

Microbial translocation, toll-like and vitamin D receptor polymorphisms in blood and risk of recurrence in stage III colorectal cancer

3531

Background: Microbial translocation from the intestinal lumen into the blood circulation is significantly linked to intestinal dysbiosis; thus, leading to colorectal cancer (CRC), disease progression and decreased survival. Toll-like (TLRs) and vitamin D receptors (VDRs) play essential role in immunity and gut microbiome determination. Polymorphisms in such receptors have been associated with increased CRC incidence risk and mortality. The aim was to evaluate the microbial translocation in the blood of stage III CRC patients and correlate the presence of TLR and VDR genetic variants with microbial DNA fragments at risk of CRC development and progression. Methods: A total of 132 stage III CRC patients and 100 healthy donors were enrolled in the study. Peripheral blood DNA was analyzed using PCR for the amplification of microbial DNA encoding 16S rRNA, β-galactosidase gene of Escherichia coli, glutamine synthase of Bacteroides fragilis, and 5.8S rRNA of Candida albicans. Moreover, DNA from patients and controls was analyzed using PCR and PCR-RFLP for genotyping functional polymorphisms of both TLR (TLR2, TLR4, TLR9) and VDR ( TaqI, ApaI, FokI and BsmI) genes. Results: Median age of patients was 62 years, 59.8% were males, 92.7% had a colon/sigmoid tumor, 24.4% had a right colon tumor and 99.2% had a good performance status. Microbial DNA fragments from 16S rRNA, E. coli, B. fragilis, and C. albicans were detected in 43.2%, 20.5%, 31.8% and 36.4% of patients, respectively. Significantly higher rates of all microbial fragments, but E. coli, were detected in the group of patients in comparison to healthy donors ( p < 0.001). Similarly, higher rates of both TLR and VDR genetic variants were detected in CRC patients compared to healthy donors ( p < 0.001). Moreover, individuals with homozygous mutant alleles of either TLR or VDR polymorphisms had significantly higher detection rates of microbial DNA fragments. KRAS, BRAF and MSI status were significantly correlated with TLR9 genetic variants ( p= 0.001, p= 0.013 and p= 0.011, respectively) and MSI status was significantly correlated with all four VDR polymorphisms ( TaqI, p= 0.044; ApaI, p= 0.037; FokI, p= 0.002 and BsmI, p< 0.001). Cox regression analysis revealed that BRAF mutations, histology type and ApaI genetic variants are significantly associated with shorter disease-free survival (DFS). C. albicans detection is significantly associated with shorter overall survival, and B. fragilis is an independent poor prognostic factor for decreased DFS (HR = 33.85; p = 0.018). Conclusions: The detection of higher frequencies of the TLR/ VDR genetic variants was correlated with significantly higher detection rates of microbial DNA fragments. The detection of these TLR/VDR polymorphisms and microbial DNA fragments in CRC patients highlighted their role in cancer development, progression, and patients’ survival.

Evaluation of circulating tumor cells in stage III colorectal cancer patients under three or six months of adjuvant therapy

e15601

Background: The duration of adjuvant oxaliplatin-combination treatment in stage III colorectal cancer (CRC) patients is still debatable. Circulating Tumor Cells (CTCs) have been proposed as a potential markers for detection of micrometastatic disease. The aim was to compare the elimination rate of CTCs in patients treated with three- and six-months treatment with FOLFOX or CAPOX, in stage III CRC patients. Methods: Peripheral blood samples were collected from 132 patients at baseline, after three (for all patients) and after six months (for those under six months treatment). Surgical specimens were collected from all patients for the evaluation of their genetic profiling using Sanger sequencing (Ras/Raf) and fragment analysis (microsatellite instability status). The detection and number of circulating tumor cells (CTCs) were evaluated using double immunofluorescence and a real time-polymerase chain reaction assay, at all three time points. Results: Median age of the patients was 62 years, 59.8% were males, 92.7% had a colon/sigmoid tumor location, 24.4% had tumor on the right colon and 99.2% had a good performance status (PS). Of all patients, 44.3% and 55.7% were treated with FOLFOX and CAPOX, respectively; patients received treatment for three and six months, were equally distributed. KRAS, NRAS and BRAFmutations were detected in 41.5%, 2.1% and 12.8%, respectively; whereas MSI-High status was detected in 9.8% of the patients. CTCs were detected in 43.2%, 42.4% and 54.2% of the patients, at baseline, after three and six months of treatment, respectively. Both positivity rate ( p< 0.001) and absolute number of CTCs ( p= 0.022) were decreased between baseline and three months of treatment. Moreover, a significant increase was observed both on the positivity rate ( p= 0.053) and absolute number of CTCs ( p< 0.001) between three and six months of treatment. Following Cox regression analysis, BRAF status and the detection of CTCs are significantly correlated with decreased time to progression. Conclusions: To conclude, the current study indicates that 3 months of adjuvant treatment is at least as efficacious as 6 months in eliminating CTCs. However, the increase of both the rate and number of positive CTCs after three months of treatment might highlight the emergence of resistant cancer cell clones.

Evaluation of the Role of Circulating Tumor Cells and Microsatellite Instability Status in Predicting Outcome of Advanced CRC Patients

Colorectal cancer (CRC) remains one of the leading causes of cancer-related death due to its high metastatic potential. This study aimed to investigate the detection and heterogeneity of circulating tumor cells (CTCs) and the microsatellite instability (MSI) status in advanced CRC patients prior to any systemic front-line treatment. Peripheral whole blood was obtained from 198 patients. CTCs were detected using double immunofluorescence and a real time-polymerase chain reaction assay; whereas MSI status was evaluated using fragment analysis. Median age of the patients was 66 years, 63.1% were males, 65.2% had a colon/sigmoid tumor location and 90.4% had a good performance status (PS). MSI-High status was detected in 4.9% of the patients; 33.3%, 56.1% and 8.6% patients had at least one detectable CEACAM5⁺/EpCAM⁺, CEACAM5⁺/EpCAM^- and CEACAM5^-/EpCAM⁺ CTC, respectively, and 9.1% of the patients had CEACAM5mRNA-positive CTCs. Following multivariate analysis, age, PS and MSI were confirmed as independent prognostic factors for decreased time to progression, whereas age, PS and CTC presence were confirmed as independent prognostic factors for decreased overall survival. In conclusion, our data support the use of CEACAM5 as a dynamic adverse prognostic CTC biomarker in patients with metastatic CRC and MSI-High is considered an unfavorable prognostic factor in metastatic CRC patient tumors.

The Prognostic Value of the Detection of Microbial Translocation in the Blood of Colorectal Cancer Patients

Dysbiosis has been associated with various diseases and is of major health importance. Dysbiosis leads to microbial translocation, which is the passage of microorganisms, their fragments, or their metabolites from the intestinal lumen into the blood circulation and other sites. The aim of the study was to determine whether microbial translocation occurs in stage II/III-IV colorectal cancer (CRC) patients. The aim was also to evaluate the usefulness of blood PCR for diagnosis of such translocation and correlate the presence of toll-like receptor/vitamin D receptor (TLR/VDR) gene polymorphisms with microbial DNA fragments detected in the blood of CRC patients. Three hundred and ninety-seven CRC patients enrolled in the study. Peripheral blood DNA was analyzed using PCR for the amplification of genomic DNA encoding 16S rRNA, the β-galactosidase gene of Escherichia coli, glutamine synthase gene of Bacteroides fragilis, and 5.8S rRNA of Candida albicans. Significantly higher rates of all microbial fragments, but E. coli, detected were observed in the CRC patients (p < 0.001); such detection of all four microbial fragments was also significantly associated with the metastatic disease (p < 0.001), leading to shorter survival rates (p < 0.001). Tumor location in the right colon also significantly correlated with shorter survival (p = 0.016). Individuals with homozygous mutant alleles of TLR/VDR polymorphisms had significantly higher detection rates of microbial DNA fragments. The detection of microbial DNA fragments in CRC patients highlighted the role of these microbes in cancer development, progression, and patients' survival.

Correlation of PKM2 and CD44 Protein Expression with Poor Prognosis in Platinum-Treated Epithelial Ovarian Cancer: A Retrospective Study

CD44, a surface marker for cancer stem cells, interacts with PKM2, a key regulator of aerobic glycolysis, and enhances the glycolytic phenotype of cancer cells leading to antioxidant protection and macromolecules’ synthesis. To clarify the clinical importance of this “cross-talk” as a mechanism of drug resistance, we assessed the expression both of PKM2 and of CD44 in cancer cells of patients with epithelial ovarian cancer (EOC) treated with platinum-based treatment. One hundred and seventy-one patients with EOC were assessed for PKM2mRNA expression and PKM2 and CD44 proteins detection. Associations with progression-free survival (PFS) and overall survival (OS) were assessed with Kaplan–Meier and adjusted Cox regression models. PKM2mRNA and protein as well as CD44 protein were detectable in the majority of patients. Positive correlation between PKM2 and CD44 protein expression was observed (Spearman rho = 0.2, p = 0.015). When we used the median to group patients into high versus low expression, high PKM2mRNA and protein levels were significantly associated with lower progression-free survival (PFS; p = 0.003 and p = 0.002, respectively) and shorter overall survival (OS; p ≤ 0.001 and p = 0.001, respectively). However, high CD44 protein expression was significantly correlated only with shorter OS (p = 0.004). Moreover, patients with both high PKM2 and CD44 protein levels experienced shorter PFS and OS (p = 0.007 and p = 0.003, respectively) compared to patients with low expression of both proteins. Finally, higher PKM2mRNA and protein expression as well as CD44 protein expression (HR: 2.16; HR: 1.82; HR: 1.01, respectively) were independent prognostic factors for decreased median OS (mOS), whereas only PKM2 protein expression (HR: 1.95) was an independent prognostic factor for decreased median PFS (mPFS). In conclusion, PKM2 expression is a negative prognostic factor in EOC patients, but the interaction between CD44 and PKM2 that may be implicated in EOC platinum-resistance needs further investigation.

Detection of microbial DNA in the blood of colorectal cancer patients for the diagnosis of microbial translocation

171

Background: Dysbiosis has been associated with diseases and is of a major public health importance. Can lead to the passage of viable bacteria, their products or their fragments from the intestinal lumen through the mesenteric lymph nodes and other sites, known as bacterial translocation. The aim of the study was to determine whether microbial translocation occurs in stage II/III-IV colorectal cancer (CRC) patients and evaluate the usefulness of blood PCR for diagnosis of such translocation. Also to correlate the presence of Toll-Like Receptor and Vitamin D Receptor polymorphisms with the detection of microbial DNA fragments in the blood of CRC patients. Methods: Peripheral blood was obtained from 397 CRC patients (adjuvant n = 202 and metastatic n = 195) and 32 healthy individuals. DNA from all subjects was analyzed using PCR for amplification of genomic DNA encoding 16S rRNA, β-galactosidase gene of E. coli, Glutamine synthase gene of B. fragilis and 5.8S rRNA found in C. albicans. Results: Significantly higher rates of 16S rRNA, β-galactosidase, Glutamine synthase and 5.8S rRNA detection was observed in the pool of CRC patients than the controls ( p< 0.001). All microbial DNA fragments detected were also significantly associated with the metastatic disease ( p< 0.001) leading to shorter survival rates ( p< 0.001). Moreover, individuals with the homozygous mutant alleles of either TLR or VDR gene polymorphisms had significantly higher detection rates of microbial DNA fragments. Conclusions: The detection of microbial DNA fragments in patients with CRC highlights the role of these microbes in cancer development, progression and therefore in patients’ survival.