Search

AT-rich interactive domain 1A (ARID1A), which is a tumor suppressor gene, is frequently mutated in Epstein-Barr virus-positive gastric cancer [EBV (+) GC]. While most ARID1A mutations in GC are truncating mutations, leading to loss of ARID1A protein expression, epigenetic modifications appear to contribute to ARID1A deficiency in EBV (+) GC harboring wild-type ARID1A. Based on the significant role of epigenetic modifications in EBV (+) GC that contributes to ARID1A deficiency, the methylation status of ARID1A was evaluated in EBV-infected cells and GC patients using a publicly available microarray and the Cancer Genome Atlas (TCGA) database. EBV-encoded miRNAs that potentially target ARID1A were identified as an additional epigenetic modulator by computational prediction. In vitro experiments were conducted to evaluate how EBV-encoded miRNAs affected ARID1A mRNA and protein levels. In clinical GC samples, the expression of predicted miRNAs and ARID1A and the mutation status of ARID1A was evaluated. As results, ARID1A was not hypermethylated in EBV (+) GC samples or EBV-infected GC cells. EBV infection did not alter ARID1A mRNA levels, suggesting that ARID1A protein deficiency was caused by post-transcriptional gene silencing in ARID1A -WT EBV (+) GC. Overexpression of miR-BART11-3p and miR-BART12, which were identified as miRNAs that potentially bind ARID1A , suppressed ARID1A protein expression in MKN7 and NCI-N87 cells. Highly expressed miR-BART11-3p and miR-BART12 were correlated with decreased ARID1A levels in GC tumors which did not harbor ARID1A mutations. The present findings revealed that ARID1A expression was epigenetically regulated by miR-BART11-3p and miR-BART12 in EBV (+) GC. [ABSTRACT FROM AUTHOR]

Adjuvant chemotherapy is considered for patients with stage II colorectal cancer (CRC) characterized by poor prognostic clinicopathological features; however, current stratification algorithms remain inadequate for identifying high-risk patients. To develop prognostic assays, we conducted a step-wise screening and validation strategy using nine cohorts of stage II patients based on multiple platforms, including microarray, RNA-sequencing (RNA-seq) and immunohistochemistry (IHC) on formalin-fixed paraffin-embedded (FFPE) tissues. Four microarray datasets (total n = 458) were used as the discovery set to screen for single genes associated with postoperative recurrence. Prognostic values of candidate genes were evaluated in three independent microarray/RNA-seq validation cohorts (n = 89, n = 93 and n = 183, respectively), and then IHC for KRT17 was conducted in two independent FFPE series (n = 110 and n = 44, respectively). We found that high levels of KRT17 transcript expression were significantly associated with poor relapse-free survival (RFS) not only in the discovery set, but also in three validation cohorts, and its prognostic impact was independent of conventional factors by multivariate analyses. Positive staining of KRT17 protein was significantly associated with poor RFS in two independent FFPE cohorts. KRT17 protein expression had independent prognostic impact on RFS in a multivariate model adjusted for conventional variables, including high-risk clinicopathological features. In conclusion, using nine independent cohorts consisting of 997 stage II patients, we identified and validated the expression of KRT17 transcript and KRT17 protein as a robust prognostic biomarker that can discriminate postoperative stage II patients who are at high probability of disease recurrence, providing additional prognostic stratification beyond the currently available high-risk factors. [ABSTRACT FROM AUTHOR]

Background Recently, endoscopic submucosal dissection (ESD) has been used as a less invasive treatment for superficial esophageal cancer. Additional treatment is often required after non-curative resection to prevent local recurrence and lymph node metastasis. Here, we present the outcomes of various additional treatments for patients with superficial esophageal cancer who underwent ESD. Methods Between 2006 and 2017, we performed ESD in 179 patients (210 lesions) with superficial esophageal cancer and 44 cases resulted in the non-curative resection diagnosed by the pathological examination. Among them, 29 patients received additional treatment, whereas 15 patients with no additional treatment were followed up. Additional treatment included esophagectomy (8 patients), chemoradiotherapy (15 patients), ablation using argon plasma coagulation (4 patients), and chemotherapy alone (2 patients). We examined the clinicopathological characteristics and prognosis of patients in the additional esophagectomy group (S group) and chemoradiotherapy group (CRT group). Results Twenty-three patients with pT1a-MM, pT1b, lymphatic invasion, venous invasion, and positive resection margins (both horizontal and vertical) were divided into two treatment groups. Clinicopathological characteristics of patients in the S and CRT groups were not significantly different. Pathological findings after additional esophagectomy showed one residual tumor and one lymph node metastasis. There were no recurrences in the two groups. There was no statistically significant difference in the 5-year overall survival rate between the S group (87.5%) and the CRT group (93.3%). One patient from the S group died due to respiratory pneumonia, and one patient died due to radiation pneumonia. However, five out of the 15 (33.3%) patients who were followed up with no additional treatment developed recurrence. The 5-year overall survival rate was 40.4%, which was not significantly different from that in the additional treatment group. However, the 5-year relapse-free survival rate (30%) was significantly different from that in the additional treatment group (P  > 0.05). Conclusion Additional treatment is essential after non-curative endoscopic submucosal resection for esophageal cancer. Additional esophagectomy and chemoradiotherapy were both safe and effective in this cohort. Disclosure All authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]

Background Circulating tumor cells (CTCs) in patients with malignant tumors can be used as a prognostic marker. Recently the existence of mesenchymal CTCs have been detected by new methods. However, it has been not yet clarified how CTCs are associated with the treatment effects in esophageal cancer patients. We assessed CTCs in esophageal cancer patients and investigated the relationship between CTCs and treatment effect. Methods Seven patients who had potential of curative resection have been enrolled and peripheral blood samples (10ml) were collected before and after treatment. All patients received chemotherapy (5-FU and cisplatin) and four patients of them received as neoadjuvant therapy. Other patients received only chemotherapy and radiation therapy without operation. CTCs were analyzed using a Microfluidic Chip devise provide with the Nihon Gene Research Laboratories. This system can isolates CTCs from blood samples, based on their size and deformability differences from blood cells. Phenotypes of CTCs are determined by staining and scanning systems. A previous report revealed that this method had higher sensitivity for CTCs than conventional methods (the Cell Search system) in 61 metastatic breast cancer. Results Treatments effects were stable disease or better in all cases. Multiple CTCs were detected in all cases before treatment. Five patients had epithelial CTCs and others had only mesenchymal CTCs. Total number of CTCs after treatment whose data can be available decreased except for two cases. One patient had no CTC after treatment. Two cases have been currently analyzing. Conclusion CTCs may exist almost all patients of Stage II or more esophageal cancer. Decreasing the number of CTCs after treatment suggests some relationship between CTCs and treatment effect, and the accumulation of more cases is necessary. Disclosure All authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]