Publications by authors named "King Tan"

Pregnancy in women with early-onset Parkinson's disease (PD) is likely to have a higher frequency given the trend toward increasing maternal age, thus resulting in a greater overlap time between childbearing age and PD risk. Deep brain stimulation (DBS) therapy is nowadays offered to PD patients at earlier stage of the disease, when women can still be pre-menopausal. However, few data are available about DBS safety during pregnancy.

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Objective: To investigate the utility of quantitative susceptibility mapping (QSM) and diffusion kurtosis imaging (DKI) as complementary tools in characterizing pathological changes in the deep grey nuclei in early Parkinson's disease (PD) and their clinical correlates to aid in diagnosis of PD.

Method: Patients with a diagnosis of PD made within a year and age-matched healthy controls were recruited. All participants underwent clinical evaluation using the Unified Parkinson's Disease Rating Scale (MDS-UPDRS III) and Hoehn & Yahr stage (H&Y), and brain 3 T MRI including QSM and DKI.

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The importance of molecular testing of gliomas is highlighted in the 2016 revised 4th edition of the WHO Classification of Tumours of the Central Nervous System, which applies an integrated diagnosis of histological and molecular features. In this classification system, oligodendrogliomas (ODG) are defined as IDH-mutant and 1p/19q-codeleted. Fluorescence in situ hybridization (FISH) analysis of formalin-fixed paraffin-embedded (FFPE) tissue is a standard method of determining 1p/19q-codeletion.

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This study compared breast cancer survival and the prognostic factors across different age groups of women in Penang, Malaysia. Data on 2,166 women with breast cancer who had been diagnosed between 2010 and 2014 were extracted from the Penang Breast Cancer Registry and stratified into 3 age groups: young (< 40 years old), middle-aged (40-59 years old), and elderly (≥ 60 years). The overall and relative survival rates were calculated using the life table method, median survival time was calculated using the Kaplan-Meier method, and comparisons between groups were conducted using the log-rank test.

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Aldehyde dehydrogenases (ALDHs) are overexpressed in various types of cancers. One of the ALDH family genes, ALDH1A2, is aberrantly expressed in more than 50% of T-cell acute lymphoblastic leukemia (T-ALL) cases. However, its molecular function and role in T-ALL pathogenesis are largely unknown.

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The objective of this study was to evaluate the distribution and prognostic impact of a broad range of molecular attributes in a large cohort of immunocompetent patients with primary central nervous system lymphoma (PCNSL) by using tissue microarray. Patients diagnosed with PCNSL were initially identified in the BC Cancer Lymphoid Cancer clinical and pathology databases. Tissue microarrays were constructed by using archival formalin-fixed paraffin-embedded diagnostic biopsy tissue.

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Objective: Treatment options are limited for patients with recurrent/metastatic low-grade ovarian cancers (LGOCs) and serous borderline ovarian tumors (SBOTs) as response rates to chemotherapy are low. A subset of patients appears to derive clinical benefit from antiestrogens, but most studies have been retrospective and clinical benefit rates (CBR) remain uncertain. The primary aim of PARAGON was to prospectively investigate the CBR of anastrozole, an aromatase inhibitor, in patients with estrogen receptor (ER) and/or progesterone receptor (PR) positive LGOC and SBOT.

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Marchiafava-Bignami disease (MBD) is a rare condition often associated with chronic alcohol abuse. Clinical presentation is diverse. Characteristic magnetic resonance imaging (MRI) changes in the corpus callosum are the mainstay of radiological diagnosis.

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Background: Follicular lymphoma (FL) is an indolent, yet incurable B cell malignancy. A subset of patients experience an increased mortality rate driven by two distinct clinical end points: histological transformation and early progression after immunochemotherapy. The nature of tumor clonal dynamics leading to these clinical end points is poorly understood, and previously determined genetic alterations do not explain the majority of transformed cases or accurately predict early progressive disease.

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The addition of rituximab has improved outcomes in diffuse large B-cell lymphoma (DLBCL), however, there remains limited information on the impact of rituximab in those with testicular involvement. All patients with diffuse large cell lymphoma and testicular involvement treated with curative intent were identified in the British Columbia Cancer Agency Lymphoid Cancer Database. In total, 134 patients diagnosed between 1982 and 2015 with diffuse large cell lymphoma involving the testis were identified: 61 received CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone)-like chemotherapy and 73 received CHOP plus rituximab (R-CHOP).

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Dual expression of MYC and BCL2 by immunohistochemistry (IHC) is associated with poor outcome in diffuse large B-cell lymphoma (DLBCL). Dual translocation of MYC and BCL2, so-called "double-hit lymphoma," has been associated with a high risk of central nervous system (CNS) relapse; however, the impact of dual expression of MYC and BCL2 (dual expressers) on the risk of CNS relapse remains unknown. Pretreatment formalin-fixed paraffin-embedded DLBCL biopsies derived from patients subsequently treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) were assembled on tissue microarrays from 2 studies and were evaluated for expression of MYC and BCL2 by IHC.

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Follicular lymphoma (FL) is an indolent disease but transforms in 2% to 3% of patients per year into aggressive, large cell lymphoma, a critical event in the course of the disease associated with increased lymphoma-related mortality. Early transformation cannot be accurately predicted at the time of FL diagnosis and the biology of transformed FL (TFL) is poorly understood. Here, we assembled a cohort of 126 diagnostic FL specimens including 40 patients experiencing transformation (<5 years) and 86 patients not experiencing transformation for at least 5 years.

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Purpose: We aimed to assess the prognostic significance of follicular lymphoma-associated macrophages in the era of rituximab treatment and maintenance.

Experimental Design: We applied immunohistochemistry for CD68 and CD163 to two large tissue microarrays (TMA). The first TMA included samples from 186 patients from the BC Cancer Agency (BCCA) who had been treated with first-line systemic treatment including rituximab, cyclophosphamide, vincristine, and prednisone.

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Primary testicular diffuse large B cell lymphoma (PTL) is an aggressive malignancy that occurs in the immune-privileged anatomical site of the testis. We have previously shown that structural genomic rearrangements involving the MHC class II transactivator CIITA and programmed death ligands (PDLs) 1 and 2 are frequent across multiple B cell lymphoma entities. Specifically in PTL, we found rearrangements in the PDL locus by fluorescence in situ hybridization (FISH).

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Classical Hodgkin lymphoma and primary mediastinal B cell lymphoma (PMBCL) are related lymphomas sharing pathological, molecular and clinical characteristics. Here we discovered by whole-genome and whole-transcriptome sequencing recurrent somatic coding-sequence mutations in the PTPN1 gene. Mutations were found in 6 of 30 (20%) Hodgkin lymphoma cases, in 6 of 9 (67%) Hodgkin lymphoma-derived cell lines, in 17 of 77 (22%) PMBCL cases and in 1 of 3 (33%) PMBCL-derived cell lines, consisting of nonsense, missense and frameshift mutations.

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Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease and "double-hit" DLBCL, with both MYC and BCL2 translocations has a poor prognosis. In this study, we investigated whether MYC and BCL2 protein expression in tissue would predict survival in DLBCL. The study included 106 cases of de novo DLBCL treated with rituximab and cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) or CHOP-like regimens.

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The pathogenesis of primary mediastinal large B-cell lymphoma (PMBCL) is incompletely understood. Recently, specific genotypic and phenotypic features have been linked to tumor cell immune escape mechanisms in PMBCL. We studied 571 B-cell lymphomas with a focus on PMBCL.

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Gain of function mutations in the H3K27 methyltransferase EZH2 represent a promising therapeutic target in germinal center lymphomas. In this study, we assessed the frequency and distribution of EZH2 mutations in a large cohort of patients with follicular lymphoma (FL) (n = 366) and performed a longitudinal analysis of mutation during the disease progression from FL to transformed FL (tFL) (n = 33). Mutations were detected at 3 recurrent mutation hot spots (Y646, A682, and A692) in 27% of FL cases with variant allele frequencies (VAF) ranging from 2% to 61%.

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Purpose: To review the treatment and outcomes of patients with primary cutaneous B-cell lymphoma (CBCL).

Methods And Materials: Clinical characteristics, treatment, and outcomes were analyzed for all patients referred to our institution from 1981 through 2011 with primary CBCL without extracutaneous or distant nodal spread at diagnosis (n=136). Hematopathologists classified 99% of cases using the World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) guidelines.

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Epstein-Barr virus (EBV) is associated with Hodgkin lymphoma (HL) and can be detected by in situ hybridization (ISH) of viral nucleic acid (EBER) in tumor cells. We sought to determine whether plasma EBV-DNA could serve as a surrogate for EBER-ISH and to explore its prognostic utility in HL. Specimens from the Cancer Cooperative Intergroup Trial E2496 were used to compare pretreatment plasma EBV-DNA quantification with EBV tumor status by EBER-ISH.

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Purpose: Our aim was to reliably identify patients with advanced-stage classical Hodgkin lymphoma (cHL) at increased risk of death by developing a robust predictor of overall survival (OS) using gene expression measured in routinely available formalin-fixed paraffin-embedded tissue (FFPET).

Methods: Expression levels of 259 genes, including those previously reported to be associated with outcome in cHL, were determined by digital expression profiling of pretreatment FFPET biopsies from 290 patients enrolled onto the E2496 Intergroup trial comparing doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and Stanford V regimens in locally extensive and advanced-stage cHL. A model for OS separating patients into low- and high-risk groups was produced using penalized Cox regression.

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In classical Hodgkin lymphoma (CHL), 20%-30% of patients experience relapse or progressive disease after initial treatment. The pathogenesis and biology of treatment failure are still poorly understood, in part because the molecular phenotype of the rare malignant Hodgkin Reed-Sternberg (HRS) cells is difficult to study. Here we examined microdissected HRS cells from 29 CHL patients and 5 CHL-derived cell lines by gene expression profiling.

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Increased tumor-associated macrophages (TAMs) are reported to be associated with poor prognosis in classic Hodgkin lymphoma (CHL). We investigated the prognostic significance of TAMs in the E2496 Intergroup trial, a multicenter phase 3 randomized controlled trial comparing ABVD and Stanford V chemotherapy in locally extensive and advanced stage CHL. Tissue microarrays were constructed from formalin-fixed, paraffin-embedded tumor tissue and included 287 patients.

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