Joseph Wee

National Cancer Centre Singapore, Singapore

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Publications (71)311.81 Total impact

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    ABSTRACT: BACKGROUND The current study was performed to report the long-term results of a trial comparing concurrent chemotherapy and radiotherapy (CCRT) with surgery and adjuvant radiotherapy (RT) in patients with stage III/IV nonmetastatic head and neck squamous cell carcinoma.METHODS Patients with stage III/IV resectable head and neck squamous cell carcinoma were randomized to surgery followed by RT or CCRT. The trial was halted prematurely due to poor accrual. Human papillomavirus status was tested on archival material using polymerase chain reaction sequencing.RESULTSOf the total of 119 patients, 60 patients were randomized to primary surgery (S arm) and 59 patients were randomized to CCRT (C arm). Human papillomavirus status was tested in 75 patients, and only 3 were found to be positive. The median follow-up for surviving patients was 13 years. Analysis of the entire cohort demonstrated no statistically significant difference in overall survival and disease-specific survival (DSS): 5-year rates were 45% versus 35% for overall survival (P = .262) and 56% versus 46% for DSS (P = .637) for the S arm and C arm, respectively. Analysis by subsites indicated that this difference favoring the S arm was mainly driven by survival data among patients with cancers of the oral cavity and maxillary sinus. For patients with oral cavity cancer, survival was significantly better in those who underwent primary surgery compared with CCRT; the 5-year DSS rate was 68% versus 12% for the S arm and C arm, respectively (P = .038). For patients with cancers of the maxillary sinus, the 5-year DSS rate was 71% for patients on the S arm and 0% for patients on the C arm (P = .05).CONCLUSIONS These long-term results demonstrate a significant advantage for primary surgery in patients with cancers of the oral cavity or maxillary sinus, providing strong support for primary surgery as the main modality of treatment for these subsites. In other subsites, CCRT and surgery with adjuvant RT were found to demonstrate similar efficacy for survival in patients with advanced resectable tumors. Cancer 2015. © 2015 American Cancer Society.
    Cancer 01/2015; DOI:10.1002/cncr.29251 · 5.20 Impact Factor
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    ABSTRACT: Purpose/Objective(s): Distant metastasis represents a significant source of treatment failure in patients with locally advanced nasopharyngeal carcinoma (NPC) who are treated with concurrent cisplatin and radiation therapy (RT). A recent randomized trial investigating the efficacy of adding induction chemotherapy (gemcitabine, carboplatin, and paclitaxel, GCP) to the current standard regime of concurrent cisplatin and RT, failed to indicate further improvement in survival outcomes with the experimental strategy. In this secondary analysis, we test the hypothesis that raised plasma EBV DNA levels measured pre-treatment predicts for a therapeutic benefit with induction GCP. Materials/Methods: Patients with biopsy-proven stage 3/4 NPC with no evidence of distant metastasis were eligible. All patients underwent intensity modulated RT, delivered to a dose of 69.96 and 60 Gy in 33 fractions to the gross tumor and high risk subclinical and nodal regions, respectively. Cisplatin, at a dose of 40 mg/m2, was administered concurrently once a week with RT. In the experimental arm, the 3-weekly GCP combination regime comprised of gemcitabine, 1 gm/m2, carboplatin, AUC 2.5, paclitaxel, 70 mg/m2, given at days 1 and 8 for a total of 3 cycles. Plasma EBV DNA levels were quantified using real-time quantitative polymerase chain reaction assay. Results: A total of 172 patients were accrued for the primary randomized study. Median follow-up of all patients was 3.25 (range, 1.07-8.42) and 2.69 years (range, 0.11 - 8.32) in the GCP and control arms, respectively. Overall survival (OS), disease-free survival (DFS), anddistant metastasis-free survival (DMFS) were comparable between both treatment arms (HR: OS Z 1.05, 95% CI Z 0.44-2.53, p Z 0.915; DFS Z 0.77, 95% CI Z 0.44-1.35, p Z 0.362; DMFS Z 0.81, 95% CI Z 0.39-1.71, p Z 0.585). One hundred twelve patients had EBV DNA analysis pre-treatment (N Z 56, GCP and control). Of this group of patients, 37 (66.1%) and 41 (73.2%) in the control and GCP arms, respectively, had detectable levels of EBV DNA pre-treatment. For patients with detectable EBV DNA levels, induction GCP seems to confer a favorable DFS and DMFS (HR: DFS Z 0.39, 95% CI Z 0.14- 1.11, p Z 0.056; DMFS Z 0.45, 95% CI Z 0.13-1.49, p Z 0.166). In contrast, DFS and DMFS were comparable between both treatment arms in patients with undetectable EBV DNA levels at baseline (HR: DFS Z 0.74, 95% CI Z 0.18-2.97, p Z 0.617; DMFS Z 0.80, 95% CI Z 0.11- 5.69, p Z 0.864). Local regional failure rates were comparable between both arms, independent of baseline EBV DNA levels. Conclusions: The addition of induction chemotherapy to concurrent chemoradiation therapy in locally advanced NPC remains controversial. Nonetheless, patients with detectable EBV DNA levels pre-treatment appear to benefit from induction GCP, both in terms of DFS and DMFS. Baseline EBV DNA level potentially has a role as a predictive marker in stratifying patients with stage 3/4 NPC for induction chemotherapy.
    56th ASTRO Annual Meeting; 09/2014
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    ABSTRACT: To recommend contouring methods and atlas of organs at risk (OARs) for nasopharyngeal carcinoma (NPC) patients receiving intensity-modulated radiotherapy, in order to help reach a consensus on interpretations of OARs delineation. Two to four contouring methods for the middle ear, inner ear, temporal lobe, parotid gland and spinal cord were identified via systematic literature review; their volumes and dosimetric parameters were compared in 41 patients. Areas under the receiver operating characteristic curves for temporal lobe contouring were compared in 21 patients with unilateral temporal lobe necrosis (TLN). Various contouring methods for the temporal lobe, middle ear, inner ear, parotid gland and spinal cord lead to different volumes and dosimetric parameters (P<0.05). For TLN, D1 of PRV was the most relevant dosimetric parameter and 64Gy was the critical point. We suggest contouring for the temporal lobe, middle ear, inner ear, parotid gland and spinal cord. A CT-MRI fusion atlas comprising 33 OARs was developed. Different dosimetric parameters may hinder the dosimetric research. The present recommendation and atlas, may help reach a consensus on subjective interpretation of OARs delineation to reduce inter-institutional differences in NPC patients.
    Radiotherapy and Oncology 04/2014; 110(3). DOI:10.1016/j.radonc.2013.10.035 · 4.86 Impact Factor
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    ABSTRACT: Background and purpose To recommend contouring methods and atlas of organs at risk (OARs) for nasopharyngeal carcinoma (NPC) patients receiving intensity-modulated radiotherapy, in order to help reach a consensus on interpretations of OARs delineation. Methods and materials Two to four contouring methods for the middle ear, inner ear, temporal lobe, parotid gland and spinal cord were identified via systematic literature review; their volumes and dosimetric parameters were compared in 41 patients. Areas under the receiver operating characteristic curves for temporal lobe contouring were compared in 21 patients with unilateral temporal lobe necrosis (TLN). Results Various contouring methods for the temporal lobe, middle ear, inner ear, parotid gland and spinal cord lead to different volumes and dosimetric parameters (P < 0.05). For TLN, D1 of PRV was the most relevant dosimetric parameter and 64 Gy was the critical point. We suggest contouring for the temporal lobe, middle ear, inner ear, parotid gland and spinal cord. A CT–MRI fusion atlas comprising 33 OARs was developed. Conclusions Different dosimetric parameters may hinder the dosimetric research. The present recommendation and atlas, may help reach a consensus on subjective interpretation of OARs delineation to reduce inter-institutional differences in NPC patients.
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    ABSTRACT: Objective: To determine the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on caries progression in nasopharyngeal carcinoma patients treated with radiotherapy. Methods: 24 patients were randomized into two groups before starting intensity-modulated radiotherapy. Subjects had at least eight remaining teeth after oral health clearance and gave informed consent. Individuals with previous history of head and neck radiotherapy or with known milk allergy were excluded. The test group used 0.4% stannous fluoride gel in a custom tray and a crème containing 10% CPP-ACP daily; the placebo group used a similar crème without CPP-ACP and otherwise identical care. Subjects were instructed to apply the crème three-times-daily and fluoride gel once daily throughout the radiotherapy period and thereafter. Tooth surface caries status according to the ICDAS II criteria, saliva and plaque parameters were measured before radiotherapy, and at 2-weeks and 3-months post-radiotherapy. Results: 21 males and three females with a median age of 50 years (IQR: 45~59) were recruited. 22 patients returned for the 3-month post-radiotherapy review, at which time reduced plaque pH, salivary flow rates, pH and buffering capacity were observed. 9 subjects in the intervention group and 8 subjects in the placebo group developed 32 and 59 new caries lesions respectively. The intervention group showed a lower rate of caries progression as compared to the placebo group for all tooth surfaces (OR: 0.51, 95% CI: 0.17 to 1.59) with the occlusal surfaces showing lower caries progression (OR: 0.20, 95% CI: 0.03 to 1.29) as compared to smooth surfaces (OR: 0.61, 95% CI: 0.16 to 2.38). Conclusion: Within the limitations of this study, CPP-ACP use reduced the rate of caries progression in nasopharyngeal carcinoma patients in the first three months after radiotherapy.
    IADR Asia/Pacific Region (APR) Regional Meeting and Co-Annual Scientific Meeting of IADR Divisions 2013; 08/2013
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    ABSTRACT: There are at least five cancers with uniquely high incidence amongst East and Southeast Asian ethnic groups - namely nasopharyngeal carcinoma (NPC); gastric carcinoma; hepatocellular carcinoma (HCC); adeno-carcinoma of the lung in female non-smokers and nasal NK/T-cell lymphomas. They all appear to be related to an infective cause (Epstein Barr Virus, Helicobacter pylori, hepatitis B virus). We hypothesize that a genetic bottleneck 30,000years ago at the Last Glacial Maximum could have resulted in unique genetic polymorphisms in Toll-like receptor 8, making East Asians more vulnerable to these infective associated cancers. This bottleneck could have been caused by the presence of malaria in the southern Himalayan conduit between central and East Asia; and only those with an attenuated innate immune response to the malarial parasite (perhaps reflected by the TLR8 polymorphism) were spared the ravages of cerebral malaria; allowing these people to cross into east Asia, but then rendering them susceptible to later endemic infections and their associated cancers.
    Medical Hypotheses 10/2012; 79(6). DOI:10.1016/j.mehy.2012.09.003 · 1.15 Impact Factor
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    ABSTRACT: Populations in Southern China (Bai-yue) and Borneo (Bidayuh) with high incidence of nasopharyngeal cancer(NPC) share similar mitochondrial DNA signatures, supporting the hypothesis that these two populations may share the same genetic predisposition for NPC, which may have first appeared in a common ancestral reference population before the sea levels rose after the last ice age.
    Chinese journal of cancer 08/2012; 31(9):455-6. DOI:10.5732/cjc.012.10192
  • The Lancet Oncology 05/2012; 13(6):568-9. DOI:10.1016/S1470-2045(12)70115-8 · 25.12 Impact Factor
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    ABSTRACT: We sought to evaluate the nature and frequency of late toxicities in a cohort of nasopharyngeal cancer (NPC) patients treated with conventional radiotherapy alone. Seven-hundred and ninety-six consecutive NPC patients treated using conventional radiotherapy at a single center from 1992 to 1995 were retrospectively analyzed. Patients with histology proven, completely staged, Stage I-IVB World Health Organization Type I-III NPC and completed radical radiotherapy were included. Patients with incomplete staging investigations, distant metastases at diagnosis, previous treatment, and incomplete radiotherapy were excluded. Radiotherapy-related complications were categorized using the RTOG Late Radiation Morbidity Scoring Criteria. Median follow-up was 7.2years. The 5-year overall survival and disease free survival were 69% and 56%, respectively, and the corresponding 10-year rates were 52% and 44%. Among 771 patients with at least 3months of follow-up post treatment, 565 (73%) developed RT-related complications. Diagnosed neurological complications were cranial nerve palsies (n=70; 9%), temporal lobe necrosis (n=37; 5%), Lhermitte's syndrome (n=7; 1%), and brachial plexopathy (n=2; 0.3%). Non-neurological complications included xerostomia (n=353; 46%), neck fibrosis (n=169; 22%), hypo-pituitarism (n=48; 6%), hearing loss (n=120; 16%), dysphagia (n=116; 15%), otorrhea (n=101; 13%), tinnitus (n=94; 12%), permanent tube feeding (n=61; 8%), trismus (n=45; 6%), second malignancies within treatment field (n=17; 2%), and osteo-radionecrosis (n=13; 2%). While radiotherapy is curative in NPC, many patients suffer significant late treatment morbidities with conventional radiotherapy techniques.
    Radiotherapy and Oncology 01/2012; 104(3):305-11. DOI:10.1016/j.radonc.2011.12.028 · 4.86 Impact Factor
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    ABSTRACT: It is essential to determine local tumour extent in patients with nasopharyngeal carcinoma (NPC), as it affects prognosis and accuracy of primary target delineation during radiotherapy treatment planning. This study aims to evaluate the efficacy of three imaging modalities (MRI, CT and 18F-FDG-PET/CT) in detecting intracranial extension of NPC. The study population comprised of 78 patients with histologically proven NPC. Cancer staging was performed with MRI of the neck, whole body 18F-FDGPET/ CT and contrast-enhanced CT of the neck, thorax, abdomen and pelvis. MRI detected 14 patients with intracranial extension of disease, constituting a detection rate of 17.9%. CT identified 5 out of these 14 patients (detection rate of 6.4%) while 18F-FDG-PET/CT identified 6 out of these 14 patients (detection rate of 7.7%). Using MRI as the reference imaging modality, the sensitivity and specificity of CT was 35.7% and 100% while the sensitivity and specificity of 18F-FDG-PET/CT was 42.9% and 100%. MRI remains the modality of choice for detecting intracranial disease extension of NPC.
    Head & Neck Oncology 01/2012; 4(2):49. · 3.13 Impact Factor
  • Joseph Wee
    The Lancet Oncology 12/2011; 13(2):116-8. DOI:10.1016/S1470-2045(11)70321-7 · 25.12 Impact Factor
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    Bee-Choo Tai, Joseph Wee, David Machin
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    ABSTRACT: In randomised clinical trials involving time-to-event outcomes, the failures concerned may be events of an entirely different nature and as such define a classical competing risks framework. In designing and analysing clinical trials involving such endpoints, it is important to account for the competing events, and evaluate how each contributes to the overall failure. An appropriate choice of statistical model is important for adequate determination of sample size. We describe how competing events may be summarised in such trials using cumulative incidence functions and Gray's test. The statistical modelling of competing events using proportional cause-specific and subdistribution hazard functions, and the corresponding procedures for sample size estimation are outlined. These are illustrated using data from a randomised clinical trial (SQNP01) of patients with advanced (non-metastatic) nasopharyngeal cancer. In this trial, treatment has no effect on the competing event of loco-regional recurrence. Thus the effects of treatment on the hazard of distant metastasis were similar via both the cause-specific (unadjusted csHR = 0.43, 95% CI 0.25 - 0.72) and subdistribution (unadjusted subHR 0.43; 95% CI 0.25 - 0.76) hazard analyses, in favour of concurrent chemo-radiotherapy followed by adjuvant chemotherapy. Adjusting for nodal status and tumour size did not alter the results. The results of the logrank test (p = 0.002) comparing the cause-specific hazards and the Gray's test (p = 0.003) comparing the cumulative incidences also led to the same conclusion. However, the subdistribution hazard analysis requires many more subjects than the cause-specific hazard analysis to detect the same magnitude of effect. The cause-specific hazard analysis is appropriate for analysing competing risks outcomes when treatment has no effect on the cause-specific hazard of the competing event. It requires fewer subjects than the subdistribution hazard analysis for a similar effect size. However, if the main and competing events are influenced in opposing directions by an intervention, a subdistribution hazard analysis may be warranted.
    Trials 05/2011; 12:127. DOI:10.1186/1745-6215-12-127 · 2.12 Impact Factor
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    ABSTRACT: To assess whether the benefits of adding cisplatin (CDDP) concurrent with radiotherapy, followed by adjuvant CDDP and fluorouracil, justifies the toxicity cost for nasopharyngeal cancer (NPC) using the quality-adjusted time without symptoms or toxicity (Q-TWiST) approach. One hundred seven patients treated with radiotherapy (RT) and 111 with concurrent chemotherapy and radiotherapy (CRT) were analyzed. The overall survival was divided into three health states: time on active treatment only, during which any subjective nonhematologic toxic event of grade > = 3 was reported; time without symptoms of disease relapse; or treatment and time following first disease RELapse. The relative advantage of CRT and RT was examined by conducting the analysis cumulatively at restriction times 3, 6, 24, 36, 48 months. At 48 months, the improvement in disease-free survival was 14.4% for CRT, whereas that for overall survival was 18.9%. The differences in Q-TWiST were -0.4, -0.7, 0.1, 1.6, and 3.6 months at 3, 6, 24, 36, and 48 months, respectively, with positive differences favoring CRT. At 24 months, the difference in Q-TWiST began to favor CRT. At 36 months, CRT may be the preferred option from the patient's viewpoint if the time spent in the REL state is valued to be <0.83, with the value of perfect health being 1. Finally, Q-TWiST accumulated within 48 months indicated a significant advantage in quality-adjusted survival time for CRT (p = 0.020). Irrespective of how patients valued periods of toxicity and delayed disease progression, concurrent chemotherapy and radiotherapy offered NPC patients significantly more quality-adjusted survival than radiotherapy alone in the long term.
    International journal of radiation oncology, biology, physics 10/2010; 78(2):454-60. DOI:10.1016/j.ijrobp.2009.07.1702 · 4.59 Impact Factor
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    ABSTRACT: To evaluate the treatment outcome of patients with stage IIB nasopharyngeal carcinoma (NPC) after definitive intensity-modulated radiotherapy (IMRT) without concurrent chemotherapy. Between August 2003 and December 2006, 107 patients with T1N1M0 (8%), T2N0M0 (13%), or T2N1M0 (79%) NPC were definitively treated with IMRT. Sixty-one received IMRT only, and 46 patients had various strategies of systemic treatment, consisting of abbreviated neoadjuvant (38 patients), concurrent (8 patients), or adjuvant (16 patients) chemotherapy. Radiation doses prescribed to the planning tumor volume of the gross disease, high-risk clinical tumor volume, and low-risk clinical tumor volume were 66 to 70 Gy, 54 to 60 Gy, and 50-54 Gy, respectively. With a median follow-up of 39 months (range, 7-77 months), 6 patients had locoregional relapse: 1 local only, 1 locoregional, and 4 regional only. Five patients had distant failure. Five of 6 total deaths were cancer related. The 3-year estimated local control, regional control, metastasis-free survival, disease-free survival, and overall survival were 96.5%, 98%, 94.8%, 90.7%, and 95.8%, respectively. No significant difference in treatment outcome was demonstrated in patients treated with or without chemotherapy of any schedule. IMRT without concurrent chemotherapy provides good outcome for patients with stage IIB NPC with acceptable toxicity. Neoadjuvant chemotherapy did not appear to provide significant additional benefit for this patient subgroup. Further investigation in the prospective setting is warranted to explore the role of systemic agents in the treatment of NPC with limited primary disease and cervical lymphadenopathy when IMRT is used.
    American journal of clinical oncology 06/2010; 33(3):294-9. DOI:10.1097/COC.0b013e3181d2edab · 2.21 Impact Factor
  • Joseph Tien Seng Wee, Tam Cam Ha, Susan Li Er Loong, Chao-Nan Qian
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    ABSTRACT: Nasopharyngeal cancer (NPC) is endemic in Southern China, with Guandong province and Hong Kong reporting some of the highest incidences in the world. The journal Science has called it a "Cantonese cancer". We propose that in fact NPC is a cancer that originated in the Bai Yue ("proto Tai Kadai" or "proto Austronesian" or "proto Zhuang") peoples and was transmitted to the Han Chinese in southern China through intermarriage. However, the work by John Ho raised the profile of NPC, and because of the high incidence of NPC in Hong Kong and Guangzhou, NPC became known as a Cantonese cancer. We searched historical articles, articles cited in PubMed, Google, monographs, books and Internet articles relating to genetics of the peoples with high populations of NPC. The migration history of these various peoples was extensively researched, and where possible, their genetic fingerprint identified to corroborate with historical accounts. Genetic and anthropological evidence suggest there are a lot of similarities between the Bai Yue and the aboriginal peoples of Borneo and Northeast India; between Inuit of Greenland, Austronesian Mayalo Polynesians of Southeast Asia and Polynesians of Oceania, suggesting some common ancestry. Genetic studies also suggest the present Cantonese, Minnans and Hakkas are probably an admixture of northern Han and southern Bai Yue. All these populations have a high incidence of NPC. Very early contact between southern Chinese and peoples of East Africa and Arabia can also account for the intermediate incidence of NPC in these regions.
    Chinese journal of cancer 05/2010; 29(5):517-26. DOI:10.5732/cjc.009.10329
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    ABSTRACT: The aim of this study was to review our experience and demonstrate the safety of intracavitary brachytherapy (ICB) in patients with nasopharyngeal carcinoma (NPC). Hundred seventy-eight patients with early T1-2b disease underwent radical external beam radiation therapy (EBRT) followed by ICB boost. The primary tumor received 66 Gy of EBRT over 33 fractions using 6 or 10 MV photons. ICB insertions were performed 1 week later, delivering 10 Gy in 2 fractions over 8 days. Kaplan-Meier survival analyses were used to calculate the actuarial 5-year overall survival (OS), cause-specific survival, local control, and disease-free survival (DFS). Five-year local control rates were 91.6%. OS, DFS, and cause-specific survival were estimated to be 85.25%, 81.7%, and 87.9%, respectively. Median follow-up was 86 months. There were no documented serious complications noted with ICB. ICB boost supplementing radical EBRT is an excellent method of enhancing local control for patients with NPC with early T1-2b disease.
    Head & Neck 12/2009; 31(12):1610-8. DOI:10.1002/hed.21130 · 2.83 Impact Factor
  • Fuel and Energy Abstracts 09/2009; 75(3). DOI:10.1016/j.ijrobp.2009.07.936
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    ABSTRACT: Retropharyngeal lymph node (RLN) staging in nasopharyngeal carcinoma (NPC) can be controversial. We retrospectively reviewed all patients with T(2-4), N(0-1) NPC treated between 1992 and 1994 to examine if RLN metastasis resulted in an increased incidence of distant metastases. Of the 667 patients with NPC, 395 had T(2-4), N(0-1) disease, 140 had N(0), and 255 had N(1). All had staging CT scans and were treated with radiotherapy. Median follow-up was 8.3 years. Seventy-four percent showed undifferentiated histology. In this cohort, 187 (47%) had RLN metastases. Multivariate analysis showed that RLN conferred a higher hazard for distant metastasis (p = .04). Using the Kaplan-Meier method, patients with N(0) disease and RLN had a similar hazard for distant metastases as patients with N(1) disease when compared with patients with N(0) disease and without RLN. Patients with N(0) disease and RLN appear to share a similar prognosis to patients with N(1) disease.
    Head & Neck 04/2009; 31(4):468-74. DOI:10.1002/hed.21008 · 2.83 Impact Factor
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    ABSTRACT: Health-related quality of life is an important aspect of health outcome. The assessment of it must be done by validated instruments. There is no published data on the validity, reliability and sensitiveness to change of the official Chinese translation of the Functional Assessment of Cancer Therapy-General (version 4; FACT-G). A Chinese questionnaire package comprising the FACT-G and Functional Living Index-Cancer (FLIC, which was translated, modified and validated in Singapore) was filled in by 165 ethnic Chinese patients recruited from the National Cancer Centre, Singapore. Four weeks later, the patients were assessed again by a postal questionnaire survey. The FACT-G and FLIC total scores were strongly correlated (r = 0.85). The Physical, Social/Family, Emotional and Functional Well-being scales of the FACT-G converged to and diverged from FLIC components as conceptually expected. The FACT-G and its 4 scales also demonstrated known-groups validity in differentiating patients with different performance status (each P <0.001). Their internal consistency ranged from 0.81 to 0.93 and test-retest reliability ranged from 0.74 to 0.85. The FACT-G and its Physical, Emotional and Functional Well-being scales showed trends of change in relation to change in performance status. The Social/Family Well-being scale was sensitive to decline but not improvement in performance status. The Chinese version of the FACT-G can be used to assess overall level and some specific aspects of health-related quality of life. However, researchers should be cautious in using this instrument to specifically investigate the social aspect of quality of life.
    Annals of the Academy of Medicine, Singapore 03/2009; 38(3):225-9. · 1.22 Impact Factor
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    ABSTRACT: Endemic nasopharyngeal carcinoma (NPC) commonly metastasizes to the lungs, liver, and bones. This study aims to assess the efficacy of 4 distant metastasis staging modalities, namely (1) conventional work-up comprising chest X-ray, liver ultrasound, and skeletal scintigraphy, (2) CT of the thorax, abdomen, and skeletal scintigraphy, (3) (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET), and (4) integrated FDG-PET/CT. Seventy-eight consecutive patients diagnosed with NPC were enrolled and followed up for a minimum of 6 months to confirm the staging at diagnosis. Six patients (7.7%) had distant metastases at diagnosis. The sensitivities and specificities of conventional work-up, combined CT and skeletal scintigraphy, FDG-PET, and FDG-PET/CT were 33.3%, 66.7%, 83.3%, and 83.3%; and 90.3%, 91.7%, 94.4%, and 97.2%, respectively. The corresponding accuracies were 85.9%, 89.7%, 93.6%, and 96.2%. FDG-PET/CT is the most sensitive, specific, and accurate modality for distant metastasis staging of endemic NPC.
    Head & Neck 03/2009; 31(3):346-54. DOI:10.1002/hed.20974 · 2.83 Impact Factor

Publication Stats

1k Citations
311.81 Total Impact Points


  • 2001–2015
    • National Cancer Centre Singapore
      • • Department of Radiation Oncology
      • • Division of Clinical Trials and Epidemiological Sciences
      • • Department of Medical Oncology
  • 2011–2012
    • Duke-NUS Graduate Medical School Singapore
      Tumasik, Singapore
  • 2005
    • The University of Hong Kong
      Hong Kong, Hong Kong
  • 2003–2004
    • Drexel University
      Philadelphia, Pennsylvania, United States