Displaying publications 41 - 54 of 54 in total

Abstract:
Sort:
  1. Yip CH, Bhoo-Pathy N, Uiterwaal CS, Taib NA, Tan GH, Mun KS, et al.
    Breast, 2011 Apr;20 Suppl 2:S60-4.
    PMID: 21349715 DOI: 10.1016/j.breast.2011.02.004
    Estrogen receptor (ER) positive rates in breast cancer may be influenced by grade, stage, age and race. This study reviews the ER positive rates over a 15-year period at the University Malaya Medical Centre, Kuala Lumpur, Malaysia. Data on ER status of 3557 patients from 1994 to 2008 was analyzed. ER status was determined by immunohistochemistry with a cut-off point of 10%. ER positivity increased by about 2% for every 5-year cohort, from 54.5% in 1994-1998 to 58.4% in 2004-2008. Ethnicity and grade were significantly associated with ER positivity rates: Malay women were found to have a higher risk of ER negative tumors compared with Chinese women. Grade 1 cancers were nine times more likely to be ER positive compared with grade 3 cancers. In summary, the proportion of ER positive cancers increased with each time period, and ethnicity and grade were independent factors that influenced ER positive rates.
  2. Roethlisberger M, Jayapalan RR, Hostettler IC, Bin Abd Kadir KA, Mun KS, Brand Y, et al.
    World Neurosurg, 2020 Jan;133:381-391.e2.
    PMID: 31476461 DOI: 10.1016/j.wneu.2019.08.102
    BACKGROUND: Data on the endonasal endoscopic approach (EEA) to treat sellar/parasellar synchronous tumors remain sparse. This work aims to describe a minimally invasive approach with intraoperative magnetic resonance imaging (MRI) to remove a large sellar/parasellar synchronous tumor, and presents a systematic literature review.

    METHODS: The preoperative MRI of a 54-year-old woman revealed a sellar lesion (28 × 19 × 16 mm), presumably a pituitary macroadenoma, and a second extra-axial lesion (22 × 36 × 20 mm) expanding from the tuberculum sellae to the planum sphenoidale with encasement of the anterior communicating complex, presumably a meningioma. We used intraoperative MRI to assess the extent of the resection before reconstructing the large skull base defect. Furthermore, we systematically reviewed pertinent articles retrieved by a PubMed/Embase database search between 1961 and December 2018.

    RESULTS: Out of 63 patients with synchronous tumors reported in 43 publications, we found 3 patients in which the tumor was removed by EEA. In these 3 patients and the presented case, the resection of both lesions was successful, without major approach-related morbidity or mortality. More extensive removal of endonasal structures to gain an adequate tumor exposure was not necessary. We did not find any previous reports describing the benefits of intraoperative MRI in the presented setting.

    CONCLUSIONS: In the rare case of a synchronous meningioma and pituitary adenoma of the sellar region, intraoperative MRI might be beneficial in confirming residual disease before skull base reconstruction, and therefore radiologic follow-up.

  3. Cheah PL, Li J, Looi LM, Koh CC, Lau TP, Chang SW, et al.
    Malays J Pathol, 2019 Aug;41(2):91-100.
    PMID: 31427545
    Since 2014, the National Comprehensive Cancer Network (NCCN) has recommended that colorectal carcinoma (CRC) be universally tested for high microsatellite instability (MSI-H) which is present in 15% of such cancers. Fidelity of resultant microsatellites during DNA replication is contingent upon an intact mismatch repair (MMR) system and lack of fidelity can result in tumourigenesis. Prior to commencing routine screening for MSI-H, we assessed two commonly used methods, immunohistochemical (IHC) determination of loss of MMR gene products viz MLH1, MSH2, MSH6 and PMS2 against PCR amplification and subsequent fragment analysis of microsatellite markers, BAT25, BAT26, D2S123, D5S346 and D17S250 (Bethesda markers) in 73 unselected primary CRC. 15.1% (11/73) were categorized as MSI-H while deficient MMR (dMMR) was detected in 16.4% (12/73). Of the dMMR, 66.7% (8/12) were classified MSI-H, while 33.3% (4/12) were microsatellite stable/low microsatellite instability (MSS/MSI-L). Of the proficient MMR (pMMR), 95.1% (58/61) were MSS/MSI-L and 4.9% (3/61) were MSI-H. The κ value of 0.639 (standard error =0.125; p = 0.000) indicated substantial agreement between detection of loss of DNA mismatch repair using immunohistochemistry and the detection of downstream microsatellite instability using PCR. After consideration of advantages and shortcomings of both methods, it is our opinion that the choice of preferred technique for MSI analysis would depend on the type of laboratory carrying out the testing.
  4. Poh ME, Liam CK, Mun KS, Chai CS, Wong CK, Tan JL, et al.
    Thorac Cancer, 2019 09;10(9):1841-1845.
    PMID: 31350945 DOI: 10.1111/1759-7714.13156
    Adjuvant chemotherapy has long been indicated to extend survival in completely resected stage IB to IIIA non-small cell lung cancer (NSCLC). However, there is accumulating evidence that chemotherapy or chemoradiotherapy can induce epithelial-to-mesenchymal transition (EMT) in disseminated or circulating NSCLC cells. Here, we describe the first case of EMT as the cause of recurrence and metastasis in a patient with resected stage IIB lung adenosquamous carcinoma after adjuvant chemotherapy. We review the literature and explore the possible mechanisms by which EMT occurs in disseminated tumor cells (DTC) or circulating tumor cells (CTC) in response to adjuvant chemotherapy (cisplatin) as a stressor. We also explore the possible therapeutic strategies to reverse EMT in patients with recurrence. In summary, although adjuvant cisplatin-based chemotherapy in resected NSCLC does extend survival, it may lead to the adverse phenomenon of EMT in disseminated tumor cells (DTC) or circulating tumor cells (CTC) causing recurrence and metastasis.
  5. Perumal K, Mun KS, Yap NY, Razack AHA, Gobe GC, Ong TA, et al.
    Biomed Res Int, 2020;2020:3682086.
    PMID: 32802842 DOI: 10.1155/2020/3682086
    Background: The mechanisms that link obesity and cancer development are not well-defined. Investigation of leptin and leptin receptor expressions may help define some of the mechanisms. These proteins are known for associating with the immune response, angiogenesis and, signalling pathways such as JAK2/STAT3, PI3K, and AKT pathways. Tissue proteins can be easily detected with immunohistochemistry (IHC), a technique widely used both in diagnostic and research laboratories. The identification of altered levels of leptin and leptin receptor proteins in tumour tissues may lead to targeted treatment for cancer.

    Objective: The objective of this study was to use IHC to compare leptin and leptin receptor expressions in clear cell renal cell carcinomas (ccRCC) in non-obese and obese patients to determine the association between these proteins with the clinicopathological features and prognosis of ccRCC. Patients and Methods. The study involved 60 patients who underwent nephrectomy of which 34 were obese, as assessed using body mass index (BMI). Nephrectomy samples provided tissues of ccRCC and adjacent non-cancerous kidney. The intensity and localization of leptin and leptin receptor protein expressions were evaluated using IHC and correlated with clinicopathological features and clinical outcomes. Aperio ImageScope morphometry and digital pathology were applied to assess the IHC results. The chi-square test was used to determine if there was any significant association between the proteins and the clinicopathological features. The Kaplan-Meier test was used to determine the overall survival, disease-free survival, and recurrence-free survival. A value of p < 0.05 was considered significant.

    Results: There was neither significant difference in the overall cellular and nuclear expressions of leptin and leptin receptor between non-cancerous kidney and ccRCC tissues nor in non-obese and obese individuals with ccRCC.

    Conclusion: In this present study, it was revealed that leptin and leptin receptor were not associated with tumour characteristics and progression of ccRCC patients. Interestingly, nuclear expression of leptin was significantly associated with overall survival. However, the significance of these proteins as biomarkers in other RCC histotypes is still unclear.

  6. Kong PL, Cheah PL, Mun KS, Chiew SF, Lau TP, Koh CC, et al.
    Malays J Pathol, 2020 Dec;42(3):369-376.
    PMID: 33361717
    Together with isocitrate dehydrogenase (IDH) mutation, co-deletion of 1p19q (1p19q codel) is a prerequisite for diagnosis of oligodendroglioma, making it imperative that histopathology laboratories introduce testing for 1p19q codel. To date there is still no consensus reference range and cut-offs that confirm deletion of 1p or 19q. We embarked on determining our reference range in 11 formalinfixed, paraffin-embedded non-neoplastic brain tissue using fluorescence in situ hybridisation (FISH) with the Vysis 1p36/1q25 and 19q13/19p13 FISH Probe Kit (Abbott Molecular Inc., USA). At same time we attempted to validate our methodology in 13 histologically-confirmed IDH-mutant oligodendrogliomas. For 1p, percentage cells with deletion (range=8-23%; mean±SD = 15.73±5.50%) and target: control (1p36:1q25) ratio (range = 0.89-0.96; mean±SD = 0.92±0.03) in non-neoplastic brain, differed significantly (p<0.000) from oligodendroglioma (percentage cells with deletion: range = 49-100%; mean±SD = 82.46±15.21%; target:control ratio range:0.50-0.76; mean±SD = 0.59±0.08). For 19q, percentage cells with deletion (range = 7-20%; mean±SD = 12.00±3.49%) and target:control (19q13/19p13) ratio (range:0.90-0.97; mean±SD = 0.94±0.02) in non-neoplastic brain also differed significantly from oligodendroglioma (percentage cells with deletion: range = 45-100%; mean±SD = 82.62±18.13%; target:control ratio range:0.50-0.78; mean±SD = 0.59±0.09). Using recommended calculation method, for diagnosis of 1p deletion, percentage of cells showing deletion should be >32-33% and/or target:control ratio <0.83. For 19q, percentage of cells showing deletion should be >22% and target:control ratio <0.88. Using these cut-offs all 13 oligodendroglioma demonstrated 1p19q codel.
  7. Rajandram R, Yap NY, Ong TA, Mun KS, Mohamad Wali HA, Hasan MS, et al.
    Malays J Pathol, 2017 Apr;39(1):47-53.
    PMID: 28413205 MyJurnal
    INTRODUCTION: In recent years, prolonged ketamine abuse has been reported to cause urinary tract damage. However, there is little information on the pathological effects of ketamine from oral administration. We aimed to study the effects of oral ketamine on the urinary tract and the reversibility of these changes after cessation of ketamine intake.

    METHODS: Rats were fed with illicit (a concoction of street ketamine) ketamine in doses of 100 (N=12), or 300 mg/kg (N=12) for four weeks. Half of the rats were sacrificed after the 4-week feeding for necropsy. The remaining rats were taken off ketamine for 8 weeks to allow for any potential recovery of pathological changes before being sacrificed for necropsy. Histopathological examination was performed on the kidney and urinary bladder.

    RESULTS: Submucosal bladder inflammation was seen in 67% of the rats fed with 300 mg/kg illicit ketamine. No bladder inflammation was observed in the control and 100 mg/kg illicit ketamine groups. Renal changes, such as interstitial nephritis and papillary necrosis, were observed in rats given illicit ketamine. After ketamine cessation, no inflammation was observed in the bladder of all rats. However, renal inflammation remained in 60% of the rats given illicit ketamine. No dose-effect relationship was established between oral ketamine and changes in the kidneys.

    CONCLUSION: Oral ketamine caused pathological changes in the urinary tract, similar to that described in exposure to parenteral ketamine. The changes in the urinary bladder were reversible after short-term exposure.

  8. Kanmalar M, Abdul Sani SF, Kamri NINB, Said NABM, Jamil AHBA, Kuppusamy S, et al.
    Cell Mol Biol Lett, 2022 Jan 29;27(1):9.
    PMID: 35093030 DOI: 10.1186/s11658-022-00307-x
    Bladder cancer is the fourth most common malignancy in males. It can present across the whole continuum of severity, from mild through well-differentiated disease to extremely malignant tumours with poor survival rates. As with other vital organ malignancies, proper clinical management involves accurate diagnosis and staging. Chemotherapy consisting of a cisplatin-based regimen is the mainstay in the management of muscle-invasive bladder cancers. Control via cisplatin-based chemotherapy is threatened by the development of chemoresistance. Intracellular cholesterol biosynthesis in bladder cancer cells is considered a contributory factor in determining the chemotherapy response. Farnesyl-diphosphate farnesyltransferase 1 (FDFT1), one of the main regulatory components in cholesterol biosynthesis, may play a role in determining sensitivity towards chemotherapy compounds in bladder cancer. FDFT1-associated molecular identification might serve as an alternative or appendage strategy for early prediction of potentially chemoresistant muscle-invasive bladder cancer tissues. This can be accomplished using Raman spectroscopy. Developments in the instrumentation have led to it becoming one of the most convenient forms of analysis, and there is a highly realistic chance that it will become an effective tool in the pathology lab. Chemosensitive bladder cancer tissues tend to have a higher lipid content, more protein genes and more cholesterol metabolites. These are believed to be associated with resistance towards bladder cancer chemotherapy. Herein, Raman peak assignments have been tabulated as an aid to indicating metabolic changes in bladder cancer tissues that are potentially correlated with FDFT1 expression.
  9. Zainal NS, Lee BKB, Wong ZW, Chin IS, Yee PS, Gan CP, et al.
    Cancer Biol Med, 2019 May;16(2):264-275.
    PMID: 31516747 DOI: 10.20892/j.issn.2095-3941.2018.0257
    Objective: Lack of effective therapies remains a problem in the treatment of oral squamous cell carcinoma (OSCC), especially in patients with advanced tumors. OSCC development is driven by multiple aberrancies within the cell cycle pathway, including amplification of cyclin D1 and loss of p16. Hence, cell cycle inhibitors of the CDK4/6-cyclin D axis are appealing targets for OSCC treatment. Here, we determined the potency of palbociclib and identified genetic features that are associated with the response of palbociclib in OSCC.

    Methods: The effect of palbociclib was evaluated in a panel of well-characterized OSCC cell lines by cell proliferation assays and further confirmed by in vivo evaluation in xenograft models. PIK3CA-mutant isogenic cell lines were used to investigate the effect of PIK3CA mutation towards palbociclib response.

    Results: We demonstrated that 80% of OSCC cell lines are sensitive to palbociclib at sub-micromolar concentrations. Consistently, palbociclib was effective in controlling tumor growth in mice. We identified that palbociclib-resistant cells harbored mutations in PIK3CA. Using isogenic cell lines, we showed that PIK3CA mutant cells are less responsive to palbociclib as compared to wild-type cells with concurrent upregulation of CDK2 and cyclin E1 protein levels. We further demonstrated that the combination of a PI3K/mTOR inhibitor (PF-04691502) and palbociclib completely controlled tumor growth in mice.

    Conclusions: This study demonstrated the potency of palbociclib in OSCC models and provides a rationale for the inclusion of PIK3CA testing in the clinical evaluation of CDK4/6 inhibitors and suggests combination approaches for further clinical studies.

  10. Yee PS, Zainal NS, Gan CP, Lee BKB, Mun KS, Abraham MT, et al.
    Target Oncol, 2019 04;14(2):223-235.
    PMID: 30806895 DOI: 10.1007/s11523-019-00626-8
    BACKGROUND: Given that aberrant activation of epidermal growth factor receptor family receptors (ErbB) is a common event in oral squamous cell carcinoma, and that high expression of these receptor proteins is often associated with poor prognosis, this rationalizes the approach of targeting ErbB signaling pathways to improve the survival of patients with oral squamous cell carcinoma. However, monotherapy with the ErbB blocker afatinib has shown limited survival benefits.

    OBJECTIVES: This study was performed to identify mechanisms of afatinib resistance and to explore potential afatinib-based combination treatments with other targeted inhibitors in oral squamous cell carcinoma.

    METHODS: We determined the anti-proliferative effects of afatinib on a panel of oral squamous cell carcinoma cell lines using a crystal violet-growth inhibition assay, click-iT 5-ethynyl-2'-deoxyuridine staining, and cell-cycle analysis. Biochemical assays were performed to study the underlying mechanism of drug treatment as a single agent or in combination with the MEK inhibitor trametinib. We further evaluated and compared the anti-tumor effects of single agent and combined treatment by using oral squamous cell carcinoma xenograft models.

    RESULTS: In this study, we showed that afatinib inhibited oral squamous cell carcinoma cell proliferation via cell-cycle arrest at the G0/G1 phase, and inhibited tumor growth in xenograft mouse models. Interestingly, we demonstrated reactivation of the mitogen-activated protein kinase (ERK1/2) pathway in vitro, which possibly reduced the effects of ErbB inhibition. Concomitant treatment of oral squamous cell carcinoma cells with afatinib and trametinib synergized the anti-tumor effects in oral squamous cell carcinoma-bearing mouse models.

    CONCLUSIONS: Our findings provide insight into the molecular mechanism of resistance to afatinib and support further clinical evaluation into the combination of afatinib and MEK inhibition in the treatment of oral squamous cell carcinoma.

  11. Dean SJ, Perks CM, Holly JM, Bhoo-Pathy N, Looi LM, Mohammed NA, et al.
    Am J Clin Pathol, 2014 Mar;141(3):323-33.
    PMID: 24515759 DOI: 10.1309/AJCPR11DEAYPTUSL
    OBJECTIVES: To investigate the association between PTEN loss and IGFBP2 expression in a series of triple-negative breast cancers and to relate this expression to basal cytokeratin expression and clinicopathologic features.

    METHODS: One hundred and one formalin-fixed and paraffin-processed triple-negative breast cancer cases from the University of Malaya Medical Centre were tested immunohistochemically for cytokeratins 5/6 and 14, PTEN, and IGFBP2. The resulting slides were scored for proportion and intensity of staining.

    RESULTS: Loss of tumor nuclear and cytoplasmic staining for PTEN occurred in 48.3% of cases and was significantly associated with younger age at diagnosis (47 years compared with 57 years in those without PTEN loss; P = .005). Independent predictors of PTEN loss were late stage at presentation (P = .026), cytokeratin 5/6 positivity (P = .028), and IGFBP2 expression (P = .042). High levels of IGFBP2 expression were seen in 32% of cases; an independent predictor of high levels was cytokeratin 14 negativity (P = .005). PTEN loss and high levels of IGFBP2 expression were associated with poorer survival, but neither of these trends was significant.

    CONCLUSIONS: PTEN loss is a frequent event in triple-negative breast cancers and is significantly associated with younger age at onset of breast cancer, late stage, and IGFBP2 expression.

  12. Foo JC, Jawin V, Yap TY, Ahmad Bahuri NF, Ganesan D, Mun KS, et al.
    Childs Nerv Syst, 2021 05;37(5):1573-1580.
    PMID: 33580355 DOI: 10.1007/s00381-021-05080-4
    PURPOSE: Multidisciplinary team meetings (MDTMs) are essential in the clinical management of pediatric central nervous system (CNS) tumors. Evaluations of the impact of MDTMs on childhood CNS tumors and clinicians' perspectives on their effectiveness are scarce.

    METHODS: We retrospectively reviewed the clinical data of pediatric patients (aged <18 years) with CNS tumors diagnosed and treated in the Pediatric Hematology-Oncology Division at the University Malaya Medical Center from 2008 to 2019. We also conducted a web-based survey of the core members of the multidisciplinary team to evaluate the impact of the MDTMs.

    RESULTS: During the pre-MDTM era (2008-2012), 29 CNS tumors were diagnosed and treated, and during the MDTM era (2014-2019), 49 CNS tumors were diagnosed and treated. The interval for histologic diagnosis was significantly shorter during the MDTM era (p=0.04), but the interval from diagnosis to chemotherapy or radiotherapy and the 5-year overall survival of the 78 patients did not improve (62.1% ± 9.0% vs. 68.8% ± 9.1%; p=0.184). However, the 5-year overall survival of patients with medulloblastoma or rare tumors significantly improved in the MDTM era (p=0.01). Key factors that contributed to delayed treatment and poor outcomes were postoperative complications, the facility's lack of infrastructure, poor parental education about early treatment, cultural beliefs in alternative medicine, and infection during chemotherapy. Eighteen clinicians responded to the survey; they felt that the MDTMs were beneficial in decision-making and enhanced the continuity of coordinated care.

    CONCLUSION: MDTMs significantly reduced the diagnostic interval and improved the overall outcomes. However, delayed treatment remains a major challenge that requires further attention.

  13. Rajagopal R, Leong SH, Jawin V, Foo JC, Ahmad Bahuri NF, Mun KS, et al.
    J Pediatr Hematol Oncol, 2021 Oct 01;43(7):e913-e923.
    PMID: 33633029 DOI: 10.1097/MPH.0000000000002116
    BACKGROUND: A higher incidence of pediatric intracranial germ cell tumors (iGCTs) in Asian countries compared with Western countries has been reported. In Malaysia, the literature regarding pediatric iGCTs have been nonexistent. The aim of this study was to review the management, survival, and long-term outcomes of pediatric iGCTs at a single tertiary center in Malaysia.

    PATIENTS AND METHODS: We retrospectively reviewed data from patients below 18 years of age with iGCTs treated at the University Malaya Medical Center (UMMC) from 1998 to 2017.

    RESULTS: Thirty-four patients were identified, with a median follow-up of 3.54 years. Sixteen (47%) patients had pure germinoma tumors (PGs), and the remaining patients had nongerminomatous germ cell tumors (NGGCTs). The median age was 12 years, with a male:female ratio of 4.7:1. Abnormal vision, headache with vomiting, and diabetes insipidus were the commonest presenting symptoms. Twenty-eight patients received initial surgical interventions, 24 were treated with chemotherapy, and 28 received radiotherapy. Eight patients experienced relapses. The 5- and 10-year event-free survival rates were similar at 61.1%±12.6% and 42.9%±12.1% for PG and NGGCT, respectively. The 5- and 10-year overall survival rates were the same at 75.5%±10.8% and 53.3%±12.3% for PG and NGGCT, respectively. Four patients died of treatment-related toxicity. Most of the survivors experienced good quality of life with satisfactory neurologic status.

    CONCLUSIONS: The survival rate of childhood iGCTs in UMMC was inferior to that reported in developed countries. Late diagnosis, poor adherence to treatment, and treatment-related complications were the contributing factors. Although these results highlight a single institution experience, they most likely reflect similar treatment patterns, outcomes, and challenges in other centers in Malaysia.

  14. Wang C, Zainal NS, Chai SJ, Dickie J, Gan CP, Zulaziz N, et al.
    Front Immunol, 2021;12:763086.
    PMID: 34733290 DOI: 10.3389/fimmu.2021.763086
    HPV-independent head and neck squamous cell carcinoma (HNSCC) is a common cancer globally. The overall response rate to anti-PD1 checkpoint inhibitors (CPIs) in HNSCC is ~16%. One major factor influencing the effectiveness of CPI is the level of tumor infiltrating T cells (TILs). Converting TILlow tumors to TILhigh tumors is thus critical to improve clinical outcome. Here we describe a novel DNA vaccines to facilitate the T-cell infiltration and control tumor growth. We evaluated the expression of target antigens and their respective immunogenicity in HNSCC patients. The efficacy of DNA vaccines targeting two novel antigens were evaluated with or without CPI using a syngeneic model. Most HNSCC patients (43/44) co-expressed MAGED4B and FJX1 and their respective tetramer-specific T cells were in the range of 0.06-0.12%. In a preclinical model, antigen-specific T cells were induced by DNA vaccines and increased T cell infiltration into the tumor, but not MDSC or regulatory T cells. The vaccines inhibited tumor growth and improved the outcome alone and upon combination with anti-PD1 and resulted in tumor clearance in approximately 75% of mice. Pre-existence of MAGED4B and FJX1-reactive T cells in HNSCC patients suggests that these widely expressed antigens are highly immunogenic and could be further expanded by vaccination. The DNA vaccines targeting these antigens induced robust T cell responses and with the anti-PD1 antibody conferring excellent tumor control. This opens up an opportunity for combination immunotherapy that might benefit a wider population of HNSCC patients in an antigen-specific manner.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links