The occurrence rate of colorectal cancer is increasing. Metastasis and recurrence are the leading causes of death in colorec-tal cancer. Tumor cells in the circulation have the ability to proliferate or to migrate, thereby providing a reliable means for neoplasm staging and assessment of recurrence or metastasis, and evaluation of efficacy by detecting circulating tumor cells (CTC). Optimizing the development of detection technology will provide better support for clinical applications. This review mainly discusses CTC detec-tion and advances in colorectal cancer relapse or metastasis.

Objective To investigate the expression of CYP2W1 in gastric cancer and its effect on proliferation and invasion.Methods CYP2W1 protein expression in 326 gastric cancertissues and in the corresponding normal gastric mucosa was measured by immunohistochemstry.The expression of CYP2W1 mRNA in 10 randomly chosen gastric cancer tissues and its corresponding normal gastric mucosa was tested by semi-quantitative RT-PCR.4 groups pairs of gastric cancer and normal gastric mucosa cell lines were constructed.CYP2W1 expression in each of the cell line was tested.The effect of CYP2W1 expression on the proliferation and invasion capacity of the gastric cancer cells was studied by MTT experiment and transwell cell experiment.Results Expression of CYP2W1 protein in the gastric cancer tissues is higher than that in normal gastric mucosa (26.7％ vs.0,x2 =100.396,P ＜ 0.05).CYP2W1 mRNA in the gastric cancer tissues is higher than that in normal gastric mucosa [(0.413 ± 0.026) vs.(0.074 ± 0.005),t =28.115,P ＜ 0.05].CYP2W1 protein expression in the gastric cancer cell lines is higher than that in normal gastric mucosa cell lines [(0.481 ± 0.024) vs.0,t =49.097,P ＜ 0.05].The growth capacity of CYP2W1 positive gastric cancer cell is stronger than that of CYP2W1 negative cells (P ＜ 0.05),and CYP2W1 positive gastric cancer cells are also more of invasiveness,[(63 ±8) vs.(18 ±3),t =24.134,P ＜0.05].Conclusions CYP2W1 is only expressed in the gastric cancer tissues,hence it is closely related to the growth multiplication,and invasiveness of gastric cancer cells.

Objective To compare endoscopic stenting with surgery for pyloric obstruction caused by unresectable gastric cancer.Methods Between June 2002 and June 2012,6 patients underwent endoscopic stenting and 70 did surgery for gastric outlet obstruction caused by gastric cancer.Results There were no significant difference in technical success rate and clinical success rate between the stenting and surgery groups (P ＞ 0.05).The stenting group had shorter time to oral intake,and shorter length of hospital stay [(2.5-± 3.1) d vs.(6.6 ± 3.5) d,t =-7.0,P ＜ 0.001].The incidence of early complications was significantly higher in the surgery group.However,the rates of late complications were significantly lower in the surgery group.Moreover,the surgery group was significantly associated with a longer patency duration [(295.8 d,95％ CI:260.7-330.8) vs.(168.2 d,95％ CI:134.7-201.7 d),P ＜0.001] and overall survival [(307.6 d,95％ CI:272.4-342.8 d) vs.(229.6 d,95％ CI:195.1-264.3 d),P =0.003].Conclusions Both endoscopic stenting and surgery are effective palliative therapy for gastric outlet obstruction caused by gastric cancer.Endoscopic stenting is associated with better shortterm outcomes.Surgery is preferable to ES in longer patency duration.

Objective:To explore the differences in bacterial community structure between proximal colon cancer (PC), distal colon cancer (DC), and rectal cancer (RC), and the values of featured microbiota in differentiating PC with tumor markers.Methods:This case-control study enrolled 85 newly diagnosed colorectal cancer patients, including 22 PC, 15 DC and 48 RC patients, and 8 colorectal adenoma patients from May 2019 to July 2022 at the Department of General Surgery, Anyang Oncology Hospital. The blood and fecal samples were collected before surgery and then subjected to biochemical tests for tumor markers and 16S rDNA tests, respectively. SPSS (27.0.1) was applied to perform the t-test, one-way ANOVA, Mann-Whitney U test, Kruskal-Wallis H test, and Chi-Squared Test. Also, the receiver operating characteristic curve (ROC) was plotted on tumor markers and/or f_Bacteroidaceae with SPSS software .Results:All groups had significant differences in the CA125 ( F=3.543, P<0.05), CA72-4 ( F=3.596, P<0.05), and serum tumor-associated materials (TAM) levels ( F=5.787, P<0.01). In PC group, the levels of CA125 [PC vs RC, (36.84±6.30) kU/L vs (12.73±4.21) kU/L, P<0.01] and CA72-4 [PC vs RC, (45.56±10.86) kU/L vs (3.30±7.63) kU/L, P<0.01] were significantly higher than that of the RC group, while the level of TAM was remarkably elevated in PC group than in RC group [PC vs RC, (124.84±5.19) U/ml vs (102.44±3.63) U/ml, P<0.001] and CRA group [PC vs CRA, (124.84±5.19) U/ml vs (95.39±8.42) U/ml, P<0.01]. The LEfSe analysis showed that the featured microbiota in the PC group included f_Bacteroidaceae, f_Neisseriaceae, f_Clostridiaceae_1, f_Spirochaetaceae, and so on. The largest area under the ROC belonged to the combination of TAM and f_Bacteroidaceae, which reached 0.845 (95% CI 0.747-0.944), with sensitivity being 0.857 and specificity being 0.815. Conclusions:There is heterogeneity in gut microbiota composition among PC, DC, RC, and CRA. The combination of gut microbiota and tumor biomarkers demonstrated good differentiating effects in proximal colon cancers.