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Background: Additional surgery is recommended when early colorectal cancer (ECRC) is resected by non-curative endoscopic submucosal dissection (ESD) and there is significant risk of lymph node metastasis (LNM). The aim of this study was to investigate the efficacy and safety of additional surgery after non-curative ESD for ECRC and evaluate long-term outcomes.Methods: Patients with ECRC who underwent ESD and additional surgery between July 2007 and November 2013 were identified. Histology and patient data were collected during an average period of more than 5 years to determine tumor stage and type, resection status, complications, tumor recurrence, and distant metastasis.Results: Fifty-one patients who underwent additional surgery were eligible for analysis. Overall, regional LNM was detected in 5 patients (9.8%) and presence of lymphovascular infiltration was a significant risk factor. Surgery-related complications occurred in 3 patients (5.9%). During a median follow-up period of 59 months, no metastasis or local recurrence was observed. Three patients died of other diseases and no CRC-related deaths took place.Conclusions: Additional surgery after non-curative ESD for ECRC is effective and safe and should be encouraged to foster curative treatment and better long-term outcomes. [ABSTRACT FROM AUTHOR]

Background: Known as solid tumors of intermediate malignant potential, most inflammatory myofibroblastic tumors (IMTs) are treatable as long as the tumor is en-bloc resected. However, in some cases, the tumors have recurred and grown rapidly after successful surgery. Some of these tumors were classified as an epithelioid inflammatory myofibroblastic sarcoma (EIMS). Most previously reported EIMSs have been caused by RANBP2-ALK fusion gene. We herein report an EIMS case caused by an EML4-ALK fusion gene.Methods: RNAseq was conducted to find out the new ALK fusion gene which could not be detected following previously reported RT-PCR methods for EIMS cases with RANBP2-ALK fusion gene. After that, RT-PCR was also conducted to further prove the newly found fusion gene. Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) test were applied to find out the unique morphological characters compared with the previous reported EIMS cases.Results: We found an EIMS case who was suffering from a rapid recurrence after cytoreducyive surgery was done to relieve the exacerbating symptoms. The patient finally died for tumor lysis syndrome after the application of crizotinib. Distinctive ALK staining under the membrane and relatively weak ALK staining in the cytoplasm could also be observed. RNAseq and RT-PCR further revealed that the tumor harbored an EML4-ALK fusion gene.Conclusion: In conclusion, this is the first EIMS demonstrated to have been caused by the formation of an EML4-ALK fusion gene. This enriches the spectrum of EIMS and enlarges the horizon for the study of EIMS. The experience we shared in managing this kind of disease by discussing aspects of its success and failure could be of great value for surgeons and pathologists. [ABSTRACT FROM AUTHOR]

Introduction: To investigate the impact of KIT and PDGFRA gene mutations on the prognosis of gastrointestinal stromal tumors (GIST).Material and Methods: Tumor tissue from 184 patients with primary GIST was submitted to mutational analysis of exons 9, 11, 13, and 17 of the KIT gene and exons 12 and 18 of the PDGFRA gene. Clinical and pathological parameters were analyzed and correlated to the risk of recurrence and disease-free survival (DFS).Results and Discussion: The authors found that somatic mutations were detected in 162 tumors (88.0%). Age, clinical stage, mitotic count, and tumor size were of prognostic relevance on both univariate and multivariate analysis. Five-year DFS was 41.9%. While the presence of a KIT or PDGFRA mutation per se was not associated with tumor recurrence and/or disease-free survival, exon 11 deletion and hemizygous mutation status were both independent factors highly predictive for poor survival.Conclusion: The authors conclude that KIT exon 11 deletions and somatic loss of the wild-type KIT identified patients with poor prognosis. Age, clinical stage, tumor size, and mitotic count were standard clinicopathologic features that significantly influenced the prognosis. Mutation type of the mitogen receptor c-kit has a potential for predicting the course of the disease and might contribute to management individualization of GIST patients. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To evaluate the clinical value of diffusion-weighted imaging (DWI) in combination with T2-weighted imaging (T2WI) for the detection of rectal cancer as compared with T2WI alone. Materials and methods: Forty-five patients with rectal cancer and 20 without rectal cancer underwent DWI with parallel imaging and T2WI on a 1.5T scanner. Images were independently reviewed by two readers blinded to the results to determine the detectability of rectal cancer. The detectability of T2W imaging without and with DW imaging was assessed by means of receiver operating characteristic analysis. The interobserver agreement between the two readers was calculated with kappa statistics. Results: The ROC analysis showed that each of two readers achieved more accurate results with T2W imaging combined with DW imaging than with T2W imaging alone significantly. The A z values for the two readers for each T2WI and T2WI combined with DWI were 0.918 versus 0.991 (p =0.0494), 0.934 versus 0.997 (p =0.0475), respectively. The values of kappa were 0.934 for T2WI and 0.948 for T2WI combined with DWI between the two readers. Conclusion: The addition of DW imaging to conventional T2W imaging provides better detection of rectal cancer. [Copyright &y& Elsevier]

Patient-derived tumor xenografts (PDTX) generally represent a kind of more reliable model of human disease, by which a potential drugs' preclinical efficacy could be evaluated. To date, no stable gastrointestinal stromal tumor (GIST) PDTX models have been reported. In this study, we aimed to establish stable GIST PDTX models and to evaluate whether these models accurately reflected the histological feature of the corresponding patient tumors and create a reliable GIST PDTX models for our future experiment. By engrafting fresh patient GIST tissues into immune-compromised mice (BALB/c athymic mice), 4 PDTX models were established. Histological features were assessed by a qualified pathologist based on H&E staining, CD117 and DOG-1. We also conduct whole exome sequencing(WES) for the 4 established GIST PDTX models to test if the model still harbored the same mutation detected in corresponding patient tumors and get a more intensive vision for the genetic profile of the models we have established, which will help a lot for our future experiment. To explore the tumorigenesis mechanism for GIST, we also have a statistical analysis for the genes detected as nonsynchronous-mutated simultaneously in 4 samples. All 4 GIST PDTX models retained the histological features of the corresponding human tumors, with original morphology type and positive stains for CD117 and DOG-1. Between the GIST PDTX models and their parental tumors, a same mutation site was detected, which confirmed the genetic consistency. The stability of molecular profiles observed within the GIST PDTX models provides confidence in the utility and translational significance of these models for in vivo testing of personalized therapies. To date, we conducted the first study to successfully establish a GIST PDTX model whose genetic profiles were revealed by whole exome sequencing. Our experience could be of great use.

Succinate dehydrogenase (SDH), which is located on the mitochondrial inner membrane, is essential to the Krebs cycle. Mutations of the SDH gene are associated with many tumors, such as renal cell carcinoma, wild type gastrointestinal stromal tumors (WT GISTs) and hereditary paragangliomas/pheochromocytomas. Herein we present a rare case diagnosed as a WT GIST complicated with a renal chromophobe cell tumor and detected a novel germline heterozygous mutation (c.2T>C: p.M1T) in the initiation codon of the SDHA gene. We also conduct a preliminary exploration for the mechanism of reduced expression of SDHB without mutation of SDHB gene. Our case enriches the mutation spectrum of the SDH gene. After reviewing previous studies, we found it to be the first case diagnosed as a WT GIST complicated with a synchronous renal chromophobe cell tumor and identified a novel germline heterozygous mutation. It was also the second reported case of a renal cell carcinoma associated with an SDHA mutation.

Objective: Gastrointestinal stromal tumors (GISTs) have a broad spectrum of biological behaviors ranging from benign, borderline and malignant. This study aimed to screen differentially expressed microRNAs (miRNAs) between malignant and borderline GISTs and to investigate the potential role of miRNAs in the malignant transformation of GISTs., Methods: Six GIST samples including borderline tumors (n = 3) and malignant tumors (n = 3) were collected based on the clinical and pathological characteristics. Total RNA was extracted, followed by miRNA microarray analysis to screen the differentially expressed miRNAs. The most significantly expressed 4 miRNAs were then chosen for further validation by real-time PCR in 22 additional GIST samples., Results: Direct comparison of malignant group versus borderline group revealed 14 significantly and differentially expressed miRNAs (P < 0.05, with a fold change of < 0.5 or > 2). Five miRNAs were up-regulated and nine were down-regulated in the malignant group. Four miRNAs (miR-221, miR-135b, miR-675(*) and miR-218) were most significantly and differentially expressed between the two groups. The differential expression of 2 miRNAs (miR-221 and miR-675(*)) were subsequently confirmed with good concordance by real-time PCR., Conclusions: The differential miRNA expression profiles between two groups are revealed by miRNA microarray assay, and confirmed by real-time PCR. Among differentially expressed miRNAs, miR-221 and miR-675(*) might be related to the malignant transformation of GISTs, and have a potential value in predicting biological behavior of GISTs.

Objective: To investigate the clinical stage and histological grade of gastrointestinal stromal tumors., Methods: Twelve clinical and pathological parameters were assessed in 613 patients with follow-up information. These parameters were classified into two gross spread parameters including liver metastasis and peritoneal dissemination, five microscopic spread parameters including lymph node metastasis, vascular, fat, nerve and mucosal infiltration, and five histological parameters including mitotic count ≥ 10 per 50 high-power fields, muscularis propria infiltration, coagulative necrosis, perivascular pattern and severe nuclear atypia., Results: The accumulated 5-year disease-free survival (DFS) and overall survival (OS) of 293 patients without any of these predictive parameters of malignancy were 99.3% and 100.0%, respectively. They were regarded as nonmalignant and further evaluations on the stage and grade of these tumors were not performed. At least one and at most seven predictive parameters of malignancy were identified in 320 patients. For these patients, the accumulated 5-year DFS and OS rates were 43.9% (mean 6.7 years) and 59.7% (mean 9.3 years), respectively. The DFS showed significant difference between patients with and without gross spread (P < 0.01), with and without microscopic spread (P = 0.001). DFS and OS were associated with the number of predictive parameters of malignancy in patients without gross spread (P < 0.01 for both DFS and OS), but not in patients with gross spread (P = 0.882 and 0.441, respectively)., Conclusions: Malignant GIST could be divided into clinical stages I and II based on the absence and presence of gross spread, respectively. The degree of malignancy of patients in clinical stage I could be graded according to the number of predictive parameters of malignancy. Patients in clinical stage II were of the highest degree of malignancy regardless of the number of parameters. The staging and grading of gastrointestinal stromal tumors in this study are strongly associated with prognosis.

Objective: To explore the clinical significance of KRAS mutation detection in colorectal adenocarcinoma., Methods: Paraffin-embedded tissue specimens were obtained from 440 patients with colorectal adenocarcinoma. The genomic DNA was extracted. Mutations of exon 2 of KRAS gene were examined by PCR and direct sequencing., Results: Somatic mutations of KRAS gene were identified in 146 cases, with the mutation rate of 33.2% (146/440). Among these 146 patients, KRAS mutation involved codon 12 in 118 patients, including 35G > A (Gly12Asp, 62 cases), 35G > T (Gly12Val, 35 cases), 34G > T (Gly12Cys, 9 cases), 34G > A (Gly12Ser, 6 cases), 35G > C (Gly12Ala, 5 cases), and 34G > C (Gly12Arg, 1 case); in 27 patients the mutation involved codon 13, including 38G > A (Gly13Asp, 25 cases), 38G > C (Gly13 Val, 1 case) and 37G > T (Gly13 Cys, 1 case); and in one patient, the mutation involved codon 14 with 40G > A (Val14Ile). The status of KRAS or codon 12 mutations in colorectal adenocarcinoma was related to patients' gender (P = 0.021 and P = 0.030, respectively), and this significant correlation to females was conserved in clinical stage III (P = 0.007 and P = 0.003, respectively), but not in stages I, II, and IV. The status of KRAS or codon 12 mutations was also related to tumor stage. Between stage II and stage IV, the mutation rate of KRAS and codon 12 showed significant difference (P = 0.028 and 0.034, respectively). Between stage III and stage IV, only the codon 12 mutation rate showed significant difference (P = 0.011). Codon 13 mutation was not related to tumor stage., Conclusion: About one third of patients with colorectal adenocarcinoma have KRAS gene mutation, which might be related to patients' gender; and could be consistently detected by PCR and direct sequencing.

Background & Aims: Sporadic multiple gastrointestinal stromal tumors (GISTs) are rare events especially those developed metachronously. This study aimed to investigate the clinico-pathologic and genetic features defining multiple GISTs., Methods: 624 cases of GISTs were retrieved for retrospective review. 15 cases were identified as multiple GISTs including 13 synchronous and 2 metachronous ones. 32 tumors and 15 normal tissues were obtained from these cases each containing 2-3 tumor nodules and the genomic DNA was extracted for mutational analysis of KIT and PDGFRA genes. The associated patients were recruited for clinical follow-up studies, including 5 males and 10 females at 49 to 84 years of age., Results: Multiple GISTs comprised of 2.4% of GIST cases in our consecutive series. Twenty-six tumors showed mutations at KIT gene in exon 11 and one at PDGFRA gene in exon 18. In seven synchronous cases, different tumors from the same patients displayed different genotypes of KIT or PDGFRA, suggesting their polyclonal origin. In the two multiple GISTs occurring metachronously, the tumors from each patient showed different KIT mutations, suggesting that the second tumors were not the relapse or metastasis of the primary GISTs., Conclusions: Based on types of KIT or PDGFRA mutations and other pathological features, multiple primary GISTs can be differentiated from multiple GISTs resulting from recurrence or metastasis of a single primary tumor. Unlike recurrence or metastasis of GISTs that are malignant, most multiple GISTs are mostly benign and do not require aggressive adjuvant therapy. Therefore, correct diagnosis is critical for proper treatment.