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Edmond S K Ma

Publications and source records attributed to Edmond S K Ma.

13 recordsLinked to original sources
PubMed2026

Genomic Landscape of 6597 Hong Kong HBOC Patients: Implications for Beyond-BRCA Multi-Gene Panel Testing and Cancer Surveillance.

Breast cancer remains highly prevalent, where the lifetime risk before age 75 is one in 13. However, known genetic factors were only identified in 14.7% of cases in our Hong Kong Hereditary Breast Cancer Family Registry. Our current local policy for genetic testing does not cover the detection of beyond BRCA1/2. Here we highlight the clinical value of extending testing to beyond BRCA susceptibility genes for improved prevention, diagnosis, and management. We recruited 6597 hereditary breast and ovarian cancer (HBOC) patients from our registry based on family history and clinical criteria. Germline mutations were identified by multi-gene sequencing analysis using next-generation sequencing (NGS). Clinical-pathological characteristics of BRCA and beyond BRCA carriers were compared and the real-world management and surveillance services adopted in Hong Kong were highlighted. In this multi-gene hereditary cancer cohort, germline mutations were identified in 10.9% of cases for BRCA1/2 and 3.5% for beyond BRCA susceptibility genes. These beyond BRCA mutations constitute a considerable proportion of actionable hereditary risk. Notably, PALB2 emerged as the most prevalent non-BRCA gene, followed by TP53, ATM, and BARD1. New cancers or recurrences were detected during their surveillance; the overall pick up rates were 8.3% (PALB2), 29.4% (TP53), 33.3% (PTEN) and 5.6% (BARD1). This study provides the first comprehensive characterization of the beyond BRCA germline landscape in a Hong Kong hereditary cancer cohort and highlights the current need for implementing multi-gene sequencing analysis and surveillance services for HBOC patients, establishing the predominant non-BRCA drivers and providing a robust empirical basis for expanding public genetic screening frameworks.

Humans↗
PubMed2003

Chromosomal aberrations of primary lung adenocarcinomas in nonsmokers.

BACKGROUND: Lung carcinoma is a common malignancy, and tobacco carcinogenesis is the major cause. Studies on individual genes or loci have suggested, that in tumors from nonsmokers, different genetic alterations are present compared with tumors from smokers. It is possible that distinct genetic pathways may be involved. However, the targets remain largely unknown; and, to the authors' knowledge, molecular cytogenetics studies on lung carcinomas from nonsmokers have not been reported. METHODS: Comparative genomic hybridization (CGH) analysis was performed on primary lung adenocarcinoma samples from 32 patients who never smoked to identify loci of frequent aberrations. RESULTS: Different extents of aberration were found in 31 of the 32 samples studied. The most frequently altered locus was gain of 16p (59% of samples) followed by gain of 20q (44% of samples), with the minimal overlapping regions at 16p13.1-p13.2 and 20q13.2, respectively. Other over-represented loci with > 30% frequency were observed at 5p (34% of samples), 7p (41% of samples), 8q (31% of samples), 17q (34% of samples), and 19q (34% of samples); and high-level DNA amplifications were detected at 1q, 7p, 12q, 19q, and 20q. DNA under-representation was observed less commonly and included 8p (28% of samples), 9p (22% of samples), 13q (28% of samples), and 18q (38% of samples). CONCLUSIONS: The current study identified targets of frequent genetic aberration in primary adenocarcinomas from nonsmokers. Compared with reported CGH findings in the literature, the current findings suggest that DNA gain at 16p is the distinct aberration involved in these tumors. Other frequently altered loci involve commonly reported oncogenic and tumor suppressor loci, suggesting an overlap with the genetic pathways of tobacco-induced lung carcinogenesis.

Adenocarcinoma↗
PubMed2003

Desmopressin does not decrease blood loss and transfusion requirements in patients undergoing hepatectomy.

PURPOSE: To determine the effects of desmopressin on coagulation and blood loss in patients undergoing elective partial hepatectomy. METHODS: A randomized, controlled and double-blind study on 59 patients who received either 0.3 micro g x kg(-1) of desmopressin or an equal volume of normal saline (control) infused intravenously over 20 min after induction of general anesthesia. RESULTS: There was an increase in plasma levels of factors VIII and von Willebrand after the infusion of study drug in both groups (P < 0.001). The activated partial thromboplastin time was shortened in Group D whereas prothrombin time was prolonged in Group C; (P = 0.02). A large range of intraoperative blood loss (400-7128 mL) was observed, with no significant differences between groups. There were no changes in plasma electrolyte levels or osmolality. Transfusion requirements were similar in both groups. CONCLUSION: Desmopressin did not reduce intraoperative blood loss or transfusion requirements during hepatectomy despite raising clotting factor levels and improving tests of hemostasis.

Blood Coagulation Tests↗
PubMed2003

Plasmablastic transformation of multiple myeloma.

We describe morphological, immunophenotypic, and cytogenetic characterization of a case of multiple myeloma (MM) that showed plasmablastic transformation at the terminal phase with a picture resembling acute leukemia. The plasmablasts expressed monotypic cytoplasmic immunoglobulin together with myeloid and megakaryocytic markers at disease transformation. Conventional cytogenetic study of bone marrow cells showed coexistence of hypodiploid and hyperdiploid cells, with the former being the predominant clone as evidenced by an interphase fluorescence in situ hybridization study. The clinical course in our case shows that plasmablastic transformation should be considered in the differential diagnoses of disease progression in MM. Whether de novo plasmablastic myeloma and plasmablastic transformation can be distinguished as a progression from underlying MM merits further investigation, especially in terms of biologic features and relevance to prognosis.

Aged↗
PubMed2003

The spectrum of acute lymphoblastic leukemia with mature B-cell phenotype.

We showed heterogeneous disease spectrum among 15 acute lymphoblastic leukemia (ALL) cases with mature B-cell phenotype diagnosed over the past 7 years at our institution. Besides those with typical L3 morphology and 8q24 (c-myc) translocation (n=6), there were cases showing L1 or L2 morphology without 8q24 translocation (n=6), unusually large L3 blasts in hyperdiploid clone (n=2) and blastoid variant of mantle cell lymphoma (n=1). The expression of CD5 and cyclin D1 may need to be routinely determined on ALL cases with mature B-cell phenotype and non-L3 morphology to facilitate timely diagnosis of blastoid MCL and institution of suitable management.

Adolescent↗
PubMed2002

Establishment, characterization, karyotyping, and comparative genomic hybridization analysis of HKESC-2 and HKESC-3: two newly established human esophageal squamous cell carcinoma cell lines.

The establishment of esophageal cancer cell lines can facilitate the search for molecular mechanisms underlying its pathogenesis. Two novel human esophageal squamous cell carcinoma (ESCC) cell lines, HKESC-2 and HKESC-3, were established from a moderately differentiated ESCC of a 46-year-old Chinese woman and a well-differentiated ESCC of a 74-year-old Chinese man, both from Hong Kong. The pathological characteristics (morphological, immunohistochemical, and electron microscopic studies), tumorigenicity in nude mice, cytogenetic features, and DNA ploidy of the two cell lines were investigated. The two cell lines have been maintained in vitro for more than 17 months and passaged over 85 times for HKESC-2 and 58 times for HKESC-3. Both grew as monolayers, with a doubling time of 24 hours for HKESC-2 and 48 h for HKESC-3. Their squamous epithelial nature was authenticated by their strong immunopositivity with the anti-cytokeratin antibodies and the ultrastructural demonstration of tonofilaments and desmosomes. They are tumorigenic in nude mice and had DNA aneuploidy. G-banding cytogenetic analysis showed hyperdiploidy in HKESC-2 and near-tetraploidy in HKESC-3. Frequent breakpoints were noted at 1p22, 1p32, and 9q34 in HKESC-2 and at 1p31, 3p25, 3p14, 6q16, 6q21, 8p21, 9q34, 13q32, and 17q25 in HKESC-3. Comparative genomic hybridization analysis found that chromosomal gains were at 3q24-qter, 5q21-qter, 8q11-qter, 13q21-q31, 17q11-qter, 19, 22q22 for HKESC-2 and at 3q13-qter, 5p, 6p, 9q21-qter, 10q21-q22, 12q15-pter, 14q24-qter, 16, 17q24-qter, 20 for HKESC-3. Chromosomal losses were at 3p13-pter, 18q12-qter for HKESC-3. These two newly established cell lines will be useful tools in the study of the molecular pathogenesis and biological behavior of ESCC cells and for testing new therapeutic reagents for ESCC in the future.

Aged↗