Analysis Of Fecal Microbiota And Metabolomics Features And Prognosis In Patients With Left-And Right-Sided Colon Cancer

Objective:This study aimed to explore the differences in gut microbiota composition and short-chain fatty acids(SCFAs)levels between left-and right-sided colon cancer patients and their relationships with clinical and pathological characteristics and prognosis,in order to provide a basis for individualized treatment of colon cancer.Methods:This study retrospectively analyzed 353 patients diagnosed with colon cancer who were treated at the Second Affiliated Hospital of Nanchang University from January 2015 to December 2017,including 191 cases of left-sided colon cancer and 162 cases of right-sided colon cancer.The clinical and pathological characteristics and prognosis of the two groups of patients were compared.From October 2021 to May 2022,fecal samples were collected from 33 colon cancer patients for microbiome and targeted metabolomics analysis,including 16 cases of left-sided colon cancer and 17 cases of right-sided colon cancer.Differences in gut microbiota composition and SCFAs levels between the two groups were compared,and their relationship with clinical and pathological characteristics and prognosis was analyzed.Results:1.Comparison of general characteristics between patients with left-sided colon cancer and right-sided colon cancer: There was no statistical difference in age and gender composition between patients with left-sided and right-sided colon cancer(P>0.05).The first presenting symptom was more commonly hemafecia or black stool in patients with left-sided colon cancer(47.1%),while abdominal pain was more common in patients with right-sided colon cancer(75.3%)at presentation,and the difference was statistically significant(P<0.05).2.Comparison of pathological characteristics between patients with left-sided colon cancer and right-sided colon cancer: The proportion of tumors with a diameter greater than 5 cm was 48.7% and 65.4% for left-sided and right-sided colon cancer,respectively,with a statistically significant difference(P<0.05).Ulcerative type is more common in left-sided colon cancer,while the raised type is more common in right-sided colon cancer,but the difference is not statistically significant(P>0.05).The histological classification of both left-sided colon cancer and right-sided colon cancer is mostly adenocarcinoma,but other types such as mucinous adenocarcinoma and signet ring cell carcinoma are more common in right-sided colon cancer,and the difference was statistically significant(P<0.05).In left-sided colon cancer,88.0% are moderately differentiated and 12.0% are poorly differentiated,while in right-sided colon cancer,77.8% are moderately differentiated and 22.2% are poorly differentiated,and the difference was statistically significant(P<0.05).The proportion of patients with different stages of pTNM classification is slightly different between patients with left-sided and right-sided colon cancer,but the difference is not statistically significant(P>0.05).3.Comparison and analysis of prognosis between patients with left-sided colon cancer and right-sided colon cancer: The 5-year survival rates of patients with leftsided and right-sided colon cancer were 71.1% and 60.7%,respectively.The survival curve was compared using the Log-rank test,and the difference was statistically significant(P<0.05).Multivariate regression analysis showed that right-sided colon cancer(HR=1.492,95%CI:1.005-2.216),poorly differentiated tumors(HR=1.864,95%CI:1.084-3.124),and pTNM stage III(HR=1.792,95%CI:1.209-2.654)were independent risk factors for poor prognosis in patients with colon cancer(P<0.05).4.Comparison of gut microbiota composition and SCFA levels between patients with left-sided colon cancer and right-sided colon cancer: The alpha diversity index of gut microbiota in patients with right-sided colon cancer was significantly lower than that in patients with left-sided colon cancer(P<0.05).At the phylum level,compared with left-sided colon cancer,the abundance of Verrucomicrobia in fecal samples from patients with right-sided colon cancer was lower,while the abundance of Fusobacteria was higher,and the difference was statistically significant(P<0.05).At the genus level,compared with left-sided colon cancer,the abundance of Akkermansia and Faecalibacterium in fecal samples from patients with right-sided colon cancer was lower,while the abundance of Fusobacterium and Parvimonas was higher,and the difference was statistically significant(P < 0.05).The levels of propionic acid and butyric acid in fecal samples from right-sided colon cancer were lower than those from patients with left-sided colon cancer(P<0.05).5、Relationship between intestinal microbiota and SCFAs levels with clinical and pathological characteristics in patients with colon cancer: The abundance of Fusobacterium genus is related to tumor differentiation,and the abundance of Fusobacterium genus in the feces of poorly differentiation group of colon cancer patients is significantly higher than that in the moderately differentiated group,with statistical significance(P < 0.05).The level of fecal butyric acid is related to lymph node metastasis in patients with colon cancer,and the level of butyric acid in the feces of colon cancer patients with lymph node metastasis is significantly lower than that of patients without lymph node metastasis,with statistical significance(P < 0.05).Conclusion:1.There are differences in clinical and pathological characteristics between patients with left-sided colon cancer and right-sided colon cancer.Compared to leftsided colon cancer,right-sided colon cancer has a larger tumor diameter and a higher proportion of poorly differentiated mucinous adenocarcinoma and signet ring cell carcinoma.2.There are differences in prognosis between patients with left-sided colon cancer and right-sided colon cancer,and the prognosis of left-sided colon cancer is better than that of right-sided colon cancer.Univariate and multivariate analyses found that right-sided colon cancer,poorly differentiated tumors,and pTNM stage III are independent risk factors for poor prognosis in colon cancer patients.3.There are differences in the composition of intestinal microbiota and fecal SCFAs levels between patients with left-sided colon cancer and right-sided colon cancer,and these differences are closely related to the degree of tumor differentiation and lymph node metastasis,which are important factors affecting the prognosis of patients with left-sided colon cancer and right-sided colon cancer.