The Role of Staging Laparoscopy for Gastric Cancer Patients: Current Evidence and Future Perspectives

Selecting Targets for Molecular Imaging of Gastric Cancer: An Immunohistochemical Evaluation

PURPOSE

Tumor-targeted positron emission tomography (PET) and fluorescence-guided surgery (FGS) could address current challenges in pre- and intraoperative imaging of gastric cancer. Adequate selection of molecular imaging targets remains crucial for successful tumor visualization. This study evaluated the potential of integrin αvβ6, carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), epidermal growth factor receptor (EGFR), epithelial cell adhesion molecule (EpCAM) and human epidermal growth factor receptor-2 (HER2) for molecular imaging of primary gastric cancer, as well as lymph node and distant metastases.

METHODS

Expression of αvβ6, CEACAM5, EGFR, EpCAM and HER2 was determined using immunohistochemistry in human tissue specimens of primary gastric adenocarcinoma, healthy surrounding stomach, esophageal and duodenal tissue, tumor-positive and tumor-negative lymph nodes, and distant metastases, followed by quantification using the total immunostaining score (TIS).

RESULTS

Positive biomarker expression in primary gastric tumors was observed in 86% for αvβ6, 72% for CEACAM5, 77% for EGFR, 93% for EpCAM and 71% for HER2. Tumor expression of CEACAM5, EGFR and EpCAM was higher compared to healthy stomach tissue expression, while this was not the case for αvβ6 and HER2. Tumor-positive lymph nodes could be distinguished from tumor-negative lymph nodes, with accuracy ranging from 82 to 93% between biomarkers. CEACAM5, EGFR and EpCAM were abundantly expressed on distant metastases, with expression in 88-95% of tissue specimens.

CONCLUSION

Our findings show that CEACAM5, EGFR and EpCAM are promising targets for molecular imaging of primary gastric cancer, as well as visualization of both lymph node and distant metastases. Further clinical evaluation of PET and FGS tracers targeting these antigens is warranted.

Management of Peritoneal Metastasis in Patients with Pancreatic Ductal Adenocarcinoma

The peritoneum is the second most common site of metastasis in patients with pancreatic ductal adenocarcinoma (PDAC). Up to half of all patients that undergo curative-intent resection eventually develop peritoneal metastasis (PM), which accounts for significant morbidity and drives mortality. Despite recent advances in management, PM is associated with very poor prognosis, which is often measured in weeks to months. Clinical manifestations including bowel obstruction, ascites, and urinary obstruction have profound impact on quality of life. Even with relatively advanced disease, PM often remains occult on imaging and thus tend to be underdiagnosed and understudied. Many patients with peritoneal-only PM are excluded from clinical trials because response cannot be measured by standard radiographic criteria. Furthermore, as patients with PM are not eligible for surgical resection and low-volume peritoneal disease is often not amenable to percutaneous biopsy, tissue samples for peritoneal-specific translational studies are limited. Intraperitoneal therapeutics have been proposed as an attractive option for PM, as better penetration of tumor tissue can be achieved with less systemic toxicity compared with intravenous chemotherapy. Heated intraperitoneal chemotherapy (HIPEC), typically combined with cytoreductive surgery (CRS), is an option for select patients with PM from gynecologic or gastrointestinal primary, and for patients with primary peritoneal mesothelioma. However, the incorporation of locoregional therapy for PM in patients with PDAC has been poorly studied given the aggressive nature of pancreatic cancer and overall poor prognosis. With recent advances in existing treatment options, there may be a subset of patients who may derive benefits from locoregional control with cytoreduction and/or intraperitoneal chemotherapy. Critically, additional work is needed to determine PM-favorable clinical and tumoral predictive biomarkers to identify patients who may benefit from a more aggressive approach. We describe the current state of management of patients with peritoneal metastasis from PDAC and review the available data exploring peritoneal-directed therapy with cytoreductive surgery and/or intraperitoneal chemotherapy.

Intraperitoneal paclitaxel with systemic S-1 plus oxaliplatin for advanced or recurrent gastric cancer with peritoneal metastasis: A single-arm, multicenter phase II clinical trial

BACKGROUND

Patients with peritoneal metastasis from gastric cancer show poor prognosis with standard systemic chemotherapy. This prospective multicenter phase II clinical trial was performed to evaluate the efficacy and safety of intraperitoneal paclitaxel combined with systemic S-1 plus oxaliplatin for patients with advanced or recurrent gastric cancer with peritoneal metastasis.

PATIENT AND METHOD

Patients with advanced or recurrent gastric cancer with histologically or radiologically confirmed peritoneal metastases were eligible for the study. The chemotherapy regimen consisted of eight cycles of intraperitoneal paclitaxel 80 mg/m2 on days 1 and 8, combined with 80 mg/m2 S-1 for days 1-14, and 100 mg/m2 oxaliplatin on day 1, repeated every 21 days. The primary endpoint was 6-month progression-free survival. One-year progression-free and overall survival, response rate, and safety were set as the secondary endpoints.

RESULT

In total, 28 patients were included in the study, of which 24 were analyzed, with the exception of those lost to follow-up and withdrawal of consent. The 6-months progression-free survival was 82.6 % (95 % CI: 68.5-99.6 %). The one-year progression-free and overall survival rates were 69.6 % (95 % CI: 53.1-91.2 %) and 76.9 % (95 % CI: 61-97 %), respectively. The overall response rate was 41.67 %. The hematologic toxicity profile showed grade 3/4 hematologic toxicities such as leukopenia (20.8 %), neutropenia (41.7 %), and thrombocytopenia (8.3 %). The only non-hematologic adverse event was grade 3 diarrhea. Three (12.5 %) patients experienced intraperitoneal chemoport-related adverse events.

CONCLUSION

Bidirectional intraperitoneal paclitaxel with systemic S-1 plus oxaliplatin shows promising efficacy and safety in the treatment of peritoneal metastatic gastric cancer.

Artificial intelligence assisted real-time recognition of intra-abdominal metastasis during laparoscopic gastric cancer surgery

Laparoscopic exploration (LE) is crucial for diagnosing intra-abdominal metastasis (IAM) in advanced gastric cancer (GC). However, overlooking single, tiny, and occult IAM lesions during LE can severely affect the treatment and prognosis due to surgeons' visual misinterpretations. To address this, we developed the artificial intelligence laparoscopic exploration system (AiLES) to recognize IAM lesions with various metastatic extents and locations. The AiLES was developed based on a dataset consisting of 5111 frames from 100 videos, using 4130 frames for model development and 981 frames for evaluation. The AiLES achieved a Dice score of 0.76 and a recognition speed of 11 frames per second, demonstrating robust performance in different metastatic extents (0.74-0.76) and locations (0.63-0.90). Furthermore, AiLES performed comparably to novice surgeons in IAM recognition and excelled in recognizing tiny and occult lesions. Our results demonstrate that the implementation of AiLES could enhance accurate tumor staging and assist individualized treatment decisions.

Emerging Trends in the Management of Gastric Malignancy with Peritoneal Dissemination: Same Disease, Heterogeneous Prognosis

Gastric cancer is a significant global contributor to cancer-related mortality. Stage IV gastric cancer represents a significant percentage of patients in Western countries, with peritoneal dissemination being the most prevalent site. Peritoneal disease comprises two distinct entities, macroscopic (P1) and microscopic (P0CY1), which are associated with poor long-term survival rates. Although the present standard of treatment is palliative chemotherapy, a global controversy has arisen concerning specific patients with limited disease burden or conversion to negative lavage cytology following chemotherapy. Available approaches include systemic or intraperitoneal chemotherapy, upfront gastrectomy, and conversion surgery. This review consolidated the current evidence regarding multimodal management, indicating prolonged survival for this distinct subgroup of patients. Considering the complexity of peritoneal metastases, the potential of the multimodal approach unveils promising prospects for identifying the optimal treatment for this particular subset of stage IV patients and thus enhancing their survival outcomes.

Diagnostic Efficacy of Staging Laparoscopy Compared to CT and PET-CT in Gastric Cancer: A Retrospective Cohort Analysis

Background and Objectives: This study aimed to assess the diagnostic accuracy and prognostic significance of staging laparoscopy (SL) compared to computed tomography (CT) and positron emission tomography-computed tomography (PET-CT) in gastric cancer staging. We evaluated the ability of SL to detect occult peritoneal metastases and influence of SL on survival outcomes across cancer stages and treatment approaches. Materials and Methods: In this retrospective cohort study, 95 patients with gastric cancer underwent preoperative assessment using CT, PET-CT, and SL between 2018 and 2024. Diagnostic performance metrics were calculated for SL, CT, and PET/CT across the local, locally advanced, and metastatic stages. Survival outcomes were analyzed using Kaplan-Meier curves, and comparisons were made using log-rank tests. A multivariable Cox proportional hazards model incorporating interaction terms was used to determine the independent prognostic factors affecting survival, focusing on SL findings and cytology results. Results: The cohort comprised 75 males (78.9%) and 20 females (21.1%), with a mean age of 57.4 ± 10.1 years. The tumor location distribution was predominant in the corpus (31.1%) and cardia. Tumor staging revealed that 48.1% were classified as T3 and 28.8% as T4, respectively. Diagnostic accuracy analysis showed that SL outperformed CT and PET-CT in detecting peritoneal metastasis across all stages. Specifically, SL demonstrated a sensitivity and specificity of 85% and 95% for local disease, 92% and 80% for locally advanced disease, and 95% and 99% for metastatic disease, significantly exceeding those of CT and PET-CT. Patients with SL findings had a median overall survival (OS) of 30 months compared with 20 months for those assessed only with CT and PET-CT (p < 0.05). The stage-specific median OS for SL patients was 40 months in the local, 25 months in the locally advanced (p < 0.05), and 15 months in the metastatic disease (p < 0.01) groups, indicating significant survival benefits. Multivariable Cox regression identified SL findings as an independent factor associated with reduced mortality risk (HR: 0.70, 95% CI: 0.50-0.90, p < 0.01), while positive cytology findings predicted poorer survival (HR: 1.80, 95% CI: 1.25-2.60, p < 0.01). Interaction terms revealed that SL yielded greater survival benefits in patients with metastatic disease (hazard ratio [HR]: 0.60, p < 0.01) and those undergoing systemic therapy (HR: 0.75, p = 0.04). Conclusions: SL provides superior diagnostic accuracy and prognostic information for advanced gastric cancer staging compared with CT and PET-CT. By accurately detecting peritoneal metastasis, SL aids in optimizing treatment plans, particularly in advanced stages, thus potentially improving patient outcomes.

Emerging Treatment Modalities for Gastric Cancer With Macroscopic Peritoneal Metastases: A Systematic Review

Gastric cancer with macroscopic peritoneal metastases represents a major therapeutic challenge and is associated with a poor prognosis. This review aims to evaluate the efficacy and safety of new treatment modalities. A systematic search of PubMed was conducted to identify studies published between January 2014 and April 2024. Inclusion criteria were trials investigating novel therapies for gastric cancer with peritoneal metastases. Data on treatment efficacy, survival outcomes, and side effects were extracted.

The clinical implications of staging laparoscopy in the diagnostic workup of gastric cancer patients: A population based study

BACKGROUND

Since 2016, staging laparoscopy has been implemented in the diagnostic workup of patients with gastric cancer. Staging laparoscopy aims to detect incurable disease (peritoneal metastases and irresectable tumors) and to prevent futile laparotomies.

METHODS

In this population-based nationwide study, we sought patient- and tumor characteristics associated with undergoing a staging laparoscopy. Additionally, we analyzed the prevalence of synchronous peritoneal metastases, the outcome of the staging laparoscopy and its clinical impact on treatment decisions. All patients diagnosed with non-cardia gastric cancer from the Netherlands Cancer Registry between 2016 and 2021 were included.

RESULTS

Alongside tumor characteristics, patient characteristics such as younger age, absence of comorbidities and lower WHO performance status were associated with performing a staging laparoscopy. In the study period, an increase in the proportion of patients who underwent a staging laparoscopy was observed, from 19.6% in 2016 to 32.3% in 2021 (p-value<0.001). In the same period, the prevalence of synchronous peritoneal metastases increased from 25% to 31%. In 37.6% of the patients who had the outcome of their staging laparoscopy reported, had incurable disease diagnosed during staging laparoscopy. Significantly less of these patients were treated with triplet regimens as compared to patients with a negative staging laparoscopy (18.5 vs. 76.3%; p-value<0.001).

CONCLUSION

The implementation of staging laparoscopy in gastric cancer patients paralleled the increase in diagnosis of incurable disease and a decrease in the application of triplet systemic therapies in these patients.

Transcriptomics-based liquid biopsy panel for early non-invasive identification of peritoneal recurrence and micrometastasis in locally advanced gastric cancer

BACKGROUND

This study aimed to develop a novel six-gene expression biomarker panel to enhance the early detection and risk stratification of peritoneal recurrence and micrometastasis in locally advanced gastric cancer (LAGC).

METHODS

We used genome-wide transcriptome profiling and rigorous bioinformatics to identify a six-gene expression biomarker panel. This panel was validated across multiple clinical cohorts using both tissue and liquid biopsy samples to predict peritoneal recurrence and micrometastasis in patients with LAGC.

RESULTS

Through genome-wide expression profiling, we identified six mRNAs and developed a risk prediction model using 196 samples from a surgical specimen training cohort. This model, incorporating a 6-mRNA panel with clinical features, demonstrated high predictive accuracy for peritoneal recurrence in gastric cancer patients, with an AUC of 0.966 (95% CI: 0.944-0.988). Transitioning from invasive surgical or endoscopic biopsy to noninvasive liquid biopsy, the model retained its predictive efficacy (AUC = 0.963; 95% CI: 0.926-1.000). Additionally, the 6-mRNA panel effectively differentiated patients with or without peritoneal metastasis in 95 peripheral blood specimens (AUC = 0.970; 95% CI: 0.936-1.000) and identified peritoneal micrometastases with a high efficiency (AUC = 0.941; 95% CI: 0.874-1.000).

CONCLUSIONS

Our study provides a novel gene expression biomarker panel that significantly enhances early detection of peritoneal recurrence and micrometastasis in patients with LAGC. The RSA model's predictive capability offers a promising tool for tailored treatment strategies, underscoring the importance of integrating molecular biomarkers with clinical parameters in precision oncology.

Benefit of a multimodal approach combining chemotherapy and surgery in oligometastatic gastric cancer: experience from a tertiary referral center

Introduction

Gastric cancer (GC) is the fourth leading cause of cancer-related death worldwide with limited therapeutic options. The aim of this study was to analyze the value of adding surgery to the first-line treatment in patients with oligometastatic GC (OGC).

Methods

This retrospective study included patients with OGC who underwent induction chemotherapy followed by surgery of both primary tumor and synchronous metastasis between April 2012 and April 2022. Endpoints were overall survival (OS) and relapse-free survival (RFS) analyzed by the Kaplan-Meier method. Prognostic factors were assessed with the Cox model.

Results

Data from 39 patients were collected. All cases were referred to our multidisciplinary tumor board (MTB) to evaluate the feasibility of radical surgery. After a median follow-up of 33.6 months (mo.), median OS was 26.6 mo. (95% CI 23.8-29.4) and median RFS was 10.6 mo. (95% CI 6.3-14.8). Pathologic response according to the Mandard criteria (TRG 1-3, not reached versus 20.5 mo. for TRG 4-5; HR 0.23, p=0.019), PS ECOG ≤ 1 (26.7 mo. for PS ≤ 1 versus 11.2 mo. for PS >1; HR 0.3, p=0.022) and a low metastatic burden (26.7 mo. for single site versus 12.9 mo. for ≥2 sites; HR 0.34, p=0.039) were related to good prognosis. No major intraoperative complications nor surgery-related deaths occurred in our series.

Discussion

A sequential strategy of preoperative chemotherapy and radical surgical excision of both primary tumor and metastases was demonstrated to significantly improve OS and RFS. Multidisciplinary evaluation is mandatory to identify patients who could benefit from this strategy.

Staging laparoscopy in gastric cancer patients: From a Dutch nationwide Delphi consensus towards a standardized protocol

BACKGROUND

Staging laparoscopy is a common diagnostic tool in gastric cancer, but its performance varies widely. The aim of this study was to gain Dutch nationwide consensus regarding the indications for and execution of staging laparoscopy in patients with gastric cancer.

METHODS

All surgeons in the Netherlands specialized in gastric cancer surgery (n = 52) were asked to participate in a Delphi consensus study. The study involved an initial questionnaire with a 3-point Likert scale, an online consensus meeting, and a second questionnaire using a 2-point Likert scale (agree/disagree). Consensus was defined as 70% or more agreement among participants.

RESULTS

In total, 45 experts completed both questionnaires (87% response rate). Consensus was reached on the indication to perform staging laparoscopy in cT3-4 or cN + or diffuse-type gastric cancer, including Siewert type III oesophagogastric junctional cancer. The experts agreed that if preoperative scans suggest infiltration of surrounding organs (cT4), the tumour's resectability should explicitly be investigated. Consensus was also reached for a systematic peritoneal cavity inspection according to Sugarbaker's Peritoneal Cancer Index (PCI) score. All regions should be inspected routinely, although the omental bursa may be inspected on indication. Aspiration of ascites or peritoneal washing should be performed for cytology. The experts agreed that restaging laparoscopy should be performed before resection in case of progressive disease on preoperative imaging. Without progression, global inspection was considered sufficient.

CONCLUSIONS

The results of this Dutch nationwide Delphi consensus study exposed the variability of performing staging laparoscopy in patients with gastric cancer and provided the concept for a standardized protocol.

The exploration of surgery and survival prediction in patients with peritoneal metastasis from gastric adenocarcinoma based on the SEER database

Background

As one of the most common diseases in terms of cancer-related mortality worldwide, gastric adenocarcinoma (GA) frequently develops peritoneal metastases (PMs) in advanced stages. Systemic therapy or optimal supportive care are recommended for advanced GA; however, patients frequently develop drug resistance. Surgical resection is not recommended for stage IV patients, and there have been some controversies regarding the role of it in GA patients with PMs. The aim of the study was to preliminarily evaluate the possible effect of surgical treatments on patients with only PMs from GA.

Methods

Data were collected from the Surveillance, Epidemiology and End Results (SEER) database (year 2000-2022). A propensity score matching (PSM) was performed to reduce the influence of selection bias and confounding variables on comparisons. Then Cox proportional hazard regression, Kaplan-Meier analysis, and log-rank test were performed to assess the efficacy of surgical treatment in patients with PMs from GA.

Results

A total of 399 patients diagnosed with PMs from GA were enrolled for our analysis, of which, 180 (45.1%) patients did not receive surgery and 219 (54.9%) patients received surgery. Multivariate Cox regression analysis before PSM indicated higher rates of overall survival (OS) outcome for patients who had received surgery [hazard ratio (HR) =0.4342, 95% confidence interval (CI): 0.3283-0.5742, P<0.001]. After PSM, a total of 172 patients were enrolled, with 86 in each group. Multivariate Cox analysis showed that surgery was the independent factor reflecting patients' survival (HR =0.4382, 95% CI: 0.3037-0.6324, P<0.001). Subgroup survival analysis revealed that surgery may bring advantages to patients with grades I-IV, stages T1-T4, stage N0, and tumor size less than 71 mm (P<0.05). We also found that the OS of chemotherapy patients who had undergone surgery was better than that of chemotherapy patients who had not undergone surgery (P<0.01).

Conclusions

Based on the SEER database, surgery has better OS for patients only with PMs from GA. Patients without lymph node metastasis and those who received chemotherapy before may benefit from surgery. These specific groups of patients may have surgery as an option to improve the prognosis.

Peritoneal Washing Cytology Positivity in Gastric Cancer: Role of Lymph Node Metastasis as a Risk Factor

PURPOSE

Peritoneal washing cytology (PWC) is a widely used diagnostic tool for detecting peritoneal metastasis of advanced gastric cancer. However, the prognosis of patients with positive PWC remains poor even after gastrectomy, and treatments vary among institutions and eras. In this study, we identified the clinical factors that can help predict cytology-positive (CY(+)) gastric cancer.

MATERIALS AND METHODS

We retrospectively reviewed the national data of patients with gastric cancer from 2019, as provided by the Information Committee of the Korean Gastric Cancer Association. Of the 13,447 patients with gastric cancer, 3,672 underwent PWC. Based on cytology results, we analyzed the clinicopathological characteristics and assessed the possibility of CY(+) outcomes in relation to T and N stages.

RESULTS

Of the 3,270 patients who underwent PWC without preoperative chemotherapy, 325 were CY(+), whereas 2,945 were negative. CY(+) was more commonly observed in patients with Borrmann type IV gastric cancer, an undifferentiated histological type, and advanced pathological stages. Multivariate analysis revealed Borrmann type IV (odds ratio [OR], 1.821), tumor invasion to T3-4 (OR, 2.041), and lymph node metastasis (OR, 3.155) as independent predictors of CY(+). Furthermore, for circular tumor location, the N stage emerged as a significant risk factor for CY(+), particularly when the tumor was located on the posterior wall (PW) side.

CONCLUSIONS

Lymph node metastasis significantly affects CY(+) outcomes, particularly when the tumor is located on the PW side. Therefore, PWC should be considered not only in suspected serosal exposure cases but also in cases of lymph node metastasis.

Timing to Surgery and Lymph Node Upstaging in Gastric Cancer: An NCDB Analysis

BACKGROUND

Prior studies have shown tumor specificity on the impact of longer time interval from diagnosis to surgery, however in gastric cancer (GC) this remains unclear. We aimed to determine if a longer time interval from diagnosis to surgery had an impact on lymph node (LN) upstaging and overall survival (OS) outcomes among patients with clinically node negative (cN0) GC.

PATIENTS AND METHODS

Patients diagnosed with cN0 GC undergoing surgery between 2004-2018 were identified in the National Cancer Database (NCDB) and divided into intervals between time of diagnosis and surgery [short interval (SI): ≥ 4 days to < 8 weeks and long interval (LI): ≥ 8 weeks]. Multivariable regression analysis evaluated the independent impact of surgical timing on LN upstaging and a Cox proportional hazards analysis and Kaplan-Meier curves evaluated survival outcomes.

RESULTS

Of 1824 patients with cN0 GC, 71.8% had a SI to surgery and 28.1% had a LI to surgery. LN upstaging was seen more often in the SI group when compared to LI group (82% versus 76%, p = 0.004). LI to surgery showed to be an independent factor protective against LN upstaging [adjusted odds ratio = 0.62, 95% CI: (0.39-0.99)]. Multivariate Cox regression analysis indicated that time to surgery was not associated with a difference in overall survival [hazard ratio (HR) = 0.91, 95% CI: (0.71-1.17)], however uncontrolled Kaplan-Meier curves showed OS difference between the SI and LI to surgery groups (p = 0.037).

CONCLUSION

Timing to surgery was not a predictor of LN upstaging or overall survival, suggesting that additional medical optimization in preparation for surgery and careful preoperative staging may be appropriate in patients with node negative early stage GC without affecting outcomes.

Neoadjuvant Chemotherapy Followed by Gastrectomy for Cytology-Positive Gastric Cancer without Any Other Non-Curative Factors in a Western Setting: An International Eastern European Cohort Study

The optimal approach for treating cytology-positive (Cy1) gastric cancer (GC) patients without additional non-curative factors remains uncertain. While neoadjuvant chemotherapy followed by gastrectomy shows promise, its suitability for Western patients is not well supported by existing data. To address this knowledge gap, a cohort study was conducted across four major GC treatment centers in Lithuania, Estonia, and Ukraine. Forty-three consecutive Cy1 GC patients who underwent neoadjuvant chemotherapy between 2016 and 2020 were enrolled. The study evaluated overall survival (OS), progression-free survival (PFS), cytology status conversion, and major pathological response rates, along with the factors influencing these outcomes. All patients underwent surgery post-neoadjuvant chemotherapy, with 53.5% experiencing cytological status conversion and 23.3% achieving a major pathological response. The median OS and PFS were 20 (95% CI: 16-25) and 19 (95% CI: 11-20) months, respectively. Conversion to negative cytology significantly reduced the relative risk of peritoneal progression (RR: 0.11; 95% CI: 0.03-0.47, p = 0.002). The study suggests that neoadjuvant chemotherapy followed by gastrectomy holds promise as a treatment option for Cy1 GC without additional non-curative factors, associating cytology status conversion with improved long-term outcomes and reduced peritoneal relapse risk.