Tokuma Tanuma

Endoscopic submucosal dissection is superior to conventional endoscopic resection as a curative treatment for early squamous cell carcinoma of the esophagus (with video)

BACKGROUND Endoscopic submucosal dissection (ESD) was originally developed in Japan for en bloc resection of gastric neoplasms. OBJECTIVE To clarify whether the novel ESD procedure is feasible and gives results that justify the pursuit of integrated minimally invasive procedures aimed at curing early squamous cell carcinoma of the esophagus (SCCE). DESIGN Retrospective cohort study. SETTING A single-institution trial by experienced endoscopists. PATIENTS This study involved 300 consecutively enrolled patients with SCCE (Tumor, Nodes, Metastasis classification T1, N0) who underwent either EMR (n = 184) or ESD (n = 116) from March 1994 to July 2007. INTERVENTION The patients underwent endoscopic resection and then were followed by periodic endoscopy for 8 to 174 months (mean 65 months). MAIN OUTCOME MEASUREMENTS Resectability, cure rates, complications, disease-free survival of the two groups, and risk factors for local recurrence were explored. RESULTS En bloc resection and the local recurrence rate were significantly better in the ESD group (P = .0009 and .065, respectively). The frequency of perforation was not significantly different between the two groups (P = .68). Four independent risk factors for local recurrence were identified by the Cox regression model: EMR, deep cancer invasion, upper esophagus location, and family history of esophageal cancer. Radical cure is mostly obtained by successful endoscopic retreatment of local recurrence after previous endoscopic resection. Disease-free survival was significantly better with ESD. LIMITATIONS The studys retrospective nature prevents definitive conclusions. CONCLUSIONS We provide evidence that ESD gives a higher cure rate and is safer than conventional endoscopic resection when applied to early SCCE. ESD warrants prospective comparative studies with conventional endoscopic resection.

Epigenetic inactivation of calcium-sensing receptor in colorectal carcinogenesis.

Ca2+ is a chemopreventive agent for colon cancer. Ion transport systems are often altered in human cancer. The aim of this study was to clarify the alterations of calcium-sensing receptor (CASR), a member of the G protein-coupled receptor family, in colorectal carcinogenesis. We analyzed the expression of CASR in colorectal cancer cell lines and in cancer and adenoma tissues by RT-PCR and immunostaining. In addition, we analyzed methylation of the CASR promoter by using bisulfite sequence analysis and methylation-specific PCR. CASR mRNA and protein expression was significantly downregulated in most of the cancer cell lines. CpG islands were densely methylated in cancer cell lines with reduced CASR mRNA expression. Treatment with a demethylating agent, 5-aza-2′-deoxycytidine, and/or a histone deacetylase inhibitor, trichostatin A, restored CASR expression in the cancer cell lines. Disruption of CASR expression in CASR-unmethylated HCT-8 cells blocked the enhancing effect of Ca2+ on the cytotoxic response to 5-fluorouracil. CASR expression was observed in normal colonic epithelial cells and was retained in most adenoma tissues. CASR mRNA and protein expression was significantly downregulated in cancer tissues. There was an inverse relationship between CASR expression and degree of differentiation. Immunohistochemical CASR staining was reduced more predominantly in less-differentiated cancer tissues and/or in cancer cells at the invasive front, where nuclear/cytoplasmic β-catenin was often localized. CASR methylation was detected in 69% of colorectal cancer tissues and 90% of lymph node metastatic tissues and was significantly correlated with reduced CASR expression. CASR methylation was also detected in 32% of advanced adenoma tissues but was detected in only 9% of adenoma tissues and was not detected in hyperplastic polyp tissues. CASR methylation seems to occur at an early stage and progress in colorectal carcinogenesis. The results suggest that epigenetic inactivation of CASR has an important role in colorectal carcinogenesis.

Phase I/II study of docetaxel/cisplatin/fluorouracil combination chemotherapy against metastatic esophageal squamous cell carcinoma.

Introduction: More effective regimens are urgently needed for squamous cell carcinoma of esophagus (SCCE), therefore, we conducted a phase I/II trial of a combination of docetaxel, platinum, and fluorouracil (TPF) for treating metastatic SCCE. Methods: This phase I/II trial (n = 12/39) was conducted in our institute from April 2005 to June 2008. Progression-free survival (PFS) and overall survival were analyzed by the Kaplan-Meier method. Results: The recommended dose of docetaxel was determined to be 50 mg/m2 in phase I. In phase II with a mean follow-up period of 13.3 months, the objective response rate was 66.6%, a median survival period of 13 months and PFS of 7 months was achieved, and the 1-year survival and PFS rates were 52.9% and 19.6%, respectively. Grade 3/4 toxicities of leukopenia, neutropenia, and anorexia were observed in 53.8%, 43.6%, and 25.6%, respectively. Conclusions: A TPF regimen against metastatic SCCE was well tolerated and achieved a favorable objective response rate and survival benefit compared with other recently reported regimens. Randomized phase III trials of the TPF regimen are warranted and urgently required.

The relationship between EZH2 expression and microRNA-31 in colorectal cancer and the role in evolution of the serrated pathway.

Polycomb group protein enhancer of zeste homolog 2 (EZH2) is a methyltransferase that correlates with the regulation of invasion and metastasis and is overexpressed in human cancers such as colorectal cancer. MicroRNA-31 (miR-31) plays an oncogenic role and is associated with BRAF mutation and poor prognosis in colorectal cancer. EZH2 is functionally considered to suppress miR-31 expression in human cancers; however, no study has reported its relationship with colon cancer. We therefore evaluated EZH2 expression using immunohistochemistry and assessed miR-31 and epigenetic alterations using 301 colorectal carcinomas and 207 premalignant lesions. Functional analysis was performed to identify the association between EZH2 and miR-31 using cancer cell lines. In the current study, negative, weak, moderate, and strong EZH2 expressions were observed in 15%, 19%, 25%, and 41% of colorectal cancers, respectively. EZH2 was inversely associated with miR-31 (P < 0.0001), independent of clinicopathological and molecular features. In a multivariate stage-stratified analysis, high EZH2 expression was related to favorable prognosis (P = 0.0022). Regarding premalignant lesions, negative EZH2 expression was frequently detected in sessile serrated adenomas/polyps (SSA/Ps) (76%; P < 0.0001) compared with hyperplastic polyps, traditional serrated adenomas, and non-serrated adenomas (25–36%). Functional analysis demonstrated that the knockdown of EZH2 increased miR-31 expression. In conclusion, an inverse association was identified between EZH2 and miR-31 in colorectal cancers. Our data also showed that upregulation of EZH2 expression may be rare in SSA/Ps. These results suggest that EZH2 suppresses miR-31 in colorectal cancer and may correlate with differentiation and evolution of serrated pathway.

Serum HER2 as an adjunct to assess HER2 status for advanced gastric cancer: A prospective multicenter trial (SHERLOCK)

Abstract Background: Intratumoral human epidermal growth factor receptor 2 (HER2) heterogeneity of gastric cancer can be an obstacle to accurate HER2 assessment. Serum HER2, concentrations of the HER2 extracellular domain shed into the bloodstream, has a potential to compensate HER2 immunohistochemistry (IHC) but has not been scrutinized in gastric cancer. This study sought to explore the clinical utility of serum HER2 in gastric cancer. Methods: We performed a prospective multicenter trial (SHERLOCK trial) involving patients with all-stage gastric or gastro-esophageal junction cancer. Serum HER2 was measured using direct chemiluminescence while tissue HER2 status was determined using IHC and fluorescent in situ hybridization. For stage IV cases, concordance between local and central laboratories in tissue HER2 assessment was also evaluated. Results: Of 224 patients enrolled, both tissue HER2 status and serum HER2 levels were successfully determined in 212 patients and 21% (45/212) were tissue HER2-positive. Serum HER2 levels, ranged from 4.5 to 148.0 ng/ml (median 10.3), correlated with tissue HER2 status (p = 0.003). At a cut-off level of 28.0 ng/ml determined by receiver operating characteristics analysis, sensitivity, specificity, positive and negative predictive values of serum HER2 were 22.6%, 100%, 100% and 82.3%, respectively. All nine cases with elevated serum HER2 were tissue HER2-positive stage IV cases. Among 61 stage IV cases, the agreement rate for IHC scoring between the local and the central laboratories was 82% and tissue HER2 judgment was conflicting in five (8.2%) cases. Of these five cases, four were confirmed as false-negative and two of these four patients demonstrated elevated serum HER2. Conclusions: Serum HER2 levels correlated with tissue HER2 status in gastric cancer. Although the low sensitivity is a drawback, serum HER2 might be a useful adjunct tool to detect tissue HER2 false-negative gastric cancer.

MicroRNA-196b is an independent prognostic biomarker in patients with pancreatic cancer

Pancreatic cancer is a highly aggressive malignancy, with <50% patients surviving beyond 6 months after the diagnosis, and thus, there is an urgent need to explore new diagnostic and therapeutic approaches for this disease. Therefore, we conducted microRNA (miRNA) array analysis to detect miRNA molecules potentially associated with pancreatic cancer malignancy. To assess the identified miRNAs, we performed quantitative reverse transcription-PCR on 248 pancreatic ductal adenocarcinomas (UICC stage II). We also examined miRNA expression [microRNA-21 (miR-21) and microRNA-31 (miR-31)] and epigenetic alterations, including CpG island methylator phenotype (CIMP), potentially associated with the identified miRNAs. For functional analysis, we conducted proliferation and invasion assays using a pancreatic cancer cell line. miRNA array analysis revealed that microRNA-196b (miR-196b) was the most up-regulated miRNA in pancreatic cancer tissues compared with normal pancreatic duct cells. High miR-196b expression was associated with miR-21 (P = 0.0025) and miR-31 (P = 0.0001) expression. It was also related to poor prognosis in the multivariate analysis using overall survival (hazard ratio: 1.66; 95% confidence interval: 1.09-2.54; P = 0.019). Functional analysis demonstrated that miR-196b inhibitor decreased cell proliferation and that miR-196b mimic promoted cancer cell invasion. In conclusion, a significant association of high miR-196b expression with poor prognosis was observed in pancreatic cancer. Our data also revealed that miR-196b played an oncogenic role and that the transfection of the miR-196b inhibitor had an anti-tumour effect in the pancreatic cancer cell line. These results suggest that miR-196b is a promising diagnostic biomarker and therapeutic target in pancreatic cancer.

MicroRNA-31 expression in colorectal serrated pathway progression

MicroRNAs have been increasingly recognized as useful biomarkers for colorectal cancers (CRC). We have recently observed that microRNA-31 (miR-31) expression is associated with BRAF mutation and prognosis in CRC. Moreover, high miR-31 expression is frequently detected in sessile serrated adenomas compared with hyperplastic polyps (HPs). These results suggest that miR-31 may contribute to the progression of serrated lesions. At a follow-up colonoscopy, we observed the case of a 75-year-old man with a 7-mm flat-elevated lesion in the cecum and diagnosed the lesion as an early invasive carcinoma with serrated features. Tissue specimens were obtained from the representative areas to compare the molecular alterations in the carcinoma component with those in the HP component. Higher miR-31 expression was observed in the carcinoma component (57-fold increase) and the HP component (8-fold increase) compared with the paired normal mucosa, suggesting that miR-31 may be one of the key molecules in serrated pathway progression.

Pharyngeal cancer surveillance using narrow band imaging during conventional upper gastrointestinal endoscopy.

Background: Recent studies have suggested that narrow band imaging (NBI) is useful for detecting superficial pharyngeal cancer. Nevertheless, pharyngeal observation is not a routine practice during upper gastrointestinal (GI) endoscopy. Two aims of this study were to evaluate the feasibility of pharyngeal observation during upper GI endoscopy and to determine the prevalence of pharyngeal cancer in asymptomatic high-risk patients. Methods: Fifty-year-old or older asymptomatic males with smoking and drinking habits were prospectively recruited as a pharyngeal cancer high-risk group. A total of 224 high-risk patients underwent pharyngeal observation using NBI before conventional upper GI endoscopy. The feasibility of pharyngeal examination without sedation was assessed by a questionnaire for the first 60 participants. Results: The median time for pharyngeal observation was 1.7 min. The questionnaire demonstrated 88% of participants thought the pharyngeal examination acceptable. The NBI examination identified 5 superficial pharyngeal cancers (2 Tis and 3 T1) in 224 high-risk patients; the prevalence of pharyngeal cancer in this group was 2.2%. Three of the 5 patients had a concurrent or past history of esophageal squamous cell carcinoma (ESCC). Conclusions: Pharyngeal observation using NBI during upper GI endoscopy is well tolerated and recommended for all high-risk patients, particularly those with a history of ESCC.