Novel management indications for conservative treatment of chylous ascites after gastric cancer surgery.

BACKGROUND: Chylous ascites (CA) presents a challenge as a relatively common postoperative complication in gastric cancer (GC). Primary conservative therapy involved total parenteral nutrition, continuous low-pressure drainage, somatostatin, and a low-fat diet. Drainage tube (DT) clamping has been presented as a potential alternative conservative treatment for GC patients with CA. AIM: To propose novel conservative treatment strategies for CA following GC surgery. METHODS: The data of patients with CA after GC surgery performed at the Fudan University Shanghai Cancer Center between 2006 and 2021 were evaluated retrospectively. RESULTS: 53 patients underwent surgery for GC and exhibited postoperative CA during the study period. Postoperative hospitalization and time of DT removal showed a significant positive association (R 2 = 0.979, P < 0.001). We further observed that delayed DT removal significantly extended the total and postoperative hospitalization, antibiotic usage duration, and hospitalization cost (postoperative hospitalization: 25.8 d vs 15.5 d, P < 0.001; total hospitalization: 33.2 d vs 24.7 d, P < 0.01; antibiotic usage duration: 10.8 d vs 6.2 d, P < 0.01; hospitalization cost: ¥9.2 × 104 vs ¥6.5 × 104, P < 0.01). Multivariate analysis demonstrated that postoperative infection and antibiotic usage were independent factors for delayed DT removal. Furthermore, DT removal times were shorter in seven patients who underwent DT clamping (clamped DT vs normal group, 11.8 d vs 13.6 d, P = 0.047; clamped DT vs delayed group, 13.6 d vs 27.4 d, P < 0.001). In addition, our results indicated that removal of the DT may be possible after three consecutive days of drainage volumes less than 300 mL in GC patients with CA. CONCLUSION: Infection and antibiotic usage were vital independent factors that influenced delayed DT removal in patients with CA. Appropriate standards for DT removal can significantly reduce the duration of hospitalization. Furthermore, DT clamping might be a recommended option for conservative treatment of postoperative CA.

The genomic architecture of EBV and infected gastric tissue from precursor lesions to carcinoma.

BACKGROUND: Epstein-Barr virus (EBV)-associated gastric carcinomas (EBVaGCs) present unique molecular signatures, but the tumorigenesis of EBVaGCs and the role EBV plays during this process remain poorly understood. METHODS: We applied whole-exome sequencing, EBV genome sequencing, and whole-genome bisulfite sequencing to multiple samples (n = 123) derived from the same patients (n = 25), which covered saliva samples and different histological stages from morphologically normal epithelial tissues to dysplasia and EBVaGCs. We compared the genomic landscape between EBVaGCs and their precursor lesions and traced the clonal evolution for each patient. We also analyzed genome sequences of EBV from samples of different histological types. Finally, the key molecular events promoting the tumor evolution were demonstrated by MTT, IC50, and colony formation assay in vitro experiments and in vivo xenograft experiments. RESULTS: Our analysis revealed increasing mutational burden and EBV load from normal tissues and low-grade dysplasia (LD) to high-grade dysplasia (HD) and EBVaGCs, and oncogenic amplifications occurred late in EBVaGCs. Interestingly, within each patient, EBVaGCs and HDs were monoclonal and harbored single-strain-originated EBV, but saliva or normal tissues/LDs had different EBV strains from that in EBVaGCs. Compared with precursor lesions, tumor cells showed incremental methylation in promotor regions, whereas EBV presented consistent hypermethylation. Dominant alterations targeting the PI3K-Akt and Wnt pathways were found in EBV-infected cells. The combinational inhibition of these two pathways in EBV-positive tumor cells confirmed their synergistic function. CONCLUSIONS: We portrayed the (epi) genomic evolution process of EBVaGCs, revealed the extensive genomic diversity of EBV between tumors and normal tissue sites, and demonstrated the synergistic activation of the PI3K and Wnt pathways in EBVaGCs, offering a new potential treatment strategy for this disease.

Pile-up effect in an infrared single-pixel compressive LiDAR system.

Compressive sensing (CS) has been used in LiDAR systems utilizing one single-photon-counting avalanche diode. We demonstrate an unexpected grayscale inversed image of an object at an unchosen depth, which appears in the reconstruction of the infrared single-pixel LiDAR system due to the pile-up effect. A correction algorithm and the sparse measurement are proposed and experimentally verified to effectively reduce the photon pile-up influence, so that the negative images can be completely removed. The correction methods in this research can improve the accuracy and the flexibility of the single-pixel LiDAR systems employing detectors with a low maximum light count.

Long non-coding RNA XIST regulates gastric cancer progression by acting as a molecular sponge of miR-101 to modulate EZH2 expression.

BACKGROUND: Long non-coding RNAs (lncRNAs) have emerged as critical regulators of tumor progression. However, the role and molecular mechanism of lncRNA XIST in gastric cancer is still unknown. METHODS: Real-time PCR analysis was performed to measure the expression levels of lncRNA XIST in gastric cancer tissues and cell lines, the correlation between lncRNA XIST expression and clinicopathological characteristics and prognosis was analyzed in gastric cancer patients. The biological function of lncRNA XIST on gastric cancer cells were determined both in vitro and in vivo. The regulating relationship between lncRNA XIST and miR-101 was investigated in gastric cancer cells. RESULTS: lncRNA XIST was significantly up-regulated in gastric cancer tissues and cell lines. Overexpression of lncRNA XIST was markedly associated with larger tumor size, lymph node invasion, distant metastasis and TNM stage in gastric cancer patients. Functionally, knockdown of lncRNA XIST exerted tumor-suppressive effects by inhibiting cell proliferation, migration and invasion in vitro and tumor growth and metastasis in vivo. Furthermore, an inverse relationship between lncRNA XIST and miR-101 was found. Polycomb group protein enhancer of zeste homolog 2 (EZH2), a direct target of miR-101, could mediated the biological effects that lncRNA XIST exerted. CONCLUSIONS: lncRNA XIST is up-regulated and is associated with aggressive tumor phenotypes and patient survival in gastric cancer, and the newly identified lncRNA XIST/miR-101/EZH2 axis could be a potential biomarkers or therapeutic targets for gastric cancer patients.

E3-ligase Skp2 regulates ß-catenin expression and maintains hematopoietic stem cell homing.

The homing ability of hematopoietic stem cells (HSCs) was a critical step for transplantation and subsequent hematopoiesis. Although the HSC transplantation was widely used for many diseases, the mechanism by which HSC homing was regulated remained poorly understood. F-box protein S-phase kinase associated protein2 (Skp2), a component of the Skp2-SCF E3 ligase complex, was regarded as a cell cycle regulator by controlling the level of p21 and p27 through ubiquitination. We recently reported an important role of Skp2 in maintaining HSC pool size, quiescent stage and self-renewal ability. In this current study, we showed that Skp2 was a novel and critical regulator for maintaining the homing of HSCs as well as their residence in the endosteal niche. Microarray analysis together with biochemical validations revealed that Skp2 deficiency profoundly reduced the expression of ß-catenin and its target genes. Knockdown of ß-catenin mimicked the decline of HSC homing upon Skp2 deficiency, suggesting that Skp2 may regulate ß-catenin and its target gene expression to orchestrate HSC homing. Our study not only identified Skp2 as a new regulator for maintaining ß-catenin expression and HSC homing, but also suggested that Skp2 may serve as a predictive marker for monitoring the transplantation efficiency.

Comparison of endoscopic ultrasonography and multislice spiral computed tomography for the preoperative staging of gastric cancer - results of a single institution study of 610 Chinese patients.

BACKGROUND: This study compared the performance of endoscopic ultrasonography (EUS) and multislice spiral computed tomography (MSCT) in the preoperative staging of gastric cancer. METHODOLOGY/PRINCIPAL FINDINGS: A total of 610 patients participated in this study, all of whom had undergone surgical resection, had confirmed gastric cancer and were evaluated with EUS and MSCT. Tumor staging was evaluated using the Tumor-Node-Metastasis (TNM) staging and Japanese classification. The results from the imaging modalities were compared with the postoperative histopathological outcomes. The overall accuracies of EUS and MSCT for the T staging category were 76.7% and 78.2% (P=0.537), respectively. Stratified analysis revealed that the accuracy of EUS for T1 and T2 staging was significantly higher than that of MSCT (P<0.001 for both) and that the accuracy of MSCT in T3 and T4 staging was significantly higher than that of EUS (P<0.001 and 0.037, respectively). The overall accuracy of MSCT was 67.2% when using the 13th edition Japanese classification, and this percentage was significantly higher than the accuracy of EUS (49.3%) and MSCT (44.6%) when using the 6th edition UICC classification (P<0.001 for both values). CONCLUSIONS/SIGNIFICANCE: Our results demonstrated that the overall accuracies of EUS and MSCT for preoperative staging were not significantly different. We suggest that a combination of EUS and MSCT is required for preoperative evaluation of TNM staging.

Time-varying pattern of recurrence risk for gastric cancer patients.

This study analyzed the time-varying pattern of the recurrence risk for gastric cancer after surgery. A total of 1,222 gastric patients undergoing D2 resection surgery were studied retrospectively. The annual recurrence hazard curve for all of the populations showed one early peak and a late rise within 10 years after the surgery. The first major recurrence peak covers the first 3 years after the surgery, rising to a maximum at 1.5 years after surgery, followed by a decline until 7.5 years after the surgery, at which point the curve began to rise again. A subgroup analysis of this pattern also revealed that the curves of the patients with bigger tumors, poorly differentiated/undifferentiated adenocarcinomas, lymphatic/venous invasion, T3 and T4, node positive or with fewer lymph nodes retrieved were steeper. Chemotherapy can reduce the hazard rate for recurrence of gastric cancer. Our study confirms the time-varying pattern of the recurrence risk for gastric cancer, and it further supports the hypothesis of tumor dormancy after surgery. To effectively reduce the recurrence risk, new adjuvant therapies beyond chemotherapy may be needed.

Beclin-1 expression is a significant predictor of survival in patients with lymph node-positive gastric cancer.

BACKGROUND: Beclin 1 is a main actor of autophagy. The expression of Beclin 1 and its prognostic role in gastric cancer is largely unexplored. The purpose of the present study is to investigate the expression of beclin 1 in gastric cancer cells, tissues and its relationship with prognosis. METHODS: The expression of Beclin 1 was detected in 271 specimens of lymph-node positive gastric cancer patients by immunohistochemistry. The correlation of Beclin 1 expression to clinicopathologic features and survival of gastric cancer was studied. Beclin-1 expression in gastric cancer cell lines and clinical specimens is also detected using reverse transcription-PCR and Western blotting. RESULTS: Beclin 1 is up-regulated at both mRNA and protein levels in six gastric cancer cell lines compared with those in normal gastric mucosa cell line (GES-1). The expression of Beclin-1 in gastric clinical specimens is also higher than those in the adjacent noncancerous tissues. Of the 271 patients, 229 (84.5%) were Beclin 1 high expression tumors by immunohistochemistry. Beclin 1 expression is closely associated with intravascular embolus. Kaplan-Meier analysis showed high beclin 1 expression was associated with longer overall survival. Both univariate analysis and multivariate analysis revealed that Beclin 1 expression were independent prognostic factors in the patients with node-positive gastric cancer. CONCLUSIONS: Our findings strongly suggest that Beclin 1 has a potential role in tumorigenesis of gastric cancer and could be a promising biomarker for predicting the prognosis of patients with lymph node-positive gastric cancer. It might also serve as a novel therapeutic target for gastric cancer treatment.

Prognostic significance of overexpression of EZH2 and H3k27me3 proteins in gastric cancer.

The enhancer of zeste homolog 2 (EZH2) methyl transferase and histone 3 lysine 27 (H3K27me3) protein can repress gene transcription, and their aberrant expression has been observed in various human cancers. This study determined their expression levels in gastric cancer tissues with reference to clinicopathological features and patient survival. We collected 117 gastric cancer and corresponding normal tissues for immunohistochemistry analysis. In gastric cancers, 82/117 (70.1%) were positive for EZH2 and 66/117 (56.4%) for H3K27me3 proteins in contrast to only 5.41% and 7.25% of normal gastric mucosa specimens, respectively. Kaplan-Meier survival data showed the average overall and disease-free survival of EZH2 high expression patients was 25.2 and 20.2 months, respectively, shorter than that with EZH2 low expression (40.5 and 35.9 months). The average overall survival and disease-free survival of high H3K27me3 expression patients was 23.4 and 17.4 months, shorter than without H3K27me3 expression (37.6 and 34.5 months). The average overall survival and disease-free survival of patients with both EZH2 and H3K27me3 expression was 18.8 and 12.9 months, respectively, shorter than that with either alone (34.7 and 31.2 months) or with low levels of both (43.9 and 39.9 months). Multivariate Cox regression analysis showed that H3K27me3 and EZH2 expression, tumor size differentiation and clinical stage were all independent prognostic factors for predicting patient survival. This study demonstrated that detection of both EZH2 and H3K27me3 proteins can predict poor survival of gastric cancer patients, superior to single protein detection. In addition, H3K27me3 and EZH2 protein expression could predict lymph node metastasis.

[Comparison of two types of digestive tract reconstruction after total gastrectomy in patients with gastric carcinoma].

OBJECTIVE: To evaluate the influence of two different types of digestive tract reconstruction on the life quality, nutritional status and tolerance to adjuvant chemotherapy after total gastrectomy in patients with gastric carcinoma. METHODS: The clinical data of a total of 107 patients treated in our department from January 2005 to december 2008 were analyzed retrospectively. Among them, 49 patients underwent digestive tract reconstruction with functional jejunal interposition (FJI group) and 58 patients underwent Roux en-Y jejunal P-type anastomosis (PR group) after total gastrectomy. 79 of 107 (73.8%) patients received postoperative adjuvant chemotherapy with XELOX regimen. The digestive complications and tolerance to chemotherapy were assessed respectively. RESULTS: Neither severe complications nor surgery-related or chemotherapy-related death were observed among the 107 patients. There were statistical differences in the incidence rate of emaciation, dumping syndrome and retention syndrome between the FJI and PR groups (P < 0.05), but no significant statistical difference in incidence rate of reflux esophagitis (P > 0.05). 28 of 40 (70.0%) patients in the FJI group completed all six cycles of chemotherapy, while 12 (30.0%) patients interrupted the treatment due to chemotherapy-related toxicity. 39 patients in the PR group received chemotherapy, 19 (48.7%) of them completed 6 cycles of chemotherapy but 20 (51.3%) patients interrupted. There was a significant difference in the incidence rate of grade III/IV chemotherapeutic toxicity and completion rate of chemotherapy (P < 0.05). CONCLUSIONS: Both functional jejunal interposition and Roux-Y operation are reasonable and safe procedures of digestive tract reconstruction. The incidence rates of emaciation, dumping syndrome and retention syndrome are lower in the patients with FJI, showing a better tolerance to adjuvant chemotherapy than Roux en-Y jejunal p type anastomosis.

No survival benefit from postoperative adjuvant chemotherapy after D2 radical resection for the patients with stage II gastric cancer.

OBJECTIVE: To evaluate the effect of 2 regimens of postoperative combination chemotherapies on the prognosis of early stage gastric cancer patients. METHODS: A total of 268 patients with stage II gastric cancer underwent D2 resection in our Cancer Center between January 1990 and December 2006 were recruited. Among them, 34 patients received the FAM regimen (5-fluorouracil [5-FU] 600 mg/m(2) intravenous [IV] drip on days 1, 8, 29, and 36; doxorubicin 30 mg/m(2) IV bolus injection on days 1 and 29; and mitomycin-C 10 mg/m(2) IV bolus injection on day 1; repeated every 8 weeks) and 81 patients received the FOLFOX regimen (oxaliplatin 100 mg/m(2) IV drip on days 1 and 15; leucovorin 400 mg/m(2) IV drip on days 1 and 15; 5-FU 400 mg/m(2) IV bolus injection; 5-FU 2.4/3.0 mg/m(2) continuous IV infusion for 48 hours on day 1, 2, 15, and 16; repeated every 4 weeks for at least 4 cycles). Patients were followed-up until December 2008. The Kaplan-Meier method was used to compare survival rates between treatment groups. RESULTS: The 1-, 3-, 5-, and 10-year survival rates for the patients who received postoperative chemotherapy versus the patients who underwent surgery only were 98%, 84%, 58%, 18% versus 96%, 78%, 59%, 22%, respectively (P > 0.05). Furthermore, the survival rates for patients who received the FAM and FOLFOX regimens were not significantly different (P > 0.05). CONCLUSIONS: Postoperative adjuvant chemotherapy did not produce survival benefits for the patients with stage II gastric cancer. Randomized controlled clinical trials are demanded to confirm the finding from this study.

Comparison of the 6th and 7th editions of the UICC TNM staging system for gastric cancer: results of a Chinese single-institution study of 1,503 patients.

AIM: To evaluate the prognostic efficacy of the 7th edition tumor-node-metastasis (TNM) classification compared with the 6th edition in gastric cancer patients. METHODS: A total of 1,503 gastric cancer patients undergoing surgical resection were staged using the 6th and 7th edition staging systems. Homogeneity, discriminatory ability, and monotonicity of gradients of the two systems were compared using linear trend χ(2), likelihood ratio χ(2) statistics, and Akaike information criterion (AIC) calculations. RESULTS: Significant differences in 5-year survival rates were observed for the T, N, and M subgroups using the 7th edition system, except for stage N2 and N3 patients in the 6th edition system. There were no significant differences in survival between IB and IIA in the 7th edition system. Patients with stage IV disease due to T4/N3 in the 6th edition system who were downstaged to stage III in the 7th edition system had significantly better survival than those who remained at stage IV. The 7th edition system had higher linear trend and likelihood ratio χ(2) scores, and smaller AIC values compared with those for the 6th edition, which represented the optimum prognostic stratification. CONCLUSIONS: Our study suggests that the 7th edition system performs better than the 6th edition in several aspects.

Activated mammalian target of rapamycin is a potential therapeutic target in gastric cancer.

BACKGROUND: The mammalian target of rapamycin (mTOR) plays a key role in cellular growth and homeostasis. The purpose of our present study is to investigate the expression of activated mTOR (p-mTOR) in gastric cancer patients, their prognostic significance and the inhibition effect of RAD001 on tumor growth and to determine whether targeted inhibition of mTOR could be a potential therapeutic strategy for gastric cancer. METHODS: The expression of p-mTOR was detected in specimens of 181 gastric cancers who underwent radical resection (R0) by immunohistochemistry. The correlation of p-mTOR expression to clinicopathologic features and survival of gastric cancer was studied. We also determined the inhibition effect of RAD001 on tumor growth using BGC823 and AGS human gastric cancer cell lines. RESULTS: Immunostaining for p-mTOR was positive in 93 of 181 (51.4%) gastric cancers, closely correlated with lymph node status and pTNM stage. Patients with p-mTOR positive showed significantly shorter disease-free survival (DFS) and overall survival (OS) rates than those with p-mTOR-negative tumors in univariable analyses, and there was a trend toward a correlation between p-mTOR expression and survival in multivariable analyses. RAD001 markedly inhibited dose-dependently proliferation of human gastric carcinoma cells by down-regulating expression of p70s6k, p-p70s6k, C-myc, CyclinD1 and Bcl-2, up-regulating expression of P53. CONCLUSIONS: In gastric cancer, p-mTOR is a potential therapeutic target and RAD001 was a promising treatment agent with inducing cell cycle arrest and apoptosis by down-regulating expression of C-myc, CyclinD1 and Bcl-2, up-regulating expression of P53.

Prognosis of 980 patients with gastric cancer after surgical resection.

BACKGROUND AND OBJECTIVE: Although surgery is the only possible means to cure gastric cancer, the prognosis is often discrepant. The American Joint Committee on Cancer / International Union against Cancer (AJCC/UICC) published the TNM classification of Malignant Tumors (seventh edition) for gastric cancer recently. This study aimed to use this new edition staging system to investigate the prognostic factors for gastric cancer. METHODS: The clinicopathologic data of 980 patients with gastric cancer treated by surgical resection in our hospital between January 2000 and December 2006 were analyzed retrospectively. The overall survival rate was determined by using Kaplan-Meier method and log-rank test was used to determine significance. The prognosis was analyzed using univariate analysis and multivariate analysis with the Cox proportional hazards model. The 6th and 7th edition AJCC/UICC TNM staging systems were used to compare the survival outcomes for the cohort of patients. RESULTS: The overall 1-, 3-, 5-year survival rates for the whole group were 82.5%, 58.7%, and 52.6%. The 5-year survival rates for patients with pTNM stage I, II, III, and IV disease classified by the 7th edition staging system were 93.2%, 72.4%, 39.1%, and 5.2%, respectively. In both univariate analysis and Cox multivariate analysis, age, tumor site, tumor size, histological type, resection type, radical resection, lymphatic/venous invasion, depth of invasion, nodal status, metastasis, retrieved lymph nodes, metastatic lymph node ratio, and adjuvant chemotherapy were prognostic factors with these patients. CONCLUSION: Compared with the 6th edition system, the new edition of TNM staging system for gastric cancer can accurately predict the survival after operation.

Relationship between H.Pylori infection and clinicopathological features and prognosis of gastric cancer.

BACKGROUND: Aimed to assess the relationship between H.Pylori and the clinicopathological features and prognosis of gastric cancer by quantitative detection of H.Pylori. METHODS: 157 patients were enrolled, all patients had a record of clinicopathological parameters. Specimens including the tumor and non-neoplastic were detected for H.Pylori by Real-Time PCR and analyzed clinical data retrospectively. Variables independently affecting prognosis were investigated by means of multivariate analysis using the Cox proportional hazards model. RESULTS: H.Pylori infection was greater in non-neoplastic tissue than the tumor tissue (p < 0.05), H.Pylori infection and its copies were related to the tumor site and N staging (p < 0.05). Overall survival (OS) in all 157 patients has no correlation with the H.Pylori infection status (p = 0.715). As to the patients who underwent a curative surgery, relapse-free survival (RFS) has no correlation with the H.Pylori infection status (p = 0.639). Among the H.Pylori positive patients, OS and RFS of those with higher copies were longer than in patients with low copies, but there was no significant statistical difference. CONCLUSIONS: H.Pylori infection status and its copies were related to N staging. The OS and RFS in patients with positive H.Pylori status has no significant difference from the patients with negative H.Pylori status.

[Relationship between the number of lymph node detection and prognosis in stage II gastric cancer after D(2) dissection].

OBJECTIVE: To explore the relationship between the lymph node count and prognosis in stage II gastric cancer. METHODS: Retrospective analysis was performed for the 268 cases with gastric cancer who underwent parallel D(2) dissection between January 1990 and December 2006 in the Sun Yat-Sen Cancer Center. The Japanese Gastric Cancer Association(JGCA) 13th edition of pathological staging system was used to define stage II gastric cancer. Patients were followed up until December 2008. The Kaplan-Meier method and chi-square test were used for data analysis. All the data were analyzed using SPSS16.0 for Windows. RESULTS: The average number of detected lymph nodes was 17.3+/-1.2. There were 109 patients with detected lymph node <15. The 1-, 3-, and 5-year survival rates were 92.7%, 67.8%, and 50.9%, respectively. The number of detected lymph node was > or =15 in 159 cases, and the 1-, 3-, and 5-year survival rates were 96.9 %, 81.0%, and 66.4%, respectively. The difference between two groups was statistically significant (P=0.003). Further analysis of the 199 cases with no lymph node metastasis (pN(0) group) showed that there were 95 cases with lymph nodes <15, and the 1-, 3-, and 5-year survival rates were 92.6%, 70.4%, and 55.9%, respectively. There were 104 patients with > or =15 lymph nodes, and the 1-, 3-, and 5-year survival rates were 97.1%, 84.4%, and 66.8%, respectively. The difference was also statistically significant (P=0.049). There were 69 cases with lymph node metastasis (PN(1) group), and the 1-, 3-, and 5-year survival rates of 14 patients with lymph nodes <15 were 92.9%,57.1%, and 34.3%, respectively. Comparing two groups, the survival rate was significantly different (P=0.034). There were 55 patients with > or =15 lymph nodes, and the 1-, 3-, and 5-year survival rates were 96.4%, 73.4%, and 63.8%. The difference was statistically significant (P=0.036). CONCLUSION: In patients with stage II gastric cancer as defined by the JGCA 13th edition, the survival rate is better in patients with more than 15 detected lymph nodes as compared to those with less than 15.

Higher percentage of CD133+ cells is associated with poor prognosis in colon carcinoma patients with stage IIIB.

BACKGROUND: Cancer stem cell model suggested that tumor progression is driven by the overpopulation of cancer stem cells and eradicating or inhibiting the symmetric division of cancer stem cells would become the most important therapeutic strategy. However, clinical evidence for this hypothesis is still scarce. To evaluate the overpopulation hypothesis of cancer stem cells the association of percentage of CD133+ tumor cells with clinicopathological parameters in colon cancer was investigated since CD133 is a putative cancer stem cell marker shared by multiple solid tumors. PATIENTS AND METHODS: Tumor tissues matched with adjacent normal tissues were collected from 104 stage IIIB colon cancer patients who were subject to radical resection between January, 1999 to July, 2003 in this center. The CD133 expression was examined with immunohistochemical staining. The correlation of the percentage of CD133+ cell with clinicopathological parameters and patients' 5-year survival was analyzed. RESULTS: The CD133+ cells were infrequent and heterogeneous distribution in the cancer tissue. Staining of CD133 was localized not only on the glandular-luminal surface of cancer cells but also on the invasive budding and the poorly differentiated tumors with ductal structures. Both univariate and multivariate survival analysis revealed that the percentage of CD133+ cancer cells and the invasive depth of tumor were independently prognostic. The patients with a lower percentage of CD133+ cancer cells (less than 5%) were strongly associated with a higher 5-year survival rate than those with a higher percentage of CD133+ cancer cells (greater than or equal to 55%). Additionally, no correlation was obtained between the percentage of CD133+ cancer cells and the other clinicopathological parameters including gender, age, site of primary mass, pathologic types, grades, and invasive depth. CONCLUSION: The fact that a higher percentage CD133+ cells were strongly associated with a poorer prognosis in patients with locally advanced colon cancer implicated that CD133+ cancer cells contribute to the tumor progression, and the overpopulation hypothesis of cancer stem cell seems reasonable.