Peritoneal carcinomatosis of gastric origin: a population-based study on incidence, survival and risk factors

Management of peritoneal gastric metastasis: An update

IMPORTANCE

Peritoneal metastases from gastric cancer (PMGC) are associated with poorer median survival and systemic chemotherapy remains the standard of care. This narrative review summarizes the current evidence for medical and surgical treatment of PMGC.

OBSERVATIONS

Treatment is moving to local ways of administering chemotherapy, either intraperitoneal normothermic chemotherapy, laparoscopic hyperthermic intraperitoneal chemotherapy (HIPEC) or even pressurized intraperitoneal aerosol chemotherapy. Furthermore, cytoreductive surgery±HIPEC could also be an alternative in specific situations.

CONCLUSIONS

and relevance: This review provides an updated summary of existing strategies that can be discussed in the management of patients with PMGC.

Peritoneal cancer index in ovarian cancer: what does the surgeon really see?

INTRODUCTION

The aim of this paper is to study the agreement between the findings described by the surgeon during surgery (surgical Peritoneal Cancer Index or sPCI) and those obtained after the histopathological analysis (pathological Peritoneal Cancer Index or pPCI) of the resection specimens, in addition to their prognostic implications.

MATERIALS AND METHODS

A consecutive series of patients diagnosed with high-grade serous ovarian cancer with peritoneal dissemination was analyzed between January 2008 and December 2022. sPCI were correlated with the pPCI results. The study considered the surgeon as a diagnostic tool and established, in ovarian cancer, the parameters of sensitivity, specificity, predictive values, and probability coefficients. Specifically, the study focused on the subgroup of patients with false-positive results from sPCI compared to pPCI and its usefulness in assessing the prognosis of the disease.

RESULTS

A total of 231 patients were included, evaluating a total of 3003 peritoneal areas. The median sPCI was 9 (range: 0-35) and 7 for pPCI. Of the 3,003 peritoneal areas evaluated, 132 areas were considered false positives for sPCI. After multivariate analysis, the location of the lesions in the supramesocolic compartment (OR 2.37, 95% CI 1.19-4.53, p = 0.014) was the only independent factor related to a false-positive sPCI result. Patients with false-positive sPCI had a better disease-free survival estimate.

CONCLUSIONS

The main usefulness of pPCI would be determined by its ability to correct prognostic estimates of the disease, especially in the case of false positives.

Molecular mechanisms of metastatic peritoneal dissemination in gastric adenocarcinoma

Peritoneal dissemination portends a dismal prognosis in patients with gastric adenocarcinoma in the context of limited effective treatments. The underlying cellular processes that drive gastric peritoneal carcinomatosis remain unclear, limiting the application of novel targeted therapies. In this comprehensive review, we aimed to identify and summarize all existing context-dependent molecular mechanisms that have been implicated in peritoneal dissemination and peritoneal carcinomatosis establishment from primary gastric adenocarcinoma. We applied a multilevel examination including data from in vivo murine models using human gastric cancer cell lines, in vitro technique-based studies, ex vivo models, and genomic/proteomic and molecular profiling analyses to report on various aspects of gastric cancer peritoneal metastasis biology. Mechanisms promoting peritoneal dissemination were grouped into three main functional categories: (1) intrinsic cancer cell biology, (2) cancer cell-peritoneal surface adhesion, and (3) peritoneal tumor microenvironment. We identified significant overlap among the three categories, indicating a complex interplay between multiple molecular mechanisms. By interrupting these pathways, peritoneal-directed therapies have the potential to improve quality and length of life in patients with high-risk primary gastric cancer.

A new locoregional mouse model of gastric cancer for identifying probes for fluorescence guided surgery

BACKGROUND

In gastric cancer, the only opportunity for a cure is with surgical resection. Fluorescence-guided surgery is an emerging field that has the potential to improve rates of R0 resections. Mouse models with patterns of disease spread that would be deemed operable in patients are required for the testing of potential fluorescence-guided surgery probes.

METHODS

One million cells of the human gastric cancer cell line MKN45 were suspended in 50 μL of phosphate-buffered saline and Matrigel and injected into the mouse stomach with a 29-gauge needle. After 8 to 12 weeks of tumor growth, mice were killed and laparotomy was performed to determine rates of tumor engraftment, local or distant spread, and involvement of celiac lymph nodes. For tumor labeling, mice were randomized to receive intravenous injection of an anti-CEA antibody (M5A), or IgG as a control, conjugated with the near-infrared dye IRDye800CW. Fluorescence imaging was performed using the LI-COR Pearl Imaging System 72 hours later.

RESULTS

Infiltrative tumors were identified in 76.5% (n = 34) of mice. Intra-abdominal or peritoneal metastases were seen in 23.5% and carcinomatosis was seen in 5.9% of mice. Celiac lymph node metastases were seen in 55.5% of mice. M5A-IR800 administration resulted in bright labeling of primary tumors and metastatic celiac lymph nodes. Hematoxylin and eosin staining demonstrated incorporation of the gastric cancer cells throughout the layers of the mouse stomach and the presence of metastatic gastric cancer cells in celiac lymph nodes.

CONCLUSION

This new locoregional mouse model can be used to validate additional agents for their use in fluorescence guided surgical resection of gastric cancer.

Educational Review: Updates on Therapeutic Strategies for Gastric Cancer with Peritoneal Metastasis

Gastric cancer (GC) commonly presents in advanced stages with metastatic spread to the peritoneal cavity, and outcomes associated with gastric cancer with peritoneal metastasis (GCPM) continue to carry a dismal prognosis. Persistent challenges in the detection of peritoneal metastasis (PM) have resulted in a relative paucity of high-quality data to inform management decisions. Several consensus groups have published recommendations to guide management, including most recently the National Comprehensive Cancer Network guidelines, which now include cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) as a potential treatment modality in select patients with GCPM. Multiple clinical trials have investigated the use of CRS/HIPEC and other peritoneal-directed therapies, such as intraperitoneal chemotherapy (IPC) and pressurized intraperitoneal aerosolized chemotherapy (PIPAC). As high-volume centers work to incorporate such therapies into their practice, ongoing clinical trials are aimed at understanding their efficacy. Recent findings have improved understanding of the mechanisms and pathophysiology underlying GCPM while the discovery of novel targets offers potential for drug development and therapeutic strategies to overcome treatment resistance. This review highlights recent advancements and addresses the persistent challenges in managing GCPM while also offering a comprehensive summary of current guidelines and treatment strategies.

Dasatinib demonstrates efficacy in organoid derived paclitaxel-resistant Trp53/Cdh1-deficient mouse gastric adenocarcinoma with peritoneal metastasis

Gastric cancer peritoneal metastasis (GCPM) typically indicates a poor clinical prognosis and is frequently observed in diffuse gastric cancer (GC) patients with CDH1 loss of function. GCPM characterized for its aggressiveness and resistance to chemotherapy, most notably paclitaxel (PTX), poses significant treatment challenges. Previously, no mouse gastric adenocarcinoma (MGA) cell lines with Trp53 (encoding mouse p53) and Cdh1 (encoding mouse E-cadherin) mutations and a high potential for peritoneal metastasis in mice have been established. Here, we derived a mouse GC cell line, called MTC, from subcutaneously transplanted mouse Trp53-/-Cdh1-/- GC organoids. Through matching the short tandem repeat profile of MTC with those in current cell banks, we verified the uniqueness of MTC. Furtherly, we confirmed the features of MTC by detecting the expression of p53, E-cadherin, and pan-CK. After long-term exposure of the original MTC line to PTX, we developed a more aggressive, PTX-resistant cell line, termed MTC-R. Compared with MTC, MTC-R demonstrated enhanced tumorigenicity and high potential for peritoneal metastasis in subcutaneous and intraperitoneal tumour models both in BALB/c nude mice and C57BL/6 J mice. Transcriptome analysis revealed the ECM‒receptor interaction pathway activation during the development of PTX resistance, and dasatinib (DASA) was identified as a potential drug targeting this pathway. DASA showed promise in ameliorating disease progression and improving overall survival in MTC-R GCPM model in C57BL/6 J mice. Overall, we established a novel MGA cell line with Trp53 and Cdh1 mutations and its PTX-resistant variant and demonstrated the efficacy of DASA in treating PTX-resistant GCPM.

Heterogeneity of predictive biomarker expression in gastric and esophago-gastric junction carcinoma with peritoneal dissemination

BACKGROUND

Temporal and spatial molecular heterogeneity contributes to resistance to targeted and immune therapies in gastric and esophagogastric junction carcinoma (G/EGJ). This study evaluates differences in biomarker expression between primary G/EGJ and paired peritoneal metastases (PM).

METHODS

We analyzed 74 cases of primary G/EGJ and paired PM using immunohistochemistry for HER2, PD-L1, Claudin18 (CLDN18), DNA mismatch repair (MMR) proteins, p53, E-cadherin, and in situ hybridization for EBER. Biomarker concordance between primary and metastatic tumors was assessed.

RESULTS

Primary G/EGJ were predominantly poorly cohesive (45.9%) or mixed-type (37.8%). Regarding predictive biomarkers, low rates of HER2 overexpression (5.4%), MMR deficiency (4.1%), and EBER positivity (1.4%) were observed, while PD-L1 CPS ≥ 1 occurred in 79.7% of cases and CLDN18 positivity was observed in 31.1% of cases. Concordance was perfect for MMR and EBER, while PD-L1 showed the highest discordance (32.4%). HER2 had a low discordance rate (2.7%). CLDN18 exhibited good concordance (86.5%) and showed consistent positivity in PD-L1- and HER2-negative primary tumors (28.6%).

CONCLUSION

G/EGJ with PM show distinct molecular features and spatial heterogeneity, with MMR, EBER, and HER2 demonstrating strong concordance, while PD-L1 showed greater variability. As for novel biomarkers, CLDN18.2 shows substantial concordance between primary G/EGJ and PM and could be a promising target in HER2/PD-L1-negative G/EGJ with PM.

Prognostic value of diffusion-weighted imaging to cytoreductive surgery with or without hyperthermic intraperitoneal chemotherapy for patients with gastric cancer and peritoneal metastases

BACKGROUND

To investigate the prognostic value of the apparent diffusion coefficient (ADC) calculated from diffusion-weighted imaging (DWI) to cytoreductive surgery (CRS), with or without hyperthermic intraperitoneal chemotherapy (HIPEC), for gastric cancer (GC) patients with peritoneal metastasis (PM).

METHODS

Between May 2016 and December 2020, 95 newly diagnosed GC patients with PM who underwent CRS combined with HIPEC (CRS + HIPEC group, n = 61) and CRS alone (CRS group, n = 34) were retrospectively included. All patients underwent abdominal 3.0 T MRI scan, including DWI, and the mean ADC (ADCmean), minimum ADC (ADCmin), and maximum ADC (ADCmax) values of the whole-volume tumor were measured. The prognostic value of the ADC parameters and clinical and histopathological characteristics were investigated by univariate and multivariate Cox analyses.

RESULTS

The median overall survival (OS) periods of the CRS + HIPEC and CRS groups were 18 and 9 months, respectively ([hazard ratio (HR) = 0.44 [95% CI: 0.27-0.71], P<0.001). The ADCmean and ADCmin values were positively correlated with OS in all patients (Spearman's rho [R] = 0.361 and 0.470), as well as in the CRS + HIPEC (R = 0.369 and 0.417) and CRS (R = 0.192 and 0.409) groups. The multivariate Cox analysis demonstrated that the ADCmean ≤ 1.39 × 10- 3 mm2/s and ADCmin ≤ 0.77 × 10- 3 mm2/s were significantly associated with a negative prognosis in the total population (HR = 1.68 [95% CI: 1.02-2.75] and 2.48 [95% CI: 1.51-4.08], P all < 0.05) and the CRS + HIPEC group (HR = 2.22 [95% CI: 1.19-4.14] and 2.37 [95% CI: 1.26-4.37], P all < 0.05), along with pathologic T and N stages. Only the ADCmin ≤ 0.77 × 10- 3 mm2/s was identified as an independent prognostic factor in the CRS group (HR = 3.49 [95% CI: 1.19-10.20], P = 0.022).

CONCLUSIONS

The minimum ADC was identified as a strong independent prognostic factor for GC patients with PM who underwent CRS, with or without HIPEC.

Survival outcomes of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in selected patients with stage IV gastric adenocarcinoma - A Canadian case series

INTRODUCTION

Despite advances in systemic therapy, metastatic gastric cancer is associated with a poor prognosis. As peritoneal disease is common, several studies looked at the potential benefits of hyperthermic intraperitoneal chemotherapy (HIPEC) in this context, with encouraging results. However, no Canadian data currently exists on the subject.

MATERIALS AND METHODS

This study aims to report characteristics and outcomes of Canadian patients who underwent cytoreductive surgery and HIPEC (CRS-HIPEC) for gastric cancer associated with peritoneal disease or positive peritoneal cytology. This multicenter retrospective study included patients 18 years or older with gastric cancer associated with isolated peritoneal involvement who underwent CRS-HIPEC in five tertiary centers from 2016 to 2022.

RESULTS

CRS-HIPEC was performed on 20 patients aged 34-69 years old, most of whom presented with poorly differentiated (90 %) adenocarcinoma, with synchronous peritoneal disease (95 %). Median PCI was 3 (0-13). The associated 90-day morbidity rate, defined as Clavien-Dindo grade III and above complications, was 10 %. At a mean follow-up of 23.3 months (range 4-48), 25 % of patients remained disease-free, with an estimated median overall survival of 24.2 months.

CONCLUSION

CRS-HIPEC for gastric cancer can achieve longer term survival in highly selected patients with low-burden peritoneal disease or positive cytology. Ongoing randomized trials will further clarify patients' selection criteria and benefits of this approach.

Molecular and Genetic Markers of Peritoneal Metastasis

Peritoneal surface malignancies (PSMs) represent a biologically diverse group of cancers that range from primary peritoneal mesothelioma to metastatic gastrointestinal cancers. Because of the heterogenous nature of PSM, there is a large gap in molecular characterization of these cancers. This article reviews the underlying molecular and genetic mechanisms for PSM.

The Role of Perirenal Adipose Tissue in Carcinogenesis-From Molecular Mechanism to Therapeutic Perspectives

Perirenal adipose tissue (PRAT) exhibits particular morphological features, with its activity being mainly related to thermogenesis. However, an expanded PRAT area seems to play a significant role in cardiovascular diseases, diabetes mellitus, and chronic kidney disease pathogenesis. Numerous studies have demonstrated that PRAT may support cancer progression and invasion, mainly in obese patients. The mechanism underlying these processes is of dysregulation of PRAT's secretion of adipokines and pro-inflammatory cytokines, such as leptin, adiponectin, chemerin, apelin, omentin-1, vistatin, nesfatin-1, and other pro-inflammatory cytokines, modulated by tumor cells. Cancer cells may also induce a metabolic reprogramming of perirenal adipocytes, leading to increased lipids and lactate transfer to the tumor microenvironment, contributing to cancer growth in a hypoxic milieu. In addition, the PRAT browning process has been specifically detected in renal cell carcinoma (RCC), being characterized by upregulated expression of brown/beige adipocytes markers (UCP1, PPAR-ɣ, c/EBPα, and PGC1α) and downregulated white fat cells markers, such as LEPTIN, SHOX2, HOXC8, and HOXC9. Considering its multifaceted role in cancer, modulation of PRAT's role in tumor progression may open new directions for oncologic therapy improvement. Considering the increasing evidence of the relationship between PRAT and tumor cells, our review aims to provide a comprehensive analysis of the perirenal adipocytes' impact on tumor progression and metastasis.

The artificial intelligence revolution in gastric cancer management: clinical applications

Nowadays, gastric cancer has become a significant issue in the global cancer burden, and its impact cannot be ignored. The rapid development of artificial intelligence technology is attempting to address this situation, aiming to change the clinical management landscape of gastric cancer fundamentally. In this transformative change, machine learning and deep learning, as two core technologies, play a pivotal role, bringing unprecedented innovations and breakthroughs in the diagnosis, treatment, and prognosis evaluation of gastric cancer. This article comprehensively reviews the latest research status and application of artificial intelligence algorithms in gastric cancer, covering multiple dimensions such as image recognition, pathological analysis, personalized treatment, and prognosis risk assessment. These applications not only significantly improve the sensitivity of gastric cancer risk monitoring, the accuracy of diagnosis, and the precision of survival prognosis but also provide robust data support and a scientific basis for clinical decision-making. The integration of artificial intelligence, from optimizing the diagnosis process and enhancing diagnostic efficiency to promoting the practice of precision medicine, demonstrates its promising prospects for reshaping the treatment model of gastric cancer. Although most of the current AI-based models have not been widely used in clinical practice, with the continuous deepening and expansion of precision medicine, we have reason to believe that a new era of AI-driven gastric cancer care is approaching.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for gastric cancer with peritoneal metastases at an Australian centre

INTRODUCTION

Gastric cancer is a major cause of cancer mortality, with poorer prognosis in the presence of peritoneal metastases as low as 2.8-9 months. Systemic therapy has a limited role. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been shown to improve survival. This study evaluates survival of patients with gastric cancer and peritoneal metastases (GCPM) undergoing CRS and HIPEC at an Australian centre.

METHODS

A retrospective analysis was conducted on a prospectively collected database of patients who underwent CRS and HIPEC for GCPM from January 2009 to December 2023. Data included demographics, perioperative factors, histopathology and survival.

RESULTS

Twenty-four patients were identified, with median postoperative overall survival of 11.7 months (95% CI 8.6-34.2 months). Most patients had poorly differentiated adenocarcinoma (n = 23, 96%), with 14 (58%) exhibiting signet cell pathology. 62% (n = 15) received preoperative chemotherapy. Median PCI was 5, with a CC score of 0 in 96% of patients (n = 23). Clavien-Dindo III/IV morbidity was noted in 8 patients (33%) with no perioperative mortality. No survival differences were found between those with signet cell pathology and those without (10.6 vs. 11.7 months, p = 0.83), nor between those receiving preoperative chemotherapy and those who did not (11.7 vs. 10.6 months, p = 0.60). Age, sex, PCI, CC and tumour markers demonstrated correlations with survival in linear regression, but no individual factor significantly influenced outcomes.

CONCLUSION

CRS and HIPEC for low volume GCPM should be considered in select patients.

Gastric cancer peritoneal metastasis: a bibliometric study from 2000 to 2024 using VOSviewer software

Background

Gastric cancer remains a prevalent malignancy worldwide, with peritoneal metastasis being the predominant form of recurrence and metastasis, which are clear predictors of prognosis. The aim of this comprehensive bibliometric analysis was to assess the current status of the research landscape and to identify impending trends in gastric cancer peritoneal metastasis (GCPM).

Methods

Relevant studies of GCPM were retrieved from the Web of Science Core Collection database. Qualified articles were screened based on the inclusion and exclusion criteria for further analysis. The selected publications were then subjected to bibliometric analysis utilizing VOSviewer software.

Results

In total, 1,100 publications were included for analysis. The results revealed a consistent upward trend in the number of publications annually from 2000 to 2024, with an anticipated continuation of this growth in future research. The National Cancer Center Japan, emerged as the institution with the most publications and Professor Kodera and Annals of Surgical Oncology were identified as the most influential author and journal, respectively, in the domain of GCPM. In terms of international collaborations, the USA, Japan, and France were the most engaged countries. Yonemura was recognized as the most frequently cited author. Gastrectomy, systemic chemotherapy, and intraperitoneal therapy are the current research hotspots within this domain.

Conclusion

Research related to GCPM had rapidly increased over the past two decades. These findings identify the most influential countries, institutions, authors, journals, and academic collaboration networks, while also clarifying hotspots and future trends in GCPM research.

The prognostic value of peritoneal metastases in patients with gastric cancer: a nationwide population-based study

BACKGROUND

The peritoneum is a common metastatic site in gastric cancer. The prognosis of synchronous peritoneal metastases compared to other metastatic sites in gastric cancer remains understudied. This study aims to evaluate the impact of peritoneal metastases on survival in patients with metastatic gastric cancer.

METHODS

Patients with gastric cancer and synchronous metastases between 2015 and 2020 were identified from the nationwide Netherlands Cancer Registry. Patients were categorized based on the site of metastases. Median overall survival (OS) was calculated for each metastatic site group. Multivariable Cox regression analyses were performed to evaluate the association between patient, tumour, and treatment characteristics, including the impact of systemic therapy, on OS.

FINDINGS

A total of 4072 patients were included, of whom 1835 (45.1%) had peritoneal metastases. Of these, 58.1% had isolated peritoneal metastases. For patients with metastatic gastric cancer treated with systemic therapy, the median OS was 9.0 months (95% confidence interval (CI): 8.6-9.5), compared to 1.7 months (95% CI: 1.7-1.9) for treatment-naïve patients, who received only palliative care. The survival for patients with isolated peritoneal metastases (4.4 months, 95% CI: 4.0-4.8 months) was similar to those with isolated non-peritoneal metastases (4.6 months, 95% CI: 4.2-5.1 months, adjusted HR: 0.94, 95% CI: 0.86-1.03, p = 0.185). Systemic therapy was associated with comparable survival in patients with peritoneal metastases and those with metastases at other sites.

INTERPRETATION

This study demonstrates that there is no statistically significant difference in survival between patients with isolated peritoneal metastases and those with isolated non-peritoneal metastases in gastric cancer. Our findings emphasize the unique prognostic landscape for peritoneal metastases in gastric cancer, underscoring the need for disease-specific evaluations, rather than relying on assumptions derived from other cancer types.

FUNDING

None.

Imaging in malignant peritoneal neoplasms

Peritoneal malignancies encompass a diverse range of tumors originating within the peritoneum, including primary tumors such as mesothelioma and primary serous peritoneal carcinoma or secondary tumors resulting from the spread of cancers from gastrointestinal, gynecological, and extra-abdominal sources. The traditional approach of palliative care for these malignancies is being replaced by a multimodal strategies that integrates surgery with systemic or intraperitoneal chemotherapy. Notably, cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy has shown significant improvements in survival rates. Imaging is crucial in the multidisciplinary management of these tumors, aiding in diagnosis, staging, restaging, and monitoring therapy response. It is also vital for appropriate patient selection, using the acronym "PAUSE", which involves assessing tumor burden via the peritoneal carcinomatosis index, evaluating patients pre- and post-therapy, detecting complications following therapy, and predicting treatment outcomes. This review explores the imaging manifestations of peritoneal malignancies, distinguishing them from various mimics, and underscores the importance of imaging modalities such as CT, MRI, PET/CT, and PET/MRI in effective decision-making and management.

Treatment of Gastric Cancer Carcinomatosis

Patients with gastric cancer peritoneal metastases (GCPM) have Stage IV disease. Systemic therapy is a crucial aspect of their care. Patients with GCPM should have their tumors tested for HER2 and PD-L1 expression and microsatellite instability for potential targeted therapies. If patients with synchronous GCPM have stable disease following neoadjuvant therapy, surgical intervention can be considered. Patients with positive cytology or low-volume peritoneal disease (peritoneal carcinomatosis index [PCI] < 7) may "convert" to negative cytology or resolution of peritoneal metastases following intraperitoneal therapy and may be candidates for subsequent gastrectomy.

Outcomes of intraperitoneal chemotherapy for the treatment of gastric cancer with peritoneal metastasis: A comprehensive systematic review and meta-analysis

BACKGROUND

Peritoneal metastasis is common in gastric cancer and linked to poor survival. Treatment of peritoneal metastasis with intraperitoneal chemotherapy has become an accepted practice in some centres. This systematic review and meta-analysis intends to provide a comprehensive evaluation of published evidence for the use of intraperitoneal chemotherapy is gastric cancer patients with peritoneal metastasis.

METHODS

A systematic literature search for studies reporting the use of intraperitoneal chemotherapy for the treatment gastric cancer with macroscopic peritoneal metastasis was performed up until June 2024. Studies were not eligible for inclusion if they described the use of intraperitoneal chemotherapy solely as an adjunct to gastrectomy or cytoreductive surgery. Pooled- and meta-analysis was used to summarise study outcomes.

RESULTS

Fifty-three studies reporting the outcomes of 2446 gastric cancer patients who received intraperitoneal chemotherapy for the treatment of peritoneal metastasis, were included. Three principal methods of intraperitoneal chemotherapy administration were described: catheter based (normothermic) intraperitoneal chemotherapy (n = 28); pressurised intraperitoneal aerosolised chemotherapy (n = 14), and; hyperthermic intraperitoneal chemotherapy (n = 11). The proportion of patients with complete peritoneal disease regression after receiving intraperitoneal chemotherapy was 27 % (95%CI, 14-41). Median overall survival determined was 16.4 months (95%CI, 14.4-18.4). Meta-analysis of data from eight studies comparing combined intraperitoneal and systemic chemotherapy with systemic chemotherapy alone identified a survival benefit for patients receiving intraperitoneal chemotherapy (Hazard ratio 0.57 [95%CI, 0.48-0.67],P < 0.001).

CONCLUSION

Despite variation in published treatment approaches and a lack of evidence from well-designed clinical trials, intraperitoneal chemotherapy may be considered safe and in selected circumstances efficacious.

Characteristics and clinical significance of immune cells in omental milky spots of patients with gastric cancer

The omentum is a common site of peritoneal metastasis in various cancers, including gastric cancer. It contains immune cell aggregates known as milky spots, which provide a microenvironment for peritoneal immunity by regulating innate and adaptive immune responses. In this study, we investigated gene expression profiles in cells from omental milky spots of patients with gastric cancer (n = 37) by RNA sequencing analysis and classified the patients into four groups (G1-4). Notably, significant differences were observed between the groups in terms of macroscopic type, lymphatic invasion, venous invasion, and pathological stage (pStage). G3, which was enriched in genes related to acquired immunity, showed earlier tumor stages (macroscopic type 0, Ly0, V0, and pStage I) and a better prognosis. In contrast, G4 showed enrichment of genes related to neutrophils and innate immunity; G1 and G2 showed no enrichment of innate or adaptive immune-related genes, suggesting an immune desert microenvironment. Cytometric analysis revealed significantly more T and B cells and fewer neutrophils in G3. Accordingly, the immune microenvironment in omental milky spots may vary depending on the stage of gastric cancer progression. When univariate Cox proportional hazards regression models were used to search for prognostically relevant genes specific to G3, 23 potential prognostic genes were identified as common genes associated with relapse-free survival and overall survival. In addition, the multivariate Cox proportional hazards model using these prognostic genes and clinicopathological information showed that combining the B cell marker CD19 and Ly had a high predictive accuracy for prognosis. Based on this study's results, it is possible that tumor progression, such as lymphatic and/or venous infiltration of tumor cells, may affect the immune cell composition and proportions in omental milky spots of patients with gastric cancer and analysis of gene expression in omental milky spots may help to predict gastric cancer prognosis.

Iterative Intraperitoneal Chemotherapy in Gastric Cancer Peritoneal Carcinomatosis

Background/objectives: Despite the incremental improvement of survival with systemic therapy in metastatic gastric cancer (GC), the outcomes of patients with peritoneal carcinomatosis (PC) remain poor. The limited effectiveness of systemic therapy is attributed to the blood-peritoneal barrier and anarchic intra-tumoral circulation, which reduce the penetration of systemic therapy. Approaches that incorporate intraperitoneal (IP) chemotherapy, in addition to systemic therapies, may be a viable alternate strategy. Therefore, we provide a review of biology of gastric cancer peritoneal metastasis and evidence for bidirectional iterative IP chemotherapy in GCPC. Methods: A comprehensive search in PubMed, Scopus, Embase, Web of Science, Google Scholar, and ClinicalTrials.gov was performed to find the relevant articles and ongoing phase II/III clinical trials in iterative IP chemotherapy in GCPC. Results: Intraperitoneal (IP) chemotherapy leverages the blood-peritoneal barrier to allow for the administration of high concentrations of chemotherapy directly to the peritoneal metastases, with a significant reduction in the systemic toxicity and enhanced drug efficacy against peritoneal metastasis. This pharmacokinetic advantage of IP chemotherapy can be further enhanced by additional measures such as heat or aerosolization. There are three IP chemotherapy approaches, namely, heated intraperitoneal chemotherapy (HIPEC), pressurized intraperitoneal aerosolized chemotherapy (PIPAC), and normothermic intraperitoneal chemotherapy (NIPEC). Recent evidence suggests that iterative IP chemotherapy combined with systemic therapy may offer significant survival benefits for patients with peritoneal metastasis. Furthermore, bidirectional treatment approaches may also increase the chances of surgical resection and survival. Conclusions: IP chemotherapy plays a pivotal role in the management of gastric carcinomatosis, particularly in combination with cytoreduction in highly selected patients. The combination of systemic and regional control may increase the chances of surgical resection and may ultimately lead to significant survival benefits.

Efficacy analysis of prophylactic hyperthermic intraperitoneal chemotherapy in patients with locally advanced gastric cancer: a retrospective study

Purpose

This study aims to evaluate the effectiveness and safety of prophylactic hyperthermic intraperitoneal chemotherapy (P-HIPEC) in patients with locally advanced gastric cancer (AGC) after laparoscopic radical gastrectomy. Additionally, it explores how the frequency and timing of P-HIPEC influence treatment outcomes.

Methods

A retrospective analysis was conducted on 227 patients with locally AGC who underwent laparoscopic surgery at Maoming People's Hospital from January 2016 to December 2022. Patients were stratified into the HIPEC group (n=101) and the non-HIPEC group (n=126), based on whether they received postoperative P-HIPEC. Propensity score matching (PSM) was used to adjust for baseline characteristics, facilitating a comparative analysis of survival outcomes, postoperative complications and recurrence patterns. Cox regression analysis was performed to identify prognostic factors. Furthermore, the impact of varying P-HIPEC frequencies and initiation timings was evaluated.

Results

No significant differences in overall survival (OS) or postoperative complication rates were observed between the two groups in the original and PSM cohorts. But the disease-free survival (DFS) of the HIPEC group was significantly higher than that of the non-HIPEC group (HR 0.569; 95% CI 0.362-0.894; p = 0.013) in the PSM cohort, with 1-year, 3-year, and 5-year DFS rates showing notable improvement (77.9% vs. 69.7%, 60.1% vs. 43.0%, and 46.2% vs. 25.5%). The incidence of isolated peritoneal metastasis (PM) was significantly lower in the HIPEC group (5.3% vs. 17.3%, p = 0.039). Multivariate Cox regression analysis identified P-HIPEC as an independent protective factor for DFS. Further analysis indicated that neither the number of P-HIPEC sessions had a significant impact on OS (p = 0.388) or DFS (p = 0.735), nor did the timing of P-HIPEC initiation affect OS (p = 0.620) or DFS (p = 0.488). Likewise, different P-HIPEC frequencies or initiation timings had no significant impact on postoperative complication rates or recurrence patterns.

Conclusion

P-HIPEC effectively reduces the risk of postoperative PM and improves DFS in patients with locally AGC without increasing postoperative complications. However, it does not significantly impact OS. Additionally, variations in the frequency and timing of P-HIPEC initiation do not significantly affect survival outcomes, postoperative complications, or recurrence patterns.

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.

Exploring the Efficacy of Hyperthermic Intraperitoneal Perfusion Chemotherapy in Gastric Cancer: Meta-analysis Based on Randomized Controlled Trials

PURPOSE

Based on randomized clinical trials, this meta-analysis evaluated the efficacy and safety of intent-to-cure or prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) for the treatment of gastric cancer.

METHODS

PubMed, Cochrane Library, Medline, and Embase databases were all systemically searched from 2004 to 2023. The quality of the study was assessed by using the Cochrane risk of bias method. The certainty of the evidence was determined by using the GRADE evaluation.

RESULTS

In this study, 12 articles with a total of 1181 patients were analyzed based on the inclusion criteria. The findings revealed that HIPEC had a higher survival rate (risk ratio [RR] 0.60; 95% confidence interval [CI] [0.43, 0.86], P = 0.005, RR 0.82; 95% CI [0.70, 0.97], P = 0.02, RR 0.83; 95% CI [0.71, 0.96], P < 0.01, and RR 0.63 [0.54, 0.73], P < 0.00001) after 1, 2, 3, and 5 years compared with the control group. The RR was statistically significant for 1, 2, 3, and 5 years. Furthermore, the observed overall recurrence rate for the HIPEC group was lower than control group and statistically significant (RR 0.59; 95% CI [0.50, 0.68], P < 0.0001). Higher disease-free survival rate (RR 1.42; 95% CI [1.07, 1.89], P < 0.01) was observed in the HIPEC group and statistically significant.

CONCLUSIONS

Gastric cancer patients treated with HIPEC have shown promising outcomes with regard to survival, recurrence, disease-free survival, and adverse reactions. However, multicenter trials with larger sample sizes consisting of different ethnicities is suggested.

Evolution in the Surgical Management of Gastric Cancer Peritoneal Metastases

Despite therapeutic treatments and the growing utilization of multimodal therapies, gastric cancer (GC) remains a highly aggressive malignancy with high mortality worldwide. Much of the complexity in treating GC is due to the high incidence of peritoneal metastasis (PM), with mean overall survival typically ranging from 4 to 10 months. With current systemic therapy, targeted therapies, and immunotherapies continuing to remain ineffective for GC/PM, there has been a significant growing interest in intraperitoneal (IP) therapies for the treatment of GC/PM. In this review, we summarize the development of PM and evolving treatment strategies for GC/PM. Furthermore, we explore the various advancements and outcomes of IP therapies, including heated intraperitoneal chemotherapy (HIPEC), neoadjuvant HIPEC, and pressurized intraperitoneal aerosolized chemotherapy (PIPAC).

Transcriptional landscape and predictive potential of long noncoding RNAs in peritoneal recurrence of gastric cancer

BACKGROUND

Long noncoding RNAs (lncRNAs) play a critical role in gastric cancer (GC) progression and metastasis. However, research comprehensively exploring tissue-derived lncRNAs for predicting peritoneal recurrence in patients with GC remains limited. This study aims to investigate the transcriptional landscape of lncRNAs in GC with peritoneal metastasis (PM) and to develop an integrated lncRNA-based score to predict peritoneal recurrence in patients with GC after radical gastrectomy.

METHODS

We analyzed the transcriptome profile of lncRNAs in paired peritoneal, primary gastric tumor, and normal tissue specimens from 12 patients with GC in the Sun Yat-sen University Cancer Center (SYSUCC) discovery cohort. Key lncRNAs were identified via interactive analysis with the TCGA database and SYSUCC validation cohort. A score model was constructed using the LASSO regression model and nomogram COX regression and evaluated using receiver operating characteristic curves. The role of lncRNAs in the PM of GC was then examined through wound healing, Transwell, 3D multicellular tumor spheroid invasion, and peritoneal cavity xenograft tumorigenicity assays in mice.

RESULT

Five essential lncRNAs were screened and incorporated into the PM risk score to predict peritoneal recurrence-free survival (pRFS). We developed a comprehensive, integrated nomogram score, including the PM risk score, pT, pN, and tumor size, which could effectively predict the 5-year pRFS with an Area under the curve of 0.79 (95% CI: 0.71-0.88). Subsequently, we demonstrated that one of these lncRNAs, CASC15, promoted the invasion and migration of GC cells in vitro and facilitated the PM of GC cells in vivo, initially verifying that lncRNAs contribute to the PM of GC. Mechanistic analysis demonstrated that CASC15 promoted EMT and metastasis by activating the JNK and p38 pathways.

CONCLUSION

A lncRNA-based integrated score was constructed in this study to predict peritoneal recurrence in patients clinically.

Conversion surgery for stage IV gastric cancer after third-line immunotherapy: a case report

The 5-year overall survival rate for stage IV gastric cancer is lower than 10%, despite the development of systemic therapy. Conversion surgery has shown to improve survival outcomes in patients with durable clinical response on chemotherapy. We report a clinical case of a patient, who underwent conversion surgery after pembrolizumab in the third-line setting for stage IV gastric cancer. The patient did not have recurrence for 22 months after conversion surgery.

Survival Outcomes of Cytoreductive Surgery with HIPEC in Gastric Adenocarcinoma: A National Cancer Database Study

BACKGROUND

This study aimed to assess the impact of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) on the survival outcomes for patients with gastric cancer and peritoneal carcinomatosis (PC).

METHODS

A retrospective analysis of the National Cancer Database from 2004 to 2020 identified patients with topography and histology codes consistent with gastric adenocarcinoma who underwent CRS/HIPEC. The exclusion criteria ruled out known other distant metastasis and missing key data. The study compared the CRS/HIPEC group with patients who had stage IV disease (with the same exclusions for distant metastases) and received systemic chemotherapy but no surgery to the primary site.

RESULTS

The study included 148 patients who underwent CRS/HIPEC. Their median age was 57 years (interquartile range [IQR], 47-66 years), with 57.4% of the patients identifying as male and 73.6% identifying as white. Most of the CRS/HIPEC patients had locally advanced disease, with 33.8% having pT4 disease and 23% patients having pN3 status. The Charlson-Deyo scores were 0 for 77% and 1 for 16.9% of the patients. The overall survival (OS) among the stage IV patients managed with CRS/HIPEC was significantly longer than for the patients receiving only systemic chemotherapy (median survival, 18.1 vs 9.3 months; p < 0.001), and the 1-year OS was 72.6% versus 38.8% (p < 0.05)). Among the stage IV patients, CRS/HIPEC showed better survival than systemic chemotherapy (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.44-0.73; p < .001) when control was used for the Charlson Deyo score, histology, age, and sex.

CONCLUSIONS

These results suggest the association of CRS/HIPEC with improved survival for selected patients with gastric adenocarcinoma and peritoneal disease. Some of this difference may have been due to selection bias, but the differences in the survival curves are robust.

A comprehensive overview of gastric cancer management from a surgical point of view

Despite advancements in medical care, surgical technologies, and the development of novel treatments over the past decade, the prognosis for patients with gastric cancer (GC) has only modestly improved. This is primarily due to the fact that the majority of patients are diagnosed at advanced stages or present with metastatic disease. Radical resection remains the cornerstone of potentially curative treatment, yet the overall 5-year survival rate remains below 35%. The management of GC varies globally, influenced by factors such as geographical disparities, patient comorbidities and performance status, surgical approaches, and available medical resources. Multidisciplinary collaboration and a multimodal treatment approach are essential for optimizing patient outcomes. Surgeons must stay updated on emerging surgical concepts and make informed decisions regarding patient selection, timing of intervention, and the adoption of appropriate surgical techniques to improve both quality of life and prognosis. This review aims to provide a surgical perspective on the management of GC across all stages, highlighting the importance of a comprehensive treatment approach. Endoscopic resection may be a viable option for early GC in patients with minimal risk of lymph node metastasis, particularly in elderly patients with high surgical risk or severe comorbidities. For advanced GC, neoadjuvant therapy followed by surgery could be a promising strategy to improve patient outcomes. Conversion surgery offers a potential survival benefit for patients who respond to treatment with tumor downstaging. The treatment of peritoneal carcinomatosis remains challenging; however, hyperthermic intraperitoneal chemotherapy combined with complete cytoreductive surgery or pressurized intraperitoneal aerosolized chemotherapy may prolong survival or improve quality of life in highly selected patients.

Optimal hyperthermic intraperitoneal chemotherapy regimen for advanced and peritoneal metastatic gastric cancer: a systematic review and Bayesian network meta-analysis

Background

Peritoneal metastasis is one of the most common modes of spread of gastric cancer. Currently, surgical treatment combined with hyperthermic intraperitoneal chemotherapy (HIPEC) and systemic chemotherapy has demonstrated promising outcomes in both the treatment and prevention of peritoneal metastasis in gastric cancer. However, various HIPEC drug regimens are in clinical use, and their efficacy remains unclear. This study aims to evaluate the effectiveness of different HIPEC drug regimens in patients with advanced gastric cancer to determine the optimal therapeutic approach.

Methods

This study conducted a systematic review and Bayesian network meta-analysis. Patients in the experimental group underwent surgery combined with HIPEC and chemotherapy. The search period covered literature from database inception to June 1, 2024. Hazard ratios (HRs) with 95% confidence intervals (CIs) were used to evaluate overall survival (OS) as the primary outcome. Odds ratios (ORs) with 95% CIs were used to assess overall disease recurrence, peritoneal recurrence, and postoperative morbidity as secondary outcomes. To ensure scientific rigor and transparency, this study has been registered with PROSPERO (CRD42024533948).

Results

A total of 11 randomized controlled trials (RCTs) involving 1092 patients were included. Compared to surgery combined with chemotherapy, the regimens of cisplatin (HRs = 0.52, 95% CI: 0.38-0.73), mitomycin C (HRs = 0.99, 95% CI: 0.55-1.79), cisplatin plus fluorouracil (HRs = 0.60, 95% CI: 0.38-0.95), and oxaliplatin plus 5-fluorouracil (HRs = 0.53, 95% CI: 0.36-0.78) all demonstrated benefits in OS. The cisplatin (ORs = 0.16, 95% CI: 0.03-0.60) and mitomycin C (ORs = 0.03, 95% CI: 0-0.71) regimens also showed advantages in reducing peritoneal recurrence, with no impact on postoperative morbidity. Importantly, the cisplatin regimen was superior to other regimens in terms of OS and overall disease recurrence, achieving a balance between efficacy and safety.

Conclusions

Compared to chemotherapy alone, HIPEC treatment shows significant benefits in OS without a notable disadvantage in postoperative morbidity. Although no single HIPEC regimen demonstrated clear benefits across all outcomes, the cisplatin regimen performed well in multiple aspects, indicating its potential for further research and clinical application.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=533948, identifier CRD42024533948.

Multitask machine learning-based tumor-associated collagen signatures predict peritoneal recurrence and disease-free survival in gastric cancer

BACKGROUND

Accurate prediction of peritoneal recurrence for gastric cancer (GC) is crucial in clinic. The collagen alterations in tumor microenvironment affect the migration and treatment response of cancer cells. Herein, we proposed multitask machine learning-based tumor-associated collagen signatures (TACS), which are composed of quantitative collagen features derived from multiphoton imaging, to simultaneously predict peritoneal recurrence (TACSPR) and disease-free survival (TACSDFS).

METHODS

Among 713 consecutive patients, with 275 in training cohort, 222 patients in internal validation cohort, and 216 patients in external validation cohort, we developed and validated a multitask machine learning model for simultaneously predicting peritoneal recurrence (TACSPR) and disease-free survival (TACSDFS). The accuracy of the model for prediction of peritoneal recurrence and prognosis as well as its association with adjuvant chemotherapy were evaluated.

RESULTS

The TACSPR and TACSDFS were independently associated with peritoneal recurrence and disease-free survival in three cohorts, respectively (all P < 0.001). The TACSPR demonstrated a favorable performance for peritoneal recurrence in all three cohorts. In addition, the TACSDFS also showed a satisfactory accuracy for disease-free survival among included patients. For stage II and III diseases, adjuvant chemotherapy improved the survival of patients with low TACSPR and low TACSDFS, or high TACSPR and low TACSDFS, or low TACSPR and high TACSDFS, but had no impact on patients with high TACSPR and high TACSDFS.

CONCLUSIONS

The multitask machine learning model allows accurate prediction of peritoneal recurrence and survival for GC and could distinguish patients who might benefit from adjuvant chemotherapy.

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.

Prediction of surgical benefit in gastric cancer patients with peritoneal metastasis treated with hyperthermic intraperitoneal chemotherapy

The objective is to evaluate whether gastric cancer patients with peritoneal metastasis can benefit from surgery through a comprehensive analysis of different clinical factors and perioperative treatment methods. A total of 135 gastric cancer patients with peritoneal metastasis were treated with Hyperthermic intraperitoneal chemotherapy (HIPEC). Patients were divided into either training group (without surgery, n = 90) or test group (with surgery, n = 45). A nomogram was constructed based on significant prognostic factors. The patients were divided into high- and low-risk groups using a nomogram. Overall survival were then compared according to whether surgery was performed in both groups. Alpha-fetoprotein (AFP), complications, conversion chemotherapy, and postoperative chemotherapy were significantly associated with overall survival (p < 0.05). A nomogram was constructed using the above four factors and validated using the test set. The area under the curve (AUC) of the model was 0.752 (95% CI 0.525-978). In the group that did not undergo surgery, the median survival times for the high-risk and low-risk groups were 7 and 11 months, respectively. In the surgery group, the median survival times for the high-risk and low-risk groups were 11 and 19 months, respectively. The difference was statistically significant (p < 0.0001). The four-factor nomogram can accurately predict high-risk and low-risk populations. Our findings suggest that cytoreductive surgery combined with HIPEC can improve the survival time of patients in both groups.

The role of DGAT1 and DGAT2 in tumor progression via fatty acid metabolism: A comprehensive review

Fatty acid metabolism is a complex biochemical process, including the production, breakdown and application of fatty acids. Not only is it an important component of lipid metabolism, fatty acid metabolism is also connected to the energy metabolism pathways of cells and plays a vital role in maintaining the energy balance of organisms. Diacylglycerol-O-acyltransferase 1 (DGAT1) and Diacylglycerol-O-acyltransferase 2 (DGAT2) are key components in regulating lipid metabolism, which provide energy for cell proliferation and growth. Recent studies have shown that DGAT1 and DGAT2 influence tumor progression through fatty acid metabolism in cancer. Although DGAT1 and DGAT2 have similar names, they differ significantly in various aspects and play distinct roles in individual tumors. A comparative analysis of the physiological roles of these enzymes and their differential expressions in different types of tumors will enhance our understanding of their unique characteristics. This article summarizes the characteristics of tumor fatty acid metabolism and explains how DGAT1 and DGAT2 specifically promote tumor progression. In addition, this review discusses the potential of lipid-lowering drugs in tumor treatment, providing a new perspective on targeting fatty acid metabolism to inhibit tumor progression in the future, while emphasizing the importance of DGAT1 and DGAT2 as potential targets for tumor treatment.

Single-cell characterization of differentiation trajectories and drug resistance features in gastric cancer with peritoneal metastasis

BACKGROUND

Gastric cancer patients with peritoneal metastasis (GCPM) experience a rapidly deteriorating clinical trajectory characterized by therapeutic resistance and dismal survival, particularly following the development of malignant ascites. However, the intricate dynamics within the peritoneal microenvironment (PME) during the treatment process remain largely unknown.

METHODS

Matched samples from primary tumours (PT), peritoneal metastases (PM), and paired pre-treatment and post-chemo/immunotherapy (anti-PD-1/PD-L1) progression malignant ascites samples, were collected from 48 patients. These samples were subjected to single-cell RNA sequencing (n = 30), multiplex immunofluorescence (n = 30), and spatial transcriptomics (n = 3). Furthermore, post hoc analyses of a phase 1 clinical trial (n = 20, NCT03710265) and an in-house immunotherapy cohort (n = 499) were conducted to validate the findings.

RESULTS

Tracing the evolutionary trajectory of epithelial cells unveiled the terminally differentially MUC1+ cancer cells with a high epithelial-to-mesenchymal transition potential, and they demonstrated spatial proximity with fibroblasts and endothelial cells, correlating with poor prognosis. A significant expansion of macrophage infiltrates, which exhibited the highest proangiogenic activity, was observed in the ascites compared with PT and PM. Besides, higher C1Q+ macrophage infiltrates correlated with significantly lower GZMA+ T-lymphocyte infiltrates in therapeutic failure cases, potentially mediated by the LGALS9-CD45 and SPP1-CD44 ligand-receptor interactions. In the chemoresistant group, intimate interactions between C1Q+ macrophages and fibroblasts through the complement activation pathway were found. In the group demonstrating immunoresistance, heightened TGF-β production activity was detected in MUC1+ cancer cells, and they were skewed to interplay with C1Q+ macrophages through the GDF15-TGF-βR2 axis. Ultimately, post hoc analyses indicated that co-targeting TGF-β and PDL1 pathways may confer superior clinical benefits than sole anti-PD-1/PD-L1 therapy for patients presenting with GCPM at the time of diagnosis.

CONCLUSIONS

Our findings elucidated the cellular differentiation trajectories and crucial drug resistance features within PME, facilitating the exploration of effective targets for GCPM treatment.

HIGHLIGHTS

MUC1+ cancer cells with a high epithelial-to-mesenchymal transition potential and exhibiting spatial proximity to fibroblasts and endothelial cells constitute the driving force of gastric cancer peritoneal metastasis (GCPM). Higher C1Q+ macrophage infiltrates correlated with significantly lower GZMA+ T-lymphocyte infiltrates within the peritoneal microenvironment in therapeutic failure cases. Co-targeting TGF-β and PDL1 pathways may confer superior clinical benefits than sole anti-PD-1/PD-L1 therapy for patients presenting with GCPM at diagnosis.

Utility of Combined Use of Imaging Features From Abdominopelvic CT and CA 125 to Identify Presence of CT Occult Peritoneal Metastases in Advanced Gastric Cancer

OBJECTIVE

The purpose of this study is to identify the presence of occult peritoneal metastasis (OPM) in patients with advanced gastric cancer (AGC) by using clinical characteristics and abdominopelvic computed tomography (CT) features.

METHODS

This retrospective study included 66 patients with OPM and 111 patients without peritoneal metastasis (non-PM [NPM]) who underwent preoperative contrast-enhanced CT between January 2020 and December 2021. Occult PMs means PMs that are missed by CT but later diagnosed by laparoscopy or laparotomy. Patients with NPM means patients have neither PM nor other distant metastases, indicating there is no evidence of distant metastases in patients with AGC. Patients' clinical characteristics and CT features such as tumor marker, Borrmann IV, enhancement patterns, and pelvic ascites were observed by 2 experienced radiologists. Computed tomography features and clinical characteristics were combined to construct an indicator for identifying the presence of OPM in patients with AGC based on a logistic regression model. Receiver operating characteristic curves and the area under the receiver operating characteristic curve (AUC) were generated to assess the diagnostic performance of the combined indicator.

RESULTS

Four independent predictors (Borrmann IV, pelvic ascites, carbohydrate antigen 125, and normalized arterial CT value) differed significantly between OPM and NPM and performed outstandingly in distinguishing patients with OPM from those without PM (AUC = 0.643-0.696). The combined indicator showed a higher AUC value than the independent risk factors (0.820 vs 0.643-0.696).

CONCLUSIONS

The combined indicator based on abdominopelvic CT features and carbohydrate antigen 125 may assist clinicians in identifying the presence of CT OPMs in patients with AGC.

[Gender medicine in peritoneal diseases]

Diseases of the peritoneum are divided into benign and malignant, whereby malignant diseases are more frequent. The incidence of peritoneal metastases is difficult to determine as they are frequently not listed separately in cancer databases and registries. Peritoneal metastases can be caused by many primary tumors but are particularly frequent in gastric, ovarian and colorectal carcinomas. Systemic chemotherapy shows gender-specific differences in the tolerability, especially gastrointestinal side effects and hematological toxicity occur more often in women. Surgical treatment options in selected patients include cytoreductive surgery with or without hyperthermic intraperitoneal chemoperfusion (HIPEC). The treatment recommendations depend on the primary tumor entity and the stage of the disease. Hysterectomy and/or salpingo-oophorectomy is often necessary during cytoreductive surgery. As the incidence of cancerous diseases is increasing in younger patients, the aspect of fertility is becoming increasingly more important. The iatrogenically induced menopause is another aspect that needs to be addressed after these types of procedures. Women with gastric and colorectal cancer tend to have a slightly better survival rate, especially in localized tumors; however, in advanced tumor stages the survival rates are comparable. Even if gender-specific differences in incidence, treatment response and adverse events are conspicuous, there is so far no exact explanation for these differences. More studies are needed in order to treat both genders as adequately as possible, with low adverse events and to achieve the best possible outcome.

Hyperthermic intraoperative peritoneal chemotherapy and cytoreductive surgery for people with peritoneal metastases: a systematic review and cost-effectiveness analysis

Background

We compared the relative benefits, harms and cost-effectiveness of hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery ± systemic chemotherapy versus cytoreductive surgery ± systemic chemotherapy or systemic chemotherapy alone in people with peritoneal metastases from colorectal, gastric or ovarian cancers by a systematic review, meta-analysis and model-based cost-utility analysis.

Methods

We searched MEDLINE, EMBASE, Cochrane Library and the Science Citation Index, ClinicalTrials.gov and WHO ICTRP trial registers until 14 April 2022. We included only randomised controlled trials addressing the research objectives. We used the Cochrane risk of bias tool version 2 to assess the risk of bias in randomised controlled trials. We used the random-effects model for data synthesis when applicable. For the cost-effectiveness analysis, we performed a model-based cost-utility analysis using methods recommended by The National Institute for Health and Care Excellence.

Results

The systematic review included a total of eight randomised controlled trials (seven randomised controlled trials, 955 participants included in the quantitative analysis). All comparisons other than those for stage III or greater epithelial ovarian cancer contained only one trial, indicating the paucity of randomised controlled trials that provided data. For colorectal cancer, hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy probably results in little to no difference in all-cause mortality (60.6% vs. 60.6%; hazard ratio 1.00, 95% confidence interval 0.63 to 1.58) and may increase the serious adverse event proportions compared to cytoreductive surgery ± systemic chemotherapy (25.6% vs. 15.2%; risk ratio 1.69, 95% confidence interval 1.03 to 2.77). Hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy probably decreases all-cause mortality compared to fluorouracil-based systemic chemotherapy alone (40.8% vs. 60.8%; hazard ratio 0.55, 95% confidence interval 0.32 to 0.95). For gastric cancer, there is high uncertainty about the effects of hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy versus cytoreductive surgery + systemic chemotherapy or systemic chemotherapy alone on all-cause mortality. For stage III or greater epithelial ovarian cancer undergoing interval cytoreductive surgery, hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy probably decreases all-cause mortality compared to cytoreductive surgery + systemic chemotherapy (46.3% vs. 57.4%; hazard ratio 0.73, 95% confidence interval 0.57 to 0.93). Hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy may not be cost-effective versus cytoreductive surgery + systemic chemotherapy for colorectal cancer but may be cost-effective for the remaining comparisons.

Limitations

We were unable to obtain individual participant data as planned. The limited number of randomised controlled trials for each comparison and the paucity of data on health-related quality of life mean that the recommendations may change as new evidence (from trials with a low risk of bias) emerges.

Conclusions

In people with peritoneal metastases from colorectal cancer with limited peritoneal metastases and who are likely to withstand major surgery, hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy should not be used in routine clinical practice (strong recommendation). There is considerable uncertainty as to whether hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy or cytoreductive surgery + systemic chemotherapy should be offered to patients with gastric cancer and peritoneal metastases (no recommendation). Hyperthermic intraoperative peritoneal chemotherapy + cytoreductive surgery + systemic chemotherapy should be offered routinely to women with stage III or greater epithelial ovarian cancer and metastases confined to the abdomen requiring and likely to withstand interval cytoreductive surgery after chemotherapy (strong recommendation).

Future work

More randomised controlled trials are necessary.

Study registration

This study is registered as PROSPERO CRD42019130504.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/135/02) and is published in full in Health Technology Assessment; Vol. 28, No. 51. See the NIHR Funding and Awards website for further award information.

Measurement of metabolite levels and treatment-induced changes in hepatic metastases of gastro-esophageal cancer using 7-T phosphorus magnetic resonance spectroscopic imaging

Methods for early treatment response evaluation to systemic therapy of liver metastases are lacking. Tumor tissue often exhibits an increased ratio of phosphomonoesters to phosphodiesters (PME/PDE), which can be noninvasively measured by phosphorus magnetic resonance spectroscopy (31P MRS), and may be a marker for early therapy response assessment in liver metastases. However, with commonly used 31P surface coils for liver 31P MRS, the liver is not fully covered, and metastases may be missed. The objective of this study was to demonstrate the feasibility of 31P MRS imaging (31P MRSI) with full liver coverage to assess 31P metabolite levels and chemotherapy-induced changes in liver metastases of gastro-esophageal cancer, using a 31P whole-body birdcage transmit coil in combination with a 31P body receive array at 7 T. 3D 31P MRSI data were acquired in two patients with hepatic metastases of esophageal cancer, before the start of chemotherapy and after 2 (and 9 in patient 2) weeks of chemotherapy. 3D 31P MRSI acquisitions were performed using an integrated 31P whole-body transmit coil in combination with a 16-channel body receive array at 7 T, with a field of view covering the full abdomen and a nominal voxel size of 20-mm isotropic. From the 31P MRSI data, 12 31P metabolite signals were quantified. Prior to chemotherapy initiation, both PMEs, that is, phosphocholine (PC) and phosphoethanolamine (PE), were significantly higher in all metastases compared with the levels previously determined in the liver of healthy volunteers. After 2 weeks of chemotherapy, PC and PE levels remained high or even increased further, resulting in increased PME/PDE ratios compared with healthy liver tissue, in correspondence with the clinical assessment of progressive disease after 2 months of chemotherapy. The suggested approach may present a viable tool for early therapy (non)response assessment of tumor metabolism in patients with liver metastases.

PIPAC in patients with peritoneal metastases from gastrointestinal tract (PIPOX01): An open label, non-comparative phase 1/2 dose escalation and expansion trial

BACKGROUND

Despite modern systemic chemotherapy, survival remains poor for patients with advanced isolated peritoneal metastases from the gastrointestinal tract. We aimed to assess the safety and efficacy of pressurized intraperitoneal aerosol chemotherapy (PIPAC) with oxaliplatin.

PATIENTS AND METHODS

We conducted a phase 1/2, open label, non-comparative, dose escalation and expansion trial of PIPAC with oxaliplatin in patients with a peritoneal cancer index (PCI) of more than 5, 13 and 15 for respectively a gastric, small bowel and colorectal primary cancer, and who had received at least three months of systemic chemotherapy. PIPAC cycle lengths were 4-6 weeks with systemic chemotherapy allowed 15 days after each PIPAC. PCI and oxaliplatin tumor concentration were assessed every PIPAC cycle. The main endpoints were tolerability, tumor response, and survival.

RESULTS

Between 2017 and 2020, 34 patients were enrolled in three centers, in this phase 1/2 study, of whom 25 were evaluable at the recommended dose determined in the phase I trial (90 mg/m2 plus systemic 5-FU). Before inclusion, patients received a median of 2 [1-4] chemotherapy lines and had a median PCI of 22.5 [7-29]. At this dose, the safety profile showed acceptable tolerability. Eight patients (32 %) had grade 3/4 treatment-related adverse events. Minor (grade 1/2) adverse events were mainly abdominal pain (n = 19, 76 %) and nausea (n = 16, 64 %). Median PFS was 6.1 months and median OS was 13 months.

CONCLUSION

In patients with advanced and refractory peritoneal metastasis, PFS of 6.1 months is encouraging. A prospective randomized phase II study is required.

Circulating Exosomal MicroRNA Signature Predicts Peritoneal Metastasis in Patients with Advanced Gastric Cancer

BACKGROUND

Despite a radical operation, about half of gastric cancer (GC) patients with advanced GC experience peritoneal metastasis (PM), and the patients with PM have a poor prognosis. However, because staging laparoscopy was a highly invasive procedure for patients, identification of PM using a liquid biopsy can be useful for patients with GC.

METHODS

This study analyzed two genome-wide miRNA expression profiling datasets (GSE164174 and TCGA). The study prioritized biomarkers in pretreatment plasma specimens from clinical training and validation cohorts of patients with GC. The authors developed an integrated exosomal miRNA panel and established a risk-stratification model, which was combined with the miRNA panel and currently used tumor markers (CEA, CA19-9, CA125, and CA72-4 levels).

RESULTS

The comprehensive discovery effort identified a four-miRNA panel that robustly predicted the metastasis with excellent accuracy in the TCGA dataset (area under the curve [AUC] 0.86). A circulating exosomal miRNA panel was established successfully with remarkable diagnostic accuracy in the clinical training (AUC 0.85) and validation (AUC 0.86) cohorts. Moreover, the predictive accuracy of the panel was significantly superior to that of conventional clinical factors (P < 0.01), and the risk-stratification model was dramatically superior to the panel and currently used clinical factors for predicting PM (AUC 0.94; univariate: odds ratio [OR] 77.00 [P < 0.01]; multivariate OR 57.71 [P = 0.01]).

CONCLUSIONS

The novel risk-stratification model for predicting PM has potential for clinical translation as a liquid biopsy assay for patients with GC. The study findings highlight the potential clinical impact of the model for improved selection and management of patients with GC.

NAT10 Overexpression Promotes Tumorigenesis and Epithelial-Mesenchymal Transition Through AKT Pathway in Gastric Cancer

BACKGROUND

N-acetyltransferase 10 (NAT10), the only RNA cytosine acetyltransferase known in humans, contributes to cancer tumorigenesis and progression. This study aims to investigate the effect of NAT10 on the malignant biological properties of gastric cancer (GC) and its underlying mechanism.

METHODS

The expression and prognostic significance of NAT10 in GC were analyzed using The Cancer Genome Atlas (TCGA) and Sun Yat-sen University (SYSU) cohorts. The influence of NAT10 on the malignant biological behaviors of GC was detected by Cell Counting Kit-8 (CCK-8) assay, plate colony formation assay, 5-ethynyl-2'-deoxyuridine (EdU), Transwell migration and invasion assays, scratch wound assay, flow cytometric analysis, and animal studies. The overall level of N4 acetylcytidine (ac4C) in GC was detected by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The downstream signal pathways of NAT10 were analyzed by Gene Set Enrichment Analysis (GSEA) and verified by Western blot (WB) and immunofluorescence (IF).

RESULTS

The significant upregulation of NAT10 expression in GC was associated with a poor prognosis. The knockdown of NAT10 markedly suppressed GC cell proliferation, migration, invasion, and cell cycle progression. Downregulating NAT10 reduced ac4C levels and inhibited AKT phosphorylation and epithelial-mesenchymal transition (EMT) in GC.

CONCLUSIONS

NAT10 functions as an oncogene and may provide a new therapeutic target in GC.

18F-FDG PET/CT Radiomics-Based Multimodality Fusion Model for Preoperative Individualized Noninvasive Prediction of Peritoneal Metastasis in Advanced Gastric Cancer

PURPOSE

This study was designed to develop and validate a machine learning-based, multimodality fusion (MMF) model using 18F-fluorodeoxyglucose (FDG) PET/CT radiomics and kernelled support tensor machine (KSTM), integrated with clinical factors and nuclear medicine experts' diagnoses to individually predict peritoneal metastasis (PM) in advanced gastric cancer (AGC).

METHODS

A total of 167 patients receiving preoperative PET/CT and subsequent surgery were included between November 2006 and September 2020 and were divided into a training and testing cohort. The PM status was confirmed via laparoscopic exploration and postoperative pathology. The PET/CT signatures were constructed by classic radiomic, handcrafted-feature-based model and KSTM self-learning-based model. The clinical nomogram was constructed by independent risk factors for PM. Lastly, the PET/CT signatures, clinical nomogram, and experts' diagnoses were fused using evidential reasoning to establish the MMF model.

RESULTS

The MMF model showed excellent performance in both cohorts (area under the curve [AUC] 94.16% and 90.84% in training and testing), and demonstrated better prediction accuracy than clinical nomogram or experts' diagnoses (net reclassification improvement p < 0.05). The MMF model also had satisfactory generalization ability, even in mucinous adenocarcinoma and signet ring cell carcinoma which have poor uptake of 18F-FDG (AUC 97.98% and 89.71% in training and testing).

CONCLUSIONS

The 18F-FDG PET/CT radiomics-based MMF model may have significant clinical implications in predicting PM in AGC, revealing that it is necessary to combine the information from different modalities for comprehensive prediction of PM.

Surgical resection and neoadjuvant therapy in patients with gastric cancer and ovarian metastasis: A real-world study

BACKGROUND

Regarding when to treat gastric cancer and ovarian metastasis (GCOM) and whether to have metastatic resection surgery, there is presently debate on a global scale. The purpose of this research is to examine, in real-world patients with GCOM, the survival rates and efficacy of metastatic vs non-metastasized resection.

AIM

To investigate the survival time and efficacy of metastatic surgery and neoadjuvant therapy in patients with GCOM.

METHODS

This study retrospectively analyzed the data of 41 GCOM patients admitted to Zhejiang Provincial People's Hospital from June 2009 to July 2023. The diagnosis of all patients was confirmed by pathology. The primary study endpoints included overall survival (OS), ovarian survival, OS after surgery (OSAS), disease-free survival (DFS), differences in efficacy.

RESULTS

This study had 41 patients in total. The surgical group (n = 27) exhibited significantly longer median OS (mOS) and median overall months (mOM) compared to the nonoperative group (n = 14) (mOS: 23.0 vs 6.9 months, P = 0.015; mOM: 18.3 vs 3.8 months, P = 0.001). However, there were no significant differences observed in mOS, mOM, median OSAS (mOSAS), and median DFS (mDFS) between patients in the surgical resection plus neoadjuvant therapy group (n = 11) and those who surgical resection without neoadjuvant therapy group (n = 16) (mOS: 26.1 months vs 21.8 months, P = 0.189; mOM: 19.8 vs 15.2 months, P = 0.424; mOSAS: 13.9 vs 8.7 months, P = 0.661, mDFS: 5.1 vs 8.2 months, P = 0.589).

CONCLUSION

Compared to the non-surgical group, the surgical group's survival duration and efficacy are noticeably longer. The efficacy and survival time of the direct surgery group and the neoadjuvant therapy group did not differ significantly.

Gut Roseburia is a protective marker for peritoneal metastasis of gastric cancer

BACKGROUND

Gastric cancer (GC), particularly for advanced stage of GC, commonly undergoes peritoneal metastasis (PM), which is the leading cause of GC-related death. However, there currently has no reliable biomarker to predict the onset of GCPM. It is well known that the imbalance of gut microbiota contributes to the development and metastasis of gastrointestinal tumors. Unfortunately, little is known about how the alternation in gut microbiota is associated with the onset of GCPM.

METHODS

Our current study analyzed structural characteristics and functional prediction of gut microbiota in GC patients with PM (PM group) and without PM (non-PM group). Fresh fecal samples were collected from a discovery cohort (PM = 38, non-PM = 54) and a validation cohort (PM = 15, non-PM = 21) of GC patients and their 16S ribosomal RNA (16s rRNA) gene amplicons were sequenced, followed by bioinformatics.

RESULTS

The results indicated an increase in the biodiversity of gut microbiota in the non-PM group of the discovery cohort, compared with the PM group. Moreover, LEfSe analysis found 31 significantly different microorganisms, of which the Roseburia ranked the fifth in the random forest (RF) model. The characteristics of intestinal microbiota in GCPM patients were changed, and the abundance of Roseburia in gut microbiota from the GCPM patients was reduced and receiver operating characteristic (ROC) analysis revealed that the reduced abundance of gut Roseburia effectively predicted the onset of GCPM.

CONCLUSION

This signature was also observed in the validation cohort. Therefore, Roseburia is a protective microbial marker and the reduced abundance of Roseburia in gut microbiota may help early diagnosis of GCPM.

Neutrophil Extracellular Traps-Inhibiting and Fouling-Resistant Polysulfoxides Potently Prevent Postoperative Adhesion, Tumor Recurrence, and Metastasis

Peritoneal metastasis (PM) is considered one of the most dreaded forms of cancer metastases for both patients and physicians. Aggressive cytoreductive surgery (CRS) is the primary treatment for peritoneal metastasis. Unfortunately, this intensive treatment frequently causes clinical complications, such as postoperative recurrence, metastasis, and adhesion formation. Emerging evidence suggests that neutrophil extracellular traps (NETs) released by inflammatory neutrophils contribute to these complications. Effective NET-targeting strategies thus show considerable potential in counteracting these complications but remain challenging. Here, one type of sulfoxide-containing homopolymer, PMeSEA, with potent fouling-resistant and NET-inhibiting capabilities, is synthesized and screened. Hydrating sulfoxide groups endow PMeSEA with superior nonfouling ability, significantly inhibiting protein/cell adhesion. Besides, the polysulfoxides can be selectively oxidized by ClO- which is required to stabilize the NETs rather than H2O2, and ClO- scavenging effectively inhibits NETs formation without disturbing redox homeostasis in tumor cells and quiescent neutrophils. As a result, PMeSEA potently prevents postoperative adhesions, significantly suppresses peritoneal metastasis, and shows synergetic antitumor activity with chemotherapeutic 5-Fluorouracil. Moreover, coupling CRS with PMeSEA potently inhibits CRS-induced tumor metastatic relapse and postoperative adhesions. Notably, PMeSEA exhibits low in vivo acute and subacute toxicities, implying significant potential for clinical postoperative adjuvant treatment.

Gastric cancer in pregnancy: a review

Malignant tumors including gastric cancer (GC) are the leading cause of deaths among reproductive women. Physiological morning sickness can mask the clinical manifestations of GC, whereas the clinical presence of metastatic tumors in the abdominal cavity may be easily mistaken for abdominal swelling caused by fetal growth. Pregnancy and delivery processes in young females could accelerate the growth of GC, leading to its rapid development and grave prognosis. Therefore, early diagnosis is critical and gastrointestinal endoscopy is recommended for any suspected pregnant woman with long-term morning sickness. Treatment strategies, including chemotherapy, resection surgery and radiotherapy, will be determined based on a comprehensive consideration of the status of both the fetus and the mother. Rational management, especially clinical multidisciplinary collaboration may significantly benefit such patients.

Prophylaxis and treatment of peritoneal carcinomatosis of gastric origin using hyperthermic intraperitoneal chemotherapy: a systematic review and meta-analysis of randomized trials

BACKGROUND

Peritoneal carcinomatosis significantly worsens the prognosis of patients with gastric cancer. Cytoreduction + hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promising results in the prevention and treatment of peritoneal carcinomatosis in advanced gastric cancer (AGC); however, its application remains controversial owing to the variability of the approaches used to perform it and the lack of high-quality evidence. This systematic review and meta-analysis aimed to investigate the role of surgery and HIPEC in the prevention and treatment of peritoneal carcinomatosis of gastric origin.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials comparing surgery + HIPEC vs surgery + chemotherapy for the prophylaxis of peritoneal carcinomatosis and cytoreduction + HIPEC vs chemotherapy or other palliative options for the treatment of peritoneal carcinomatosis.

RESULTS

Sixteen studies enrolling 1641 patients were included. Surgery + HIPEC significantly improved overall survival in both prophylactic (hazard ratio [HR], 0.56) and therapeutic (HR, 0.57) settings. When surgery + HIPEC was performed with prophylactic intent, the pooled 3-year mortality rate was 32%, whereas for the control group it was 55%. The overall and peritoneal recurrence rates were also reduced (risk ratio [RR], 0.59 and 0.40, respectively). No significant difference was found in morbidity between groups (RR, 0.92).

CONCLUSION

Based on the current knowledge, HIPEC in AGC seems to be a safe and effective tool for prophylaxis and a promising resource for the treatment of peritoneal carcinomatosis. Regarding the treatment of peritoneal carcinomatosis, the scarcity of large-cohort studies and the heterogeneity of the techniques adopted prevented us from achieving a definitive recommendation.

Perioperative intraperitoneal plus systemic chemotherapy and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for gastric cancer: phase Ib/II single-arm prospective study

BACKGROUND

In gastric cancer, peritoneal metastasis is the most common form of metastasis and leads to dismal prognosis. We aimed to evaluate the safety and efficacy of combining perioperative intraperitoneal (IP) plus systemic chemotherapy, cytoreductive surgery (CRS), and hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with gastric cancer with limited peritoneal metastasis or even after reducing peritoneal tumor burden by upfront IP chemotherapy.

METHOD

Patients were enrolled in phase Ib in a 3 + 3 dose escalation of IP paclitaxel plus a fixed dose of IP cisplatin and oral S-1. In phase II, patients were managed according to the peritoneal cancer index (PCI) by diagnostic laparoscopy. For patients with a PCI of >12, upfront IP and systemic chemotherapy were given. Patients with a PCI of ≤12 or reduced to ≤12 after upfront chemotherapy underwent CRS with HIPEC. The primary endpoints were safety and the recommended phase II dose (RP2D) confirmation for phase Ib and the 1-year overall survival rate for phase II.

RESULTS

The RP2D was defined as IP 175 mg/m2 paclitaxel and 60 mg/m2 cisplatin and oral 70 mg/m2/day S-1 for 14 days. A total of 22 patients were included. After CRS with HIPEC, there were no grade 3 or higher complications. The median hospital stay was 7 days (range, 6-11). The median overall and progression-free survival were 27.3 months (95% CI, 14.4 to not estimable) and 12.6 months (95% CI, 7.7-14.5), respectively. One-year overall and progression-free survival rates were 81.0% (95% CI, 65.8-99.6) and 54.5% (95% CI, 37.2-79.9), respectively.

CONCLUSION

A combination of IP plus systemic chemotherapy, CRS, and HIPEC was safe and resulted in good survival outcomes.

Initial Experience Using Laparoscopic HIPEC for Gastric Cancer with Peritoneal Metastasis: Safety and Outcomes

BACKGROUND

Peritoneal metastases (PM) develop in approximately 20% of patients with gastric cancer (GC). For selected patients, treatment of PM with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promising results. This report aims to describe the safety and perioperative outcomes of laparoscopic HIPEC for GC/PM.

METHODS

This retrospective cohort study evaluated patients who had GC and PM treated with laparoscopic HIPEC (2018-2022). The HIPEC involved cisplatin and mitomycin C (MMC) or MMC alone. The primary end point was perioperative safety.

RESULTS

The 22 patients in this study underwent 27 procedures. The mean age was 58 ± 13 years. All the patients were Eastern Cooperative Oncology Group (ECOG) 0 or 1 (55 and 45%, respectively). Five patients underwent a second laparoscopic HIPEC, with a median of 126 days (interquartile range [IQR], 117-166 days) between procedures. The median peritoneal carcinomatosis index (PCI) was 4 (IQR, 2-9), and the median hospital stay was 2 days (IQR, 1-3 days). No 30-day readmissions or complications occurred. Eight patients (36%) underwent gastrectomy (CRS ± HIPEC). After an average follow-up period of 11 months, 7 (32%) of the 22 patients were alive. The median overall survival was 11 months (IQR, 195-739 days) from the initial procedure and 19.3 months (IQR, 431-1204 days) from the diagnosis.

CONCLUSIONS

Laparoscopic HIPEC appears to be safe with minimal perioperative complications. Approximately one third of the patients undergoing initial laparoscopic HIPEC ultimately proceeded to cytoreduction and gastrectomy. Preliminary survival data from this highly selected cohort suggest that the addition of laparoscopic HIPEC to systemic chemotherapy does not compromise other treatment options. These initial results suggest that laparoscopic HIPEC may offer benefit to patients with GC and PM and aid in the selection of patients who may benefit from curative-intent resection.