Mk Yiu
University of Hong Kong
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Featured researches published by Mk Yiu.
Journal of Oncology | 2014
Gang Huang; Chun-Yip Yeung; Ka Kui Lee; Jianxiong Liu; Kl Ho; Mk Yiu; Karen Siu-Ling Lam; Hung-Fat Tse; Thomas Yau; Chung-Wah Siu
Background. Androgen deprivation therapy (ADT) in nonmetastatic prostate cancer is unclear. Recent data suggests possible increase in the cardiovascular risks receiving ADT. The aim of the study was to investigate the cardiovascular outcomes in a cohort of Chinese nonmetastatic prostate cancer patients with no previously documented cardiovascular disease. Methods and Results. 745 patients with no previously documented cardiovascular disease and/or diabetes mellitus diagnosed to have nonmetastatic prostate cancer were recruited. Of these, 517 patients received ADT and the remaining 228 did not. After a mean follow-up of 5.3 years, 60 patients developed primary composite endpoint including (1) coronary artery disease, (2) congestive heart failure, and (3) ischemic stroke. Higher proportion of patients on ADT (51 patients, 9.9%) developed composite endpoint compared with those not on ADT (9 patients, 3.9%) with hazard ratio (HR) of 2.06 (95% confidence interval (CI): 1.03–3.24, P = 0.04). Furthermore, Cox regression analysis revealed that only the use of ADT (HR: 2.1, 95% CI: 1.03–4.25, P = 0.04) and hypertension (HR: 2.0, 95% CI: 1.21–3.33, P < 0.01) were independent predictors for primary composite endpoint. Conclusion. ADT in Chinese patients with nonmetastatic prostate cancer with no previously documented cardiovascular disease was associated with subsequent development of cardiovascular events.
Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine | 2016
Tct Lai; Wk Ma; Mk Yiu
INTRODUCTION Patients who undergo partial nephrectomy have been shown to be at decreased risk of renal impairment compared with radical nephrectomy. We examined the oncological outcome of patients in our centre who underwent partial or radical nephrectomy for T1 renal cancer (7 cm or smaller), and compared the likelihood of developing chronic kidney disease. METHODS This historical cohort study with internal comparison was conducted in a tertiary hospital in Hong Kong. A cohort of 86 patients with solitary T1 renal cancer and a normal contralateral kidney who underwent radical (38 patients) or partial (48 patients) nephrectomy between January 2005 and December 2010 was included. The overall and cancer-free survival, change in glomerular filtration rate, and new onset of chronic kidney disease were compared between the radical and partial nephrectomy groups. RESULTS A total of 32 (84%) radical nephrectomy patients and 43 (90%) partial nephrectomy patients were alive by 31 December 2012. The mean follow-up was 43.5 (standard deviation, 22.4) months. There was no significant difference in overall survival (P=0.29) or cancer-free survival (P=0.29) between the two groups. Both groups enjoyed good oncological outcome with no recurrence in the partial nephrectomy group. Overall, 18 (21%) patients had pre-existing chronic kidney disease. The partial nephrectomy group had a significantly smaller median reduction in glomerular filtration rate (12.6% vs 35.4%; P<0.001), and radical nephrectomy carried a significantly higher risk of developing chronic kidney disease (hazard ratio=5.44; 95% confidence interval, 1.26-23.55; P=0.02). CONCLUSIONS Compared with radical nephrectomy, partial nephrectomy can prevent chronic kidney disease and still achieve an excellent oncological outcome for T1 renal tumours, in particular T1a tumours and tumours with a low R.E.N.A.L. score.
Asian Journal of Andrology | 2014
Jeremy Yc Teoh; Yuen Sk; James Hl Tsu; Charles Kw Wong; Brian Sh Ho; Ada Tl Ng; Wk Ma; Kwan-Lun Ho; Mk Yiu
We investigated the prostate cancer detection rates upon transrectal ultrasound (TRUS)-guided biopsy in relation to digital rectal examination (DRE) and prostate-specific antigen (PSA), and risk factors of prostate cancer detection in the Chinese population. Data from all consecutive Chinese men who underwent first TRUS-guided prostate biopsy from year 2000 to 2013 was retrieved from our database. The prostate cancer detection rates with reference to DRE finding and PSA level of < 4, 4-10, 10.1-20, 20.1-50 and > 50 ng ml−1 were investigated. Multivariate logistic regression analyses were performed to investigate for potential risk factors of prostate cancer detection. A total of 2606 Chinese men were included. In patients with normal DRE, the cancer detection rates were 8.6%, 13.4%, 21.8%, 41.7% and 85.2% in patients with PSA < 4, 4-10, 10.1-20, 20.1-50 and > 50 ng ml−1 respectively. In patients with abnormal DRE, the cancer detection rates were 12.4%, 30.2%, 52.7%, 80.6% and 96.4% in patients with PSA < 4, 4-10, 10.1-20, 20.1-50 and > 50 ng ml−1 respectively. Older age, smaller prostate volume, larger number of biopsy cores, presence of abnormal DRE finding and higher PSA level were associated with increased risk of prostate cancer detection upon multivariate logistic regression analyses (P < 0.001). Chinese men appeared to have lower prostate cancer detection rates when compared to the Western population. Taking the different risk factors into account, an individualized approach to the decision of TRUS-guided biopsy can be adopted.
Asian Journal of Andrology | 2017
Teoh Jy; Tsu Jh; Yuen Sk; Chiu Pk; Sy Chan; Wong Kw; Kl Ho; Chi-Fai Ng; Mk Yiu
We investigated the association of time to prostate-specific antigen nadir (TTPN) and logarithm of prostate-specific antigen velocity after progression Log(PSAVAP) in metastatic prostate cancer with prior primary androgen deprivation therapy (ADT). All metastatic prostate cancer patients treated with primary ADT from 2000 to 2009 were reviewed. Patients who developed disease progression were included in the subsequent analyses. Patients were categorized into three groups according to their TTPN: TTPN of <3 months, 3-17 months, and >17 months. We compared the Log(PSAVAP) between the different TTPN groups using Mann-Whitney U-test and Kruskal-Wallis test. Further multiple linear regression analyses on Log(PSAVAP) were performed to adjust for other potential confounding factors. Among 419 patients who were treated with primary ADT, 306 patients developed disease progression with a median follow-up of 28 months. Longer TTPN was associated with lower Log(PSAVAP) (P = 0.008) within all subgroup analyses (TTPN of <3 vs 3-17 months, P= 0.020; TTPN of 3-17 vs >17 months, P= 0.009; and TTPN of <3 vs >17 months, P= 0.001). Upon multiple linear regression analyses, baseline PSA (regression coefficient 0.001, P= 0.045), PSA nadir (regression coefficient 0.002, P= 0.040), and TTPN (regression coefficient −0.030, P= 0.001) were the three factors that were significantly associated with Log(PSAVAP). In conclusion, a longer TTPN was associated with lower Log(PSAVAP) in metastatic prostate cancer patients following primary ADT. TTPN cut-offs at 3 months and 17 months appeared to have prognostic significance in predicting Log(PSAVAP). TTPN may serve as a good prognostic indicator in deciding the treatment strategy in patients with disease progression.
Hong Kong Medical Journal | 2015
Kl Ho; Tsu Jh; Tam Pc; Mk Yiu
OBJECTIVE To review disease spectrum and treatment patterns in a local male infertility clinic. DESIGN Case series. SETTING Male infertility clinic in a teaching hospital in Hong Kong. PATIENTS Patients who were seen as new cases in a local male infertility clinic between January 2008 and December 2012. INTERVENTION Infertility assessment and counselling on treatment options. MAIN OUTCOME MEASURES Disease spectrum and treatment patterns. RESULTS A total of 387 new patients were assessed in the male infertility clinic. The mean age of the patients and their female partners was 37.2 and 32.1 years, respectively. The median duration of infertility was 3 years. Among the patients, 36.2% had azoospermia, 8.0% had congenital absence of vas deferens, and 48.3% of patients had other abnormalities in semen parameters. The commonest causes of male infertility were unknown (idiopathic), clinically significant varicoceles, congenital absence of vas deferens, mumps after puberty, and erectile or ejaculatory dysfunction. Overall, 66.1% of patients chose assisted reproductive treatment and 12.4% of patients preferred surgical correction of reversible male infertility conditions. Altogether 36.7% of patients required either surgical sperm retrieval or correction of male infertility conditions. CONCLUSIONS The present study provided important local data on the disease spectrum and treatment patterns in a male infertility clinic. The incidences of azoospermia and congenital absence of vas deferens were much higher than those reported in the contemporary literature. A significant proportion of patients required either surgical sperm retrieval or correction of reversible male infertility conditions.
Hong Kong Medical Journal | 2013
Leung L; Kl Ho; Tam Pc; Mk Yiu
OBJECTIVE To investigate the impact of subinguinal microsurgical varicocelectomy on semen parameters and pregnancy outcomes in couples with male factor subfertility. DESIGN Case series. SETTING Male Infertility Clinic in an academic institution in Hong Kong. PATIENTS The clinical records of 42 consecutive subfertile male patients who had subinguinal microsurgical varicocelectomy (from January 2000 to December 2009) were retrospectively reviewed. All the patients had a known history of subfertility and abnormalities in one or more semen parameters. Female subfertility factors were not addressed. Only grade 2 or higher clinically palpable varicoceles were operated on. MAIN OUTCOME MEASURES Preoperative and postoperative semen analyses based on the World Health Organization criteria; the outcome measures included changes in semen parameters and whether a pregnancy ensued. RESULTS The mean age of patients and their spouses were 38 and 33 years, respectively. The mean duration of infertility was 4 years; 37 patients had primary infertility and five had secondary infertility. The mean (± standard deviation) sperm concentration improved from 12 ± 19 million/mL to 23 ± 29 million/mL following varicocelectomy (P<0.001), the mean sperm motility improved from 26% ± 16% to 32% ± 18% (P<0.001), and the mean normal morphology increased from 5% ± 7% to 6% ± 6% (P<0.001). Postoperatively, 23 (55%) of the patients achieved pregnancy, 11 (26%) being spontaneous, 1 (2%) by intrauterine insemination, and 11 (26%) by in-vitro fertilisation. Among 20 patients with severe preoperative oligospermia (<5 million/mL), statistically significant improvements occurred in postoperative mean sperm concentration, motility and morphology (all P<0.001), and five (25%) of them achieved a spontaneous pregnancy. There was one intra-operative injury to the testicular artery with immediate repair and no testicular atrophy. Five (12%) of the patients had recurrences. No preoperative factors appeared predictive of a pregnancy ensuing. CONCLUSIONS In couples with male infertility due to varicoceles, subinguinal microsurgical varicocelectomy was shown to improve sperm concentrations, motility and morphology, and the likelihood of a pregnancy. Spontaneous pregnancy was achieved in 25% of the couples in which the man had severe oligospermia.
Hong Kong Medical Journal | 2013
Wong Mh; Mk Yiu; Kl Ho
Less than 5% of breast cancers present as metastasis, and urinary bladder secondaries were only sporadically reported in the literature. However, they may even be responsible for the initial presentation, for which reason they can pose a diagnostic challenge. We present here what we believe is the first such case in Hong Kong, with a review of this entity.
Quality of Life Research | 2015
Carlos K. H. Wong; Edmond P. H. Choi; James Hok-Leung Tsu; Brian Sh Ho; Ada T.L. Ng; Wy Chin; Mk Yiu
PurposeThe aim of the study was to assess the validity, reliability and sensitivity of the FACT-P (version 4) in Chinese males with prostate cancer.MethodsConstruct validity was assessed using Spearman’s correlation test against the 12-item Short Form Health Survey (SF-12v2). Internal consistency and test–retest reliability were assessed using Cronbach’s α coefficient and intra-class correlation coefficient, respectively. Sensitivity was determined by performing known-group comparisons by independent t test.ResultsFACT-P subscale scores had a moderate correlation with the corresponding SF-12v2 domain score that conceptually measures the similar construct providing evidence for adequate construct validity. Internal consistency was acceptable (α: 0.687–0.900) for all subscales aside from the Prostate Cancer Subscale (α: 0.505) and Trial Outcome Index (α: 0.562). FACT-P subscale and total scores showed good test–retest reliability (range 0.753–0.913). All total scales and most of the subscales were sensitive in detecting differences between patients with different levels of functional impairment but not different cancer stages or levels of prostate-specific antigen.ConclusionsThe measure is a valid and reliable measure to assess the health-related quality of life of Chinese males with prostate cancer. The FACT-P is sensitive to detect difference between patients with varying functional status.
Hong Kong Medical Journal | 2015
Kw Wong; Wk Ma; Cw Wong; Mh Wong; Cf Tsang; Hlj Tsu; Kl Ho; Mk Yiu
OBJECTIVE To investigate the impact of skeletal-related events on survival in patients with metastatic prostate cancer prescribed long-term androgen deprivation therapy. METHODS This historical cohort study was conducted in two hospitals in Hong Kong. Patients who were diagnosed with metastatic prostate cancer and prescribed androgen deprivation therapy between January 2006 and December 2011 were included. Details of skeletal-related events and mortality were examined. RESULTS The median follow-up was 28 (range, 1-97) months. Of 119 patients, 52 (43.7%) developed skeletal-related events throughout the study, and the majority received bone irradiation for pain control. The median actuarial overall survival and cancer-specific survival for patients with skeletal-related events were significantly shorter than those without skeletal-related events (23 vs 48 months, P=0.003 and 26 vs 97 months, P<0.001, respectively). Multivariate analysis revealed that the adjusted hazard ratio of presence of skeletal-related events on overall and cancer-specific survival was 2.73 (95% confidence interval, 1.46-5.10; P=0.002) and 3.92 (95% confidence interval, 1.87-8.23; P<0.001), respectively. A prostate-specific antigen nadir of >4 ng/mL was an independent poor prognostic factor for overall and cancer-specific survival after development of skeletal-related events (hazard ratio=10.42; 95% confidence interval, 2.10-51.66 and hazard ratio=10.54; 95% confidence interval, 1.94-57.28, respectively). CONCLUSIONS Skeletal-related events were common in men with metastatic prostate cancer. This is the first reported study to show that a skeletal-related event is an independent prognostic factor in overall and cancer-specific survival in patients with metastatic prostate cancer prescribed androgen deprivation therapy. A prostate-specific antigen nadir of >4 ng/mL is an independent poor prognostic factor for overall and cancer-specific survival following development of skeletal-related events.
Asian Journal of Andrology | 2015
Teoh Jy; Yuen Sk; Tsu Jh; Carlos K. H. Wong; Brian Sh Ho; Ada Tl Ng; Wk Ma; Kwan-Lun Ho; Mk Yiu
We investigated the performance characteristics of prostate-specific antigen (PSA) and PSA density (PSAD) in Chinese men. All Chinese men who underwent transrectal ultrasound-guided prostate biopsy (TRUS-PB) from year 2000 to 2013 were included. The receiver operating characteristic (ROC) curves for both PSA and PSAD were analyzed. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) at different cut-off levels were calculated. A total of 2606 Chinese men were included. For the ROC, the area under curve was 0.770 for PSA (P < 0.001) and 0.823 for PSAD (P < 0.001). PSA of 4.5 ng ml−1 had sensitivity of 94.4%, specificity of 14.1%, PPV of 29.5%, and NPV of 86.9%; PSAD of 0.12 ng ml−1 cc−1 had sensitivity of 94.5%, specificity of 26.6%, PPV of 32.8%, and NPV of 92.7%. On multivariate logistic regression analyses, PSA cut-off at 4.5 ng ml−1 (OR 1.61, 95% CI 1.05-2.45, P= 0.029) and PSAD cut-off at 0.12 ng ml−1 cc−1 (OR 6.22, 95% CI 4.20-9.22, P< 0.001) were significant predictors for prostate cancer detection on TRUS-PB. In conclusion, the performances of PSA and PSAD at different cut-off levels in Chinese men were very different from those in Caucasians. PSA of 4.5 ng ml−1 and PSAD of 0.12 ng ml−1 cc−1 had near 95% sensitivity and were significant predictors of prostate cancer detection in Chinese men.