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Dive into the research topics where Jonathan S.T. Sham is active.

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Featured researches published by Jonathan S.T. Sham.


Cancer | 1998

Preliminary report of the asian-oceanian clinical oncology association randomized trial comparing cisplatin and epirubicin followed by radiotherapy versus radiotherapy alone in the treatment of patients with locoregionally advanced nasopharyngeal carcinoma†

Daniel T.T. Chua; Jonathan S.T. Sham; D. Choy; Virchan Lorvidhaya; Yupa Sumitsawan; Sumitra Thongprasert; Visoot Vootiprux; Arkom Cheirsilpa; Tahir Azhar; Ary H. Reksodiputro

The aim of this trial was to compare the outcome achieved with neoadjuvant chemotherapy followed by radiotherapy to that achieved with radiotherapy alone for patients with locoregionally advanced undifferentiated or poorly differentiated nasopharyngeal carcinoma (NPC) meeting one of the following criteria: Hos T3 disease, Hos N2‐N3 disease, or lymph node size ≥3 cm.


Journal of Clinical Oncology | 2004

Concurrent and Adjuvant Chemotherapy for Nasopharyngeal Carcinoma: A Factorial Study

Dora L.W. Kwong; Jonathan S.T. Sham; Gordon K.H. Au; Daniel T.T. Chua; Philip W.K. Kwong; Ashley C. K. Cheng; P.M. Wu; Martin Law; Carol Kwok; C. C. Yau; Koon-Yat Wan; Raymond Tsz-Tong Chan; Damon D.K. Choy

PURPOSE To study the efficacy of concurrent chemoradiotherapy (CRT) and adjuvant chemotherapy (AC) for nasopharyngeal carcinoma (NPC). PATIENTS AND METHODS Patients with Hos stage T3 or N2/N3 NPC or neck node > or = 4 cm were eligible. Patients were randomly assigned to have radiotherapy (RT) or CRT with uracil and tegafur and to have AC or no AC after RT/CRT. AC comprised alternating cisplatin, fluorouracil, vincristine, bleomycin, and methotrexate for six cycles. There were four treatment groups: A, RT; B, CRT; C, RT and AC; D, CRT and AC. For CRT versus RT, groups B and D were compared with groups A and C. For AC versus no AC, groups C and D were compared with groups A and B. RESULTS Three-year failure-free survival (FFS) and overall survival (OS) for CRT versus RT were 69.3% versus 57.8% and 86.5% versus 76.8%, respectively (P =.14 and.06; n = 110 v 109). Distant metastases rate (DMR) was significantly reduced with CRT (14.8% v 29.4%; P =.026). Locoregional failure rates (LRFR) were similar (20% v 27.6%; P =.39). Three-year FFS and OS for AC versus no AC were 62.5% versus 65% and 80.4% versus 83.1%, respectively (P =.83 and.69; n = 111 v 108). DMR and LRFR were not reduced with AC (P =.34 and.15, respectively). Cox model showed CRT to be a favorable prognostic factor for OS (hazard ratio, 0.42; P =.009). CONCLUSION An improvement in OS with CRT was observed but did not achieve statistical significance. The improvement seemed to be associated with a significant reduction in DMR. AC did not improve outcome.


Cancer | 2004

Intensity-modulated radiotherapy for early-stage nasopharyngeal carcinoma: A prospective study on disease control and preservation of salivary function

Dora L.W. Kwong; Edmond H.N. Pow; Jonathan S.T. Sham; Anne S. McMillan; Lucullus H.T. Leung; W. Keung Leung; Daniel T.T. Chua; Ashley C. K. Cheng; Po M. Wu; Gordon K.H. Au

Xerostomia is a uniform complication after radiotherapy (RT) for nasopharyngeal carcinoma (NPC). Dosimetric studies suggested that intensity‐modulated RT (IMRT) can spare part of the parotid glands from high‐dose radiation. Disease control and salivary function after IMRT for early‐stage NPC was studied prospectively.


International Journal of Radiation Oncology Biology Physics | 1997

Volumetric analysis of tumor extent in nasopharyngeal carcinoma and correlation with treatment outcome

Daniel T.T. Chua; Jonathan S.T. Sham; Dora L.W. Kwong; K.S. Tai; P.M. Wu; Maggie Lo; Annie Yung; D. Choy; Lilian Leong

PURPOSE To investigate the variability of tumor volume in nasopharyngeal carcinoma using quantitative measurements of tumor bulk derived from computed tomography, and to study the prognostic value of tumor volume in comparison with other variables. METHODS AND MATERIALS Two hundred ninety patients with newly diagnosed nasopharyngeal carcinoma were included in the study. The primary tumor volume (PTV) and nodal tumor volume (NTV) were obtained by outlining the tumor contour followed by summation of areas in sequential pretreatment computed tomography axial scans. Total tumor volume (TTV) was obtained by adding the PTV and NTV. All patients had radiotherapy as the primary treatment, 67 patients also received cisplatin-based neoadjuvant chemotheraphy. RESULTS A large variation in tumor volume was observed, especially in advanced stage disease. The median PTV (cc) in Hos T1, T2, and T3 disease were: 6.9 (range: 0.9-42.7), 18.8 (1.6-127.9), and 52.4 (3.3-166.8). The median TTV (cc) in Hos stage I to IV disease were: 7.6 (range: 1.3-42.7), 19.8 (3.2-55.7), 40.7 (4.1-222.7), and 51.1 (3.1-274.7). Patients with a large PTV (>60 cc) were associated with significantly poorer local control (5-year local control rate: 56%) and disease-specific survival (5-year survival rate: 53%). In patients with a small PTV (< or =20 cc), there were no significant differences in local control among different T stages. Large NTV (>30 cc) was associated with significantly higher distant failure rate (5-year distant relapse-free survival rate: 54%) and lower disease-specific survival (5-year survival rate: 40%). In multivariate analysis, only PTV was found to be an independent factor in predicting local control. CONCLUSION A large variation of tumor volume was present in different T stage disease of nasopharyngeal carcinoma, and PTV represents an independent prognostic factor of local control that appears to be more predictive than Hos T stage classification.


Oncogene | 2004

Association of Vimentin overexpression and hepatocellular carcinoma metastasis

Liang Hu; Sze Hang Lau; Chi Hung Tzang; Jian Ming Wen; Weisheng Wang; Dan Xie; Minghui Huang; Yi Wang; Meng Chao Wu; Jie Fu Huang; Wei Fen Zeng; Jonathan S.T. Sham; Mengsu Yang; Xin Yuan Guan

The poor prognosis of hepatocellular carcinoma (HCC) has been associated with recurrence and metastasis. Recently, we established a pair of HCC cell lines from a primary (H2-P) and its matched metastatic (H2-M) HCC tumors. A high density of cDNA microarray with 9184 human cDNA was used to identify the differentially expressed genes between H2-P and H2-M. Comparing with H2-P, eight upregulated and six downregulated genes were detected in H2-M. One interesting finding is the overexpression of Vimentin (VIM), a well-defined intermediate filament, which has been linked to a more aggressive status in various tumors. The correlation of overexpression of VIM and HCC metastasis was studied by immunohistochemistry using a tissue microarray with 200 primary HCCs and 60 pairs of primary and matched metastatic HCC samples. Tissue microarray demonstrated that the overexpression of VIM was significantly associated with HCC metastasis (P<0.01). This finding strongly suggests that the overexpression of VIM may play an important role in the metastasis of HCC.


Journal of Clinical Oncology | 2004

Long-Term Survival After Cisplatin-Based Induction Chemotherapy and Radiotherapy for Nasopharyngeal Carcinoma: A Pooled Data Analysis of Two Phase III Trials

Daniel T.T. Chua; Jun Ma; Jonathan S.T. Sham; Hai Qiang Mai; D. Choy; Ming Huang Hong; Tai Xiang Lu; Hua Qing Min

5524 Background: To evaluate the long-term treatment outcome in patients with advanced stage nasopharyngeal carcinoma (NPC) treated by cisplatin-based induction chemotherapy and radiotherapy (CRT) versus radiotherapy alone (RT). METHODS The updated records of two previously reported phase III studies (the Asian-Oceania Clinical Oncology Association trial and the Guangzhou trial). testing the benefit of adding induction chemotherapy to radiotherapy in NPC were reviewed and the data were pooled together for analysis. A total of 784 patients were included for analysis, with equal number of patients in both the CRT and RT arms. The induction chemotherapy consisting of 2-3 cycles of cisplatin 100 mg/m2 day 1, bleomycin 10 mg/m2 day 1 & 5, and fluorouracil 800 mg/m2 day 1-5, or cisplatin 60 mg/m2 day 1 and epirubicin 110 mg/m2 day 1. Radiotherapy was given to the nasopharynx and neck using megavoltage radiation, with a median dose of 70 Gy. Treatment compliance was 92.6% in the CRT arm and 98% in the RT arm. The median follow-up time for surviving patients was 67 months. Analysis was done by intention to treat. RESULTS The addition of induction chemotherapy to radiotherapy was associated with a decrease in relapse by 14.3% and cancer deaths by 12.9% at 5 years. The 5-year relapse-free survival rate was 50.9% in the CRT arm and 42.7% in the RT arm (p=0.014), and the 5-year disease-specific survival rate was 63.5% in the CRT arm and 58.1% in the RT arm (p=0.029). The median disease-specific survival was not yet reached in the CRT arm and it was 82 months in the RT arm. The incidence of loco-regional failure and distant metastases were reduced by 18.3% and 13.3% at 5 years respectively with induction chemotherapy. There was no significant difference in the failure patterns between the 2 arms. CONCLUSIONS The addition of cisplatin-based induction chemotherapy to radiotherapy was associated with a modest but significant improvement in survival in advanced stage NPC. No significant financial relationships to disclose.


Genes, Chromosomes and Cancer | 2000

Recurrent chromosome alterations in hepatocellular carcinoma detected by comparative genomic hybridization

Xin Yuan Guan; Yan Fang; Jonathan S.T. Sham; Dora L.W. Kwong; Yaqi Zhang; Qiwan Liang; Huimei Li; Heng Zhou; Jeffrey M. Trent

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and has a very poor prognosis. Fifty primary HCC cases have been analyzed in the present study to explore the association between genomic alteration in primary HCC and clinical features. Several recurrent chromosomal abnormalities were identified in this study. The most frequently detected chromosomal gains involved chromosome arms 1q (33/50 cases, 66%), 8q (24/50 cases, 48%), and 20q (10/50 cases, 20%). High‐copy‐number amplifications involving 1q (4 cases), 8q (3 cases), and 20q (3 cases) were detected, and a minimum overlapping amplified region at 1q12–q22 was identified. The most frequently detected loss of chromosomal material involved 16q (35/50 cases, 70%), 17p (26/50 cases, 52%), 19p (21/50 cases, 42%), 4q (20/50 cases, 40%), 1p (18/50 cases, 36%), 8p (16/50 cases, 32%), and 22q (14/50 cases, 28%). The associations between genomic alterations detected in the present study and clinical features including clinical stage, tumor size, HBV infection, chronic liver disease, and liver cirrhosis were explored. Our CGH results suggest that the gain of 20q and deletion of 8p are late genetic alterations in HCC, because the incidence of these alterations was obviously increased in the advanced clinical stages. Another finding showed that loss of 8p and gain of 8q and 20q are associated with tumor size. The recurrent gain and loss of chromosomal regions identified in this study provide candidate regions that may contain oncogenes or tumor suppressor genes respectively involved in HCC development and progression.


International Journal of Radiation Oncology Biology Physics | 1996

Sensorineural hearing loss in patients treated for nasopharyngeal carcinoma: A prospective study of the effect of radiation and cisplatin treatment

Dora L.W. Kwong; William I. Wei; Jonathan S.T. Sham; Wai-Kuen Ho; P. W. Yuen; Daniel T.T. Chua; Dennis Kin Kwok Au; P.M. Wu; D. Choy

PURPOSE The pattern of sensorineural hearing loss (SNHL) after primary treatment for nasopharyngeal carcinoma (NPC) was studied, and the effect of cisplatin, radiotherapy does, and fractionation were evaluated. METHODS AND MATERIALS One hundred thirty-two patients, 227 ears, and 1100 audiogram reports were analyzed. Radiotherapy dose ranged from 59.5 to 76.5 Gy. Fifty-two patients received preirradiation cisplatin, total dose 100-185 mg/m(2). Serial postirradiation bone conduction thresholds at 0.5 kHz, 1 kHz, 2 kHz, and 4 kHz were compared with pretreatment thresholds at respective frequencies. Increase of at least 15 dB was considered as significant and was further grouped as transient or persistent SNHL. Univariate and multivariate analyses were performed to identify predicting factors for persistent SNHL. RESULTS At median follow-up of 30 months, 24.2% of ears developed persistent SNHL. High frequency was more affected than low frequencies, 22 vs. 5.3%. Males were more affected than females, 29.4 vs. 15.5%, p = 0.0132. Incidence of persistent SNHL increased with age, with 0, 17.2, and 37.4% of patients aged under 30, between 30-50 and over 50 affected, respectively, p = 0.0001. High incidence was found in patient with postirradiation serous otitis media (SOM), 46.9%. Chemotherapy with cisplatin and radiation dose or fractionation had no significant effect. Multivariate analysis confirmed age, sex, and postirradiation SOM as significant prognostic factors for persistent SNHL. CONCLUSIONS Transient and persistent SNHL occurred after radiotherapy, more commonly affecting high frequency. A low dose of preirradiation cisplatin did not increase the risk. A dose fractionation effect of radiotherapy was not confirmed in this study.


International Journal of Radiation Oncology Biology Physics | 1990

Nasopharyngeal carcinoma: Orderly neck node spread

Jonathan S.T. Sham; D. Choy; William I. Wei

A prospective study of 271 consecutive patients with newly diagnosed nasopharyngeal carcinoma was undertaken to assess the pattern of cervical nodal involvement with reference to 10 cervical nodal groups and three levels of neck; 204 (75.3%) patients were found to have cervical lymphadenopathy at presentation. Fifty-four (26.5%) of these patients had right cervical lymphadenopathy, 70 (34.3%) had left cervical lymphadenopathy, and 80 (39.2%) had bilateral cervical lymphadenopathy. The occurrence of lymphadenopathy in the 10 cervical nodal groups and the mean size of nodes in these nodal groups were computed. The subdigastric and upper jugular group was involved in more than 95% of cases. The lower the position in the neck, the less frequently the nodal group was involved. The mean size of nodes was largest in the subdigastric and upper jugular region compared with the other groups. The nodes in the upper neck were generally larger than those in the lower neck. The lower two levels of neck were involved without involvement of the upper level of the ipsilateral neck in fewer than 4% of cases. The present study indicates that neck node involvement by nasopharyngeal carcinoma is by orderly spread down the neck, which explains the adverse prognostic significance of neck node involvement in the lower neck. The orderly involvement of the neck nodes suggests that prophylactic irradiation of the neck should be given at least one level beyond the clinical extent of disease, which for patients with no clinically palpable node would mean prophylactic irradiation of the upper neck.


Oncogene | 2006

Clusterin plays an important role in hepatocellular carcinoma metastasis

Sze Hang Lau; Jonathan S.T. Sham; Dan Xie; Chi Hung Lawrence Tzang; Dongjiang Tang; Ningfang Ma; Liang Hu; Yi Wang; Jian Ming Wen; G. Xiao; W. M. Zhang; George K. K. Lau; Mengsu Yang; Xin Yuan Guan

To identify genes associated with tumor metastasis in hepatocellular carcinoma (HCC), gene expression profiles between a pair of primary HCC (H2-P) and their matched metastatic HCC (H2-M) were compared. Overexpression of clusterin (CLU) was found in H2-M cells. To determine the roles CLU played in HCC metastasis, CLU was transfected into H2-P cells. Overexpression of CLU in H2-P cells increased cell migration by twofold in vitro and formation of metastatic tumor nodules in liver by eightfold in vivo. To evaluate the correlation of CLU expression with HCC metastasis, the expression levels of CLU in HCCs were investigated using a tissue microarray (TMA) containing 104 pairs of primary HCCs and their matched metastases. The frequency of CLU overexpression increased significantly in metastatic HCCs (59.1%) compared with that in primary tumors (32.6%, P<0.001). To gain additional insight into the function of CLU, the expression profile of H2P-CLU was compared with vector-transfected H2-P cells by cDNA microarray. A total of 35 upregulated and 14 downregulated genes were detected in H2P-CLU. One of the upregulated genes known as YKL-40, which is implicated in matrix-remodeling and metastasis, was further studied using TMA. A significant correlation (P<0.001) between the expression levels of YKL-40 and CLU was observed, implying that the CLU-YKL-40 pathway may play an important role in HCC metastasis.

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D. Choy

University of Hong Kong

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Dan Xie

Sun Yat-sen University

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Liang Hu

University of Hong Kong

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Yan Fang

Sun Yat-sen University

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Daniel Chua

University of Hong Kong

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