Gut mucosal microbiota profiles linked to colorectal cancer recurrence

BACKGROUND Emerging evidence links gut microbiota to various human diseases including colorectal cancer(CRC)initiation and development.However,gut microbiota profiles associated with CRC recurrence and patient prognosis are not completely understood yet,especially in a Chinese cohort.AIM To investigate the relationship between gut mucosal microbiota profiles and CRC recurrence and patient prognosis.METHODS We obtained the composition and structure of gut microbiota collected from 75 patients diagnosed with CRC and 26 healthy controls.The patients were followed up by regular examination to determine whether tumors recurred.Triplet-paired samples from on-tumor,adjacent-tumor and off-tumor sites of patients diagnosed with/without CRC recurrence were analyzed to assess spatial-specific patterns of gut mucosal microbiota by 16S ribosomal RNA sequencing.Next,we carried out bioinformatic analyses,Kaplan-Meier survival analyses and Cox regression analyses to determine the relationship between gut mucosal microbiota profiles and CRC recurrence and patient prognosis.RESULTS We observed spatial-specific patterns of gut mucosal microbiota profiles linked to CRC recurrence and patient prognosis.A total of 17 bacterial genera/families were identified as potential biomarkers for CRC recurrence and patient prognosis,including Anaerotruncus,Bacteroidales,Coriobacteriaceae,Dialister,Eubacterium,Fusobacterium,Filifactor,Gemella,Haemophilus,Mogibacteriazeae,Pyramidobacter,Parvimonas,Porphyromonadaceae,Slackia,Schwartzia,TG5 and Treponema.CONCLUSION Our work suggests that intestinal microbiota can serve as biomarkers to predict the risk of CRC recurrence and patient death.

Evaluation of contrast-enhanced computed tomographic colonography in detection of local recurrent colorectal cancer

AIM： TO evaluate the diagnostic accuracy, sensitivity, specificity of contrast-enhanced computed tomographic colonography in detecting local recurrence of colorectal cancer. METHODS： From January 2000 to December 2004, 434 patients after potentially curative resection for invasive colorectal cancer were followed up for a period ranging from 20 to 55 mo. Eighty of the four hundred and thirty-four patients showing strong clinical evidence for recurring colorectal cancer during the last followup were enrolled in this study. Each patient underwent contrast-enhanced computed tomographic colonography and colonoscopy on the same day. Any lesions, biopsies, identified during the colonoscopic examination, immediate complications and the duration of the procedure were recorded. The results of contrast-enhanced computed tomographic colonography were evaluated by comparing to those of colonoscopy, surgical finding, and clinical follow-up. RESULTS： Contrast-enhanced computed tomographic colonography had a sensitivity of 100%, a specificity of 83% and an overall accuracy of 94% in detecting local recurrent colorectal cancer. CONCLUSION： Conventional colonoscopy and contrastenhanced tomographic colonography can complement each other in detecting local recurrence of colorectal cancer.

Role of serum carcinoembryonic antigen in the detection of colorectal cancer before and after surgical resection

AIM:To determine whether serum levels of carcinoembryonic antigen(CEA) correlate with the presence of primary colorectal cancer(CRC),and/or recurrent CRC following radical resection.METHODS:A total of 413 patients with CRC underwent radical surgery between January 1998 and December 2002 in our department and were enrolled in this study.The median follow-up period was 69 mo(range,3-118 mo),and CRC recurrence was experienced by 90/413(21.8%) patients.Serum levels of CEA were assayed preoperatively,and using a cutoff value of 5 ng/mL,patients were divided into two groups,those with normal serum CEA levels(e.g.,≤ 5 ng/mL) and those with elevated CEA levels(> 5 ng/mL).RESULTS:The overall sensitivity of CEA for the detection of primary CRC was 37.0%.The sensitivity of CEA according to stage,was 21.4%,38.9%,and 41.7% for stagesⅠ-Ⅲ,respectively.Moreover,for stageⅡandstageⅢcases,the 5-year disease-free survival rates were reduced for patients with elevated preoperative serum CEA levels(P < 0.05).The overall sensitivity of CEA for detecting recurrent CRC was 54.4%,and sensitivity rates of 36.6%,66.7%,and 75.0% were associated with cases of local recurrence,single metastasis,and multiple metastases,respectively.In patients with normal serum levels of CEA preoperatively,the sensitivity of CEA for detecting recurrence was reduced compared with patients having a history of elevated CEA prior to radical resection(32.6% vs 77.3%,respectively,P < 0.05).CONCLUSION:CRC patients with normal serum CEA levels prior to resection maintained these levels during CRC recurrence,especially in cases of local recurrence vs cases of metastasis.