A Japanese Prospective, Multicenter Study of Colonic Stenting for Palliation Using a High Axial Force Self-Expandable Metal Stent for Malignant Large Bowel Obstruction in 200 Patients.

Evidence of the efficacy and safety of colorectal stent placement for palliation remains insufficient. This single-arm, prospective, multicenter study with a WallFlex enteral colonic stent included 200 consecutive patients with malignant large bowl obstruction in the palliation cohort. The technical and clinical success, as well as stent patency and complications as short-term (≤7 days) and long-term (>7 days) outcomes, of high axial force self-expandable metal stent (SEMS) placement was evaluated. The technical and clinical success rates were 98.5% and 94.5%, respectively. Non-recurrent colorectal obstruction at 1 year was 63.9%, and 71.2% of the patients remained free of recurrent colorectal obstruction until death or the last follow-up. Fifty-six patients (28.0%) received chemotherapy, and five patients were administered bevacizumab after stent placement. The overall complication rate was 47%, including four (2.0%) early-onset and ten (5.0%) late-onset perforations, mostly due to stent-edge injury. Only the use of a long SEMS was a risk factor for perforation. In conclusion, endoscopic colorectal stenting using high axial force SEMS is an effective and safe procedure for palliation in patients with malignant colorectal obstruction. However, care should be taken to avoid perforation at the stent edge when using a long SEMS.

Safety, efficacy, and operability of a newly developed absorbable adhesion barrier (GM142) in patients with primary rectal cancer scheduled for diverting ileostomy during laparoscopic surgery: Randomized controlled trial.

Aim: The aim of this study was to compare the outcomes of GM142, a newly developed gelatin film with a concave and convex structure to a commercially available conventional film, hyaluronate-carboxymethylcellulose. Methods: Patients with primary rectal cancer who were scheduled for diverting ileostomy during laparoscopic surgery were eligible for this study. Patients were randomized before surgery and an antiadhesion film was applied under the umbilical incision. The primary outcome was the incidence of adhesion under the midline incision confirmed by second-look surgery for diverting ileostomy closure. The secondary outcomes were the adhesion severity score, the extent of adhesion score, the presence of intestinal obstruction, and the success of all patching. Results: A total of 146 patients were enrolled. A total of 123 patients were included in the full analysis set. The primary outcome of "no adhesion" was observed in 66.1% in the GM142 group and 55.7% in the conventional film group. The noninferiority of GM142 to conventional film was confirmed (P = .0005). The secondary outcomes were similar between the groups. For the safety evaluation, there were no safety concerns regarding allergic reactions to gelatin or increased gelatin-specific IgE antibody titers. Conclusions: The noninferiority of GM142 to conventional film was shown. GM142 showed no major safety issues. The clinical safety profiles of GM142 suggested certain physiological benefits of the gelatin film as an adhesion barrier.

Clonal Expansion of Tumor-Infiltrating T Cells and Analysis of the Tumor Microenvironment within Esophageal Squamous Cell Carcinoma Relapsed after Definitive Chemoradiation Therapy.

(1) Background: Comparable prognoses after definitive chemoradiation therapy (CRT) to surgery alone for esophageal squamous cell carcinoma (ESCC) have been previously reported; however, no robust prognostic markers have been established. The clonality of tumor-infiltrating lymphocytes (TILs) and tumor microenvironments (TMEs) in ESCC relapsed after CRT were examined to explore prognostic markers. (2) Methods: Clonality of TIL and TME were examined in ESCC with and without preceding CRT, as well as oral squamous cell carcinoma (OSCC) and healthy volunteers as controls. The clonality of TIL was assessed by T-cell receptor (TCR) α and ß repertoire analyses and evaluated by diversity indices. The TME was assessed by quantitative polymerase chain reaction evaluating PD-L1 and CD8B. (3) Results: The clonal expansion of TIL was significantly induced within ESCCs and OSCCs, when compared to healthy volunteers, and was mostly induced within ESCCs after definitive CRT. Diversity indices of TIL were not associated with the prognosis, but the ratio of PD-L1 mRNA to CD8B mRNA in TME was significantly associated with a poor prognosis after salvage surgery (p = 0.007). (4) Conclusions: The clonal expansion of TIL is induced after definitive CRT for ESCC, and the ratio of PD-L1 mRNA to CD8B mRNA within tumor tissues is a prognostic marker candidate for salvage esophagectomy after CRT.

Downregulation of epidermal growth factor receptor family receptors and ligands in a mutant K-ras group of patients with colorectal cancer.

The present study investigated the expression profiles of the epidermal growth factor receptor (EGFR) family, which consists of four transmembrane tyrosine kinase receptors and their eight ligands, in 122 patients with colorectal cancer (CRC) using reverse transcription-quantitative polymerase chain reaction analysis. On comparison of the CRC primary tumor and matched adjacent normal mucosa (ANM) tissue samples, the mRNA expression levels of ErbB3, but not ErbB1, were significantly increased in CRC tissue samples, compared with those in the ANM tissues. The expression levels of the ligands exhibited opposing trends to their corresponding receptors, including EGF, BTC, AREG, EREG and HB­EGF, which were increased in the CRC tissues, whereas NRG1 and NGR2 were decreased in thee CRC tissues, compared with those in the AMN tissues. Subsequently, the present study investigated the frequency of K-ras mutations in the patients with CRC. The K­ras mutations were found to be present in 36.8% (45/122) of the cases, however, no correlation was observed between K­ras mutations and clinicopathological characteristics. In the CRC tissues, the expression levels of the EGFR family receptors and their ligands were determined in wild-type and mutant K-ras CRC cases. The expression levels of ErbB1, ErbB2, ErbB3, BTC, AREG, EREG, NRG1 and NRG2 were significantly decreased in the mutant K­ras cases, compared with those in the wild­type K­ras cases. These results suggested that the tumorigenesis of CRC with wild­type K­ras was mediated through, not only ErbB1, but also through the ErbB2 and ErbB3 pathways. Notably, although ErbB2 does not bind any ErbB ligands, ErbB2 may activate tumorigenesis via a heterodimer, rather than a homodimer. Therefore, the results of the present study suggest that the most effective strategy to target not only ErbB1, but also ErbB2 and ErbB3, is the use of monoclonal antibody treatment.

A prospective multicenter study on self-expandable metallic stents as a bridge to surgery for malignant colorectal obstruction in Japan: efficacy and safety in 312 patients.

BACKGROUND: Endoscopic stenting with a self-expandable metallic stent (SEMS) is a widely accepted procedure for malignant colonic obstruction. The Colonic Stent Safe Procedure Research Group conducted the present prospective feasibility study. METHODS: Our objectives were to estimate the safety and feasibility of SEMS placement as a bridge to surgery (BTS) for malignant colorectal obstruction. We conducted a prospective, observational, single-arm, multicenter clinical trial from March 2012 to October 2013. Each patient was treated with an uncovered WallFlex enteral colonic stent. Patients were followed up until discharge after surgery. RESULTS: A total of 518 consecutive patients were enrolled in this study. The cohort intended for BTS consisted of 312 patients (61 %), and the stent could be released in 305 patients. Technical and clinical success rates were 98 and 92 %, respectively. Elective surgery was performed in 297 patients, and emergency surgery was performed in eight patients for the treatment of complications. The overall preoperative complication rate was 7.2 %. Major complications, including perforation, occurred in 1.6 %, persistent colonic obstruction occurred in 1.0 %, and stent migration occurred in 1.3 % patients. The median time from SEMS to surgery was 16 days. Silent perforations were observed in 1.3 %. Open and laparoscopic surgery was performed in 121 and 184 patients, respectively. The tumor could be resected in 297 patients. The primary anastomosis rate was 92 %. The rate of anastomotic leakage was 4 %, and the overall stoma creation rate was 10 %. The median duration of hospitalization following surgery was 12 days. Overall postoperative morbidity and mortality rates were 16 and 0.7 %, respectively. CONCLUSIONS: This largest, multicenter, prospective study demonstrates the feasibility of SEMS placement as a BTS for malignant colorectal obstruction. SEMS serves as a safe and effective BTS with acceptable stoma creation and complication rates in patients with acute malignant colonic obstruction.

Clinicopathological significance and prognostic value of Wilms' tumor gene expression in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is one of the most commonly diagnosed cancers, and novel effective treatments and diagnostic tools are urgently required. OBJECTIVE: The selection of appropriate targeting tumor-associated antigens (TAAs) is critical for immunotherapy. Therefore, we analyzed TAA expression levels and investigated their relationship with clinical factors in adjacent normal mucosa (ANM) and CRC tissue. METHODS: We obtained specimens of CRC primary tumors and matched ANM from 137 patients with CRC who underwent surgical resection. The mRNA levels of seven TAAs, Wilms' tumor gene (WT1), kinetochore associated-2 (KNTC2), cell division cycle associated-1 (CDCA1), M phase phosphoprotein-1 (MPHOSPH1), DEP domain-containing 1 (DEPDC1), 34-kDa translocase of the outer mitochondrial membrane (TOMM34) and ring finger protein-43 (RNF43), were analyzed using quantitative real-time reverse transcription-polymerase chain reaction, and their relationships with clinicopathological factors and the cell cycle were analyzed. RESULTS: The expression levels of all seven TAAs were significantly higher in CRC tissues than in ANM. Expression levels of WT1 in CRC tissues did not correlate with the cell cycle. Furthermore, WT1 expression in CRC tissues was significantly related to tumor progression, lymph node metastasis, distant metastasis and clinical stage. CONCLUSIONS: WT1 is a potential marker for prognosis and tumor progression in CRC.

Cluster analysis of claudin-1 and -4, E-cadherin, and ß-catenin expression in colorectal cancers.

BACKGROUND AND OBJECTIVES: Intercellular adhesion mediated by the claudin and cadherin/catenin complex is a prerequisite for epithelial integrity and differentiation, and has been suggested to be frequently disturbed in cancers. The aim of this study was to assess the relationship between such abnormality and clinicopathological features of colorectal carcinomas. METHODS: Immunohistochemical analysis of claudin-1 and -4, E-cadherin, and ß-catenin was performed on a series of 156 cases. RESULTS: Significant positive associations (P < 0.05-0.001) were found with immunoreactivity for each except nuclear ß-catenin. Reduced expression was correlated with poor tumor differentiation (claudin-1, P = 0.035; claudin-4, P = 0.011; E-cadherin, P < 0.001; membranous ß-catenin, P = 0.002), an advanced TNM stage (claudin-1, P = 0.002; claudin-4, P = 0.008), and a poor prognosis. On multivariate analysis, reduced expression of E-cadherin (P < 0.001) and ß-catenin (P = 0.048) at invasive fronts proved to be an independent predictor of short survival. Hierarchical cluster analysis identified three distinct groups with a good, intermediate, and poor prognosis, having an independent survival outcome by multivariate analysis (good or intermediate vs. poor: hazard ratio, 2.66; 95% confidence interval, 1.54-4.60; P < 0.001). CONCLUSIONS: Disruption of cell adhesion molecules correlates with tumor differentiation and progression in colorectal carcinomas. Specific marker profiles were identified here as independent prognostic indicators.

Aberrant p16((INK4a)) methylation is a frequent event in colorectal cancers: prognostic value and relation to mRNA expression and immunoreactivity.

PURPOSE: Aberrant p16((INK4a)) promoter methylation is common in colorectal cancer (CRC), but its clinicopathological significance remains controversial. The present study was therefore conducted to analyze p16((INK4a)) methylation and its relationship to clinicopathological features, mRNA levels and immunoreactivity in a series of lesions. METHODS: p16((INK4a)) methylation was assessed for normal mucosa (n = 30) and CRC samples (n = 212) by methylation-specific real-time quantitative PCR, and p16((INK4a)) expression by immunostaining in formalin-fixed paraffin-embedded specimens. In addition, fresh DNA (n = 61) was analyzed for relationships to p16((INK4a)) mRNA by reverse-transcription PCR. RESULTS: The p16((INK4a)) methylation index of normal mucosa samples ranged from 0 to 2% (mean, 0.23%; median, 0.02%), while the values for tumor samples varied widely from 0 to 100% (mean, 25.7%; median, 7.1%), the difference being statistically significant (P < 0.001). Of 151 paraffin-embedded CRC tissue samples, 51 (34%), 54 (36%), and 46 (30%) were classified as low, intermediate, and high for aberrant methylation of p16((INK4a)). High p16((INK4a)) methylation was significantly associated with large tumor size (P = 0.025). Patients with higher methylation further showed more frequent recurrence as compared with the low-methylation group, and shortened cancer-related survival (Hazard ratio [HR], 3.379; P < 0.001) and recurrence-free survival (HR, 3.962; P < 0.001 on multivariate analysis). A significant inverse relationship was apparent between the p16((INK4a)) methylation and immunoreactivity (P = 0.017). A similar tendency was also observed for the methylation status and the mRNA level (P = 0.195). CONCLUSIONS: We conclude that p16((INK4a)) methylation results in transcriptional silencing and defines a group of CRCs with a poor prognosis.

Abnormal expression of p16(INK4a), cyclin D1, cyclin-dependent kinase 4 and retinoblastoma protein in gastric carcinomas.

BACKGROUND AND OBJECTIVES: The p16(INK4a) (p16), cyclin D1, cyclin-dependent kinase (CDK) 4 and retinoblastoma (Rb) genes are components of the Rb pathway that controls the G1-S checkpoint of the cell cycle. The aim of this study was to assess the relationship between their abnormalities and clinicopathological features in gastric carcinomas. METHODS: Immunohistochemical analysis of the encoded proteins was performed on a series of 158 cases. RESULTS: Loss of p16/Rb protein (pRb) expression and overexpression of cyclin D1/CDK4 were observed in 49%/40% and 37%/37% of gastric carcinomas, respectively. At least 1 of these abnormalities was found in 86% of the cases and a positive correlation was noted between p16 and pRb (P = 0.009). Cyclin D1 (P = 0.042) and CDK4 (P = 0.008) overexpession was inversely associated with lymph node metastasis and depth of invasion, respectively. Loss of pRb expression was more frequently in diffuse type lesions than in the intestinal type (P = 0.022). The patients with p16+/pRb-/cyclin D1-/CDK4- or p16-/pRb+/cyclin D1-/CDK4- tumors demonstrated particularly poor survival. With multivariate survival analysis, only depth of invasion and TNM stage could be proven as independent predictors. CONCLUSIONS: The Rb pathway is disrupted in the vast majority of gastric carcinomas. This study also identified specific immunohistochemical marker profiles for prognosis.

Tumor budding as an index to identify high-risk patients with stage II colon cancer.

PURPOSE: High-risk patients with Stage II colon cancer may benefit from adjuvant chemotherapy, but they are difficult to identify. We assessed the value of tumor budding, defined as small clusters of undifferentiated cancer cells at invasive margins, as a predictor of outcomes in patients with Stage II colon cancer. METHODS: We studied a total of 200 patients with Stage II colon cancer who underwent curative surgery. With hematoxylin and eosin-stained specimens, the degree of tumor budding was classified as low-grade or high-grade. The survival rate of patients who had Stage II disease with low-grade or high-grade tumor budding was compared with that of 226 patients who had Stage III colon cancer. RESULTS: Univariate analysis revealed that serosal surface involvement (P = 0.04) and tumor budding (P < 0.001) were significantly related to survival. Cumulative five- and ten-year survival rates differed significantly between patients with low-grade tumor budding (93.9 and 90.6 percent, respectively) and those with high-grade (73.9 and 67.8 percent, respectively). Survival rates did not differ significantly between patients with Stage II disease who had high-grade tumor budding and patients with Stage III disease. Cox's regression analysis demonstrated that tumor budding (hazard ratio, 4.89; P < 0.001) and serosal surface involvement (hazard ratio, 2.561; P = 0.023) were independent prognostic factors. Liver (P < 0.001) and peritoneal (P = 0.003) metastases were more frequent in the patients with high-grade tumor budding than in those with low-grade. CONCLUSIONS: Tumor budding is useful for prognosis and identifying patients with Stage II colon cancer who have a high risk of disease recurrence after curative surgery.

P21WAF1/CIP1 expression in colorectal carcinomas is related to Kras mutations and prognosis.

BACKGROUND/AIM: P21WAF1/CIP1 is a cyclin-dependent kinase inhibitor activated by p53 to produce cell cycle arrest. A consensus has not been reached concerning the prognostic value of p21WAF1/CIP1 expression in colorectal cancers. PATIENTS/METHODS: P21WAF1/CIP1 expression was determined immunohistochemically in a series of 211 cases of colorectal carcinomas, together with its relation to p53, bcl-2, cell turnover (as assessed by Ki67 expression and apoptotic counts) and the Kras gene status. The expression of p21WAF1/CIP1 was also compared with reference to clinicopathological parameters and patient survival. RESULTS: The median value for nuclear p21WAF1/CIP1 expression was 31% (interquartile range, 13-47%) and the fraction of cases considered to be high expressers (>20%) was 66%. Expression of p21WAF1/CIP1 was not associated with immunoreactivity for p53 or bcl-2, or cell turnover. P21WAF1/CIP1 high-expressing tumors were more often well differentiated (P<0.001), node-negative (P=0.037), Dukes' B (P=0.027) and Kras gene-mutated cases (P=0.04). On univariate analysis, low p21WAF1/CIP1 expressers (

Contribution of TIA-1+ and granzyme B+ cytotoxic T lymphocytes to cryptal apoptosis and ulceration in active inflammatory bowel disease.

In spite of the clinicopathological differences between Crohn's disease (CD) and ulcerative colitis (UC), they share the fundamental feature of destructive inflammatory processes involving the intestinal wall. The aim of the present study was to investigate the contribution of cell-mediated cytotoxicity to mucosal damage in CD and UC. Colonic mucosal biopsy specimens from patients with active CD (n=25) and UC (n=26) and normal controls (n=12) were immunohistochemically analyzed for the expression of CD3, CD4, CD8, and T cell-restricted intracellular antigen (TIA)-1, which promotes apoptosis by alternative splicing of pre-messenger RNA of the Fas receptor, and granzyme B (GrB), which leads to apoptosis through induction of perforin. Histological scores for cryptal apoptosis and ulceration were assessed in hematoxylin- and eosin-stained sections. In patients with CD and UC, CD3+(P<0.001), CD4+(P<0.001), CD8+(P<0.01), TIA-1+(CD, P<0.01; UC, P<0.001), and GrB+(CD, P<0.01; UC, P<0.001) intraepithelial lymphocytes (IELs) were significantly increased as compared with controls. Positive relationships were found between the histological scores for apoptosis or ulceration and the numbers of CD8+or TIA-1+IELs. In conclusion, cytotoxic T lymphocytes are present in increased numbers in the mucosa of patients with active CD and UC, and local activation of IELs may contribute to mucosal damage with these diseases.

Venous invasion and down-regulation of p21(WAF1/CIP1) are associated with metastasis in colorectal carcinomas.

BACKGROUND/AIMS: Liver and lymph node metastasis the major prognostic factor in patients with colorectal carcinoma. The aim of this work was to search for tumor parameters which can be employed to predict whether this has occurred. METHODOLOGY: A total of 211 patients with a colorectal carcinoma (Dukes' B group, 83; Dukes' C, 94; Dukes' D, 34) were investigated for 10 clinicopathological variables, as well as apoptotic activity, expression of Ki-67, p21(WAF1/CIP1), p53, bcl-2 and DCC proteins, and the c-Ki-ras mutations. Data were analyzed by univariate and multivariate statistics. RESULTS: Lymph node metastasis-predictive models were developed using the venous involvement index (the number of vascular involvements per elastica van Gieson-stained slide; Odds ratio [OR], 2.38; 95% confidence interval [CI], 1.52-3.71; p=0.0001), tumor size (OR, 0.82; 95% CI, 0.70-0.97; p=0.0179), and p21(WAF1/CIP1) immunolabeled index (the percentages of positive tumor cells; OR, 0.76; 95% CI, 0.64-0.90; p=0.0011). Liver metastasis-predictive models were developed using the venous involvement index (OR, 2.40; 95% CI, 1.71-3.37; p=0.0000) and tumor location (rectum vs. colon; OR, 9.31; 95% CI, 2.41-36.01; p=0.0012). CONCLUSIONS: Down-regulation of p21(WAF1/CIP1) as well as marked venous involvement, small tumor size and colonic tumor are associated with lymph node and/or liver metastasis. Criteria for assessment of metastasis risk provide a basis for additional treatment guidelines.

Comparative histologic assessment of proctocolectomy specimens from Japanese and American patients with ulcerative colitis with or without dysplasia.

There have been no reports of histologic differences in ulcerative colitis (UC) between Japanese and American patients. We therefore compared histology in proctocolectomy resection specimens between Japanese patients with UC (19 cases with and 21 without dysplasia) at the Kitasato University East Hospital and American patients with UC (21 cases with and 24 without dysplasia) at the University of Washington Medical Center. In cases of UC with, but not without dysplasia, cryptitis (p = 0.010) and epithelial apoptosis (p < 0.001) in the nondysplastic mucosa were more frequently observed in Japanese than in American cases, whereas lamina propria fibrosis was more prominent in American counterparts (p = 0.008). In patients with UC with dysplasia, the duration of disease was significantly longer in American than in Japanese patients (median, 17 vs 14 years, respectively; p = 0.038). This might, in part, explain the histologic variation. Another possibility for the differences is that the preoperative medications may have differed in the populations.

Different apoptotic activity and p21(WAF1/CIP1), but not p27(Kip1), expression in serrated adenomas as compared with traditional adenomas and hyperplastic polyps of the colorectum.

PURPOSE: Serrated adenomas (SAs), which include a wide spectrum of lesions, can be broadly divided into two subtypes: type I, closely mimicking hyperplastic polyps (HPs), and type II, unequivocal adenomatous tumor. Our preliminary findings showed clinicopathologic differences between them. The present study was conducted to investigate apoptotic activity and expression of the cell cycle regulator proteins p21(WAF1/CIP1) and p27(Kip1) in type I and II SAs, as compared with traditional adenomas (TAs) and HPs. METHODS: Apoptotic activity was estimated in hematoxylin-eosin stained specimens, and p21(WAF1/CIP1) or p27(Kip1) immunoreactivity was determined in 62 SAs (19 type I and 43 type II), 50 TAs and 19 HPs. The numbers (percentages) of apoptotic or immunoreactive cells were counted per 1,000 epithelial cells in equally separated crypt zones (upper, middle, and lower thirds). RESULTS: The apoptotic activity in the middle, but not the upper or lower crypt zone was higher in type II SAs (median 0.2%, interquartile range 0.1-0.5%) than in HPs (0.1%, 0.1-0.2%, P<0.01), whereas it was lower in type I SAs (0.2%, 0.1-0.3%) than in TAs (0.5%, 0.2-0.6%, P<0.001). P21(WAF1/CIP1) expression in the lower crypt zone was higher in both type I and type II SAs (19.8%, 7.0-33.2% and 20.4%, 3.9-47.8%, P<0.0001) than in TAs (1.2%, 0.6-5.2%), and a similar tendency was also observed for the middle crypt zone. p27(Kip1) expression did not vary among the groups. CONCLUSIONS: The differences in apoptotic activity and p21(WAF1/CIP1) expression between SAs and TAs or HPs indicate that SA should be considered as a distinct subtype of colorectal neoplasm. The two subtypes of SA do not differ in these parameters despite specific clinicopathological features.