Staging laparoscopy in gastric cancer to detect peritoneal metastases: A systematic review and meta-analysis

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.

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.

Fluorescence-Guided Laparoscopy after Oral Hypericin Administration for Staging of Locally Advanced Gastric Cancer-A Pilot Study

(1) Background: Laparoscopic staging is essential in gastric cancer (GC) to rule out peritoneal metastasis (PM). Hypericin, a plant-derived fluorescent compound, has been suggested to improve laparoscopic visualization of PM from GC. This prospective, single-arm, open-label clinical trial aimed to assess the feasibility and safety of oral hypericin administration as well as the suitability of fluorescence-guided laparoscopy (FGL) for improving the sensitivity and specificity of staging in GC patients (EudraCT-Number: 2015-005277-21; clinicaltrials.gov identifier: NCT-02840331). (2) Methods: GC patients received Laif® 900, an approved hypericin-containing phytopharmaceutical, once orally two to four hours before white light and ultraviolet light laparoscopy. The peritoneal cancer index was evaluated, biopsies taken and hypericin concentrations in serum and peritoneal tissue were determined by mass spectrometry. (3) Results: Between 2017 and 2021, out of 63 patients screened for eligibility, 50 patients were enrolled and treated per protocol. The study intervention was shown to be feasible and safe in all patients. Standard laparoscopy revealed suspicious lesions in 27 patients (54%), among whom 16 (59%) were diagnosed with PM. FGL identified suspicious areas in 25 patients (50%), among whom PM was confirmed in 13 cases (52%). Although hypericin concentrations in serum reached up to 5.64 ng/mL, no hypericin was detectable in peritoneal tissue biopsies. (4) Conclusions: FGL in patients with GC was shown to be feasible but futile in this study. Sufficient levels of hypericin should be ensured in target tissue prior to reassessing FGL with hypericin.

A preoperative predictive tool to assess the need for staging laparoscopy in oesophagogastric cancer patients

INTRODUCTION

Staging laparoscopy (SL) has become commonplace in the preoperative staging pathway for oesophagogastric (OG) cancer. SL is often performed before curative treatment to examine for macroscopic peritoneal metastases (PM) or positive peritoneal cytology (PPC). The aim of this study was to develop an objective risk scoring system to predict both PM and PPC at SL.

METHODS

A prospectively collected and maintained database of all OG cancer patients treated between 2006 and 2020 was reviewed. Univariate and multivariate analyses were performed to identify risk factors for both PM and PPC at SL. A risk score was produced for both PM and PPC, and then validated internally.

RESULTS

Among 968 patients who underwent SL, 96 (9.9%) had PM and 81 (8.4%) had PPC at SL. Tumour site (p < 0.001), computed tomography (CT) T stage (p < 0.001) and N stage (p = 0.029) were significantly associated with PM at SL (p < 0.001). Tumour site (p < 0.001), biopsy histology (p = 0.041), CT T stage (p < 0.001) and N stage (p < 0.001) were significantly associated with PPC. The risk scoring model for PM included cancer site and CT T stage. This was successfully tested on the validation set (area under the receiver operating characteristic [AUROC] = 0.730). The risk scoring model for PPC included cancer site, CT T and N stage. This was successfully tested on the validation set (AUROC = 0.773).

CONCLUSIONS

The current risk scores are valid tools with which to predict the risk PM and PPC in patients undergoing SL for OG cancer and may help to avoid subjecting patients to unnecessary SL.

Laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for gastric cancer with intraoperative detection of limited peritoneal metastasis: a Phase II study of CLASS-05 trial

Background

Systemic chemotherapy for gastric cancer with peritoneal metastasis has limited clinical benefit; for those with intraoperative detection of occult peritoneal metastasis, cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is an alternative treatment. However, the feasibility and effects of this modality and criteria for selecting suitable groups remain unclear. This study aimed to explore the safety and efficacy of laparoscopic cytoreductive surgery (L-CRS) followed by HIPEC in gastric cancer with limited peritoneal metastasis, and this study also aimed to determine the optimized cut-off of the peritoneal cancer index.

Methods

Between March 2017 and November 2019, patients diagnosed with gastric cancer peritoneal metastases by using laparoscopy and the Sugarbaker peritoneal cancer index of ≤12 were eligible for inclusion. All patients received L-CRS (including gastrectomy with D2 lymph node dissection) and resection of visible peritoneal metastasis, followed by post-operative HIPEC, and systemic chemotherapy. The primary end points were median progression-free survival and median survival time, and the secondary outcomes were morbidity and mortality within 30 days after surgery.

Results

Thirty patients were eligible for analysis, of whom 19 (63.3%) were female, and the overall mean age was 53.0 years. The post-operative morbidity was 20% and the severe complication rate was 10%. The median survival time was 27.0 months with a 2-year overall survival rate of 52.3% and median progression-free survival was 14.0 months with a 2-year progression-free survival of 30.4%.

Conclusions

L-CRS followed by HIPEC can be safely performed for gastric cancer with limited peritoneal metastasis and potential survival benefits.

Aborted cancer surgery at a single tertiary cancer center: Rates, reasons, and outcomes

BACKGROUND

Surgical resection is typically necessary for curative-intent treatment of most solid organ cancers. However, even with meticulous preoperative evaluation, operative procedures are occasionally aborted. The incidence, outcomes, and long-term prognoses of aborted cancer surgery have not been thoroughly investigated.

METHODS

All oncologic operations performed at a single tertiary cancer center between 2011-2021 were retrospectively queried; natural language processing of operative reports was used to identify aborted cancer surgeries. Surgical indications, clinicopathologic characteristics, short- and long-term outcomes, and palliative care involvement were retrospectively reviewed from the electronic medical record.

RESULTS

Overall, 345 patients underwent aborted cancer surgery for a rate of 36 patients per year. The most common cancers were pancreatic (28%), biliary (14%), and colorectal (9%). The most commonly aborted operations were pancreatoduodenectomy (34%) and hepatectomy (22%). Most operations were aborted due to unanticipated tumor unresectability (47%) and occult metastatic disease (43%). Sixty percent of patients returned to cancer-directed therapy; 9% underwent successful reattempt at resection. The median overall survival of all patients after aborted surgery was 13.6 months (95% confidence interval, 11.2-16.0 months). Those who returned to oncologic therapy had longer survival (18.6 months vs 5.4 months, P < .001). Palliative care consultation was received by 34% and 13% of patients overall and within 30 days of surgery, respectively.

CONCLUSION

Aborted cancer surgery was associated with poor outcomes, particularly in patients with aggressive cancer types and those who did not receive further cancer-directed therapy. Future studies should identify interventions such as palliative care consultation that may improve patient-centered outcomes.

The predictive value of radiomics-based machine learning for peritoneal metastasis in gastric cancer patients: a systematic review and meta-analysis

Background

For patients with gastric cancer (GC), effective preoperative identification of peritoneal metastasis (PM) remains a severe challenge in clinical practice. Regrettably, effective early identification tools are still lacking up to now. With the popularization and application of radiomics method in tumor management, some researchers try to introduce it into the early identification of PM in patients with GC. However, due to the complexity of radiomics, the value of radiomics method in the early identification of PM in GC patients remains controversial. Therefore, this systematic review was conducted to explore the feasibility of radiomics in the early identification of PM in GC patients.

Methods

PubMed, Cochrane, Embase and the Web of Science were comprehensively and systematically searched up to 25 July, 2022 (CRD42022350512). The quality of the included studies was assessed using the radiomics quality score (RQS). To discuss the superiority in diagnostic accuracy of radiomics-based machine learning, a subgroup analysis was performed by machine learning (ML) based on clinical features, radiomics features, and radiomics + clinical features.

Results

Finally, 11 eligible original studies covering 78 models were included in this systematic review. According to the meta-analysis, the radiomics + clinical features model had a c-index of 0.919 (95% CI: 0.871-0.969), pooled sensitivity and specificity of 0.90 (0.83-0.94) and 0.87 (0.78-0.92), respectively, in the training set, and a c- index of 0.910 (95% CI: 0.886-0.934), pooled sensitivity and specificity of 0.78 (0.71-0.84) and 0.83 (0.74-0.89), respectively, in the validation set.

Conclusions

The ML methods based on radiomics + clinical features had satisfactory accuracy for the early diagnosis of PM in GC patients, and can be used as an auxiliary diagnostic tool for clinicians. However, the lack of guidelines for the proper operation of radiomics has led to the diversification of radiomics methods, which seems to limit the development of radiomics. Even so, the clinical application value of radiomics cannot be ignored. The standardization of radiomics research is required in the future for the wider application of radiomics by developing intelligent tools of radiomics.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=350512, identifier CRD42022350512.

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

A significant proportion of patients diagnosed with gastric cancer is discovered with peritoneal metastases at laparotomy. Despite the continuous improvement in the performance of radiological imaging, the preoperative recognition of such an advanced disease is still challenging during the diagnostic work-up, since the sensitivity of CT scans to peritoneal carcinomatosis is not always adequate. Staging laparoscopy offers the chance to significantly increase the rate of promptly diagnosed peritoneal metastases, thus reducing the number of unnecessary laparotomies and modifying the initial treatment strategy of gastric cancer. The aim of this review was to provide a comprehensive summary of the current literature regarding the role of staging laparoscopy in the management of gastric cancer. Indications, techniques, accuracy, advantages, and limitations of staging laparoscopy and peritoneal cytology were discussed. Furthermore, a focus on current evidence regarding the application of artificial intelligence and image-guided surgery in staging laparoscopy was included in order to provide a picture of the future perspectives of this technique and its integration with modern tools in the preoperative management of gastric cancer.

Endoscopic Ultrasound Predicts Risk of Occult Intra-Abdominal Metastases in Localized Gastric Cancer: A Validation Study

Background

In gastric cancer (GC) patients without imaging evidence of distant metastasis, diagnostic staging laparoscopy (DSL) is recommended to detect radiographically occult peritoneal metastasis (M1). DSL carries a risk for morbidity and its cost-effectiveness is unclear. Use of endoscopic ultrasound (EUS) to improve patient selection for DSL has been proposed but not validated. We aimed to validate an EUS-based risk classification system predicting risk for M1 disease.

Methods

We retrospectively identified all GC patients without positron emission tomography (PET)/computed tomography (CT) evidence of distant metastasis who underwent staging EUS followed by DSL between 2010 and 2020. T1-2, N0 disease was EUS "low-risk"; T3-4 and/or N+ disease was "high-risk".

Results

A total of 68 patients met inclusion criteria. DSL identified radiographically occult M1 disease in 17 patients (25%). Most patients had EUS T3 tumors (n = 59, 87%) and 48 (71%) patients were node-positive (N+). Five (7%) patients were classified EUS "low-risk" and 63 (93%) were classified "high-risk". Of 63 "high-risk" patients, 17 (27%) had M1 disease. The ability of "low-risk" EUS to predict M0 disease at laparoscopy was 100% and DSL would have been avoided in five patients (7%). This stratification algorithm showed a sensitivity of 100% (95% confidence interval (CI): 80.5-100%) and a specificity of 9.8% (95% CI: 3.3-21.4%).

Conclusions

Use of an EUS-based risk classification system in GC patients without imaging evidence of metastasis helps identify a subset of patients at low-risk for laparoscopic M1 disease who may avoid DSL and proceed directly to neoadjuvant chemotherapy or resection with curative intent. Larger, prospective studies are needed to validate these findings.

Staging LaParoscopy to Assess Lymph NOde InvoLvement in Advanced GAstric Cancer (POLA)-Study protocol for a single-arm prospective observational multicenter study

INTRODUCTION

In the era of neoadjuvant chemotherapy in advanced gastric cancer (GC), the role of staging laparoscopy (SL) will become more established. However, despite guidelines recommendations, SL for optimal preoperative staging remains underutilized. Diagnostic value of near-infrared (NIR) / indocyanine green (ICG) guided sentinel node (SN) mapping in GC confirmed its technical feasibility, however no data exist regarding its potential role in pathological nodal staging. To the best of our knowledge, current study is the first to evaluate the role of ICG in nodal staging of advanced GC patients undergoing SL.

MATERIALS AND METHODS

This single-arm prospective observational multicenter study was approved by the Bioethical Committee of Medical University of Lublin (Ethic Code: KE-0254/331/2018). The protocol is registered at clinicaltrial.gov (NCT05720598), and the study results will be reported according to the Strengthening of Reporting of Observational Studies in Epidemiology (STROBE) statement. The primary endpoint of this study is the identification rate of ICG-guided SN in advanced GC patients. The secondary endpoints include pathological and molecular assessment of retrieved SNs and other pretreatment clinical variables potentially associated with SL: pattern of perigastric ICG distribution according to patients' pathological and clinical characteristics, neoadjuvant chemotherapy compliance, 30-day morbidity, and mortality.

CONCLUSION

POLA study is the first to investigate the clinical value of ICG-enhanced sentinel node biopsy during staging laparoscopy in advanced GC patients in a Western cohort. Identifying pN status before multimodal treatment will improve GC staging process.

Situación actual de la laparoscopía de estadificación en pacientes con cáncer gástrico en Colombia: ¿Cómo lo estamos haciendo?

Introducción. La laparoscopía de estadificación permite identificar con gran precisión el compromiso locorregional avanzado y metastásico a peritoneo en los pacientes con cáncer gástrico. Las guías internacionales aún difieren en las indicaciones para incluir este procedimiento como parte del proceso de estadificación. Métodos. Se diseñó una encuesta dirigida a cirujanos residentes en Colombia, sobre el uso de la laparoscopía de estadificación en los pacientes con cáncer gástrico. Se analizaron los resultados y con base en la evidencia disponible se proponen algunas pautas en las indicaciones y técnica del procedimiento. Resultados. Respondieron la encuesta 74 cirujanos; el 43,8 % considera que el objetivo de la laparoscopía de estadificación es descartar la carcinomatosis peritoneal. El 54,1 % realiza el procedimiento en estadios tempranos, sin embargo, el 48,6 % considera realizarla solo en pacientes con sospecha de carcinomatosis por imágenes. Las áreas evaluadas con mayor frecuencia por los cirujanos (más del 85 %) son la superficie hepática, las cúpulas diafragmáticas, los recesos parietocólicos y la pelvis. Las zonas evaluadas en menor frecuencia son la válvula ileocecal (40,5 %) y el ligamento de Treitz (39 %). El 33 % de los cirujanos no toma rutinariamente citología peritoneal. Conclusión. Este trabajo muestra la tendencia de los cirujanos en el uso de la laparoscopía de estadificación en pacientes con cáncer gástrico. A pesar de encontrar resultados muy positivos en relación con las indicaciones y técnica del procedimiento, es necesario analizar la evidencia disponible para su uso según cada escenario y mejorar la sistematización del procedimiento.

Prognostic value of molecular cytology by one-step nucleic acid amplification (OSNA) assay of peritoneal washings in advanced gastric cancer patients

Peritoneal dissemination is a common form of gastric cancer (GC) recurrence, despite surgery with curative intent. This study aimed to evaluate the prognostic value of intraperitoneal lavage One-Step Nucleic Acid Amplification (OSNA) assay in advanced GC patients. OSNA assay targeting CK-19 mRNA was applied to detect free cancer cells (FCC) in intraperitoneal lavage samples obtained during gastrectomy. A total of 82 GC patients were enrolled to investigate the correlation between OSNA assay and patient's prognosis. Of the 82 patients, OSNA assay was positive in 25 (30.5%) patients. The median OS in OSNA positive patients was significantly lower than in OSNA negative patients (19 vs 45 months). Positive OSNA assay result was a significant unfavourable prognostic factor in both, univariable (HR 3.45, 95% CI 0.95-12.48; p = 0.0030) and multivariable analysis (HR 3.10, 95% CI 1.22-8.54; p = 0.0298). Positive OSNA assay in intraperitoneal lavage is a valuable indicator of poor survival in advanced GC patients after multimodal treatment. After further confirmation on larger sample size, OSNA assay of peritoneal washings could be considered an adjunct tool to conventional cytology, the current gold standard, to provide precise intraoperative staging and additional prognostic information.

Integration of Genomic Biology Into Therapeutic Strategies of Gastric Cancer Peritoneal Metastasis

The peritoneum is a common site of metastasis in advanced gastric cancer (GC). Diagnostic laparoscopy is now routinely performed as part of disease staging, leading to an earlier diagnosis of synchronous peritoneal metastasis (PM). The biology of GCPM is unique and aggressive, leading to a dismal prognosis. These tumors tend to be resistant to traditional systemic therapy, and yet, this remains the current standard-of-care recommended by most international clinical guidelines. As this is an area of unmet clinical need, several translational studies and clinical trials have focused on addressing this specific disease state. Advances in genomic sequencing and molecular profiling have revealed several promising therapeutic targets and elucidated novel biology, particularly on the role of the surrounding tumor microenvironment in GCPM. Peritoneal-specific clinical trials are being designed with a combination of locoregional therapeutic strategies with systemic therapy. In this review, we summarize the new knowledge of cancer biology, advances in surgical techniques, and emergence of novel therapies as an integrated strategy emerges to address GCPM as a distinct clinical entity.

A Bounding Box-Based Radiomics Model for Detecting Occult Peritoneal Metastasis in Advanced Gastric Cancer: A Multicenter Study

Purpose

To develop a bounding box (BBOX)-based radiomics model for the preoperative diagnosis of occult peritoneal metastasis (OPM) in advanced gastric cancer (AGC) patients.

Materials and Methods

599 AGC patients from 3 centers were retrospectively enrolled and were divided into training, validation, and testing cohorts. The minimum circumscribed rectangle of the ROIs for the largest tumor area (R_BBOX), the nonoverlapping area between the tumor and R_BBOX (peritumoral area; PERI) and the smallest rectangle that could completely contain the tumor determined by a radiologist (M_BBOX) were used as inputs to extract radiomic features. Multivariate logistic regression was used to construct a radiomics model to estimate the preoperative probability of OPM in AGC patients.

Results

The M_BBOX model was not significantly different from R_BBOX in the validation cohort [AUC: M_BBOX model 0.871 (95% CI, 0.814–0.940) vs. R_BBOX model 0.873 (95% CI, 0.820–0.940); p = 0.937]. M_BBOX was selected as the final radiomics model because of its extremely low annotation cost and superior OPM discrimination performance (sensitivity of 85.7% and specificity of 82.8%) over the clinical model, and this radiomics model showed comparable diagnostic efficacy in the testing cohort.

Conclusions

The BBOX-based radiomics could serve as a simpler reliable and powerful tool for the preoperative diagnosis of OPM in AGC patients. And M_BBOX-based radiomics is simpler and less time consuming.

The concept of oligometastatic disease in gastric cancer: reality or fiction?

Positive results in the RENAISSANCE Trial will establish oligometastatic gastric cancer as a real independent entity where total surgical treatment will become the standard of care.

Staging laparoscopy in patients with advanced gastric cancer: A single center cohort study

BACKGROUND

Most studies exploring the role of staging laparoscopy in gastric cancer are limited by low sample size and are predominantly conducted in Asian countries. This study sets out to determine the value of staging laparoscopy in patients with advanced gastric cancer in a Western population.

METHODS

All patients with gastric cancer from a tertiary referral center without definite evidence of non-curable disease after initial staging, and who underwent staging laparoscopy between 2013 and 2020, were identified from a prospectively maintained database. The proportion of patients in whom metastases or locoregional non-resectability was detected during staging laparoscopy was established. Secondary outcomes included the avoidable surgery rate (detection of non-curable disease during gastrectomy with curative intent) and diagnostic accuracy (sensitivity, specificity, accuracy, negative and positive predictive value).

RESULTS

A total of 216 patients were included. Staging laparoscopy revealed metastatic disease in 46 (21.3 %) patients and a non-resectable tumor in three (1.4 %) patients. During intended gastrectomy, non-curable disease was revealed in 13 (8.6 %) patients. Overall sensitivity, specificity and diagnostic accuracy were 76.6 %, 100 % and 92.6 %, respectively. The positive predictive value was 100 % and the negative predictive value was 90.3 %.

CONCLUSION

Staging laparoscopy is valuable in the staging process of gastric cancer with a high accuracy in detecting non-curable disease, thereby preventing futile treatment and its associated burden.

Surgical treatment of gastric cancer liver metastases: Systematic review and meta-analysis of long-term outcomes and prognostic factors

The prognosis of patients with metastatic gastric cancer remains dismal, with palliative treatment as standard of care. However, encouraging results have been reported for surgical resection of liver only metastatic gastric cancer in carefully selected patients. A systematic review of articles published from 2000 onwards was conducted according to PRISMA guidelines. Twenty-nine studies were included in qualitative and quantitative analysis. Meta-analysis of proportions pointed out 29.1 % 5ySR (I 2 = 39 %). The pooled weighted median of MSTs was 31.1 months. T stage > 2, metastasis greatest dimension ≥ 5 cm, the presence of multiple metastases and bilobar disease resulted among the strongest predictors of mortality. Funnel plots, Egger's tests, and P-curve analyses failed to show significant publication bias. Based on strict selection criteria and robust statistical analyses, our results show that, in very carefully selected patients without extrahepatic disease, surgical resection with curative intent may significantly improve overall survival.

Lymph Node Involvement in Advanced Gastric Cancer in the Era of Multimodal Treatment-Oncological and Surgical Perspective

Simple Summary

Gastric cancer (GC) continues to be one of the major oncological challenges on a global scale. The role of neoadjuvant chemotherapy (NAC) in GC is to downstage primary tumour, eliminate potential micrometastases, and increase the chance for radical resection. Although systemic treatment prolongs the survival in advanced GC, persistent lymph node (LN) metastases indicate poor prognosis. Therefore, further identification of prognostic factors after NAC is urgent and could positively influence clinical outcomes. This article aimed to review the actual trends and future perspectives in multimodal therapy of advanced GC, with a particular interest in the post-neoadjuvant pathological nodal stage. Since downstaged and primarily node-negative patients show a similar prognosis, the main target for NAC in advanced GC should be nodal clearance. Adequate staging and personalised perioperative therapy seem to be of great importance in the multimodal treatment of GC.

Abstract

Gastric cancer (GC) continues to be one of the major oncological challenges on a global scale. The role of neoadjuvant chemotherapy (NAC) in GC is to downstage primary tumour, eliminate potential micrometastases, and increase the chance for radical resection. Although systemic treatment prolongs the survival in advanced GC, persistent lymph node (LN) metastases indicate poor prognosis. Further identification of prognostic factors after NAC is urgent and could positively influence clinical outcomes. This article aimed to review the actual trends and future perspectives in multimodal therapy of advanced GC, with a particular interest in the post-neoadjuvant pathological nodal stage. A favourable prognostic impact for ypN0 patients is observed, either due to truly negative LN before the start of therapy or because preoperative therapy achieved a pathologically complete nodal response. Ongoing trials investigating the extent of lymphadenectomy after neoadjuvant therapy will standardise the LN dissection from the multimodal therapy perspective. Since downstaged and primarily node-negative patients show a similar prognosis, the main target for NAC in advanced GC should be nodal clearance. Adequate staging and personalised perioperative therapy seem to be of great importance in the multimodal treatment of GC.

Beyond the Guidelines: The Grey Zones of the Management of Gastric Cancer. Consensus Statements from the Gastric Cancer Italian Network (GAIN)

BACKGROUND

Management of gastric and gastroesophageal junction (GEJ) adenocarcinoma remains challenging, because of the heterogeneity in tumor biology within the upper gastrointestinal tract. Daily clinical practice is full of grey areas regarding the complexity of diagnostic, staging, and therapeutic procedures. The aim of this paper is to provide a guide for clinicians facing challenging situations in routine practice, taking a multidisciplinary consensus approach based on available literature.

METHODS

The GAIN (GAstric cancer Italian Network) group was established with the aims of reviewing literature evidence, discussing key issues in prevention, diagnosis, and management of gastric and GEJ adenocarcinoma, and offering a summary of statements. A Delphi consensus method was used to obtain opinions from the expert panel of specialists.

RESULTS

Forty-nine clinical questions were identified in six areas of interest: role of multidisciplinary team; risk factors; diagnosis; management of early gastric cancer and multimodal approach to localized gastric cancer; treatment of elderly patients with locally advanced resectable disease; and treatment of locally advanced and metastatic cancer.

CONCLUSIONS

The statements presented may guide clinicians in practical management of this disease.

Advances in the surgical management of gastric and gastroesophageal junction cancer

Since Theodore Billroth and Cesar Roux perfected the methods of post-gastrectomy reconstruction in the late 19^th century, surgical management of gastric and gastroesophageal cancer has made incremental progress. The majority of patients with localized disease are treated with perioperative combination chemotherapy or neoadjuvant chemoradiation. Staging laparoscopy before initiation of treatment or before surgical resection has improved staging accuracy and can drastically inform treatment decisions. The longstanding and contentious debate on the optimal extent of lymph node dissection for gastric cancer appears to have settled in favor of D2 dissection with the recently published 15-year follow-up of the Dutch randomized trial. Minimally invasive gastric and gastroesophageal resections are performed routinely in most centers affording faster recovery and equivalent oncologic outcomes. Pylorus-preserving distal (central) gastrectomy has emerged as a less invasive, function-preserving option for T1N0 middle-third gastric cancers, while randomized data on its oncologic adequacy are pending. Multi-visceral resections and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy has been utilized selectively for patients with locally advanced tumors who have demonstrated disease control on preoperative chemotherapy. This review summarizes the current standard of surgical care for gastroesophageal junction and gastric cancer as well as highlights recent and upcoming advances to the field.

A novel laparoscopic near-infrared fluorescence spectrum system for photodynamic diagnosis of peritoneal dissemination in pancreatic cancer

BACKGROUND

Diagnosing peritoneal dissemination is essential for selecting the appropriate therapeutic strategy for patients with pancreatic cancer. Intraoperative laparoscopic diagnosis enables the selection of less invasive surgical strategies. Photodynamic diagnosis using 5-aminolevulinic acid may improve gastrointestinal cancer diagnostic accuracy, although weak fluorescence is not easily detected. Here we aimed to improve this sensitivity using laparoscopic spectrophotometry.

METHODS

Photodynamic diagnosis was performed using serial dilutions of protoporphyrin IX, and its detectability using laparoscopic spectrophotometry was compared with that using naked-eye observation. Five-aminolevulinic acid-photodynamic diagnosis was performed for pancreatic cancer cell lines, and a murine peritoneal disseminated nodule model was established. We compared laparoscopic spectrophotometry and naked-eye observation results using white and fluorescent lights and compared them to routine histopathological examination results. Photodynamic diagnoses were made in 2017 and 2018 in eight patients with pancreatic cancer.

RESULTS

Weaker fluorescence of the diluted protoporphyrin IX samples was better detected with spectrophotometry than with naked-eye observation. Moreover, a spectrograph of protoporphyrin IX in multiple cell lines was detected by spectrophotometry. In the murine model, the detection rates were 62 %, 78 %, and 90 % for naked-eye observation with white light, fluorescent light, and spectrophotometry, respectively. Comparisons of fluorescent light-negative peritonea with and without pathological metastases showed significantly higher spectrophotometric intensities in the former (P < 0.010). In clinical studies, three fluorescent light-negative spectrophotometry-positive pathologically metastatic lesions were observed.

CONCLUSIONS

Laparoscopic spectrophotometry in the murine model and extraperitoneally photodynamic diagnoses using spectrophotometry in clinical practice are sensitive photodynamic diagnostic techniques.

A decision analysis comparing three strategies for peritoneal lavage cytology testing in staging of gastric cancer in China

BACKGROUND

Positive peritoneal cytology (PCY) indicates metastasis (M1) in gastric cancer (GC) patients; both the American and Chinese guidelines recommend laparoscopic peritoneal lavage (LPL) for cytology. However, relatively high costs impair the widespread use of LPL in some resource-limited regions in China, and the cost-effectiveness of PCY testing remains unclear. Therefore, we performed a decision analysis to evaluate the cost-effectiveness of PCY testing by comparing the guideline-recommended intraoperative LPL, a newly proposed preoperative percutaneous peritoneal lavage (PPL), and a third strategy of exploratory laparotomy with no cytology testing (ELNC) among GC patients.

METHODS

We developed a decision-analytic Markov model of the aforementioned three strategies for a hypothetical cohort of GC patients with curative intent after initial imaging, from the perspective of Chinese society. We estimated costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) as primary outcomes; we also conducted one-way and probabilistic sensitivity analyses to investigate the model's robustness.

RESULTS

We found that ELNC was dominated (i.e., more expensive and less effective) by PPL and LPL. LPL was the most cost-effective method with an ICER of US$17,200/QALY compared to PPL, which was below the Chinese willingness-to-pay (WTP) threshold of US$29,313 per QALY gained. In sensitivity analyses, PPL was more likely to be cost-effective with a lower WTP threshold.

CONCLUSIONS

Cytology testing through either LPL or PPL was less expensive and more effective than ELNC among GC patients. Moreover, LPL was the most cost-effective modality at the current WTP threshold, while PPL could potentially be cost-effective in lower-income areas.

Staging laparoscopy in gastric cancer surgery. A population-based cohort study in patients undergoing gastrectomy with curative intent

BACKGROUND

Studies on the value of a staging laparoscopy in detecting metastases in gastric cancer patients show great variation. This study investigates the avoidable surgery rate in patients with and without a staging laparoscopy scheduled for surgery with curative intent.

METHODS

This population-based cohort study included all patients with an intentional resection for a potentially curable gastric adenocarcinoma, between 2011 and 2016, registered in the Dutch Upper GI Cancer audit. Patients with and without a staging laparoscopy were compared. The primary outcome was the avoidable surgery rate (detection of metastases and/or locoregional non-resectable tumor during intentional gastrectomy). Secondary outcomes were the negative predictive value, postoperative morbidity and pathology parameters.

RESULTS

2849 patients who underwent an intentional gastrectomy were included. 414 of 2849 (14.5%) patients underwent a staging laparoscopy before initiation of treatment. The avoidable surgery rate was 16.2% in the staging laparoscopy group, compared to 8.5% in the non-staging group (P < 0.001), resulting in a negative predictive value of 83.8%. The avoidable surgery rate remained significantly different after correction for possible confounders. The main reason for not executing the gastrectomy was the presence of distant metastasis in both groups. cT and cN stage were significantly higher in patients who underwent a staging laparoscopy.

CONCLUSIONS

The staging laparoscopy group had a higher cTN and pTN stage, implicating selection of patients with more advanced disease for a staging laparoscopy. Despite the staging laparoscopy, a higher rate of avoidable surgery was found, suggesting a low sensitivity for detecting metastases or locoregional non-resectability in this patient group.

Preoperative Chemoradiotherapy Versus Postoperative Chemoradiotherapy for Patients With Locally Advanced Gastric Cancer: A Retrospective Study Based on Propensity Score Analyses

Purpose

Although adjuvant chemoradiotherapy (CRT) used to be recommended as a standard of care for locally advanced gastric cancer, this suggestion has been strongly challenged recently. However, clear evidence regarding the optimization of radiotherapy is lacking. The purpose of this study was to compare the effectiveness of preoperative CRT versus that of postoperative CRT for resectable or potentially resectable gastric cancer.

Methods

From January 2005 to December 2017, patients with clinical stage III/IVa (i.e., T3-4aN+M0 or T4bNxM0) locally advanced gastric cancer were retrospectively identified. Survival after preoperative CRT and postoperative CRT was assessed by unadjusted, propensity score matching (PSM) and inverse probability of treatment weight (IPTW) analyses. Moreover, exploratory subgroup analyses were performed, and toxicity and patterns of failure were also investigated.

Results

The median follow-up time was 32.5 months. A total of 82 and 463 patients were enrolled in the preoperative and postoperative CRT groups, respectively. After propensity score matching, preoperative CRT was associated with improved overall survival (OS) and disease-free survival (DFS) compared with postoperative CRT (3-year OS: 72.6 vs. 54.4%, log-rank p = 0.0021; 3-year DFS: 61.7 vs. 44.7%, log-rank p = 0.002). The unadjusted and IPTW analyses yielded consistent results. A complete pathologic response was achieved in 13.4% of the preoperative CRT group. Although the incidence of grade 3 or 4 adverse effects and surgical complications were similar between the two groups, significantly fewer patients experienced treatment interruptions or dose reductions due to toxic effects in the preoperative CRT setting than in the postoperative CRT setting (3.7 vs. 10.6%, p = 0.049).

Conclusions

Compared with postoperative CRT, preoperative CRT was associated with improved OS and DFS, superior treatment compliance and comparable surgical complications for patients with locally advanced gastric cancer. Our findings provide important evidence for the optimal combination modalities of surgery and CRT in the absence of randomized clinical data.

Surgical management of oligometastatic disease in gastric cancer

A distinctive subset of metastatic gastric cancer (MGC) is oligometastatic disease (OMD), which is characterized by metastatic lesions limited in number and location. Although growing evidence mainly based on retrospective analysis or single center case series has shown favorable prognosis in the management of OMD in gastric cancer with aggressive local treatment, no existing guidelines explicitely address the definition of OMD and there are still controversial opinions on how to proceed in a new era with more effective systemic therapy selection. In this review, we present the current advances and evidence as well as controversial on the management of OMD in MGC, including the definition, diagnosis, local aggressive treatments especially surgery, prognostic factors, current ongoing randomized clinical studied as well as challenges facing the field.

[Neoadjuvant chemotherapy for gastric cancer. Frequent overtreatment or meaningful concept?]

Neoadjuvant or perioperative therapy with radical surgery is a meaningful approach to improve the prognosis of gastric cancer. The FLOT regimen (5-fluorouracil, leucovorin, oxaliplatin, docetaxel) has been established as a perioperative concept in Germany and is also increasingly being used internationally. The prognostic significance of neoadjuvant chemoradiotherapy has to be awaited based on the results of currently active studies. The microsatellite instability (MSI) status has increasingly gained in importance with respect to decision-making processes in the interdisciplinary tumor board as patients with MSI tumors probably do not benefit from neoadjuvant therapy. Patients with only initial stages of locally advanced MSI tumors (cT2, N0) and those with comorbidities could be spared from neoadjuvant therapy. This article critically deals with the current state of the art concepts as well as with ongoing studies with respect to neoadjuvant and perioperative treatment of gastric cancer. For this purpose, the essential already published and the active studies are presented.

Predicting Peritoneal Dissemination of Gastric Cancer in the Era of Precision Medicine: Molecular Characterization and Biomarkers

Gastric cancer (GC) is a leading cause of worldwide cancer-related death. Being a highly heterogeneous disease, the current treatment of GC has been suboptimal due to the lack of subtype-dependent therapies. Peritoneal dissemination (PD) is a common pattern of GC metastasis associated with poor prognosis. Therefore, it is urgently necessary to identify patients at high risk of PD. PD is found to be associated with Lauren diffuse type GC. Molecular profiling of GC, especially diffuse type GC, has been utilized to identify molecular alterations and has given rise to various molecular classifications, shedding light on the underlying mechanism of PD and enabling identification of patients at higher PD risk. In addition, a series of diagnositc and prognostic biomarkers of PD from serum, peritoneal lavages and primary GCs have been reported. This comprehensive review summarizes findings on the multi-omic characteristics of diffuse type GC, the clinical significance of updating molecular classifications of GC in association with PD risk and research advances in PD-associated biomarkers.

High Level of Legumain Was Correlated With Worse Prognosis and Peritoneal Metastasis in Gastric Cancer Patients

Background: Accumulating evidence has demonstrated that legumain (LGMN) is abnormally expressed in several malignancies and functions as an oncogene. However, the association between LGMN and gastric cancer (GC) has not yet been fully elucidated. In this study, we performed a comprehensive analysis of the role of LGMN in clinicopathologic characteristics and survival of GC patients.

Methods: The study had two patient cohorts, The Cancer Genome Atlas (TCGA) cohort and the Zhongshan Hospital cohort, both of which were used to analyze the role of LGMN in GC samples. The relationship between LGMN and clinicopathologic characteristics was determined by the Chi-square test and logistic regression analysis. The Kaplan–Meier method and Cox proportional hazards regression analysis were conducted to investigate the prognostic role of LGMN in GC patients. Moreover, a nomogram was constructed based on the factors that were independently associated with peritoneal metastasis. Finally, the gene set enrichment analysis (GSEA) was conducted to explore the underlying pathways through which LGMN was involved in GC progression.

Results: The mRNA and protein levels of LGMN were significantly upregulated in GC tissues, especially for diffuse-type GC. High level of LGMN was independently associated with poor prognosis in both TCGA and Zhongshan cohorts. Further analysis showed that increased protein level of LGMN was related to peritoneal metastasis in GC patients. In a nomogram model, the LGMN expression could help predict the possibility of peritoneal metastasis in GC patients. LGMN was a strong determinant for prediction of peritoneal metastasis. GC patients with high LGMN expression tended to have worse survival together with more frequent diffuse-type tumors and increased risk of peritoneal metastasis. The GSEA results showed that focal adhesion, ecm receptor interaction, cell adhesion molecules cams, TGF-β signaling pathway, JAK-STAT signaling pathway, gap junction, etc. were differentially enriched in the phenotype with high LGMN expression.

Conclusion: LGMN was an independent prognostic factor for OS in GC patients. Increased expression of LGMN was significantly associated with peritoneal metastasis. The nomogram based on LGMN might guide the clinical decisions for patients with GC.

Comprehensive Analysis of CDC27 Related to Peritoneal Metastasis by Whole Exome Sequencing in Gastric Cancer

Introduction

The peritoneum is the most common metastatic site of gastric cancer and is associated with a dismal prognosis. However, there is no reliable biomarker for predicting peritoneal metastasis (PM).

Materials and Methods

Whole-exome sequencing (WES) was performed on formalin-fixed, paraffin-embedded (FFPE) samples from 63 patients with stage I–III gastric cancer and circulating tumor DNA (ctDNA) samples from 10 patients with stage IV gastric cancer. Differentially expressed genes (DEGs) were identified between the PM and non-PM groups and analyzed by multiple bioinformatics analyses. Univariate and multivariate Cox regression analyses were used to identify the risk factors for PM and a risk score model was developed.

Results

The number of mutant genes and the tumor mutation burden (TMB) in the PM group were higher than those in the non-PM group (p < 0.05). There was a significant positive correlation between the number of mutant genes and the TMB (R² = 0.9997). The risk of PM was significantly higher in the high TMB group than in the low TMB group (p = 0.045). Forty-nine DEGs were identified as associated with PM in gastric cancer. CDC27 mutations were associated with a higher risk for PM and poor survival. The CDC27 mutations were located in the Apc3 region, the TPR region, and the phosphorylation region, and new mutation sites were not included in the TCGA database. Multivariable Cox regression analysis demonstrated that pathological T stage, poor tumor differentiation, Borrmann type, and CDC27 mutations were independent predictive factors of PM. A risk score model was constructed that demonstrated good performance.

Conclusion

Through WES, we identified 49 DEGs relevant to PM in gastric cancer. CDC27 mutations were independently associated with PM by statistical and bioinformatics analyses. A risk score model was built and was demonstrated to effectively discriminate gastric cancer patients with and without PM.

Colorectal cancer peritoneal metastases: Biology, treatment and next steps

The presence of peritoneal metastases in patients with advanced colorectal cancer is associated with poor prognosis but the mechanisms for this are unclear. This review summarises the current knowledge of the pathophysiology, clinical features, prevalence, prognosis, and molecular biology of peritoneal metastases and the risk factors for the development of peritoneal metastases following resection of a primary colorectal tumour. Furthermore, the evidence for treatment strategies are described including cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, early post-operative intraperitoneal chemotherapy, sequential post-operative intraperitoneal chemotherapy and emerging novel strategies. Active areas of research should include the identification of individuals at high risk of peritoneal metastases after curative resection of primary tumour, development of a surveillance program for high-risk patients, optimisation of systematic therapies and further investigation of the use of intraperitoneal chemotherapy.

Surgical management of gastric adenocarcinoma. Official expert recommendations delivered under the aegis of the French Association of Surgery (AFC)

Gastric adenocarcinoma (GA) is the 5^th most common cancer in the world; in France, however, its incidence has been steadily decreasing. Twenty-five experts brought together under the aegis of the French Association of Surgery collaborated in the drafting of a series of recommendations for surgical management of GA. As concerns preoperative evaluation and work-up, echo-endoscopy aimed at clarifying lymph node status should be performed in all candidates for surgical resection and exploratory laparoscopy in cases of GA cT3/T4 and/or N+ for peritoneal carcinomatosis. On the other hand, PET-scan should not be performed systematically, but only when the other modalities for diagnosis prove insufficient. Laparotomy remains the route of choice to achieve total or partial gastrectomy with D2 lymph node lymphadenectomy for advanced lesions (>T2N0). To limit the risk of dumping syndrome and esophageal reflux and as a way of reestablishing continuity, construction of a jejunal pouch on Roux-en-Y following total gastrectomy is recommended. In cases of peritoneal carcinosis in GA with a low peritoneal cancer index (PCI) (<7) in a patient in good general condition whose disease is controlled by chemotherapy, macroscopically complete cytoreduction with intraperitoneal hyperthermal chemotherapy will probably be required, and it will have to take place in an expert center. Only in the event of Child A cirrhosis may gastrectomy with D2 lymphadenectomy be considered. Palliative gastrectomy or surgical bypass for distal stomach obstruction in a patient in good general condition may also be envisioned.

Iatrogenic diaphragmatic hernia as a late complication of laparoscopic excisional biopsy of peritoneal nodules: A case report

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We report a rare case of delayed diaphragmatic hernia caused by laparoscopic biopsy.

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Coagulation for hemostasis after biopsy could cause diaphragmatic hernia.

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The heat by soft coagulation might unexpectedly damage diaphragmatic muscle.

Introduction

Iatrogenic diaphragmatic hernias have been reported as a rare complication of abdominal surgery, and only a few reports have suggested minimal intraoperative injury to the diaphragm as a cause.

Presentation of case

We report a rare case of delayed diaphragmatic hernia caused by laparoscopic excisional biopsy of a peritoneal lesion on the diaphragmatic peritoneum. A 70-year-old woman with gastric gastrointestinal stromal tumor underwent laparoscopic partial gastrectomy and excisional biopsy for white nodules on the left diaphragmatic peritoneum using laparoscopic scissors. Slight bleeding that occurred after excisional biopsy was stopped using a soft-coagulation system. Six months after her first surgery, a left diaphragmatic defect and transverse colon migration into the thoracic cavity were detected on computed tomography. The patient subsequently underwent laparoscopic diaphragmatic hernia repair. The site at which the diaphragm defect occurred was consistent with the site of excisional biopsy. The defect was closed with interrupted suturing using non-absorbable threads, following which a composite mesh was applied above the suture site for reinforcement.

Discussion

This is the first report of an iatrogenic diaphragmatic hernia after diagnostic laparoscopy for peritoneal excision biopsy of the diaphragmatic surface. In the present case, the coagulation procedure for hemostasis after peritoneal resection was considered to be the cause of the diaphragmatic hernia. The heat generated by soft coagulation might have unexpectedly reached and damaged the deep areas of the diaphragmatic muscle.

Conclusion

Surgeons performing laparoscopic excisional biopsy of the diaphragmatic peritoneum should consider the potential risk for iatrogenic diaphragmatic hernias.

Retrospective imaging studies of gastric cancer: Study protocol clinical trial (SPIRIT Compliant)

INTRODUCTION

Peritoneal metastasis (PM) is a frequent condition in patients presenting with gastric cancer, especially in younger patients with advanced tumor stages. Computer tomography (CT) is the most common noninvasive modality for preoperative staging in gastric cancer. However, the challenges of limited CT soft tissue contrast result in poor CT depiction of small peritoneal tumors. The sensitivity for detecting PM remains low. About 16% of PM are undetected. Deep learning belongs to the category of artificial intelligence and has demonstrated amazing results in medical image analyses. So far, there has been no deep learning study based on CT images for the diagnosis of PM in gastric cancer.

WE PROPOSED A HYPOTHESIS

CT images in the primary tumor region of gastric cancer had valuable information that could predict occult PM of gastric cancer, which could be extracted effectively through deep learning.

OBJECTIVE

To develop a deep learning model for accurate preoperative diagnosis of PM in gastric cancer.

METHOD

All patients with gastric cancer were retrospectively enrolled. All patients were initially diagnosed as PM negative by CT and later confirmed as positive through surgery or laparoscopy. The dataset was randomly split into training cohort (70% of all patients) and testing cohort (30% of all patients). To develop deep convolutional neural network (DCNN) models with high generalizability, 5-fold cross-validation and model ensemble were utilized. The area under the receiver operating characteristic curve, sensitivity and specificity were used to evaluate DCNN models on the testing cohort.

DISCUSSION

This study will help us know whether deep learning can improve the performance of CT in diagnosing PM in gastric cancer.

Deep Convolutional Neural Network Based on Computed Tomography Images for the Preoperative Diagnosis of Occult Peritoneal Metastasis in Advanced Gastric Cancer

We aimed to develop a deep convolutional neural network (DCNN) model based on computed tomography (CT) images for the preoperative diagnosis of occult peritoneal metastasis (OPM) in advanced gastric cancer (AGC). A total of 544 patients with AGC were retrospectively enrolled. Seventy-nine patients were confirmed with OPM during surgery or laparoscopy. CT images collected during the initial visit were randomly split into a training cohort and a testing cohort for DCNN model development and performance evaluation, respectively. A conventional clinical model using multivariable logistic regression was also developed to estimate the pretest probability of OPM in patients with gastric cancer. The DCNN model showed an AUC of 0.900 (95% CI: 0.851-0.953), outperforming the conventional clinical model (AUC = 0.670, 95% CI: 0.615-0.739; p < 0.001). The proposed DCNN model demonstrated the diagnostic detection of occult PM, with a sensitivity of 81.0% and specificity of 87.5% using the cutoff value according to the Youden index. Our study shows that the proposed deep learning algorithm, developed with CT images, may be used as an effective tool to preoperatively diagnose OPM in AGC.

BRAZILIAN GASTRIC CANCER ASSOCIATION GUIDELINES (PART 1): AN UPDATE ON DIAGNOSIS, STAGING, ENDOSCOPIC TREATMENT AND FOLLOW-UP

BACKGROUND

The II Brazilian Consensus on Gastric Cancer by the Brazilian Gastric Cancer Association (ABCG) was recently published. On this occasion, several experts in gastric cancer expressed their opinion before the statements presented.

AIM

To present the ABCG Guidelines (part 1) regarding the diagnosis, staging, endoscopic treatment and follow-up of gastric cancer patients.

METHODS

To forge these Guidelines, the authors carried out an extensive and current review regarding each statement present in the II Consensus, using the Medline/PubMed, Cochrane Library and SciELO databases with the following descriptors: gastric cancer, staging, endoscopic treatment and follow-up. In addition, each statement was classified according to the level of evidence and degree of recommendation.

RESULTS

Of the 24 statements, two (8.3%) were classified with level of evidence A, 11 (45.8%) with B and 11 (45.8%) with C. As for the degree of recommendation, six (25%) statements obtained grade of recommendation 1, nine (37.5%) recommendation 2a, six (25%) 2b and three (12.5%) grade 3.

CONCLUSION

The guidelines presented here are intended to assist professionals working in the fight against gastric cancer with relevant and current information, granting them to be applied in the daily medical practice.

Overcoming Drug Resistance by Taking Advantage of Physical Principles: Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC)

Theoretical considerations as well as comprehensive preclinical and clinical data suggest that optimizing physical parameters of intraperitoneal drug delivery might help to circumvent initial or acquired resistance of peritoneal metastasis (PM) to chemotherapy. Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is a novel minimally invasive drug delivery system systematically addressing the current limitations of intraperitoneal chemotherapy. The rationale behind PIPAC is: (1) optimizing homogeneity of drug distribution by applying an aerosol rather than a liquid solution; (2) applying increased intraperitoneal hydrostatic pressure to counteract elevated intratumoral interstitial fluid pressure; (3) limiting blood outflow during drug application; (4) steering environmental parameters (temperature, pH, electrostatic charge etc.) in the peritoneal cavity for best tissue target effect. In addition, PIPAC allows repeated application and objective assessment of tumor response by comparing biopsies between chemotherapy cycles. Although incompletely understood, the reasons that allow PIPAC to overcome established chemoresistance are probably linked to local dose intensification. All pharmacological data published so far show a superior therapeutic ratio (tissue concentration/dose applied) of PIPAC vs. systemic administration, of PIPAC vs. intraperitoneal liquid chemotherapy, of PIPAC vs. Hyperthermic Intraperitoneal Chemotherapy (HIPEC) or PIPAC vs. laparoscopic HIPEC. In the initial introduction phase, PIPAC has been used in patients who were quite ill and had already failed multiple treatment regimes, but it may not be limited to that group of patients in the future. Rapid diffusion of PIPAC in clinical practice worldwide supports its potential to become a game changer in the treatment of chemoresistant isolated PM of various origins.

Genomewide Expression Profiling Identifies a Novel miRNA-Based Signature for the Detection of Peritoneal Metastasis in Patients With Gastric Cancer

OBJECTIVE

This study aimed to conduct a genomewide transcriptomic profiling to develop a microRNA (miRNA)-based signature for the identification of peritoneal metastasis (PM) in patients with gastric cancer (GC).

SUMMARY BACKGROUND DATA

Even though PM in patients with GC has long been recognized to associate with poor prognosis, currently there is lack of availability of molecular biomarkers for its robust diagnosis.

METHODS

We performed a systematic biomarker discovery by analyzing miRNA expression profiles in primary tumors from GC patients with and without PM, and subsequently validated the expression of candidate miRNA biomarkers in 3 independent clinical cohorts of 354 patients with advanced GC.

RESULTS

Five miRNAs (miR-30a-5p, -134-5p, -337-3p, -659-3p, and -3917) were identified during the initial discovery phase; three of which (miR-30a-5p, -659-3p, and -3917) were significantly overexpressed in the primary tumors from PM-positive patients in the testing cohort (P = 0.002, 0.04, and 0.007, respectively), and distinguished patients with versus without peritoneal metastasis with the value of area under the curve (AUC) of 0.82. Furthermore, high expression of these miRNAs also associated with poor prognosis (hazard ratio = 2.18, P = 0.04). The efficacy of the combination miRNA signature was subsequently validated in an independent validation cohort (AUC = 0.74). Finally, our miRNA signature when combined together with the macroscopic Borrmann's type score offered a much superior diagnostic in all 3 cohorts (AUC = 0.87, 0.76, and 0.79, respectively).

CONCLUSIONS

We have established an miRNA-based signature that have a potential to identify peritoneal metastasis in GC patients.

Fraser extracellular matrix complex subunit 1 promotes liver metastasis of gastric cancer

Liver metastasis is often fatal in patients with gastric cancer, therefore, we aimed to identify genes associated with the mechanisms of liver metastasis of gastric cancer (GC) and to investigate their potential to predict recurrence and to serve as targets of therapy. Recurrence pattern-specific transcriptome analysis was performed to identify liver metastasis-associated genes. A stable knockout cell line was generated to investigate metabolic pathways that contribute to the malignant phenotype in vitro and vivo. Three hundred GC patients were analyzed to demonstrate an association between gene expression levels and clinicopathological parameters. As a results extracellular matrix complex subunit 1 (FRAS1) was identified as a liver metastasis-associated gene. Pathway analysis revealed that FRAS1 expression was significantly correlated with the expression of genes encoding TGFB1, MAP1B, AHNAK, BMP2, MUC1, BIRC5, MET, CDH1, RB1 and MKI67. FRAS1 expression was associated with the activation of the EGFR and PI3K signaling pathways. The proliferation ability of FRAS1 knockout cell line (FRAS1-KO) was inhibited compared to that of the parent cell line through caspase activity increment and cell cycle alteration. FRAS1-KO cells exhibited increased responsiveness to oxygen stress and diminished stemness, invasiveness, and migration. Mouse models of GC revealed decreases in tumor formation and generation of metastasis by FRAS1-KO cells. Moreover, the cumulative liver recurrence rate was significantly increased in patients with GC with high FRAS1 expression levels. We concluded that FRAS1 contributes to the malignant phenotype of GC, especially liver metastasis, and may therefore serve as a predictive marker or a target for treating liver metastasis.

Yield of staging laparoscopy in gastric cancer is influenced by Laurén histologic subtype

BACKGROUND

Staging laparoscopy (SL) with cytologic lavage is a useful staging procedure that allows tailoring the treatment of advanced gastric cancer (GC). The current study aimed to evaluate the total yield of SL in patients with various Laurén histo-types of GC, before planned neoadjuvant chemotherapy and gastrectomy.

METHODS

After exclusion of distant metastatic disease on imaging modalities, 173 patients with primary advanced gastric adenocarcinoma who underwent SL between August 2016 and September 2018, were eligible for the analysis. Patients sex, age, Lauren histo-type, tumor location, grade, cT, and cN were assessed in bivariate analysis. Multivariable logistic regression analysis was used to identify independent factors associated with peritoneal metastases.

RESULTS

Peritoneal metastases, ascites, and positive cytology were found in 39 (22.5%), 17 (9.8%) and 38 (22%) patients, respectively. The total yield of the SL in the current study was 36.4%. Multivariable logistic regression analysis revealed that serosal involvement (cT4) and diffuse histo-type were independent predictors of peritoneal metastases (OR, 15; 95% CI, 1.9-119, P = .02 and OR, 2.4; 95% CI, 1.2-4.6, P = .01, respectively).

CONCLUSIONS

Although cT4 and diffuse tumors show the highest association with peritoneal metastases, SL is a valuable diagnostic procedure in all advanced GC patients.

Role of staging laparoscopy for gastric cancer patients

Staging laparoscopy (SL) is frequently carried out in patients with advanced gastric cancer. However, some clinical questions are being debated and consensus must be obtained. With this aim, a literature search of PubMed/MEDLINE was carried out using the keywords "gastric cancer," "SL," and "diagnostic laparoscopy". Articles published online up to February 2019 were analyzed, focusing on the following questions. (i) What is an adequate indication for SL? (ii) How do you carry out SL? (iii) Does SL provide accurate information about peritoneal dissemination? (iv) Is the yield of SL different by tumor location? (v) Is SL a safe procedure? (vi) Is "repeat SL" needed? (vii) Does SL provide oncological benefit? Results provided the following responses: (i) In Western countries, clinically resectable advanced tumor is an indication for SL. Terms to be introduced for adequate indication include "location," "type 4 (linitis feature)," "large tumor," "equivocal computed tomography (CT] findings," and "lymph node swelling". (ii) Exploration of the entire peritoneal cavity is preferable. (iii) Detection rate of peritoneal disease is 43%-52% in Japanese institutions and 7.8%-40% in other countries. False-negative findings during SL were 0%-17%, and 10%-13% when limited to cytology. (iv) Yield of SL was higher in gastric cancer compared with esophagogastric junctional tumor. (v) SL-related complications were estimated to occur in 0.4%. (vi) Repeat SL is important after treatment. (vii) If the efficacy of neoadjuvant chemotherapy for patients with P0CY1 is established, SL can provide oncological benefit. SL can be carried out safely and effectively. Considering the prevalence of neoadjuvant treatment, the role of SL will become more important.

The Diagnostic and Prognostic Value of Digital Rectal Examination in Gastric Cancer Patients with Peritoneal Metastasis

Background: Peritoneal metastasis (PM) is the most common cause of death in gastric cancer (GC) patients. However, diagnosis of PM is still difficult in clinical practice. This study aimed to explore the diagnostic and prognostic value of digital rectal examination (DRE) in GC. Methods: 247 GC patients with PM confirmed by operation were included. The diagnostic yield of DRE compared with computed tomography (CT) was calculated. In another group of 1330 cases receiving radical gastrectomy, 38 cases with DRE (+) postoperatively were analyzed to identify risk factors. A nomogram was constructed to predict postoperative DRE (+). Results: The specificity, positive predictive value and positive likelihood ratio of DRE in diagnosis of PM was 99.8%, 91.2% and 58.4, higher than CT (97.6%, 64.9% and 10.4). Though the sensitivity of DRE (12.6%) was lower than CT (24.7%), 17 of 31 patients with DRE (+) could not be found by CT. Moreover, the overall survival of confirmed PM patients with DRE (+) (PM-DRE (+)) was much lower than PM-DRE (-) patients (P<0.001). In addition, the nomogram to predict postoperative DRE (+) had a bootstrap-corrected concordance index of 0.73 and was well calibrated. Conclusions: GC patients with DRE (+) could be regarded as a special subtype of stage IV ones with poorer prognosis. Supply of palliative care and chemotherapy rather than unnecessary operation might be a better alternative for these patients. DRE was an effective supplement for CT and should be generally recommended for GC patients.

"Four-Step Procedure" of laparoscopic exploration for gastric cancer in West China Hospital: a retrospective observational analysis from a high-volume institution in China

BACKGROUND

The preoperative work-up has limitations on finding peritoneal dissemination (PD) in gastric cancer patients. Laparoscopic exploration (LE) can discover radiographically occult PD, obtain accurate stage and avert futile laparotomy. The aim of our study was to introduce "Four-Step Procedure" LE in West China Hospital and further evaluate its safety and feasibility.

METHODS

We conducted a retrospective analysis on 165 patients from July 2016 to December 2017 who underwent "Four-Step Procedure" LE in gastrointestinal surgery department of West China Hospital. All the patients were diagnosed with gastric adenocarcinoma without explicit distant metastasis through Computed Tomography and/or Gastrointestinal Ultrasonography. Peritoneal lavage cytological examination (CY) was routinely performed during LE in our research. The "Four-Step" technical process of LE was introduced comprehensively. The clinicopathologic features and the presence of PD or CY at LE were analyzed, and the stratified analysis by cT and cN stages on the proportion of P1 and/or CY1 was also reported in this study.

RESULTS

Total of 165 patients accepted LE in our study, among these patients: 27 (16.4%) patients with P1 and/or CY1: 19 (11.5%) patients were found PD (P1), 17 (10.3%) patients with positive cytological examination (CY1) and 9 (3.6%) patients with P1Cy1. The stratified analysis by cT stage indicated that there was no P1 and/or Cy1 in cT1-cT2 stages, 1 (2.7%) patient with P1 and 1 (2.7%) with Cy1 in cT3 stage, 18 (20.0%) patients with P1 and 16 (17.8%) with Cy1 in cT4 stage. After LE, there were 74 (44.8%) patients underwent laparoscopic assistant gastrectomy, 25 (15.2%) patients with open gastrectomy, 50 (30.3%) patients with neoadjuvant chemotherapy and 16 (9.7%) patients with palliative chemotherapy and/or conversion therapy.

CONCLUSION

"Four-Step Procedure" LE is reliable and feasible for gastric cancer. From our study, LE has unique superiority on ascertaining PD and cytological examination and LE should be recommended in cT4 stage gastric cancer before resection.

Hyperthermic chemotherapy intra-abdominal laparoscopic approach: development of a laparoscopic model using CO2 recirculation system and clinical translation in peritoneal carcinomatosis

INTRODUCTION

Hyperthermic intraperitoneal chemotherapy (HIPEC) is an effective treatment for peritoneal carcinomatosis (PC). Laparoscopic surgery is performed in the treatment of colorectal and appendiceal cancer, and PC from diverse origin in selected patients. HIPEC management by laparoscopic approach after cytoreductive surgery (CRS) completed locoregional treatment of PC, and may be feasible and safe after appropriate patient selection.

OBJECTIVE

Development of an experimental model of HIPEC by laparoscopic approach, with CO₂ recirculation. Clinical translation in two patients with PC and low peritoneal cancer index.

MATERIAL AND METHODS

We performed CRS in a porcine model of 5 pigs (35-38 kg) by laparoscopic approach. Laparoscopic HIPEC by CO₂ recirculation system was performed; laparoscopic access was used for catheter input and output placement (Paclitaxel 175 mg/m² for 60 min at 42 °C). The experimental variables were: blood gases, haemodynamic and intra-abdominal and central temperature. Clinical model application was performed in three cases with PC from colorectal origin.

RESULTS

No statistically significant differences was found in blood gases, haemodynamic or temperature in the experimental study. In clinical study, there were no technical complications during laparoscopic-HIPEC approach, and we observed no changes in haemodynamic variables during the procedure.

CONCLUSIONS

CRS and HIPEC laparoscopic model by CO₂ recirculation system is safe and feasible technique in selected patients, that include low PC index, local and accessible tumour recurrences or high-risk of PC tumours.