Wee Liam Ong

Dr. Wee Liam Ong


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 April 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
SLSorinel Lunca
Sorinel Lunca
SMStefan Morarasu
Stefan Morarasu
COConstantin Osman
Constantin Osman
FSFadi Al Shatarat
Fadi Al Shatarat
TGTudor Gramada
Tudor Gramada
GDGabriel Mihail Dimofte
Gabriel Mihail Dimofte
Background/Objectives: The improved long-term survival of rectal cancer patients has led to a major increase in the prevalence of functional complications. Understanding which patients are prone to develop major LARS is important for their preoperative counselling and follow-up. Herein, we aimed to assess the risk factors for LARS. Methods: This is a retrospective cohort study on rectal cancer patients. All patient and tumour variables, management plan, type of neoadjuvant therapy, radiation dose to anal sphincter, and perioperative outcomes were collected from the hospital electronic databases. We quantified LARS and compared the score before and after surgery (mean follow-up of 42.2 ± 32 months). Results: A total of 182 patients were included for the final analysis. LARS was present in 43.4% (n = 79) of patients, with 14.8% (n = 27) having minor LARS and 28.5% (n = 52) having major LARS. Age (p = 0.03), male gender (p < 0.00001), smoking (p = 0.04), neoadjuvant radiotherapy (p = 0.02), rectal stump length (p = 0.008), end-to-end anastomosis (p = 0.008), and ileostomy (p = 0.002) were found to significantly increase the rate of LARS. A logistic regression model based on the above variables was able to predict major LARS with good predictive value (AUC 0.700). Conclusions: LARS is highly common after sphincter-preserving surgery, and it is significantly more common in young, male patients with a history of smoking, having mid-lower rectal cancers with neoadjuvant radiotherapy, and undergoing TME surgery with end-to-end low anastomosis and ileostomy.

31 October 2025 in Medical Sciences
Verified
Journal Article
Open access
PDF file
SLSorinel Lunca
Sorinel Lunca
SMStefan Morarasu
Stefan Morarasu
RZRaluca Zaharia
Raluca Zaharia
AMAna-Maria Mușină
Ana-Maria Mușină
WOWee Liam Ong
Wee Liam Ong
CRCristian Ene Roata
Cristian Ene Roata
Background: Frailty is a multidimensional syndrome characterized by reduced physiological reserve and resilience and has become a crucial predictor of outcomes in liver surgery. Unlike chronological age, frailty reflects broader vulnerabilities that significantly influence postoperative recovery. Aim: To review and synthesize current evidence on the relationship between frailty and postoperative outcomes following liver resection, with an emphasis on short-term complications, mortality, and long-term survival. Methods: A comprehensive literature review was performed, drawing on recent meta-analyses, large-scale cohort studies, and prospective observational data. Frailty was evaluated using a range of assessment tools, including the Modified Frailty Index (mFI), Clinical Frailty Scale (CFS), Kihon Checklist (KCL), and claims-based measures such as the Johns Hopkins Frailty Indicator. Results: Across studies, frailty has been consistently linked to a higher incidence of postoperative complications, such as post-hepatectomy liver failure (PHLF), infections, extended hospital stays, and increased mortality. In patients undergoing liver resection for cancer, frailty is also associated with poorer long-term survival. Importantly, frailty serves as an independent risk factor, even after adjusting for age, comorbid conditions, and tumor characteristics. Preoperative identification of frailty enhances risk stratification, informs surgical planning, potentially favoring parenchymal-sparing or minimally invasive approaches, and highlights patients who may benefit from prehabilitation. Conclusions: Frailty is a strong and independent predictor of poor outcomes after liver resection. Incorporating frailty assessment into routine preoperative evaluation can improve surgical decision-making, facilitate informed patient counseling, and optimize perioperative care strategies.

26 May 2025 in Diagnostics
Verified
Journal Article
Open access
PDF file
SLSorinel Lunca
Sorinel Lunca
SMStefan Morarasu
Stefan Morarasu
RZRaluca Zaharia
Raluca Zaharia
AIAndreea-Antonina Ivanov
Andreea-Antonina Ivanov
CCCillian Clancy
Cillian Clancy
GDGabriel Mihail Dimofte
Gabriel Mihail Dimofte
Background/Objectives: Colorectal liver metastases (CRLMs) occur in 25–30% of colorectal cancer (CRC) patients, significantly impacting survival. While major liver resection (MLR) was traditionally preferred for oncologic clearance, parenchymal-sparing surgery (PSS) has emerged as a less invasive alternative. This study compares perioperative and long-term outcomes of PSS versus MLR in CRLM patients. Methods: We conducted a retrospective cohort study at the Regional Oncology Institute, Iasi, Romania, analyzing patients who underwent hepatic resection for CRLM between August 2013 and June 2024. Patients were categorized into PSS (n = 58) and MLR (n = 28) groups. Outcomes assessed included perioperative parameters, postoperative morbidity, overall survival (OS), and disease-free survival (DFS). Results: PSS was associated with a shorter operative time (235.2 vs. 302.6 min, p = 0.003), lower morbidity (18.9% vs. 57.1%, p = 0.001), and fewer major complications (Clavien–Dindo ≥ III, p = 0.005). ICU stay was significantly longer in MLR patients (p = 0.04). After propensity score matching (PSM), PSS was found to have lower morbidity compared to MLR (p = 0.023) with similar major morbidity (p = 0.473) and LOS (p = 0.579). Overall survival (31 vs. 37.1 months, p = 0.884) and disease-free survival (25.2 vs. 22.2 months, p = 0.519) were comparable between the groups before and after propensity score matching PSM (40.9 vs. 21.2 months, p = 0.741 and 24.3 vs. 13.8 months, p = 0.653). Conclusions: PSS achieves comparable oncologic outcomes to MLR while reducing postoperative morbidity and ICU stay. These findings support PSS as the preferred approach for CRLM, reserving MLR for select cases requiring extensive resection.

28 September 2023 in Medicina
Verified
Journal Article
Open access
PDF file
WOWee Liam Ong
Wee Liam Ong
SLSorinel Lunca
Sorinel Lunca
SMStefan Morarasu
Stefan Morarasu
AMAna-Maria Mușină
Ana-Maria Mușină
APAlina Puscasu
Alina Puscasu
GDGabriel Mihail Dimofte
Gabriel Mihail Dimofte
Background and Objectives: The objective of this study was to investigate quantitative changes in cell-free DNA (cfDNA) found in the bloodstream of patients with locally advanced rectal cancer who received neoadjuvant long-course chemoradiation, assuming a change in DNA fragments release during therapeutic stress. Materials and Methods: This was a prospective observational study that involved 49 patients who had three distinct pathologies requiring neoadjuvant chemoradiation: 18 patients with breast cancer, 18 patients with cervical cancer, and 13 patients with rectal cancer. Both breast cancer and cervical cancer patients were used as a control groups. Breast cancer patients were used as a control group as irradiation targeted healthy tissue after the tumor resection (R0), while cervical cancer patients were used as a control group to evaluate the effect of chemoradiation regarding cfDNA in a different setting (squamous cell carcinomas) and a different tumor burden. Rectal cancer patients were the study group, and were prospectively evaluated for a correlation between fragmentation of cfDNA and late response to chemoradiation. Blood samples were collected before the initiation of treatment and after the fifth radiation dose delivery. cfDNA was quantified in peripheral blood and compared with the patients’ clinicopathological characteristics and tumor volume. Conclusion: Thirteen patients with locally advanced rectal cancer (T3/T4/N+/M0) were included in the study, and all of them had their samples analyzed. Eight were male (61.54%) and five were female (38.46%), with an average age of 70.85 years. Most of the patients had cT3 (53.85%) or cT4 (46.15%) tumors, and 92.31% had positive lymph nodes (N2–3). Of the thirteen patients, only six underwent surgery, and one of them achieved a pathological complete response (pCR). The mean size of the tumor was 122.60 mm3 [35.33–662.60 mm3]. No significant correlation was found between cfDNA, tumor volume, and tumor regression grade. cfDNA does not seem to predict response to neoadjuvant chemoradiotherapy and it is not correlated to tumor volume or tumor regression grade.

29 April 2026 in Medical Sciences
Verified
Journal Article
Open access
PDF file
SLSorinel Lunca
Sorinel Lunca
GDGabriel Mihail Dimofte
Gabriel Mihail Dimofte
AMAna Maria Musina
Ana Maria Musina
CRCristian Ene Roata
Cristian Ene Roata
COConstantin Osman
Constantin Osman
SMStefan Morarasu
Stefan Morarasu
Background: Low anterior resection syndrome (LARS) is a frequent survivorship problem after sphincter-preserving rectal cancer surgery. Pelvic radiotherapy (RT), often combined with chemotherapy, is frequently implicated in LARS development, but its apparent effect may be confounded by low tumor location and diversion. We evaluated whether RT (±chemotherapy) separates the risk of postoperative LARS severity—especially major LARS—beyond classical anatomic and pathway determinants. Methods: We conducted a single-centre observational cohort study of operated rectal cancer patients managed between 2013 and 2024, who completed the Romanian-validated LARS score by standardized telephone interview after restoration of bowel continuity (up to 18 months postoperatively). Outcomes were postoperative LARS score, LARS category, and major LARS. Comparisons were performed by RT status and by oncologic treatment pattern. Multivariable logistic regression assessed associations with major LARS, adjusting a priori for tumor location and diverting ileostomy; furthermore, extended sensitivity models incorporated technical/pathway variables. Discrimination was explored using 5-fold cross-validated ROC/AUC. Item-level LARS responses were analyzed to characterize symptom phenotype. Results: Overall, 182 patients were included (RT: 106; no RT: 76); 43.4% had LARS (minor 14.8%, major 28.6%). RT-treated patients had higher postoperative LARS scores (median 21 vs. 12; p = 0.002) and a higher prevalence of major LARS (35.8% vs. 18.4%; p = 0.012). Across treatment patterns, LARS severity was highest in RT + chemotherapy. Item-level analyses indicated that RT-associated differences were driven mainly by urgency and clustering domains. In adjusted models, RT was not independently associated with major LARS, whereas low tumor location and diverting ileostomy were strong predictors. Discrimination for major LARS was modest: AUC 0.561 for RT alone, 0.643 for location + ileostomy, and 0.654 for location + ileostomy + RT (5-fold cross-validation). Conclusions: RT is associated with worse unadjusted postoperative bowel dysfunction after rectal cancer surgery and is linked to urgency/clustering-dominant symptom patterns. However, in this cohort, the risk of major LARS was predominantly explained by tumor location and diversion rather than RT alone, supporting integrated risk stratification and early symptom-directed survivorship care.

13 November 2025 in Medical Sciences
Verified
Journal Article
Open access
PDF file
RZRaluca Zaharia
Raluca Zaharia
SMStefan Morarasu
Stefan Morarasu
CRCristian Ene Roata
Cristian Ene Roata
AMAna Maria Musina
Ana Maria Musina
WOWee Liam Ong
Wee Liam Ong
SLSorinel Lunca
Sorinel Lunca
Background: Liver resection remains the primary curative treatment for many malignant liver diseases. Advances in patient selection, perioperative care, and surgical technique have markedly reduced procedure-related (surgical) complications in experienced centres. However, despite these improvements, medical (non-surgical) complications continue to represent a substantial source of postoperative morbidity, particularly after major liver resections. Herein, we aim to assess the incidence, nature, and predictors of medical versus surgical complications after liver resection and to develop an individual risk calculator for estimating medical morbidity after liver resection. Methods: This is an observational single-centre study including patients who underwent liver resection for cancer between 2013 and 2025. Postoperative complications were classified into medical and surgical categories based on clinical and diagnostic criteria. Demographic, clinical, and intraoperative data were analyzed to identify risk factors associated with each type of complication, and a multivariate logistic regression model was used to select significant variables, which were imputed in a prediction nomogram made available as an interactive web-based calculator. Results: Of the 231 patients included, 36 patients (15.6%) developed postoperative complications. From multivariate analysis, independent predictors of medical complications included cirrhosis (OR 2.8, 95% CI 1.2–6.8, p < 0.05), operative time > 180 min (OR 2.0, 95% CI 1.1–7.4, p < 0.05), intraoperative blood loss > 500 mL (OR 2, 95% CI: 0.9–4.8, p < 0.05), and ASA score ≥ 3 (OR 3.7, 95% CI 1.1–12.5, p < 0.05). Major hepatic resection was the only independent predictor of surgical complications (OR 7.42, 95% CI: 1.14–48.52, p = 0.036). The logistic regression model demonstrated fair discriminative ability with an AUC of 0.682 (95% CI: 0.544–0.729). The risk-prediction nomogram showed a 24.7% risk of postoperative medical morbidity in patients with all four risk factors vs. a 5.4% risk in patients without any risk factor. Conclusion: Postoperative medical complications are significantly more frequent in patients undergoing oncological liver resection with an ASA score ≥ 3, history of cirrhosis, prolonged operative time, and increased intraoperative blood loss. Our logistic regression model and web-friendly nomogram may be used for external validation in larger cohorts and could support preoperative counselling and perioperative risk stratification.