Simon Y Law

The University of Hong Kong | HKU · Department of Surgery

Endothelial PAS domain-containing protein 1 (EPAS1) is an angiogenic factor and its implications have been reported in many cancers but not in esophageal squamous cell carcinoma (ESCC). Herein, we aim to examine the genetic and molecular alterations, clinical implications, and functional roles of EPAS1 in ESCC. High-resolution melt-curve analysis a...

Family with sequence similarity 134, member B (FAM134B) is an autophagy regulator of endoplasmic reticulum first discovered to be involved in the pathogenesis of esophageal squamous cell carcinoma (ESCC). The present study examined the functional behavior of FAM134B in cancer cells and the association of FAM134B expression with clinicopathologic fa...

Esophageal cancer is one of the most lethal cancers worldwide with poor survival and limited therapeutic options. The discovery of microRNAs created a new milestone in cancer research. miR-377 is located in chromosome region 14q32, which is frequently deleted in esophageal squamous cell carcinoma (ESCC), but the biological functions, clinical signi...

For squamous cell carcinoma of the esophagus, extended mediastinal lymphadenectomy especially around the bilateral recurrent laryngeal nerves (RLN) is associated with high risk of nerve injury. This does not only result in hoarseness of voice, increase the chance of pulmonary complications, but would also affect the quality of life of patients in t...

MicroRNA-498 plays a crucial role in progression of many carcinomas. The signalling pathways that miR-498 modulates carcinogenesis are still unknown. Also, miR-498 associated molecular pathogenesis has never been studied in the oesophageal squamous cell carcinoma (ESCC). Herein, we aimed to examine the expression and functional roles of miR-498 in...

We report analytic and consensus processes that produced recommendations for pathologic stage groups (pTNM) of esophageal and esophagogastric junction cancer for the AJCC/UICC cancer staging manuals, 8th edition. The Worldwide Esophageal Cancer Collaboration provided data for 22,654 patients with epithelial esophageal cancers; 13,300 without preope...

We report analytic and consensus processes that produced recommendations for clinical stage groups (cTNM) of esophageal and esophagogastric junction cancer for the AJCC/UICC cancer staging manuals, 8th edition. The Worldwide Esophageal Cancer Collaboration (WECC) provided data on 22,123 clinically staged patients with epithelial esophageal cancers....

A 72-year-old woman had a history of carcinoma of the hypopharynx treated by total laryngectomy, circumferential pharyngectomy and free jejunal graft. Endoscopic dilation of the pharyngojejunal anastomotic stricture resulted in synchronous perforations of the oesophagus and stomach. We postulate that the perforations were caused by high intraoesoph...

We report data—simple descriptions of patient characteristics, cancer categories, and non–risk-adjusted survival—for patients with pathologically staged cancer of the esophagus and esophagogastric junction after resection or ablation with no preoperative therapy from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions fr...

To address uncertainty of whether pathologic stage groupings after neoadjuvant therapy (ypTNM) for esophageal cancer share prognostic implications with pathologic groupings after esophagectomy alone (pTNM), we report data—simple descriptions of patient characteristics, cancer categories, and non–risk-adjusted survival—for pathologically staged canc...

To address uncertainty of whether clinical stage groupings (cTNM) for esophageal cancer share prognostic implications with pathologic groupings after esophagectomy alone (pTNM), we report data—simple descriptions of patient characteristics, cancer categories, and non–risk-adjusted survival—for clinically staged patients from the Worldwide Esophagea...

Dual-tracer F-FDG and C-acetate PET/CT has been shown to demonstrate good sensitivity and specificity for the diagnosis of hepatocellular carcinoma. We present a case of gastric adenocarcinoma with liver metastasis with positive uptake of F-FDG and C-acetate highlighting an unusual appearance in dual-tracer PET/CT.

Purpose: 83b1 is a novel quinoline derivative that has been shown to inhibit cancer growth in human esophageal squamous cell carcinoma (ESCC). This study was conducted to comprehensively evaluate the cytotoxic effects of 83b1 on a series of ECSS cell lines and investigate the mechanisms by which 83b1 suppresses cancer growth based on molecular doc...

Objective: To investigate the role of fluorine-18-fluorodeoxyglucose PET/computed tomography for the prognostication and evaluation of neoadjuvant chemoradiotherapy response in locally advanced esophageal squamous cell carcinoma. Methods: All consecutive biopsy-proven esophageal squamous cell carcinoma patients with PET/computed tomography at ba...

Multimodality treatment strategies have become commonplace and stand-of-care in the management of esophageal cancer. In Japan, preoperative chemotherapy is routine, while in many centers around the globe chemoradiotherapy is widely practiced. How surgery should be integrated and the manner in which esophagectomy should be carried out remain controv...

Objective: The Pittsburgh group has suggested a perforation severity score (PSS) for better decision making in the management of esophageal perforation. Our study aim was to determine whether the PSS can be used to stratify patients with esophageal perforation into distinct subgroups with differential outcomes in an independent study population....

Esophageal cancer is the sixth most common cancer in the world [1]. There has been a divergence of histological cell type between the East and West. In western countries, adenocarcinoma has increased dramatically in incidence in the past 30 years, closely related to rising prevalence of obesity, gastroesophageal reflux disease, and Barrett’s esopha...

To review the short-term outcome of endoscopic resection of superficial upper gastro-intestinal lesions in Hong Kong. Historical cohort study. All Hospital Authority hospitals in Hong Kong. This was a multicentre retrospective study of all patients who underwent endoscopic resection of superficial upper gastro-intestinal lesions between January 201...

BACKGROUND/AIMS: Patients with gastric intestinal metaplasia and dysplasia are at increased risk of gastric cancer development. We tested the feasibility of using endoscopic radiofrequency ablation for the treatment of dysplasia and metaplasia in the stomach.

Gastric mucosa-associated lymphoid tissue lymphoma is uncommon and most patients have an indolent clinical course. The clinical presentation and endoscopic findings can be subtle and diagnosis can be missed on white light endoscopy. Magnifying endoscopy may help identify the abnormal microstructural and microvascular patterns, and target biopsies c...

Spontaneous intramural esophageal dissection (IED) is a rare disease entity. There are few reports of spontaneous IED requiring surgical treatment. Hereby, we report a 37-year-old gentleman who was diagnosed to have spontaneous extensive circumferential IED complicated with esophageal perforation, empyema, and esophageal-pleural fistula. Esophageal...

The management of esophageal cancer poses unique challenges to clinicians. Significant improvement has been made in managing this disease. Despite increase in therapeutic modalities, surgery remains the mainstay treatment. In this chapter, various surgical approaches, reconstructive techniques and the rationale of lymphadenectomy is described. Surg...

The following paper on the molecular biology of Barrett's esophagus (BE) includes commentaries on signaling pathways central to the development of BE including Hh, NF-κB, and IL-6/STAT3; surgical approaches for esophagectomy and classification of lesions by appropriate therapy; the debate over the merits of minimally invasive esophagectomy versus o...

Alport’s syndrome–diffuse leiomyomatosis (AS–DL) is a rare clinical entity. The syndrome consists of hematuric nephropathy, ocular lesions, and sensorineural deafness associated with leiomyomas of the gastrointestinal, respiratory and female reproductive tracts. Esophageal leiomyomatosis is characterized by diffuse proliferation of the esophageal w...

Esophagectomy is the mainstay treatment for esophageal carcinoma. It is not uncommon to experience new-onset pharyngeal phase dysphagia during the postoperative period. Pharyngeal phase swallowing deficits, as evidenced on semi-objective assessments, include delayed swallow trigger, reduced pharyngeal peristalsis, decreased hyoid bone excursion, ab...

Aim: To identify the downstream regulated genes of GAEC1 oncogene in esophageal squamous cell carcinoma and their clinicopathological significance. Methods: The anti-proliferative effect of knocking down the expression of GAEC1 oncogene was studied by using the RNA interference (RNAi) approach through transfecting the GAEC1-overexpressed esophag...

Esophagectomy remains the mainstay of treatment for esophageal cancer. The stomach is the commonest organ used to restore intestinal continuity after esophagectomy. Metachronous gastric cancer in the gastric conduit after esophagectomy is rare; the etiology remains unclear. Possible risk factors include Helicobacter pylori infection, biliary or pan...

Box plot of RNU6B Ct values in the plasma from Normal control and breast cancer (BC) patients. The lines inside the boxes denote the medians. The boxes mark the interval between the 25th and 75th percentiles. The whiskers denote the interval between the 10th and 90th percentiles. Filled circles indicate data points outside the 10th and 90th percent...

Box plots of plasma levels of miR-16, miR-451 and miR-21 in female (F, n = 60) and male (M, n = 40) healthy subjects. Expression levels of the miRNAs (Log10 scale at Y-axis) are normalized to RNU6B. Statistically significant differences were determined using Mann-Whitney test. NS, non-significant. (TIF)

The list of upregulated miRNAs (change >2 fold as a cutoff level) identified using real-time PCR based miRNA profiling arrays in plasma and biopsy samples of 5 breast cancer patients compared to 5 healthy controls. Highlighted in red are the markers up-regulated in both plasma and breast cancer tumors. (DOC)

Box plot of combined plasma miR-145 and miR-451 levels across stage of breast cancer patients. Expression levels of the miRNAs (Log10 scale at Y-axis) are calculated by the equation 2 -deltaCt. deltaCt was calculated by subtracting the Ct values of miR-145 from the Ct values of the miR-451. The lines inside the boxes denote the medians. The boxes m...

MiRNA-specific primer sequences for qRT-PCR. (DOC)

(A) ROC analysis using combined plasma miR-145 and miR-451 for discriminating DCIS cases from normal subjects. (B) Box plots of combined plasma levels of miR-145 and miR-451 in various DCIS graded patients. Expression levels of the miRNAs (Log10 scale at Y-axis) are calculated by the equation 2 -deltaCt. deltaCt was calculated by subtracting the Ct...

Box plot of combined serum miR-145 and miR-451 levels from Normal control and breast cancer (BC) patients. Expression levels of the miRNAs (Log10 scale at Y-axis) are calculated by the equation 2 -deltaCt. DeltaCt was calculated by subtracting the Ct values of miR-145 from the Ct values of the miR-451. The lines inside the boxes denote the medians....

ROC analysis using combined plasma miR-145 and miR-451 for discriminating BC cases from normal subjects in the blind validation. (TIF)

The list of downregulated miRNAs (change >2 fold as a cutoff level) identified using real-time PCR based miRNA profiling arrays in plasma and biopsy samples of 5 breast cancer patients compared to 5 healthy controls. Highlighted in red are the markers down-regulated in both plasma and breast cancer tumors. (DOC)

The esophageal anastomosis is prone to leak and development of stricture. Tumor recurrence at the anastomosis is also a difficult problem to treat. Many aspects of the esophageal anastomosis are controversial. The choice of the site of the anastomosis is dependent on the location of the tumor and the method of esophagectomy. An adequate proximal re...

Anastomotic leakage after oesophagectomy is a dreaded complication. It has a wide range of presentations ranging from the patient being totally asymptomatic to septic with multi-organ failure. From the literature, in general, cervical anastomoses have a higher leakage rate than those that are intra-thoracic, but leaks from the latter confer greater...

The homogeneously staining region (HSR) has been shown to contain amplified genes that give selective advantages to the progression of cancer-cell growth. In this study, fluorescent in situ hybridization and array comparative genomic hybridization analysis were conducted on SLMT-1 (an ESCC cell line of Hong Kong Chinese origin) and revealed a HSR w...

Background and aims: Deleted in esophageal cancer1 (DEC1) is a frequently down-regulated candidate tumor suppressor gene in esophageal cancer (EC). We previously showed that this gene can suppress tumor growth and up-regulate Dual specificity phosphatase 6 (DUSP6), as a downstream target of DEC1, in esophageal squamous cell carcinoma (ESCC). In thi...

E-cadherin is a well-documented tumor suppressor with downregulated expression in many cancer types. Upon proteolytic cleavage, a soluble form of 80-kDa degradation fragment, known as soluble E-cadherin (s-Ecad), is present in circulation; its level in sera of cancer patients is significantly associated with metastasis, recurrence, and prognosis in...

The efficacy of using self-expanding metallic stent (SEMS) for palliation of symptoms because of tumor recurrence after prior esophagogastrectomy has not been properly assessed despite the well recognized use of SEMS in patients without prior surgery. The aim of this study is to evaluate the efficacy and safety of using SEMS in patients who had pri...

The aim of this study is to report assemblage of a large multi-institutional international database of esophageal cancer patients, patient and tumor characteristics, and survival of patients undergoing esophagectomy alone and its correlates. Forty-eight institutions were approached and agreed to participate in a worldwide esophageal cancer collabor...

The anti-cancer effects of the anomalous fruit extract of Gleditsia sinensis (GSE) attributed to its apoptotic activity, telomerase inhibition and anti-angiogenesis in a panel of solid and non-solid tumor cell lines including esophageal squamous cell carcinoma (ESCC) have been intensively investigated by us in previous studies. Cyclooxygenase-2 (CO...

Two major surgical strategies to improve survival rates after oesophagectomy for oesophageal cancer have emerged during the past decades; (limited) transhiatal oesophagectomy and (extended) transthoracic oesophagectomy with two-field lymphadenectomy. This overview describes short and long-term advantages of these two strategies. In the short term,...

Id protein family consists of four members namely Id-1 to Id-4. Different from other basic helix-loop-helix transcription factors, they lack the DNA binding domain. Id proteins have been shown to be dysregulated in many different cancer types and their prognostic value has also been demonstrated. Recently, Id-1 has been shown to be upregulated in o...

By comparative DNA fingerprinting, we identified a 357-bp DNA fragment frequently amplified in esophageal squamous cell carcinomas (ESCC). This fragment overlaps with an expressed sequence tag mapped to 7q22. Further 5′ and 3′-rapid amplification of cDNA ends revealed that it is part of a novel, single-exon gene withfu ll-length mRNA of 2052 bp and...

Thoracoscopic mobilization of the esophagus for pharyngolaryngoesophagectomy allows dissection under direct vision, and therefore it potentially results in fewer complications than conventional transhiatal mobilization. In this article we report our experience with this approach. It was also hypothesized that a learning curve existed and that resul...

A gene critical to esophageal cancer has been identified. Functional studies using microcell-mediated chromosome transfer of intact and truncated donor chromosomes 3 into an esophageal cancer cell line and nude mouse tumorigenicity assays were used to identify a 1.61 Mb tumor suppressive critical region (CR) mapping to chromosome 3p14.2. This CR is...

Pneumomediastinum usually occurs following an airleak from the lungs, or from a perforated oesophagus. We report on a 30-year-old man who developed pneumomediastinum after scuba diving. The patient presented with acute onset of throat pain, odynophagia, and hoarseness of voice. The literature is reviewed for this condition.

3p21 is ail important locus harbouring critical tumour suppressor genes (TSG), which are implicated in the pathogenesis of multiple tumours, including oesophageal carcinoma. RASSF1A is a 3p21.3 candidate TSG frequently inactivated by promoter methylation in multiple tumours. We investigated RASSF1A promoter methylation and gene expression in Chines...

Hematoma of the esophagus is an uncommon condition. Patients often present with acute odynophagia or retrosternal pain, which may be confused with other diagnoses. We report herein two patients with esophageal hematoma caused by foreign body ingestion. Conservative treatment resulted in complete resolution. The literature is reviewed for the etiolo...

To determine the extent of Fas expression in oesophageal squamous cell carcinomas (ESCCs) from Chinese patients and to correlate Fas expression with clinicopathological prognostic parameters. Clinicopathological data were collected from 58 patients with ESCC who underwent oesophagectomy and had no prior radiotherapy or chemotherapy. Immunostaining...

Optimal management of esophageal perforation is controversial, especially in the presence of malignancy. Esophagectomy has traditionally been employed for patients with malignant perforations. However, in patients with advanced disease, other less invasive treatment options may be of benefit. We present two cases of spontaneous perforation of advan...

A 14-year-old boy presented with regurgitation, malnutrition, and chronic lung insufficiency with a history of successful repair of esophageal atresia and tracheoesophageal fistula in the newborn period. Barium swallow and manometry results showed achalasia. Hellar operation with antireflux procedure resulted in complete symptomatic relief. Histolo...

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignances in China and remains a significant problem with low 5-year survival rates. Gene amplifications and overexpressions have been suggested as the major genomic aberrations involved in the pathogenesis of ESCC. Application of comparative DNA fingerprinting using inter-simple...

Autopsy studies provide information that may guide future patient management. This study analyzed autopsy findings in patients with esophageal cancers, with emphasis on the prevalence of incidentally diagnosed esophageal cancer, histologic subtypes, early-stage lesions, and any associated pathology. Autopsies detected 346 patients (306 men; 40 wome...

The establishment of esophageal cancer cell lines can facilitate the search for molecular mechanisms underlying its pathogenesis. Two novel human esophageal squamous cell carcinoma (ESCC) cell lines, HKESC-2 and HKESC-3, were established from a moderately differentiated ESCC of a 46-year-old Chinese woman and a well-differentiated ESCC of a 74-year...

The establishment of esophageal cancer cell lines can facilitate the search for molecular mechanisms underlying its pathogenesis. Two novel human esophageal squamous cell carcinoma (ESCC) cell lines, HKESC-2 and HKESC-3, were established from a moderately differentiated ESCC of a 46-year-old Chinese woman and a well-differentiated ESCC of a 74-year...

Squamous cell carcinoma (SCC) and adenocarcinoma (ADC) of the lower esophagus and gastric cardia were compared in their clinical features and long-term prognosis. Two hundred and ninety-five patients with SCC and 263 with ADC were reviewed. Resectability rates for SCC and ADC were 74.2% and 73.2% respectively (P=0.8). Among those who underwent rese...

To examine the global gene expression of cancer-related genes in esophageal squamous cell carcinoma (ESCC) through the use of Atlas Human Cancer Array membranes printed with 588 well-characterized human genes involved in cancer and tumor biology. Two human ESCC cell lines (HKESC-1 and HKESC-2) and one morphologically normal esophageal epithelium ti...

Oesophageal basaloid squamous cell carcinoma (BSCC) is uncommon and has been reported to have a worse prognosis than squamous cell carcinomas (SCCs), but this tumour has not been fully characterized. The aim of the present study was to analyse the clinicopathological features of a large cohort of patients with oesophageal BSCC treated at a single i...

This study aims to identify differentially expressed genes in esophageal squamous cell carcinoma (ESCC) through the use of a membrane-based cDNA array. Two newly established human ESCC cell lines (HKESC-1 and HKESC-2) and one corresponding to a morphologically normal, esophageal epithelium tissue specimen, prospectively collected from the HKESC-2-r...

In this study, we screened 19 esophageal squamous cell carcinomas (ESCCs) for the detection of genetic alterations using inter-simple sequence repeat PCR, a DNA fingerprinting approach. Three simple repetitive unanchored primers representing tri- and tetranucleotide repeats [(GTG)(5), (GACA)(4), and (GATA)(4)] were used, and evidence of gains and l...

Gastric cancer remains a major cause of cancer mortality globally but no good prognostic tumour marker is available. Soluble fragment of E-cadherin protein has been reported to increase in the sera of patients with cancer and recently was found to be elevated in 67% of patients with gastric cancer. To investigate if serum soluble E-cadherin is a va...

The occurrence of blue nevus has seldom been reported in extracutaneous sites and with no record in the esophagus. A blue nevus was reported in the esophagus of a 58-year-old Chinese woman. On endoscopic examination, the lesion presented as linear patches of bluish pigmentation in the esophagus. The patient was free of symptoms 3 years after the en...

Leakage from esophageal anastomoses is higher than that for other gastrointestinal anastomoses. An intrathoracic anastomotic leak is a potentially catastrophic event. Patients with and without thoracic anastomotic leakage were compared for predisposing factors. Leak-related mortality was analyzed. Of 475 patients, there were 17 leaks (3.5%). Predis...

To identify factors that have contributed to reduced rates of death and complications after esophageal resection in a 17-year period at a tertiary referral center. There has been an evolving refinement in surgical technique and perioperative management of patients undergoing esophageal resection at Queen Mary Hospital during the past two decades. A...

Three-field lymphadenectomy for esophageal cancer remains controversial. The high prevalence of cervical lymph node involvement is the basis of cervical lymphadenectomy. Studies of recurrence patterns after esophagectomy, however, indicate that clinically relevant cervical nodal recurrence is uncommon, and that the incidence of such recurrence is s...

Small cell carcinoma of the esophagus is a rare and aggressive malignant tumor. Telomerase activation is common in human cancers. There is a lack of data on telomerase activity in esophageal small cell cancers. The present report studied the role of telomerase activity in esophageal small cell carcinoma. The clinicopathologic data of five patients...

A new human esophageal cancer cell line, named SLMT-1, was established from a nude-mouse xenograft of a well-differentiated esophageal squamous cell carcinoma (ESCC) of the lower esophagus from a male Hong Kong Chinese patient. SLMT-1, passaged over 34 times and with a doubling time of 31 hours, has the microscopic features of epithelial cells with...

Choking is a common emergency problem. The Heimlich maneuver is unquestionably effective in relieving airway obstruction. Serious and life-threatening complications may arise, however, if the maneuver is applied incorrectly. Two cases of gastric rupture after Heimlich maneuver are reported. Lay public, paramedics and the medical professionals shoul...

The treatment of malignant obstruction of the left colon or rectum usually requires emergency surgery on poor-risk patients, and the creation of a stoma is usually inevitable. With the use of self-expanding metallic stents, the prompt relief of large-bowel obstruction without surgery has become possible. This report describes our results in the use...