Publications by authors named "Chin-Ann Johnny Ong"

Article Synopsis
  • Ascites is a common issue in patients with advanced gastrointestinal cancers that have spread to the peritoneum, impacting survival negatively; this study is the first to look specifically at ascites, peritoneal metastases (PM), and survival in metastatic colorectal cancer (mCRC) and metastatic gastric cancer (mGC).
  • A retrospective analysis of clinical trial data showed that mCRC patients with ascites had significantly shorter progression-free and overall survival compared to those without PM, while gastric cancer patients with ascites also had poorer survival outcomes and higher disease severity scores.
  • The findings suggest that ascites can indicate worse prognoses for certain cancer patients, highlighting the need for more focused research and tailored treatments for these individuals.
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Article Synopsis
  • The study investigates the genetic and environmental factors that lead to peritoneal metastasis (PM) in gastric cancer (GC), which typically has a poor prognosis.
  • Researchers conducted a detailed analysis of samples from 326 patients, looking at various genetic and expression changes in tumors and their surroundings.
  • Findings revealed specific genetic mutations and tumor microenvironment characteristics that enhance the risk of PM, along with potential therapeutic targets to improve treatment strategies for patients with GC.
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Peritoneal metastasis (PM), the regional progression of intra-abdominal malignancies, is a common sequelae of colorectal cancer (CRC). Immunotherapy is slated to be effective in generating long-lasting anti-tumour response as it utilizes the specificity and memory of the immune system. In the tumour microenvironment, tumour associated macrophages (TAMs) are posited to create an anti-inflammatory pro-tumorigenic environment.

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Background: Peritoneal sarcomatosis (PS) is a difficult entity to treat with limited options and guarded prognosis. We aimed to determine if the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) could offer superior local recurrence-free survival in patients with retroperitoneal sarcoma at high risk of developing PS as opposed to extended resection alone.

Methods: This is a single arm, phase II intervention study where all patients with recurrent localized retroperitoneal sarcoma considered at high risk of developing PS were considered for enrolment (ClinicalTrials.

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Objective: To examine the association between the performance of mapping biopsies and surgical outcomes postexcision of extramammary Paget's disease (EMPD).

Background: Primary EMPD is a rare entity associated with poorly defined surgical margins and difficult-to-access sites of lesions. Surgical resection with clear margins remains the preferred management method.

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The use of open cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has shown improved oncological survival in terms of treating peritoneal surface malignancies (PSM). However, this procedure often comes with associated morbidity. The move towards use of laparoscopic surgery in this field is postulated to lead to a reduction in morbidity and earlier return to function, but literature on its use for CRS and HIPEC has been scarce.

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Background: Peritoneal surface malignancies (PSM) present insidiously and often pose diagnostic challenges. There is a paucity of literature quantifying the frequency and extent of therapeutic delays in PSM and its impact on oncological outcomes.

Methods: A review of a prospectively maintained registry of PSM patients undergoing Cytoreductive Surgery and Hyperthermic Intra-peritoneal Chemotherapy (CRS-HIPEC) was conducted.

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Background: The COVID-19 pandemic has led to a decrease in cancer screening due to the redeployment of health care resources and public avoidance of health care facilities. Breast cancer is the most common cancer diagnosed in female individuals, with improved survival rates from early detection. An avoidance of screening, resulting in late detection, greatly affects survival and increases health care resource burden and costs.

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Background: Extranodal natural killer/T-cell lymphoma (NKTL) is an aggressive type of non-Hodgkin lymphoma with dismal outcome. A better understanding of disease biology and key oncogenic process is necessary for the development of targeted therapy. Super-enhancers (SEs) have been shown to drive pivotal oncogenes in various malignancies.

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Background: Immunonutrition has been shown to reduce hospital stay and postoperative morbidity in patients undergoing gastrointestinal, and head and neck surgery. However, its use has not been demonstrated in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). This study aims to determine the effectiveness of perioperative immunonutrition on patients undergoing CRS-HIPEC in reducing length of hospitalization and postoperative complications.

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Objective: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) represent a mainstay of treatment for peritoneal malignancies. There is evidence that HIPEC using high intra-abdominal pressure (IAP) results in increased tissue penetration, although its safety profile remains relatively unknown. We thus aim to evaluate differences in intra- and post-operative outcomes in patients undergoing CRS-HIPEC with different levels of IAP.

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Retroperitoneal liposarcomas (RPLPSs) are a rare tumor group for which current guidelines recommend aggressive resection to attain microscopically negative (R0) margins. To ensure R0 margins, resection of adherent or adjacent organs is often required. However, it is still unclear if R0 margins confer any additional benefit to patients over a grossly negative but microscopically positive (R1) margin.

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Clinically relevant animal models are crucial for effective development of therapeutics for peritoneal carcinomatosis (PC). This protocol describes the generation of patient-derived ascites-dependent xenograft (PDADX) models from the cellular component of ascites. The use of routine intraperitoneal injection of the fluid component of ascites is analogous to the biological events occurring intra-abdominally in patients with PC.

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Objectives: Various studies have shown that good quality of life (QoL) can be achieved after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). There is prognostic value of baseline QoL in post-operative outcome in Western setting. Our prospective study aims to validate these observations and elucidate clinical factors that predict poorer QoL in Asian peritoneal carcinomatosis patients.

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Background: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) has recently emerged as a palliative alternative for patients with unresectable peritoneal metastasis (PM). Quality of life (QoL) has increasingly been used as an endpoint to evaluate treatment outcomes. This review aims to identify evidence on how PIPAC would impact the QoL of PM patients.

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Objectives: Peritoneal cancer index (PCI) score is a common prognostication tool in peritoneal metastases (PM). We hypothesize that the distribution of PCI score and involvement of specific regions affects survival and morbidity outcomes.

Methods: Data was collected from a prospective database of patients who underwent CRS and HIPEC for PM at the National Cancer Centre Singapore.

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Background: The performance of MRI versus CT in the detection and evaluation of peritoneal surface malignancies (PSM) remains unclear in the current literature. Our study is the first prospective study in an Asian center comparing the two imaging modalities, validated against intra-operative findings. Methods: A total of 36 patients with PSM eligible for CRS-HIPEC underwent both MRI and CT scans up to 6 weeks before the operation.

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Article Synopsis
  • - The study analyzed over 373,000 single-cell transcriptomes from colorectal cancer patients to better understand the diversity of epithelial cells, revealing distinct genetic and gene expression differences among malignant cells.
  • - Two new intrinsic subtypes, iCMS2 and iCMS3, were identified, with iCMS3 linked to worse outcomes and encompassing both microsatellite unstable (MSI-H) and some microsatellite-stable (MSS) cancers.
  • - The research proposes a refined 'IMF' classification that incorporates intrinsic epithelial subtype, microsatellite instability status, and fibrosis, leading to five distinct subtypes of colorectal cancer.
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The peritoneum is a common site of metastasis in advanced gastric cancer (GC). Diagnostic laparoscopy is now routinely performed as part of disease staging, leading to an earlier diagnosis of synchronous peritoneal metastasis (PM). The biology of GCPM is unique and aggressive, leading to a dismal prognosis.

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Inflammatory myofibroblastic tumours (IMT) are spindle cell neoplasms most commonly seen in the lungs, with a wide variety of less common extrapulmonary sites including the mesentery, omentum, and intrabdominal sites. On cytological evaluation, these tumours can be difficult to diagnose, given the morphological mimics of other submucosal spindle cell neoplasms, which may be compounded by the relatively small amount of tissue and the uncommon nature of the diagnosis. Immunohistochemical staining and molecular studies for the ALK gene can prove useful for diagnosing this tumour.

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Background: Palliative gastrointestinal (GI) surgery potentially relieves distressing symptoms arising from intestinal obstruction (IO) in patients with advanced peritoneal carcinomatosis (PC). As surgery is associated with significant morbidity risks in advanced cancer patients, it is important for surgeons to select patients who can benefit the most from this approach. Hence, we aim to determine predictors of morbidity and mortality after palliative surgery in patients with PC.

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Background: Peritoneal metastasis (PM) is a late-stage manifestation of intra-abdominal malignancies. The current standard of care indicates that cure can only be achieved with cytoreductive surgery (CRS) which is often indicated with concurrent adjuvant hyperthermic intraperitoneal chemotherapy (HIPEC). However, the utility of HIPEC within subsets of PM is not fully understood.

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