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Featured researches published by Yok-Lam Kwong.


The Lancet | 2003

Angiogenesis in ischaemic myocardium by intramyocardial autologous bone marrow mononuclear cell implantation

Hung-Fat Tse; Yok-Lam Kwong; John K.F. Chan; Gladys Lo; Chi-Lai Ho; Chu-Pak Lau

Results of experimental studies have shown that intramyocardial implantation of bone marrow cells induces neovascularisation and improves heart function after myocardial infarction. Our aim was to test this notion in people. We implanted autologous mononuclear bone marrow cells into the ischaemic myocardium of eight patients with severe ischaemic heart disease as guided by electromechanical mapping with a percutaneous catheter procedure. After 3 months of follow-up, there was improvement in symptoms, myocardial perfusion, and function at the ischaemic region on MRI. Future randomised, controlled studies are required to validate this initial encouraging result.


Journal of Clinical Oncology | 2011

Phase II Study of SMILE Chemotherapy for Newly Diagnosed Stage IV, Relapsed, or Refractory Extranodal Natural Killer (NK)/T-Cell Lymphoma, Nasal Type: The NK-Cell Tumor Study Group Study

Motoko Yamaguchi; Yok-Lam Kwong; Won Seog Kim; Yoshinobu Maeda; Chizuko Hashimoto; Cheolwon Suh; Koji Izutsu; Fumihiro Ishida; Yasushi Isobe; Eisaburo Sueoka; Junji Suzumiya; Takao Kodama; Hiroshi Kimura; Rie Hyo; Shigeo Nakamura; Kazuo Oshimi; Ritsuro Suzuki

PURPOSE To explore a more effective treatment for newly diagnosed stage IV, relapsed, or refractory extranodal natural killer/T-cell lymphoma, nasal type (ENKL), we conducted a phase II study of the steroid (dexamethasone), methotrexate, ifosfamide, L-asparaginase, and etoposide (SMILE) regimen. PATIENTS AND METHODS Patients with newly diagnosed stage IV, relapsed, or refractory disease and a performance status of 0 to 2 were eligible. Two cycles of SMILE chemotherapy were administered as the protocol treatment. The primary end point was the overall response rate (ORR) after the protocol treatment. RESULTS A total of 38 eligible patients were enrolled. The median age was 47 years (range, 16 to 67 years), and the male:female ratio was 21:17. The disease status was newly diagnosed stage IV in 20 patients, first relapse in 14 patients, and primary refractory in four patients. The eligibility was revised to include lymphocyte counts of 500/μL or more because the first two patients died from infections. No treatment-related deaths were observed after the revision. The ORR and complete response rate after two cycles of SMILE chemotherapy were 79% (90% CI, 65% to 89%) and 45%, respectively. In the 28 patients who completed the protocol treatment, 19 underwent hematopoietic stem-cell transplantation. The 1-year overall survival rate was 55% (95% CI, 38% to 69%). Grade 4 neutropenia was observed in 92% of the patients. The most common grade 3 or 4 nonhematologic complication was infection (61%). CONCLUSION SMILE chemotherapy is an effective treatment for newly diagnosed stage IV, relapsed or refractory ENKL. Myelosuppression and infection during the treatment should be carefully managed.


Gut | 2003

Promoter methylation of E-cadherin gene in gastric mucosa associated with Helicobacter pylori infection and in gastric cancer.

Aoo Chan; S. K. Lam; B. C. Y. Wong; Wm Wong; M.-F. Yuen; Y. H. Yeung; Wm Hui; A. Rashid; Yok-Lam Kwong

Background:E-cadherin is an adhesion molecule involved in tumour invasion/metastasis. Silencing of E-cadherin by promoter CpG methylation has been shown in both familial and sporadic gastric cancers. Helicobacter pylori is a class I carcinogen in gastric cancer. Aims: This study was undertaken to investigate the association between methylation of E-cadherin and H pylori in gastric mucosa from dyspeptic patients, and in intestinal metaplasia and primary and metastatic adenocarcinoma from surgical specimens of patients with gastric cancer. Methods:E-cadherin methylation was studied using methylation specific polymerase chain reaction in microdissected tissue from biopsies or surgical resection specimens. E-cadherin expression was studied by immunohistochemistry. Results:E-cadherin methylation was present in 31% (11/35) of gastric mucosae from dyspeptic patients, and was associated with H pylori infection (p=0.002), but was independent of the age of the patient or presence or absence of gastritis. E-cadherin methylation was present in 0% (0/8) of normal mucosa, 57% (12/21) of intestinal metaplasias, and 58% (15/26) of primary and 65% (21/32) of metastatic cancers. E-cadherin methylation status was concordant in 92% (11/12) of intestinal metaplasias and primary cancers, and in 85% (17/20) of primary and metastatic cancers from the same resected specimen. E-cadherin methylation in gastric cancer was associated with depth of tumour invasion (p=0.02) and regional nodal metastasis (p=0.05). Conclusion:E-cadherin methylation is an early event in gastric carcinogenesis, and is initiated by H pylori infection.


Clinical Infectious Diseases | 2005

Ciprofloxacin Decreased Polyoma BK Virus Load in Patients Who Underwent Allogeneic Hematopoietic Stem Cell Transplantation

Anskar Y. H. Leung; Maggie Chan; Kwok-Yung Yuen; Vincent C. C. Cheng; Kwok-Hung Chan; Chris L. P. Wong; Raymond Liang; Albert K. W. Lie; Yok-Lam Kwong

BACKGROUND Polyoma BK virus (BKV) is associated with hemorrhagic cystitis during hematopoietic stem cell transplantation (HSCT). The objective of this study was to test whether standard-dose ciprofloxacin might suppress reactivation of BKV infection during HSCT. METHODS Sixty-eight patients received ciprofloxacin or a cephalosporin as antibiotic prophylaxis after undergoing allogeneic HSCT. Urine samples were collected weekly from day 7 before HSCT to day 50 after HSCT. Laboratory investigations included quantification of BKV load and urinary ciprofloxacin levels and in vitro drug sensitivity of BKV. RESULTS Twenty-two patients received ciprofloxacin, 21 received cephalosporins, 12 received concomitant corticosteroids and antibiotics (9 received ciprofloxacin, and 3 received cephalosporins), and 13 received interrupted ciprofloxacin therapy. Ciprofloxacin recipients developed a significantly lower peak BKV load, compared with cephalosporin recipients (median, 3x10(5) copies/mL vs. 2.6x10(9) copies/mL; P=.021), irrespective of concomitant receipt of corticosteroid therapy. Fewer ciprofloxacin recipients than cephalosporin recipients (P=.013) developed BKV viruria with a > or =3-log increase in BKV load during HSCT, which was associated with significantly more cases of hemorrhagic cystitis (8 of 29 patients with a peak increase of > or =3 log vs. 0 of 39 patients without a peak increase of this level; P<.001). Ciprofloxacin recipients excreted ciprofloxacin in urine at a mean 24-h rate of 71.7 microg/mL (range, 23.0-152.9 microg/mL), which was comparable with the in vitro inhibitory concentration of 125-250 microg/mL of ciprofloxacin found for 3 of 7 BKV isolates. CONCLUSIONS Ciprofloxacin decreased urinary BKV reactivation after HSCT.


Blood | 2012

SMILE for natural killer/T-cell lymphoma: analysis of safety and efficacy from the Asia Lymphoma Study Group

Yok-Lam Kwong; Won Seog Kim; Soon Thye Lim; Seok Jin Kim; Tiffany Tang; Eric Tse; Anskar Y. H. Leung; Chor-Sang Chim

Natural killer/T-cell lymphoma is rare and aggressive, with poor outcome. Optimal treatment remains unclear. A novel regimen dexamethasone, methotrexate, ifosfamide, l-asparaginase, and etoposide (SMILE) showed promise in phase 1/2 studies with restrictive recruitment criteria. To define the general applicability of SMILE, 43 newly diagnosed and 44 relapsed/refractory patients (nasal, N = 60, nonnasal, N = 21; disseminated, N = 6; male, N = 59; female, N = 28) at a median age of 51 years (23-83 years) were treated. Poor-risk factors included stage III/IV disease (56%), international prognostic index of 3 to 5 (43%), and Korean prognostic scores of 3 to 4 (41%). A median of 3 (0-6; total = 315) courses of SMILE were administered. Significant toxicities included grade 3/4 neutropenia (N = 57; 5 sepsis-related deaths); grade 3/4 thrombocytopenia (N = 36); and nephrotoxicity (N = 15; 1 acute renal failure and death). Interim analysis after 2 to 3 cycles showed complete remission rate of 56%, partial remission rate of 22%, giving an overall response rate of 78%. On treatment completion, the overall-response rate became 81% (complete remission = 66%, partial remission = 15%). Response rates were similar for newly diagnosed or relapsed/refractory patients. At a median follow-up of 31 months (1-84 months), the 5-year overall survival was 50% and 4-year disease-free-survival was 64%. Multivariate analysis showed that international prognostic index was the most significant factor impacting on outcome and survivals.


Leukemia | 2007

Aldehyde dehydrogenase activity in leukemic blasts defines a subgroup of acute myeloid leukemia with adverse prognosis and superior NOD/SCID engrafting potential.

Alice M.S. Cheung; T. S. K. Wan; Joseph C.K. Leung; Loretta Y.Y. Chan; H Huang; Yok-Lam Kwong; Rhs Liang; Anskar Y. H. Leung

Aldehyde dehydrogenase (ALDH) activity is used to define normal hematopoietic stem cell (HSC), but its link to leukemic stem cells (LSC) in acute myeloid leukemia (AML) is currently unknown. We hypothesize that ALDH activity in AML might be correlated with the presence of LSC. Fifty-eight bone marrow (BM) samples were collected from AML (n=43), acute lymphoblastic leukemia (ALL) (n=8) and normal cases (n=7). In 14 AML cases, a high SSCloALDHbr cell population was identified (ALDH+AML) (median: 14.89%, range: 5.65–48.01%), with the majority of the SSCloALDHbr cells coexpressing CD34+. In another 29 cases, there was undetectable (n=23) or rare (⩽5%) (n=6) SSCloALDHbr population (ALDH−AML). Among other clinicopathologic variables, ALDH+AML was significantly associated with adverse cytogenetic abnormalities. CD34+ BM cells from ALDH+AML engrafted significantly better in NOD/SCID mice (ALDH+AML: injected bone 21.11±9.07%; uninjected bone 1.52±0.75% vs ALDH−AML: injected bone 1.77±1.66% (P=0.05); uninjected bone 0.23±0.23% (P=0.03)) with the engrafting cells showing molecular and cytogenetic aberrations identical to the original clones. Normal BM contained a small SSCloALDHbr population (median: 2.92%, range: 0.92–5.79%), but none of the ALL cases showed this fraction. In conclusion, SSCloALDHbr cells in ALDH+AML might denote primitive LSC and confer an inferior prognosis in patients.


Cancer Science | 2008

Phase I study of dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide (SMILE) chemotherapy for advanced-stage, relapsed or refractory extranodal natural killer (NK)/T-cell lymphoma and leukemia.

Motoko Yamaguchi; Ritsuro Suzuki; Yok-Lam Kwong; Won Seog Kim; Yuichi Hasegawa; Koji Izutsu; Junji Suzumiya; Takayuki Okamura; Shigeo Nakamura; Keisei Kawa; Kazuo Oshimi

Extranodal natural killer (NK)/T‐cell lymphoma, nasal type, and aggressive NK‐cell leukemia are rare, and their standard therapy has not been established. They are Epstein–Barr virus‐associated lymphoid malignancies, and tumor cells express P‐glycoprotein leading to multidrug resistance of the disease. Patients with stage IV, relapsed or refractory diseases have a dismal prognosis, with survival measured in months only. To develop an efficacious chemotherapeutic regimen, we conducted a dose‐escalation feasibility study of a new chemotherapeutic regimen, SMILE, comprising the steroid dexamethasone, methotrexate, ifosfamide, l‐asparaginase, and etoposide. The components of SMILE are multidrug resistance‐unrelated agents and etoposide. Etoposide shows both in vitro and in vivo efficacy for Epstein–Barr virus‐associated lymphoproliferative disorders. Eligible patients had newly diagnosed stage IV, relapsed or refractory diseases after first‐line chemotherapy, were 15–69 years of age, and had satisfactory performance scores (0–2). Four dose levels of methotrexate and etoposide were originally planned to be evaluated. At level 1, six patients with extranodal NK/T‐cell lymphoma, nasal type, were enrolled. Their disease status was newly diagnosed stage IV (n = 3), first relapse (n = 2), and primary refractory (n = 1). All of the first three patients developed dose‐limiting toxicities, and one of them died of sepsis with grade 4 neutropenia. A protocol revision stipulating early granulocyte colony‐stimulating factor administration was made. Two out of three additional patients developed dose‐limiting toxicities that were all manageable and transient. For the six enrolled patients, the overall response rate was 67% and the complete response rate was 50%. Although its safety and efficacy require further evaluation, we recommend a SMILE chemotherapy dose level of 1 for further clinical studies. (Cancer Sci 2008; 99: 1016–1020)


American Journal of Pathology | 1999

Comparative genomic hybridization analysis of natural killer cell lymphoma/leukemia. Recognition of consistent patterns of genetic alterations.

Lisa L.P. Siu; Kit-Fai Wong; John K. C. Chan; Yok-Lam Kwong

Putative natural killer (NK) cell lymphoma/leukemia is a rare group of recently characterized hematolymphoid malignancies. They are highly aggressive and frequently present in extranodal sites, including the nasal area and the upper aerodigestive system, and nonnasal areas such as the skin and the gastrointestinal tract. According to clinicopathological features, they can be classified into nasal NK cell lymphoma, nasal-type NK cell lymphoma occurring in nonnasal areas, and NK cell lymphoma/leukemia. Genetic alterations in NK cell lymphoma/leukemia are not well defined. In this study, we have performed comparative genomic hybridization (CGH) on DNA extracted from fresh or frozen tissues of 10 patients with NK cell lymphoma/leukemia. They comprised four nasal NK cell lymphomas, one nasal-type NK cell lymphoma, and five NK cell lymphomas/leukemias. CGH showed frequent deletions at 6q16-q27 (four cases), 13q14-q34 (three cases), 11q22-q25 (two cases), 17p13 (two cases), and loss of the whole chromosome X (two cases). DNA amplification was observed in a majority of the chromosomes. Five cases showed DNA gains at region 1p32-pter. Frequent DNA gains were also found in chromosomes 6p, 11q, 12q, 17q, 19p, 20q, and Xp (three cases each). Interestingly, DNA gains were more frequent in nasal/nasal-type NK cell lymphomas than NK cell lymphoma/leukemia. These genetic alterations correlated well with karyotypic features found in some of the cases. The frequent DNA losses at 6q and 13q suggest that the presence of tumor suppressor genes at these regions is important in NK cell transformation. In addition to establishing novel patterns of genomic imbalances in these rare NK cell malignancies, which may be targets for future molecular analysis, this study also provides important information on genetic alterations in NK cell lymphomas that may be useful in defining their positions in current lymphoma classification schemes, which are increasingly focusing on phenotypic and genotypic correlations.


Journal of Clinical Oncology | 1995

Treatment outcome and prognostic factors for primary nasal lymphoma.

Rhs Liang; D. Todd; T. K. Chan; E. Chiu; Albert K. W. Lie; Yok-Lam Kwong; D. Choy; F. C. S. Ho

PURPOSE To report our experience managing a large series of Chinese patients with primary nasal lymphoma. PATIENTS AND METHODS From January 1975 to December 1993, 100 patients (median age, 50 years) with newly diagnosed primary nasal lymphoma were studied. There were four low-grade, 62 intermediate-grade, nine high-grade, and 25 unclassifiable lymphomas. Immunophenotyping was performed in 45 patients: eight B cell, 35 T cell, and two uncertain. All cases of angiocentric lymphoma that were typed were T cell. Fifty-two patients had stage I disease, 15 had stage II, four had stage III, and 29 had stage IV. Only 15 patients had B symptoms (weight loss, night sweats, and/or fever), and 11 had bulky disease. Thirty-nine patients with clinically localized stage I and II disease received local radiotherapy alone (before 1980), and the remaining 28 stage I and II patients received combination chemotherapy followed by local radiotherapy. The 33 patients with advanced stage III and IV disease were given combination chemotherapy, and additional radiotherapy was given to five of them who had bulky local disease. RESULTS Significantly higher complete remission rates were observed in patients with early stages of disease and those without B symptoms. Superior disease-free survival after complete remission was observed in patients with stage I/II disease. Univariate factors associated with a better overall survival included age less than 60 years, stage I disease, and absence of B symptoms. Survival was significantly better in the subgroup of patients with stage I disease. CONCLUSION Patients with nasal lymphoma, especially those with advanced disease, seemed to have a poor prognosis, and their clinical outcome was not improved significantly by the use of chemotherapy instead of radiotherapy or the use of doxorubicin-containing chemotherapeutic regimens.


Gut | 2005

Hepatitis B reactivation after withdrawal of pre-emptive lamivudine in patients with haematological malignancy on completion of cytotoxic chemotherapy

Chee-Kin Hui; Winnie W.W. Cheung; Wing-Yan Au; Albert K. W. Lie; Hai-Ying Zhang; Yui-Hung Yueng; B. C. Y. Wong; Nancy Leung; Yok-Lam Kwong; Raymond Liang; George K. K. Lau

Background: The hepatic outcome of hepatitis B surface antigen (HBsAg) positive patients undergoing chemotherapy after withdrawal of pre-emptive lamivudine is unknown. Aims: To examine the occurrence of hepatitis B virus (HBV) reactivation after withdrawal of pre-emptive lamivudine. Methods: Pre-emptive lamivudine was started one week before initiation of chemotherapy in 46 consecutive HBsAg positive patients and continued for the entire duration of chemotherapy. Pre-emptive lamivudine was stopped at a median 3.1 (range 3.0–3.4) months after completion of chemotherapy. Patients were longitudinally followed up after withdrawal of pre-emptive lamivudine. Results: Median time of follow up after withdrawal of lamivudine was 25.7 (range 5.7–75.7) months. Eleven of the 46 patients (23.9%) developed HBV reactivation after withdrawal of pre-emptive lamivudine. Eight of the 16 patients with high pre-chemotherapy HBV DNA (⩾104 copies/ml) compared with three of the 30 patients with low pre-chemotherapy HBV DNA (<104 copies/ml) developed HBV reactivation (50.0% v 10.0%, respectively; p<0.001). Hepatitis B e antigen positive patients were also more likely to develop HBV reactivation (5/11 (45.5%) v 6/35 (17.1%), respectively; p = 0.041). A high pre-chemotherapy HBV DNA (⩾104 copies/ml) was the most important risk factor for HBV reactivation after withdrawal of pre-emptive lamivudine on Cox proportional hazards analysis (relative risk 16.13, (95% confidence interval 2.99-87.01; p = 0.001). Conclusions: HBV reactivation is more likely to occur in patients with high pre-chemotherapy HBV DNA after withdrawal of pre-emptive lamivudine. A more prolonged course of antiviral therapy may be necessary in these patients after completion of chemotherapy in order to reduce post-chemotherapy HBV reactivation.

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Wing-Yan Au

University of Hong Kong

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Eric Tse

University of Hong Kong

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A. K. W. Lie

University of Hong Kong

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Rhs Liang

University of Hong Kong

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Wy Au

University of Hong Kong

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