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Dive into the research topics where I-Wei Chang is active.

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Featured researches published by I-Wei Chang.


Gastrointestinal Endoscopy | 2014

Circumferential balloon-based radiofrequency ablation for ultralong and extensive flat esophageal squamous neoplasia

Wen-Lun Wang; I-Wei Chang; Chi-Yang Chang; Jaw-Town Lin; Lein-Ray Mo; Hsiu-Po Wang; Ching-Tai Lee

Esophageal cancer is highly lethal and causes more than 400,000 deaths per year worldwide. In the Asia-Pacific region, esophageal squamous cell carcinoma is the major form of the disease, and its incidence is increasing. Recent advances in image-enhanced endoscopy have led to earlier diagnosis of esophageal squamous mucosal cancer or precancerous lesions. Endoscopic submucosal dissection (ESD) enables large en bloc resection of these superficial esophageal cancers, but the technique is complicated and requires considerable expertise. In particular, when there are large lesions or lesions that occupy more than threefourths of the circumference of the esophagus, patients will have esophageal stenosis. Stenosis can decrease quality of life, and treatment requires multiple sessions of endoscopic balloon dilation. Therefore, it is important to have an alternative and more convenient method to treat these large and extensive esophageal squamous neoplasias. Radiofrequency ablation (RFA) is a rapidly evolving therapeutic modality, and recent studies have shown its efficacy and safety for eradicating high-grade dysplasia in cases of Barrett’s esophagus. RFA also has theoretical potential for treating squamous epithelial neoplasias. However, only a few studies have demonstrated the potential efficacy for squamous neoplasia, and no studies have


Oral Oncology | 2015

Quantification of tumor infiltrating Foxp3+ regulatory T cells enables the identification of high-risk patients for developing synchronous cancers over upper aerodigestive tract

Wen-Lun Wang; Wei Lun Chang; Hsiao-Bai Yang; I-Wei Chang; Ching-Tai Lee; Chi-Yang Chang; Jaw-Town Lin; Bor-Shyang Sheu

OBJECTIVES Patients with squamous cell carcinomas (SCC) of upper aerodigestive tract, either over head and neck (HNSCC) or esophagus (ESCC), frequently developed synchronous multiple cancers, leading to worse prognosis. This study validated whether suppression of host cancer immunosurveillance mediated by regulatory T cells (Treg) may predispose to the development of synchronous cancers. METHODS Tumor tissues of 200 patients (100 ESCC only, 50 HNSCC only, and 50 synchronous SCCs) were quantitatively accessed for the tumor infiltrating Treg by immunohistochemistry. The density of Treg was also correlated to the level of Treg-associated inhibitory cytokines (IL-10, IL-35 and TGF-β1), and chemokine (CCL22). RESULTS The density of tumor infiltrating Treg in the index tumor (i.e. the first malignancy diagnosed) of synchronous SCC group was higher than those of HNSCC or ESCC only (p<0.05). Selecting the optimal cut-off value of Treg density as 34.6 cells/mm(2) by ROC curve, an increased Treg density of the index tumor can be an independent factor for developing synchronous SCCs (OR: 6.13; 95% CI: 2.84-13.26). The Treg density was positively correlated with serum IL-10 level and the degree of CCL22-positive cells infiltration in tumor. Furthermore, the serum inhibitory cytokine IL-10 level was higher in synchronous SCC than in non-synchronous ones (p<0.001), that indicated the cellular immunosuppression in patients with synchronous cancers. CONCLUSIONS A more severe defect in cellular immunity may predispose to multifocal tumor. The Treg cell number in SCC may serve as a novel predictive biomarker for the risk of synchronous cancer development to initiate a proper surveillance program.


Medicine | 2015

Radiofrequency Ablation Versus Endoscopic Submucosal Dissection in Treating Large Early Esophageal Squamous Cell Neoplasia

Wen-Lun Wang; I-Wei Chang; Chien-Chuan Chen; Chi-Yang Chang; Lein-Ray Mo; Jaw-Town Lin; Hsiu-Po Wang; Ching-Tai Lee

AbstractRadiofrequency ablation (RFA) and endoscopic submucosal dissection (ESD) can potentially be applied for early esophageal squamous cell neoplasia (ESCN); however, no study has directly compared these 2 modalities.We retrospectively enrolled the patients with flat-type “large” (length ≥3 cm extending ≥1/2 of the circumference of esophagus) early ESCNs treated endoscopically. The main outcome measurements were complete response at 12 months, and adverse events.Of a total of 65 patients, 18 were treated with RFA and 47 with ESD. The procedure time of RFA was significantly shorter than that of ESD (126.6 vs 34.8 min; P < 0.001). The complete resection rate of ESD and complete response rate after primary RFA were 89.3% and 77.8%, respectively. Based on the histological evaluation of the post-ESD specimens showed 14 of 47 (29.8%) had histological upstaging compared with the pre-ESD biopsies, and 4 of them had lymphovascular invasion requiring chemoradiation or surgery. After additional therapy for residual lesions, 46 (97.9%) patients in the ESD group and 17 (94.4%) patients in the RFA group achieved a complete response at 12 months. Four patients (8.5%) developed major procedure-related adverse events in the ESD group, but none in the RFA group. In patients with lesions occupying more than 3/4 of the circumference, a significantly higher risk of esophageal stenosis was noted in the ESD group compared with RFA group (83% vs 27%, P = 0.01), which required more sessions of dilatation to resolve the symptoms (median, 13 vs 3, P = 0.04). There were no procedure-related mortality or neoplastic progression in either group; however, 1 patient who received ESD and 1 who received RFA developed local recurrence during a median follow-up period of 32.4 (range, 13–68) and 18.0 (range, 13–41) months, respectively.RFA and ESD are equally effective in the short-term treatment of early flat large ESCNs; however, more adverse events occur with ESD, especially in lesions extending more than 3/4 of the circumference. RFA does not allow for pathology to evaluate the curability after ablation, and thus currently the use for invasive ESCNs should be conservative until longer follow-up studies are available.


Therapeutic Advances in Gastroenterology | 2016

Predictors for postoperative esophageal stricture after balloon-based radiofrequency ablation for early esophageal squamous neoplasia: a multicenter validation study

Wen-Lun Wang; I-Wei Chang; Chien-Chuan Chen; Wei Lun Chang; Yin-Yi Chu; Ping-Hsiu Wu; Wei-Chen Tai; Po-Yueh Chen; Ping-Hsin Hsieh; Chen-Shuan Chung; Chi-Yang Chang; Jaw-Town Lin; Hsiu-Po Wang; Ching-Tai Lee

Background: Endoscopic radiofrequency ablation (RFA) is a rapidly evolving therapeutic modality for early flat esophageal squamous cell neoplasms (ESCNs), but the risk factors for postoperative stricture have not been elucidated. The objective of this study was to identify and validate a predictor for post-RFA stenosis. Methods: We consecutively enrolled patients with flat-type ‘large’ (length no less than 3 cm extending no less than half the circumference of the esophagus), early ESCNs, treated with balloon-based RFA (12 J/cm2–clean–12 J/cm2 regimen). The tumor and technical factors for postoperative stricture were investigated and we validated the results externally with a society-based multicenter cohort using the same ablation regimen. Results: A total of 51 patients were enrolled (30 in the development set and 21 in the validation set). The complete remission rate at 12 months was 93%, and the rates of perforation and postoperative stenosis were 0% and 17%, respectively. Patients with post-RFA stenosis had a significantly larger longitudinal tumor size (mean 115 versus 61 mm, p = 0.003). There were no significant differences in age, body mass index, tumor circumferential extension, pretreatment histological grade, treatment efficacy or size of balloon catheter between the groups with or without stenosis. The optimal cut-off value was set as 9 cm to predict post-RFA stenosis by receiver operating characteristic curve [area under curve (AUC) = 0.881], which was then confirmed to be a reliable predictor by multivariate analysis (odds ratio, 12.7, 95% confidence interval, 1.18–136.28, p = 0.03) and have a good predictive performance in the validation set (AUC = 0.876). Conclusions: The most frequent adverse event of RFA was esophageal stenosis, for which the longitudinal tumor size was a significant predictive factor. Early intervention or prevention for stricture should be applied for those with long segment (⩾9 cm) ESCNs.


Oncotarget | 2016

Low disabled-2 expression promotes tumor progression and determines poor survival and high recurrence of esophageal squamous cell carcinoma

Wen-Lun Wang; Wei Lun Chang; Hsiao-Bai Yang; Yu-Chi Wang; I-Wei Chang; Ching-Tai Lee; Chi-Yang Chang; Jaw-Town Lin; Bor-Shyang Sheu

Patients with esophageal squamous cell carcinomas (ESCCs) have poor survival and high recurrence rate, but lack a prognostic biomarker. Disabled-2 (DAB2) is a crucial tumor suppressor, but its roles in ESCCs are uncertain. We investigated whether low DAB2 expression in ESCCs could lead into tumor progression and poor prognosis. Our results found patients with low-DAB2 expression ESCCs had significantly larger tumor size, deeper tumor invasion depth, lymph node metastasis, worse survival, and higher recurrence rate (P<0.05). The Cox-regression model revealed low-DAB2 expression was an independent factor of poor survival (P<0.05), and also of tumor recurrence with the predictive performance superior to clinical TNM stage (P<0.05). Low-DAB2 cancer cells, validated by DAB2 knockdown or over-expression, had higher phosphorylated ERK and migration abilities, which could be suppressed by ERK inhibitor treatment. TGF-β-induced epithelial-to-mesenchymal transition (EMT) only existed in the high-DAB2 cells, and related to worse prognosis of high-DAB2 ESCCs (P<0.05). In conclusion, DAB2 can suppress the ERK signaling, but correlate to have TGF-β-induced EMT in ESCCs. DAB2 expression could be a biomarker to identify patients with worse survival and high recurrence. Our data suggest DAB2 expression can stratify patients in need of aggressive surveillance and with possible benefit from anti-ERK or anti-TGF-β therapies.


Medicine | 2016

The Spatial Predilection for Early Esophageal Squamous Cell Neoplasia: A "Hot Zone" for Endoscopic Screening and Surveillance.

Wang Wl; I-Wei Chang; Ching Chu Chen; Chi-Yang Chang; Jou-Wei Lin; Lein-Ray Mo; Wang Hp; Lee Ct

AbstractEarly esophageal squamous cell neoplasias (ESCNs) are easily missed with conventional white-light endoscopy. This study aimed to assess whether early ESCNs have a spatial predilection and the patterns of recurrence after endoscopic treatment.We analyzed the circumferential and longitudinal location of early ESCNs, as well as their correlations with exposure to carcinogens in a cohort of 162 subjects with 248 early ESCNs; 219 of which were identified by screening and 29 by surveillance endoscopy. The circumferential location was identified using a clock-face orientation, and the longitudinal location was identified according to the distance from the incisor.The most common circumferential and longitudinal distributions of the early ESCNs were found in the 6 to 9 o’clock quadrant (38.5%) and at 26 to 30 cm from the incisor (41.3%), respectively. A total of 163 lesions (75%) were located in the lower hemisphere arc, and 149 (68.4%) were located at 26 to 35 cm from the incisor. One hundred eleven (51%) early ESCNs were centered within the “hot zone” (i.e., lower hemisphere arc of the esophagus at 26 to 35 cm from the incisor), which comprised 20% of the esophageal area. Exposure to alcohol, betel nut, or cigarette was risk factors for the development of early ESCNs in the lower hemisphere. After complete endoscopic treatment, the mean annual incidence of metachronous tumors was 10%. In addition, 43% of the metachronous recurrent neoplasias developed within the “hot zone.” Cox regression analysis revealed that the index tumor within the hot zone (hazard ratio [HR]: 3.19; 95% confidence interval [CI]: 1.17–8.68; P = 0.02) and the presence of numerous Lugol-voiding lesions in the esophageal background mucosa were independent predictors for metachronous recurrence (HR: 4.61; 95% CI: 1.36–15.56; P = 0.01).We identified a hot zone that may be used to enhance the detection of early ESCNs during endoscopic screening and surveillance, especially in areas that lack resources and have a high prevalence of ESCNs.


Advances in Digestive Medicine | 2016

Endoscopic balloon-based radiofrequency ablation for long-segment early esophageal squamous cell neoplasia

Ying-Nan Tsai; Ching-Tai Lee; Tao-Qian Tang; I-Wei Chang; Chi-Yang Chang; Lein-Ray Mo; Wen-Lun Wang

Esophageal cancer is a common and highly lethal disease. In the Asia‐Pacific region, esophageal squamous cell neoplasias are the major forms of the disease. Recent advances in endoscopic therapy enable curative treatment of early esophageal squamous cell neoplasias, however, the technique is complicated and requires a high level of expertise, especially for those with long‐segment lesions. Endoscopic radiofrequency ablation is a rapidly evolving treatment modality and has been shown to have good efficacy and safety for the treatment of dysplasia in cases of Barretts esophagus. Theoretically, it can also be used to treat squamous dysplasia. We report a case of a 48‐year‐old man with an 8‐cm‐long circumferential squamous high‐grade dysplasia over the esophagus (from 21 cm to 29 cm below the incisor) that was treated successfully and safely with balloon‐based radiofrequency ablation. The procedure took only around 30 minutes to complete. There were no major adverse events during and after the procedure. In addition, we examined the histology of the esophageal coagulum, which showed an extensive cauterization effect with focal dysplasia within the ablated epithelium. Follow‐up endoscopy at 1 month, 3 months, and 6 months showed no residual lesion, and biopsies also confirmed complete remission.


United European gastroenterology journal | 2018

The in vivo tissue effect of endoscopic balloon-based radiofrequency ablation in treating esophageal squamous cell neoplasia

Wen-Lun Wang; I-Wei Chang; Chien-Chuan Chen; Chi-Yang Chang; Cheng-Hao Tseng; Chi-Ming Tai; Jaw-Town Lin; Hsiu-Po Wang; Ching-Tai Lee

Background Endoscopic radiofrequency ablation (RFA) is a rapidly evolving therapeutic modality for early flat esophageal squamous cell neoplasms (ESCNs). However, the in vivo tissue effects of RFA on the esophageal wall are uncertain. Methods We prospectively enrolled eight patients with flat-type early ESCNs who were treated with balloon-based RFA. We evaluated the in vivo tissue effect on the esophagus using endoscopic ultrasound (EUS) and the histology of retrieved coagulum. Results The mean tumor length was 6.1 cm, and six of the eight patients achieved a complete response after primary RFA. Real-time evaluation of the tissue effect showed that the mucosa and submucosal layer were more edematous and thicker after RFA than before the procedure (mean 4.89 vs. 2.04 mm, p<.001), suggesting that the thermal effect of RFA may injure the submucosa. Histological evaluation of retrieved coagulum showed a severe cauterization (burning) effect with extensive cell necrosis; however, four cases had some residual viable neoplastic cells. Even though there were viable cells in the sloughed coagulum, half of the patients still achieved complete remission after RFA. Conclusions Our findings suggest that the thermal effect of RFA may injure the submucosal layer and enable neoplastic epithelium to slough off without “burning.”


Tumor Biology | 2017

High endothelin-converting enzyme-1 expression independently predicts poor survival of patients with esophageal squamous cell carcinoma

Ching-Fang Wu; Ching-Tai Lee; Yao-Hung Kuo; Tzu-Haw Chen; Chi-Yang Chang; I-Wei Chang; Wen-Lun Wang

Patients with esophageal squamous cell carcinoma have poor survival and high recurrence rate, thus an effective prognostic biomarker is needed. Endothelin-converting enzyme-1 is responsible for biosynthesis of endothelin-1, which promotes growth and invasion of human cancers. The role of endothelin-converting enzyme-1 in esophageal squamous cell carcinoma is still unknown. Therefore, this study investigated the significance of endothelin-converting enzyme-1 expression in esophageal squamous cell carcinoma clinically. We enrolled patients with esophageal squamous cell carcinoma who provided pretreated tumor tissues. Tumor endothelin-converting enzyme-1 expression was evaluated by immunohistochemistry and was defined as either low or high expression. Then we evaluated whether tumor endothelin-converting enzyme-1 expression had any association with clinicopathological findings or predicted survival of patients with esophageal squamous cell carcinoma. Overall, 54 of 99 patients with esophageal squamous cell carcinoma had high tumor endothelin-converting enzyme-1 expression, which was significantly associated with lymph node metastasis (p = 0.04). In addition, tumor endothelin-converting enzyme-1 expression independently predicted survival of patients with esophageal squamous cell carcinoma, and the 5-year survival was poorer in patients with high tumor endothelin-converting enzyme-1 expression (p = 0.016). Among patients with locally advanced and potentially resectable esophageal squamous cell carcinoma (stage II and III), 5-year survival was poorer with high tumor endothelin-converting enzyme-1 expression (p = 0.003). High tumor endothelin-converting enzyme-1 expression also significantly predicted poorer survival of patients in this population. In patients with esophageal squamous cell carcinoma, high tumor endothelin-converting enzyme-1 expression might indicate high tumor invasive property. Therefore, tumor endothelin-converting enzyme-1 expression could be a good biomarker to identify patients with worse survival and higher risks of recurrence, who might benefit from the treatment by endothelin-converting enzyme-1 inhibitor.


Gastroenterology | 2017

An Unusual Rectal Mass

Wen-Lun Wang; I-Wei Chang; Ching-Tai Lee

Gastroenterology 2018;154:e10–e11 Question: A 35-year-old previously well man presented with tenesmus and small caliber stool in recent 3 months. A weight loss of around 5 kg was also noted. He denied having hematochezia or abdominal pain. He visited the outpatient department and underwent colonoscopy, which revealed a 3-cm mass in the rectum (Figure A); the rest of the colon seemed to be normal. An endoscopic ultrasound examination of the rectal mass was performed (Figure B). What is your diagnosis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.

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Jaw-Town Lin

Fu Jen Catholic University

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Hsiu-Po Wang

National Taiwan University

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Chien-Chuan Chen

National Taiwan University

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Wei Lun Chang

National Cheng Kung University

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Bor-Shyang Sheu

National Cheng Kung University

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