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Dive into the research topics where Guan Hee Tan is active.

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Featured researches published by Guan Hee Tan.


British Journal of Cancer | 2015

Utility of pre-treatment neutrophil-lymphocyte ratio and platelet-lymphocyte ratio as prognostic factors in breast cancer.

Koh Ch; Nirmala Bhoo-Pathy; Khoon Leong Ng; Jabir Rs; Guan Hee Tan; Mee-Hoong See; Suniza Jamaris; Nur Aishah Taib

Background:Peripheral blood-derived inflammation-based scores such as the neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR) have recently been proposed as prognostic markers in solid tumours. Although evidence to support these markers as unfavourable prognostic factors is more compelling in gastrointestinal cancers, very little is known of their impact on breast cancer. We investigated the association between the NLR and PLR, and overall survival after breast cancer.Methods:Data from the University of Malaya Medical Centre Breast Cancer Registry was used. Of 2059 consecutive patients diagnosed from 2000 to 2008, we included 1435 patients with an available pre-treatment differential blood count (∼70%). Patients were stratified into quintiles of the NLR/PLR. Multivariable Cox regression was used to determine the independent prognostic significances of the NLR/PLR.Results:Compared with the first quintile of the NLR, women in quintile 5 were younger, had bigger tumours, nodal involvement, distant metastases and higher tumour grades. Higher NLR quintiles were significantly associated with poorer survival with a 5-year relative survival ratio (RSR) of 76.4% (95% CI: 69.6–82.1%) in quintile 1, 79.4% (95% CI: 74.4–83.7%) in quintile 2, 72.1% (95% CI: 66.3–77.3%) in quintile 3, 65.6% (95% CI: 59.8–70.8%) in quintile 4 and 51.1% (95% CI: 43.3–58.5%) in quintile 5. Following adjustment for demography, tumour characteristics, treatment and the PLR, the adjusted hazard ratio (HR) for quintile 5 vs quintile 1 was 1.50 (95% CI: 1.08–1.63); Ptrend=0.004. Results were unchanged when the NLR was analysed as a dichotomous variable using different cutoff points. Although patients in PLR quintile 5 had lower survival than in quintile 1 (5-year RSR: 53.2% (95% CI: 46.9–59.2%) vs 77.0% (95% CI: 70.9–82.2%)), this association was not significant after multivariable adjustment. However, a PLR >185 was significantly associated with poorer survival; adjusted HR: 1.25 (95% CI: 1.04–1.52).Conclusions:Both the NLR and PLR are independently associated with an increased risk of mortality in breast cancer. Their added value in the prognostication of breast cancer in clinical practice warrants investigation.


PLOS ONE | 2015

Cardiovascular risk factors and ethnicity are independent factors associated with lower urinary tract symptoms.

Jasmine Lim; Nirmala Bhoo-Pathy; Selvalingam Sothilingam; Rohan Malek; Murali Sundram; Guan Hee Tan; Badrulhisham Bahadzor; Teng Aik Ong; Keng Lim Ng; Azad Hassan Razack

Objectives To determine the lower urinary tract symptoms (LUTS) profile and factors affecting its degree of severity including cardiovascular risk profile, age, ethnicity, education level and prostate volume in a multiethnic Asian setting. Materials and Methods We conducted a cross-sectional study of 1021 men aged 40–79 years with no clinical evidence of prostate cancer, prostate surgery or 5α-reductase inhibitor treatment of known prostate conditions. The severity of LUTS was assessed using the International Prostate Symptom Score (IPSS). Potential factors associated with LUTS including age, ethnicity, education, history of hypertension, diabetes and hypercholesterolemia, height, weight, and prostate volume were evaluated using univariable and multivariable analyses. Results There were 506 (50%) men found to have moderate-to-severe LUTS attaining an IPSS above 7. Overall, nocturia (45.5%) was the most frequently reported symptom. Multivariable analysis showed that age, ethnicity, prostate volume and history of hypertension and hypercholesterolemia were independent factors associated with severity of LUTS (p < 0.05). Considering individual lower urinary tract symptoms, we found a strong association of storage symptom with history of hypertension and hypercholesterolemia. Malay men were significantly bothered by post micturition symptom compared to their Chinese and Indian counterparts. Stratified analyses of LUTS demonstrated a mutually exclusive cardiovascular risk factors profile defined by ethnicity. Conclusion Severity of LUTS varies between different ethnicities across all age groups. In addition to age and prostate volume, ethnicity and cardiovascular risk factors including hypertension and hypercholesterolemia may also need to be taken into account in managing men with LUTS.


Korean Journal of Urology | 2015

Ureteral stricture formation after ureteroscope treatment of impacted calculi: A prospective study

Xeng Inn Fam; Praveen Singam; Christopher Chee Kong Ho; Radhika Sridharan; Rozita Hod; Badrulhisham Bahadzor; Eng Hong Goh; Guan Hee Tan; Zulkifli Md Zainuddin

Purpose Urinary calculi is a familiar disease. A well-known complication of endourological treatment for impacted ureteral stones is the formation of ureteral strictures, which has been reported to occur in 14.2% to 24% of cases. Materials and Methods This was a prospective study. Ureterotripsy treatment was used on patients with impacted ureteral stones. Then, after 3 months and 6 months, the condition of these patients was assessed by means of a kidney-ureter-bladder (KUB) ultrasound. If the KUB ultrasound indicated moderate to serious hydronephrosis, the patient was further assessed by means of a computed tomography intravenous urogram or retrograde pyelogram to confirm the occurrence of ureteral strictures. Results Of the 77 patients who participated in the study, 5 developed ureteral strictures. Thus, the stricture rate was 7.8%. An analysis of the intraoperative risk factors including perforation of the ureter, damage to the mucous membrane, and residual stone impacted within the ureter mucosa revealed that none of these factors contributed significantly to the formation of the ureteric strictures. The stone-related risk factors that were taken into consideration were stone size, stone impaction site, and duration of impaction. These stone factors also did not contribute significantly to the formation of the ureteral strictures. Conclusions This prospective study failed to identify any predictable factors for ureteral stricture formation. It is proposed that all patients undergo a simple postoperative KUB ultrasound screening 3 months after undergoing endoscopic treatment for impacted ureteral stones.


British Journal of Cancer | 2014

Spectrum of very early breast cancer in a setting without organised screening

Nirmala Bhoo-Pathy; Shridevi Subramaniam; Nur Aishah Taib; Mikael Hartman; Zarifah Alias; Guan Hee Tan; Rasha I Ibrahim; C-H Yip; Helena M. Verkooijen

Background:Within a setting without organised breast cancer screening, the characteristics and survival of very early breast cancer were determined.Methods:All 4930 women diagnosed with breast cancer in University Malaya Medical Center, Malaysia from 1993 to 2011 were included. Factors associated with very early presentation (stage I) at diagnosis were identified. Tumour characteristics, management patterns, and survival of very early breast cancer were described, and where appropriate, compared with other settings.Results:Proportion of women presenting with stage I breast cancer significantly increased from 15.2% to 25.2% over two decades. Factors associated with very early presentation were Chinese ethnicity, positive family history of breast cancer, and recent period of diagnosis. Within stage I breast cancers, median tumour size at presentation was 1.5 cm. A majority of stage I breast cancer patients received mastectomy, which was associated with older age, Chinese ethnicity, postmenopausal status, and larger tumours. Chemotherapy was administered in 36% of patients. Five-year age-adjusted relative survival for women with stage I breast cancer was 99.1% (95% CI: 97.6–99.6%).Conclusions:The proportion of women presenting with very early breast cancer in this setting without organised screening is increasing. These women seem to survive just as well as their counterparts from affluent settings.


Asian Pacific Journal of Cancer Prevention | 2013

Stratifying patients with haematuria into high or low risk groups for bladder cancer: A novel clinical scoring system

Guan Hee Tan; Shamsul Azhar Shah; Ho Sue Ann; Siti Nurhafizah Hemdan; Lim Chun Shen; Nurudin Al-Fahmi Abdul Galib; Praveen Singam; Ho Chee Christopher Kong; Goh Eng Hong; Badrulhisham Bahadzor; Zulkifli Md Zainuddin

Haematuria is a common presentation of bladder cancer and requires a full urologic evaluation. This study aimed to develop a scoring system capable of stratifying patients with haematuria into high or low risk groups for having bladder cancer to help clinicians decide which patients need more urgent assessment. This cross- sectional study included all adult patients referred for haematuria and subsequently undergoing full urological evaluation in the years 2001 to 2011. Risk factors with strong association with bladder cancer in the study population were used to design the scoring system. Accuracy was determined by the area under the receiver operating characteristic (ROC) curve. A total of 325 patients with haematuria were included, out of which 70 (21.5%) were diagnosed to have bladder cancer. Significant risk factors associated with bladder cancer were male gender, a history of cigarette smoking and the presence of gross haematuria. A scoring system using 4 clinical parameters as variables was created. The scores ranged between 6 to 14, and a score of 10 and above indicated high risk for having bladder cancer. It was found to have good accuracy with an area under the ROC curve of 80.4%, while the sensitivity and specificity were 90.0% and 55.7%, respectively. The scoring system designed in this study has the potential to help clinicians stratify patients who present with haematuria into high or low risk for having bladder cancer. This will enable high-risk patients to undergo urologic assessment earlier.


Investigative and Clinical Urology | 2017

Urethral strictures after bipolar transurethral resection of prostate may be linked to slow resection rate

Guan Hee Tan; Shamsul Azhar Shah; Nurayub Md Ali; Eng Hong Goh; Praveen Singam; Christopher Chee Kong Ho; Zulkifli Md Zainuddin

PURPOSE This study aimed to determine the urethral stricture (US) rate and identify clinical and surgical risk factors associated with US occurrence after transurethral resection of the prostate using the bipolar Gyrus PlasmaKinetic Tissue Management System (PK-TURP). MATERIALS AND METHODS This was an age-matched case-control study of US occurrence after PK-TURP. Retrospective data were collected from the hospital records of patients who had a minimum of 36 months of follow-up information. Among the data collected for analysis were prostate-specific antigen level, estimated prostate weight, the amount of prostate resected, operative time, history of urinary tract infection, previous transurethral resection of the prostate, and whether the PK-TURP was combined with other endourological procedures. The resection rate was calculated from the collected data. Univariate and multivariate analyses were performed to identify clinical and surgical risk factors related to US formation. RESULTS A total of 373 patients underwent PK-TURP between 2003 and 2009. There were 13 cases of US (3.5%), and most of them (10 of 13, 76.9%) presented within 24 months of surgery. Most of the US cases (11 of 13, 84.6%) occurred at the bulbar urethra. Multivariable logistic regression analyses identified slow resection rate as the only risk factor significantly associated with US occurrence. CONCLUSIONS The US rate of 3.5% after PK-TURP in this study is comparable to contemporary series. A slow resection rate seems to be related to US occurrence. This should be confirmed by further studies; meanwhile, we must be mindful of this possibility when operating with the PK-TURP system.


Clinica Terapeutica | 2013

An unusual cause of a penetrating injury to the anterior urethra: a thorny situation.

Guan Hee Tan; Christopher Chee Kong Ho; Badrulhisham Bahadzor; S. Praveen; Eng Hong Goh; A. R. Afdzillah; M. Z. Zulkifli

Concurrent penetrating injury to the male external genitalia and the anterior urethra is uncommon. This case illustrates an unusual cause of such an injury, and its subsequent management and outcome. A 69-year-old man had his scrotum and anterior urethra pierced by a long thorn when he fell in his farm. He presented with urine leakage from the scrotal wound each time he micturated. Cystoscopic examination confirmed the cause and extent of the injury, and also facilitated the extraction of the thorn. The injury was allowed time to heal by urinary diversion with a urinary catheter. There were no stricture or fistula formations and the patient remained symptom-free at 3 months follow-up. Careful cystoscopic examination was both diagnostic and therapeutic in this case. A conservative approach is a feasible option in the management of selected cases of penetrating anterior urethral injury.


Investigative and Clinical Urology | 2018

The authors reply: Urethral strictures after bipolar transurethral resection of prostate may be linked to slow resection rate

Guan Hee Tan

To the editor: I appreciate your interest in our study and thanks for the comments made. It was indeed an interesting find in this study, that slow resection rate was associated with urethral stricture (US) formation [1]. We observed that the resection rate was generally slower in the US group. In response to your query, it was noted that the resection rates did not seem to differ very much between consultants and trainees, whose patients went on to develop US. What this suggests was that even in surgeons with greater experience, US would be more likely to occur if the resection rate was slow. However, the small sample population of this group (n=13) limited our ability to determine the statistical difference between the resection rates of consultants and trainees. The authors reply: Urethral strictures after bipolar transurethral resection of prostate may be linked to slow resection rate


Urology Annals | 2017

Paratesticular aggressive angiomyxoma: A rare case

Muhamad Izwan Ismail; Yin Ping Wong; Guan Hee Tan; Xeng Inn Fam

Aggressive angiomyxoma (AAM) particularly testicular origin is a rare benign mesenchymal myxoid tumor which is locally aggressive, blatant for local recurrence, and may metastasize. It occurs mostly in females of childbearing age and extremely rare in males. AMM particular testicular origin is not reported in literature yet. This is a 65-year-old man who had a right scrotal swelling. Ultrasound scrotum showed a soft tissue tumor of the right testis. The patient underwent radical right orchidectomy of which histopathologically confirmed to be a paratesticular AAM with clear resection margins. There were no signs of local recurrence or metastasis 2 years postsurgical resection.


Medeniyet Medical Journal | 2017

Embolization in Haemorrhage-associated Transurethral Resection of Prostate: An Advancement of Endovascular Technique

Firdaus Hayati; Zainal Adwin Zainal Abidin; Fairrul Kadir; Nik Azuan Nik Ismail; Guan Hee Tan

Received: 19.02.2017 Accepted: 19.03.2017 1Department of Surgery, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Sabah, Malaysia 2Department of General Surgery, Surgical Sciences Cluster, Faculty of Medicine, Universiti Teknologi MARA, Selangor, Malaysia 3Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Sabah, Malaysia 4Interventional Radiology Unit, Department of Radiology, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia 5Urology Unit, Department of Surgery, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia Yazışma adresi: Firdaus Hayati, Department of Surgery, Faculty of Medicine and Health Science, Universiti Malaysia Sabah, Sabah, Malaysia e-mail: [email protected] INTROdUCTION

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Eng Hong Goh

National University of Malaysia

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Badrulhisham Bahadzor

National University of Malaysia

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Praveen Singam

National University of Malaysia

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Christopher Chee Kong Ho

National University of Malaysia

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Zulkifli Md Zainuddin

National University of Malaysia

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C.C.K. Ho

National University of Malaysia

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Z. Md Zainuddin

National University of Malaysia

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Akhavan Adel

National University of Malaysia

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Firdaus Hayati

Universiti Malaysia Sabah

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