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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.
RESUMO
BACKGROUND: Meta-analyses and guidelines recommend that deep submucosal invasion (>1 mm) of malignant sessile colonic polyps is an important risk factor for lymph node metastasis. However, existing data are based on small retrospective studies with marked heterogeneity. We herein aimed to investigate the long-term outcomes of patients who underwent complete endoscopic mucosal resection (EMR) of malignant colonic sessile polyps invading the submucosal layer. METHODS: Endoscopy records for the period 2000-2016 were reviewed retrospectively. All enrolled patients exhibited an endoscopically resected malignant colonic sessile polyp. All patients were advised to undergo surgery, but some opted for conservative treatment and endoscopic follow up. RESULTS: Fifty-one patients with confirmed infiltrative submucosal adenocarcinoma in sessile colonic polyps that had undergone complete EMR were detected. A total of 32 (62.7%) patients opted for surgery after EMR and 19 (37.3%) chose endoscopic follow up. In 44 (86.3%) patients the submucosal invasion was >1 mm. Residual malignant disease was identified in the surgical pathological specimen of only 1 patient. During a median follow up of 23.41 months (interquartile range 33.45, range 1.84-144.92), no local recurrences or lymph node metastasis were identified. Forty-nine patients are alive without evidence of disease and 2 died of other causes (without evidence of local or metastatic disease at last follow up). CONCLUSION: Our data suggest that complete EMR of cancerous colonic sessile polyps, even in cases of submucosal invasion >1 mm carries a low risk of recurrence and therefore may need further evaluation as an alternative strategy to surgical resection.
