Peritoneal Tumor DNA as a Prognostic Biomarker in Gastric Cancer: A Systematic Review and Meta-Analysis.

PURPOSE: Gastric cancers commonly spread to the peritoneum. Its presence significantly alters patient prognosis and treatment-intent; however, current methods of peritoneal staging are inaccurate. Peritoneal tumor DNA (ptDNA) is tumor-derived DNA detectable in peritoneal lavage fluid. ptDNA positivity may indicate peritoneal micrometastasis and may be more sensitive than cytology in staging the peritoneum. In this meta-analysis, we evaluated the prognostic potential of ptDNA in gastric cancer. METHODS: PubMed, Embase, Scopus, and Web of Science databases were searched using PRISMA guidelines. Studies published between January 1, 1990, and April 30, 2023, containing quantitative data relating to ptDNA in gastric cancer were meta-analyzed. RESULTS: Six studies were analyzed. Of the total 757 patients with gastric adenocarcinoma, 318 (42.0%) were stage I, 311 (41.0%) were stage II/III, 116 (15.3%) were stage IV, and 22 (2.9%) were undetermined. Overall, ptDNA detected cytology-positive cases with a sensitivity and specificity of 85.2% (95% CI, 66.5 to 100.0) and 91.5% (95% CI, 86.5 to 96.6), respectively. Additionally, ptDNA was detected in 54 (8.5%) of 634 cytology-negative patients. The presence of ptDNA negatively correlated with pathological stage I (relative risk [RR], 0.29 [95% CI, 0.13 to 0.66]) and positively correlated with pathological stage IV (RR, 8.61 [95% CI, 1.86 to 39.89]) disease. Importantly, ptDNA positivity predicted an increased risk of peritoneal-specific metastasis (RR, 13.81 [95% CI, 8.11 to 23.53]) and reduced 3-year progression-free (RR, 5.37 [95% CI, 1.39 to 20.74]) and overall (hazard ratio, 4.13 [95% CI, 1.51 to 11.32]) survival. CONCLUSION: ptDNA carries valuable prognostic information and can detect peritoneal micrometastases in patients with gastric cancer. Its clinical utility in peritoneal staging for gastric cancer deserves further investigation.

A Practical Approach to Interpreting Circulating Tumor DNA in the Management of Gastrointestinal Cancers.

BACKGROUND: There is accumulating evidence supporting the clinical use of circulating tumor DNA (ctDNA) in solid tumors, especially in different types of gastrointestinal cancer. As such, appraisal of the current and potential clinical utility of ctDNA is needed to guide clinicians in decision-making to facilitate its general applicability. CONTENT: In this review, we firstly discuss considerations surrounding specimen collection, processing, storage, and analysis, which affect reporting and interpretation of results. Secondly, we evaluate a selection of studies on colorectal, esophago-gastric, and pancreatic cancer to determine the level of evidence for the use of ctDNA in disease screening, detection of molecular residual disease (MRD) and disease recurrence during surveillance, assessment of therapy response, and guiding targeted therapy. Lastly, we highlight current limitations in the clinical utility of ctDNA and future directions. SUMMARY: Current evidence of ctDNA in gastrointestinal cancer is promising but varies depending on its specific clinical role and cancer type. Larger prospective trials are needed to validate different aspects of ctDNA clinical utility, and standardization of collection protocols, analytical assays, and reporting guidelines should be considered to facilitate its wider applicability.

The prognostic impact of peritoneal tumour DNA in gastrointestinal and gynaecological malignancies: a systematic review.

Peritoneal metastases from various abdominal cancer types are common and carry poor prognosis. The presence of peritoneal disease upstages cancer diagnosis and alters disease trajectory and treatment pathway in many cancer types. Therefore, accurate and timely detection of peritoneal disease is crucial. The current practice of diagnostic laparoscopy and peritoneal lavage cytology (PLC) in detecting peritoneal disease has variable sensitivity. The significant proportion of peritoneal recurrence seen during follow-up in patients where initial PLC was negative indicates the ongoing need for a better diagnostic tool for detecting clinically occult peritoneal disease, especially peritoneal micro-metastases. Advancement in liquid biopsy has allowed the development and use of peritoneal tumour DNA (ptDNA) as a cancer-specific biomarker within the peritoneum, and the presence of ptDNA may be a surrogate marker for early peritoneal metastases. A growing body of literature on ptDNA in different cancer types portends promising results. Here, we conduct a systematic review to evaluate the prognostic impact of ptDNA in various cancer types and discuss its potential future clinical applications, with a focus on gastrointestinal and gynaecological malignancies.

Pre-existing hiatal mesh increases morbidity during and after revisional antireflux surgery: A retrospective multicenter study.

BACKGROUND: Revisional antireflux surgery, including hiatus hernia repair, is increasingly common. Mesh-augmented hiatal closure at the time of index operation is controversial but commonly performed. Although a meta-analysis of randomized data has demonstrated no additional benefit of routine mesh placement, it is unclear whether this practice results in harm, particularly at the time of revisional antireflux surgery. We determined whether pre-existing mesh at the hiatus increases morbidity during and after revisional antireflux surgery. METHODS: Analysis of prospectively-maintained databases of all elective revisional antireflux surgery cases in 36 hospitals across Australia took place over 10 years. Intraoperative and postoperative outcomes of patients with and without prior hiatal mesh were compared. Propensity score-matched analysis was used to validate primary findings. RESULTS: A total of 346 revisional cases (35 with pre-existing mesh) were analyzed. The 2 groups had comparable baseline characteristics. In total, 77 (22.2%) patients had 148 intraoperative adverse events. Pre-existing mesh was associated with a higher risk of intraoperative complications (48.6% vs 22.5%, odds ratio 3.25, 95% confidence interval 1.63-6.38, P = .002), secondary to bleeding, and lacerations to pleura, lung, and liver. Overall, 63 (18.2%) patients developed postoperative complications. Pre-existing mesh was associated with increased postoperative morbidity (37.1% vs 16.1%, odds ratio 3.09, 95% confidence interval 1.50-6.43, P = .005), particularly due to bleeding and respiratory complications. Importantly, pre-existing mesh independently predicted the occurrence of intraoperative and postoperative complications. CONCLUSION: Prior hiatal mesh significantly increases morbidity during and after revisional antireflux surgery. Given that revisional surgery is increasingly being performed, our findings discourage routine mesh use during primary antireflux surgery.

A case of endometriosis causing acute large bowel obstruction.

INTRODUCTION: Endometriosis is a gynaecological condition which produce symptoms such as pelvic pain, abnormal menstruation and infertility. Intestinal endometriosis can occur however endometriosis causing acute large bowel obstruction is extremely rare. PRESENTATION OF CASE: We present a 37-year-old lady with acute large bowel obstruction caused by endometriosis. Despite initial endoscopic decompression being unsuccessful due to severe mucosal stenosis, she underwent emergency laparoscopic wedge resection and decompression successfully. DISCUSSION: Diagnosing intestinal endometriosis is difficult. While different modalities of investigation help, definitive diagnosis is achieved via laparoscopy. Treatment of obstruction is decompression followed by surgical resection. CONCLUSION: Diagnosing intestinal endometriosis with or without obstruction is challenging. Correct diagnosis is needed for definitive management.

Traumatic diaphragmatic rupture with underlying lung laceration and tension pneumoperitoneum.

Tension pneumoperitoneum is commonly caused by gastrointestinal perforation and pulmonary causes are extremely rare. We present a case of a 47-year-old male post motor vehicle accident with a suspected left-sided haemopneumothorax on initial chest x-ray. CT of the chest post chest tube insertion showed a left-sided diaphragmatic rupture and an extensive diaphragmatic hernia. While en-route to the operating theatre, the intubated patient developed tension pneumoperitoneum with positive pressure ventilation and required immediate surgical intervention and repair. A review of the literature around tension pneumoperitoneum and diaphragmatic hernia in trauma is discussed.