Long-term follow up of patients who were positive for peritoneal lavage cytology: final report from the CCOG0301 study

Macroscopic type is implicated in the prognostic impact of initial chemotherapy on peritoneal lavage cytology-positive gastric cancer with no other noncurative factors

BACKGROUND

Initial chemotherapy (Initial-C) followed by surgery is a promising treatment strategy for peritoneal lavage cytology-positive gastric cancer (CY1 GC) with no other noncurative factors. The aim of this study was to investigate the survival advantage of Initial-C compared to initial surgery (Initial-S) for this disease according to the macroscopic type, which was associated with prognosis and the efficacy of chemotherapy in GC.

METHODS

One hundred eighty-nine patients who were diagnosed with CY1 GC with no other noncurative factors at four institutions from January 2007 to December 2018 were enrolled. The patients were divided into a macroscopic type 4 group (N = 48) and a non-type 4 group (N = 141). The influence of initial treatment on overall survival (OS) in each group was evaluated.

RESULTS

In the type 4 group, the 5-year OS rates of Initial-C (N = 35) and Initial-S (N = 13) were 11.6% and 0%, respectively (P = 0.801). The multivariate analysis could not show the survival advantage of Initial-C. In the non-type 4 group, the 5-year OS rates of Initial-C (N = 41) and Initial-S (N = 100) were 48.4% and 29.0%, respectively (P = 0.020). The multivariate analysis revealed that Initial-C was independently associated with prolonged OS (hazard ratio, 0.591; 95% confidence interval, 0.375-0.933: P = 0.023).

CONCLUSIONS

Initial-C improves the prognosis of non-type 4 CY1 GC with no other noncurative factors. On the other hand, further development of effective chemotherapeutic regimens and innovative treatment strategies are required for type 4 CY1 GC.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Oligometastasis of Gastric Cancer: A Review

The concept of oligometastasis is not yet fully established in the field of gastric cancer. However, metastatic lesions that are localized, technically resectable at diagnosis, present a certain response to preoperative chemotherapy, and present favorable survival outcomes with local treatments, sometimes in combination with chemotherapy, are recognized as oligometastasis in the field of gastric cancer. Oligometastasis is noted in European Society for Medical Oncology guidelines and Japanese gastric cancer treatment guidelines, and local treatment is mentioned as one of the pivotal treatment options for oligometastasis. Solitary liver metastasis or a small number of liver metastases; retroperitoneal lymph node metastasis, especially localized para-aortic lymph node metastasis; localized peritoneal dissemination; and Krukenberg tumor are representative types of oligometastasis in gastric cancer. The AIO-FLOT3 trial prospectively evaluated the efficacy of multimodal treatments for gastric cancer with oligometastasis, including surgical resection of primary and metastatic lesions combined with chemotherapy, confirming favorable survival outcomes. Two phase 3 studies are ongoing to investigate the efficacy of surgical resection combined with perioperative chemotherapy compared with palliative chemotherapy. Thus far, the evidence suggests that multimodal treatment for oligometastasis of gastric cancer is promising.

Treatment strategy for successful conversion surgery in clinical stage IVB gastric cancer

INTRODUCTION

Recent advances in chemotherapy have resulted in successful conversion surgery (CS) for clinical stage (cStage) IVB gastric cancer (GC). This study aimed to evaluate the success rate of CS in clinical practice and determine optimal treatment strategies.

METHODS

Totally, 166 patients with cStage IVB gastric and gastroesophageal junction adenocarcinoma, who underwent chemotherapy at Hyogo Medical University Hospital between January 2017 and June 2022, were included. CS was performed after confirming tumor to be M0 based on imaging and/or staging laparoscopy, except for resectable liver metastases. Preoperative chemotherapy was continued for at least 6 months provided that adverse events were manageable.

RESULTS

Of 125 eligible patients, 23 were treated with CS, achieving a conversion rate of 18.4% and an R0 resection rate of 91.3%. The median duration of preoperative chemotherapy was 8.5 months; the median number of cycles was eight. The highest conversion rate was observed in patients receiving first-line treatment (14.4%), followed by those receiving second and third lines (5.8% and 2.3%, respectively). The median survival time in patients who received CS was significantly longer than that in patients who continued chemotherapy alone (56.7 versus 16 months, respectively, P < 0.0001). There was no significant difference in the 3-year overall survival between the patients who achieved CS after first-line treatment (63.2%, n = 18) and those who achieved CS after second- or third-line treatment (66.7%, n = 5).

CONCLUSION

Consistent chemotherapy strategies could lead to successful CS and improved prognosis in a greater number of patients with cStage IVB GC, regardless of line of treatment.

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

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

The Clinical Implication of Conversion Surgery in Patients with Stage IV Gastric Cancer Who Received Systemic Chemotherapy

With the advances in chemotherapy and immunotherapy, a small subset of patients may be eligible for conversion surgery after achieving tumor regression with chemotherapy. This is a retrospective cohort study of 118 patients with stage IV gastric cancer who received palliative chemotherapy and conversion surgery with a negative resection margin at Samsung Medical Center. Baseline features included comorbidities, body mass index (BMI), carcinoembryonic antigen (CEA) level, primary tumor size, biopsy histology, distant metastatic sites, and molecular markers-HER2, MSI/MMR, PD-L1, and EBV. Post-chemotherapy features included BMI, CEA level, chemotherapy regimen, objective response to chemotherapy, and number of preoperative chemotherapy cycles. Post-operational features included tumor size, histologic differentiation and Lauren's classification, pathologic tumor and nodal stages, invasion of lymphatics/vessels/nerves, peritoneal cytology, and the receipt of postoperative chemotherapy. Of 118 patients, 60 patients received total gastrectomy and 58 patients received subtotal gastrectomy. In all, 21 patients achieved a pathologic complete response, and 97 patients achieved downstaging to yp stage I, II, or III. Before conversion surgery, patients received first-line capecitabine/oxaliplatin (62%), HER2 inhibitors combined with chemotherapy (18%), immune checkpoint inhibitors (15%), and inhibitors of MET or VEGFR2 (5%). In the multivariable analysis, BMI at the time of diagnosis, either HER2 positive, high MSI, or deficient MMR, and the use of targeted agents were significant prognostic factors. Conversion surgery could be considered in patients with stage IV gastric cancer regardless of the initial disease burden. BMI and molecular markers are important prognostic factors that can be used to select candidates.

Efficacy of chemotherapy versus surgery as initial treatment for gastric cancer with positive peritoneal cytology

BACKGROUND

The prognosis of gastric cancer (GC) patients with positive peritoneal cytology (CY1) without other distant metastasis is poor, and there are no standard treatment strategies. Our study aimed to compare the survival outcomes of CY1 GC patients receiving chemotherapy or surgery as initial treatment.

METHODS

From February 2017 to January 2020, clinical and pathological data of patients diagnosed with CY1 GC without other distant metastasis in the Peking University Cancer Hospital was reviewed. Patients were divided into two groups: chemotherapy-initial group and surgery-initial group. In chemotherapy-initial group, patients received preoperative chemotherapy initially. According to the treatment response, the patients were divided into three subgroups: conversion gastrectomy group, palliative gastrectomy group, and further systematic chemotherapy group. In surgery-initial group, patients underwent gastrectomy followed by postoperative chemotherapy.

RESULTS

A total of 96 CY1 GC patients were included with 48 patients in each group. In chemotherapy-initial group, preoperative chemotherapy yielded an objective response rate of 20.8% and disease control rate of 87.5%. Conversion to CY0 after preoperative chemotherapy was obtained in 24 (50%) patients. The median overall survival was 36.1 months in chemotherapy-initial group and 29.7 months in surgery-initial group (p = 0.367). The median progression-free survival was 18.1 months in chemotherapy-initial group and 16.1 months in surgery-initial group (p = 0.861). The 3-year overall survival rates were 50.0% and 47.9%, respectively. In chemotherapy-initial group, twenty-four patients who converted to CY0 by preoperative chemotherapy and received surgery obtained a significantly better prognosis. The median overall survival was still not reached in these patients.

CONCLUSION

There was no significant difference in survival outcomes between chemotherapy-initial group and surgery-initial group. CY1 GC patients who converted to CY0 by preoperative chemotherapy and received radical surgery could obtain a favorable long-term prognosis. Further investigation should focus on preoperative chemotherapy to eliminate peritoneal cancer cell.

TRIAL REGISTRATION

This study is retrospectively registered.

Does resection after neoadjuvant chemotherapy of docetaxel, oxaliplatin, and S-1 (DOS regimen) benefit for gastric cancer patients with single non-curable factor? a multicenter, prospective cohort study (Neo-REGATTA)

BACKGROUND

The Neo-REGATTA study evaluated the effectiveness and safety of Docetaxel, oxaliplatin, and S-1 (DOS regimen) followed by radical resection vs. chemotherapy in advanced gastric adenocarcinoma patients with single non-curable factor.

METHODS

This cohort study prospectively enrolled advanced gastric adenocarcinoma patients with single non-curable factor between November 2017 and June 2021. Patients without progression after four cycles of DOS were divided into resection group and chemotherapy group. The outcomes included overall survival (OS), progression-free survival (PFS) and safety. Effectiveness analysis was also performed by propensity score matching (PSM).

RESULTS

A total of 73 patients were enrolled and 13 patients were withdrawn due to disease progression after 4 cycles of DOS. Afterwards, 35 and 25 participants were in the resection and chemotherapy groups, respectively. After a median follow-up time of 30.0 months, the median PFS and OS were 9.0 months, and 18.0 months for the chemotherapy group, but not reached in the resection group. After PSM, 19 matched participants were in each group, and the median PFS and OS were longer in resection group than that in chemotherapy group. The most common grade 3 or 4 adverse events both in the resection group and chemotherapy groups were neutropenia (5.7%, 8.0%) and leukopenia (5.7%, 8.0%).

CONCLUSIONS

Radical resection might provide survival benefit compared with continuous chemotherapy alone in advanced gastric adenocarcinoma patients who had a disease control after DOS, with a good safety profile.

TRIAL REGISTRATION

The study protocol was registered on ClinicalTrial.gov (NCT03001726, 23/12/2016).

Preoperative neutrophil-to-platelet ratio as a potential prognostic factor for gastric cancer with positive peritoneal lavage cytology in the absence of other non-curative factors: a multi-institutional dataset analysis

PURPOSE

Peritoneal dissemination is the key to the prognosis of gastric cancer (GC) and can be detected early with peritoneal lavage cytology. No studies have examined preoperative prognostic factors in GC patients who have positive cytology but no other non-curative factors.

METHODS

We conducted a retrospective analysis using a multicenter database of 3575 patients who underwent gastrectomy between 2010 and 2014. Patients with positive peritoneal lavage cytology as a sole non-curative factor were retrieved, and correlations between parameters and the prognosis were compared.

RESULTS

A total of 66 patients were identified as eligible. In the receiver operating characteristic (ROC) curve analysis, the neutrophil-to-platelet ratio (NPR) had the greatest area under the curve value and was selected. We divided the NPR into two groups based on the optimal cutoff value of the NPR (2.000), as determined by the ROC curve analysis. A high preoperative NPR was the only prognostic factor. The NPR-high group had shorter overall survival than the NPR-low group (hazard ratio 1.85, 95% confidence interval 1.05-3.28, P = 0.032).

CONCLUSION

Our analysis indicated that the preoperative NPR serves as a prognostic factor in GC patients with positive peritoneal lavage cytology in the absence of other non-curative factors.

Conversion surgery for stage IV gastric cancer: a multicenter retrospective study

Background

Recent improvements in systemic chemotherapy have provided an opportunity for patients with stage IV gastric cancer (GC) to undergo conversion surgery (CS). The aim of this study was to evaluate the long-term outcomes of patients who underwent CS and to elucidate the prognostic factors for CS in stage IV GC.

Methods

A total of 79 patients who underwent CS with the aim of R0 resection for stage IV GC at six institutions from January 2008 to July 2019 were enrolled. We retrospectively reviewed the clinicopathological data and prognosis.

Results

Of the 79 patients, 23 (31.1%) had initially resectable disease (IR) before chemotherapy, defined as positive for cancer on peritoneal cytology (CY1), resectable hepatic metastasis, or para-aortic lymph node No. 16a2/b1 metastasis. Of the 56 remaining patients with primary unresectable disease, 39 had peritoneal dissemination. R0 resection was accomplished in 63 patients (79.7%). The 3-year OS rates for patients with IR and unresectable disease were 78.3% and 44.5%, respectively. Multivariate analysis showed that IR (P = 0.014) and R0 (P = 0.014) were statistically significant independent prognostic factors for favorable OS. Among patients with peritoneal dissemination alone, OS was significantly better for patients with R0 resection than for patients with R1/2 resection, with the 3-year OS rates of 65.5% and 23.1%, respectively (P = 0.011).

Conclusions

CS is a treatment option for selected patients with stage IV GC. Patients with IR and patients who achieve R0 resection may obtain a survival benefit from CS.

A study protocol of a randomized phase II trial of perioperative chemoimmunotherapy verses perioperative chemoimmunotherapy plus preoperative chemoradiation for locally advanced gastric (G) or gastroesophageal junction (GEJ) adenocarcinoma: the NeoRacing study

Background

Perioperative chemotherapy (ChT) and preoperative chemoradiation (CRT) are both the standard treatments for locally advanced gastric cancer (LAGC). CRT can achieve a higher pathological complete regression (pCR) rate, but whether this higher pCR rate can be transformed into a long-term survival benefit remains inconclusive. Therefore, relevant studies are in progress. On the other hand, immunotherapy has been established for the first-line treatment of advanced gastric cancer (AGC) and has been widely explored in the perioperative setting. The combination of chemotherapy/radiotherapy and immunotherapy may have a synergistic effect, which will lead to a better antitumor effect. The preliminary reports of ongoing studies show promising results, including a further improved pCR rate. However, the preferred treatment combination for LAGC is still not established. To solve this problem, we are carrying out this randomized phase II trial, which aims to evaluate the efficacy and safety of perioperative chemotherapy plus the use of PD-1 antibody with or without preoperative chemoradiation for LAGC.

Methods

Eligible patients with LAGC or gastroesophageal junction (GEJ) adenocarcinoma were randomized to receive perioperative ChT, PD-1 antibody, surgery with (Arm A) or without preoperative CRT (Arm B), and PD-1 antibody maintenance until one year after surgery. The primary endpoint of this study is that the pCR rate of Arm A will be significantly higher than that of Arm B. The secondary endpoints include the pathological partial regression (pPR) rate, R0 resection rate, objective response rate (ORR), event-free survival (EFS), overall survival (OS), safety and surgical complications. Moreover, several explorative endpoints will be evaluated to find and validate the predictive biomarkers of immunotherapy.

Discussion

The results of the NeoRacing study will provide important information concerning the application of PD-1 antibody in LAGC patients during the perioperative setting. Meanwhile, the two treatment protocols will be compared in terms of efficacy and safety.

Trial registration

ClinicalTrials.gov, NCT05161572. Registered 17 December 2021 - Retrospectively registered.

Clinical significance of initial treatment for peritoneal lavage cytology-positive gastric cancer: outcomes according to treatment strategy

Background

Although patients with positive lavage cytology (CY1) are classified as having stage IV disease, long-term survival without other unresectable factors (P0CY1) has been reported. Conversion gastrectomy in patients with a change in cytology status after induction chemotherapy might improve survival, but appropriate treatment remains controversial. Here, we reviewed our experience in treating CY1 gastric cancer to evaluate the best treatment strategy.

Methods

Clinical and pathological findings of patients with a diagnosis of P0CY1 gastric cancer at Toranomon Hospital between February 2006 and April 2019 were retrospectively analyzed. Patients were classified into two groups according to initial treatment: a surgery-first group and a chemotherapy-first group. In addition, the patients were categorized into subgroups based on the subsequent treatment pattern. The surgery-first group was divided into two subgroups: adjuvant chemotherapy and palliative gastrectomy only. The chemotherapy-first group was divided into three subgroups with the subsequent treatment pattern depending on the response to chemotherapy: conversion gastrectomy, palliative gastrectomy after induction therapy, and palliative chemotherapy.

Results

In total, 38 patients were eligible for inclusion in this study. After initial assessment of cytology status, 21 patients underwent gastrectomy as initial treatment (surgery first) and 17 received induction chemotherapy (chemotherapy first). Ten patients underwent surgery first with adjuvant chemotherapy, 11 underwent palliative gastrectomy alone, 5 underwent conversion surgery, 5 with CY1 disease after induction chemotherapy underwent palliative gastrectomy, and 7 received palliative chemotherapy only. The 3-year survival rate was 23.4% (median survival, 17.7 months) in the surgery-first group and 27.3% (median survival, 19.7 months) in the chemotherapy-first group. The 3-year survival rate was 75% for conversion gastrectomy, 16.7% for palliative chemotherapy, and 0% for palliative gastrectomy after induction chemotherapy.

Conclusions

There was no significant difference in outcome according to whether surgery or chemotherapy was performed first. The prognosis of conversion surgery with curative resection was better than that of the other types of treatment. However, the outlook after induction chemotherapy was poor. Patients with advanced gastric cancer should be treated cautiously until more effective treatment options become available.

Clinical impact of gastrectomy for gastric cancer patients with positive lavage cytology without gross peritoneal dissemination

BACKGROUND

The prognosis of gastric cancer patients with positive lavage cytology without gross peritoneal dissemination (P0CY1) is poor. The survival benefit of gastrectomy for these patients has not been established.

PATIENTS AND METHODS

In this population-based cohort study, we investigated the impact of radical gastrectomy with lymph node dissection for P0CY1 patients. Patients who were diagnosed with Stage IV gastric cancer from 2008 to 2015 in all nine cancer-designated hospitals in a tertiary medical area were listed. Patients who were diagnosed with histologically proven adenocarcinoma in both the primary lesion and lavage cytology during the operation or a diagnostic laparoscopic examination were enrolled. Patients with a gross peritoneal lesion or other metastatic lesions were excluded. The primary outcome was the adjusted hazard ratio (aHR) of gastrectomy for overall survival. We also evaluated the survival time in patients who underwent gastrectomy or chemotherapy in comparison to patients managed without primary surgery or with best supportive care.

RESULTS

One hundred patients were enrolled. The aHR (95% confidence interval) of gastrectomy was 0.677 (0.411-1.114, p = 0.125). The median survival time in patients who received gastrectomy (n = 74) was 21.7, while that in patients managed without primary surgery (n = 30) was 20.5 months (p = 0.155). The median survival time in patients who received chemotherapy (n = 76) was 23.0 months, while that in patients managed without chemotherapy was 8.6 months (p < 0.001).

CONCLUSION

Gastrectomy was not effective for improving the survival time in patients with P0CY1 gastric cancer. Surgeons should prioritize the performance of chemotherapy over surgery as the initial treatment.

Molecular classification of gastric cancer predicts survival in patients undergoing radical gastrectomy based on project HOPE

BACKGROUND

Gastric cancer (GC) has been classified based on molecular profiling like The Cancer Genome Atlas (TCGA) and Asian Cancer Research Group (ACRG), and attempts have been made to establish therapeutic strategies based on these classifications. However, it is difficult to predict the survival according to these classifications especially in radically resected patients. We aimed to establish a new molecular classification of GC which predicts the survival in patients undergoing radical gastrectomy.

METHODS

The present study included 499 Japanese patients with advanced GC undergoing radical (R0/R1) gastrectomy. Whole-exome sequencing, panel sequencing, and gene expression profiling were conducted (High-tech Omics-based Patient Evaluation [Project HOPE]). We classified patients according to TCGA and ACRG subtypes, and evaluated the clinicopathologic features and survival. Then, we attempted to classify patients according to their molecular profiles associated with biological features and survival (HOPE classification).

RESULTS

TCGA and ACRG classifications failed to predict the survival. In HOPE classification, hypermutated (HMT) tumors were selected first as a distinctive feature, and T-cell-inflamed expression signature-high (TCI) tumors were then extracted. Finally, the remaining tumors were divided by the epithelial-mesenchymal transition (EMT) expression signature. HOPE classification significantly predicted the disease-specific and overall survival (p < 0.001 and 0.020, respectively). HMT + TCI showed the best survival, while EMT-high showed the worst survival. The HOPE classification was successfully validated in the TCGA cohort.

CONCLUSIONS

We established a new molecular classification of gastric cancer that predicts the survival in patients undergoing radical surgery.

Current treatment strategies for patients with only peritoneal cytology positive stage IV gastric cancer

Gastric cancer (GC) is one of the most common malignancies worldwide and surgery remains the only potentially curative treatment option for it. Although a significant proportion of GC patients are found with distant metastases already at the initial diagnosis. Peritoneal dissemination is the most common site of metastases. Positive peritoneal cytology (Cy1) is associated with poor long-term outcomes; thus, these patients are considered as stage IV even if macroscopic carcinomatosis is absent. Currently, there is no clear evidence for the most optimal treatment for this distinct subpopulation of the stage IV cohort. Available strategies vary from palliative chemotherapy to upfront gastrectomy. This comprehensive review summarized current evidence of different treatment strategies for Cy1 GC including roles of surgery, systemic and intraperitoneal chemotherapy.

The Chinese Society of Clinical Oncology (CSCO): Clinical guidelines for the diagnosis and treatment of gastric cancer, 2021

There exist differences in the epidemiological characteristics, clinicopathological features, tumor biological characteristics, treatment patterns, and drug selections between gastric cancer patients from the Eastern and Western countries. The Chinese Society of Clinical Oncology (CSCO) has organized a panel of senior experts specializing in all sub-specialties of gastric cancer to compile a clinical guideline for the diagnosis and treatment of gastric cancer since 2016 and renews it annually. Taking into account regional differences, giving full consideration to the accessibility of diagnosis and treatment resources, these experts have conducted expert consensus judgment on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes in China. The 2021 CSCO Clinical Practice Guidelines for Gastric Cancer covers the diagnosis, treatment, follow-up, and screening of gastric cancer. Based on the 2020 version of the CSCO Chinese Gastric Cancer guidelines, this updated guideline integrates the results of major clinical studies from China and overseas for the past year, focused on the inclusion of research data from the Chinese population for more personalized and clinically relevant recommendations. For the comprehensive treatment of non-metastatic gastric cancer, attentions were paid to neoadjuvant treatment. The value of perioperative chemotherapy is gradually becoming clearer and its recommendation level has been updated. For the comprehensive treatment of metastatic gastric cancer, recommendations for immunotherapy were included, and immune checkpoint inhibitors from third-line to the first-line of treatment for different patient groups with detailed notes are provided.

High postoperative neutrophil-lymphocyte ratio and low preoperative lymphocyte-monocyte ratio predict poor prognosis in gastric cancer patients receiving gastrectomy with positive lavage cytology: a retrospective cohort study

BACKGROUND

Long-term outcomes in gastric cancer patients with positive lavage cytology (CY1) are generally poor. This multi-institutional retrospective cohort study aims to evaluate the clinical significance of the neutrophil-lymphocyte ratio (NLR) and the lymphocyte-monocyte ratio (LMR) in CY1 gastric cancer patients.

METHODS

A total of 121 CY1 gastric cancer patients without other non-curative factors, who underwent macroscopically curative resection, were enrolled in this study. The cutoff values of preoperative NLR (pre-NLR), postoperative NLR (post-NLR), preoperative LMR (pre-LMR), and postoperative LMR (post-LMR) were defined by the Contal and O'Quigley method as 2.3, 3.0, 2.5, and 3.2, respectively. A Cox proportional hazard model was used to identify the independent prognostic factors among NLR, LMR, and other clinicopathological factors.

RESULTS

There were significant differences in the overall survival (OS) between the two groups: high post-NLR groups vs. low post-NLR group (median survival time, months) (10.9 vs. 22.8, P = 0.006) and high pre-LMR group vs. low pre-LMR group (21.3 vs. 11.0, P = 0.001). The LMR value elevated significantly after gastrectomy (P = 0.020), although not in the NLR value (P = 0.733). On multivariate analysis, high post-NLR (hazard ratio = 1.506; 95% confidence interval = 1.047-2.167; P = 0.027), low pre-LMR (1.773; 1.135-2.769, 0.012), and no postoperative chemotherapy (1.558; 1.053-2.305, 0.027) were found to be independent prognostic factors for adverse OS.

CONCLUSIONS

Because a combination of high post-NLR and low pre-LMR may be an adverse prognostic marker in resectable CY1 gastric cancer patients, it is necessary to conduct a prospective trial to confirm a useful perioperative chemotherapeutic regimen for these patients.

Comparative Outcomes of Laparoscopic Gastrectomy and Open Gastrectomy for Scirrhous Gastric Cancer: A Multicenter Retrospective Cohort Study

Objective

A multicenter retrospective cohort study was performed to compare the outcomes of laparoscopic gastrectomy (LG) versus open gastrectomy (OG) for scirrhous gastric cancer (GC) as a unique subtype also known as type 4 gastric cancer or linitis plastica.

Background

Although data on the efficacy and safety of LG as an alternative to OG are emerging, the applicability of LG to scirrhous GC remains unclear.

Methods

Patients with clinical type 4 GC undergoing gastrectomy at 13 hospitals from 2005 to 2015 were retrospectively reviewed. As the primary endpoint, we compared overall survival (OS) between the LG and OG groups. To adjust for confounding factors, we used multivariate Cox regression analysis for the main analyses and propensity-score matching for sensitivity analysis. Short-term outcomes and recurrence-free survival were also compared.

Results

A total of 288 patients (LG, 62; OG, 226) were included in the main analysis. Postoperative complications occurred in 25.8% and 30.1%, respectively (P = 0.44). No significant difference in recurrence-free survival was observed (P = 0.72). The 5-year OS rates were 32.4% and 31.6% in the LG and OG groups, respectively (P = 0.60). The hazard ratio (LG/OG) for OS was 0.98 (95% confidence interval [CI], 0.65-1.43) in the multivariate regression analysis. In the sensitivity analyses after propensity-score matching, the hazard ratio for OS was 0.92 (95% CI, 0.58-1.45).

Conclusions

Considering the hazard ratios and 95% CIs for OS, LG for scirrhous GC was not associated with worse survival than that for OG.

Impact of preoperative chemotherapy as initial treatment for advanced gastric cancer with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) or localized peritoneal metastasis (P1a): a multi-institutional retrospective study

BACKGROUND

Gastric cancer (GC) patients with peritoneal metastasis are defined as stage IV in the Japanese classification of GC. For patients with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) and/or localized peritoneal metastasis (P1a), gastrectomy followed by S1 monotherapy is one of the most widely accepted therapeutic strategy in Japan. This study investigated the efficacy of preoperative chemotherapy as initial treatment in GC patients with CY1 and/or P1a.

METHODS

We retrospectively reviewed GC patients diagnosed with CY1 and/or P1a at 34 institutions in Japan between 2008 and 2012. Selection criteria were: adenocarcinoma, no distant metastasis except CY1 or P1a, and no prior treatment. The subjects were divided into an Initial-Chemotherapy group and an Initial-Surgery group, according to the initial treatment.

RESULTS

A total of 824 patients were collected and 713 eligible patients were identified for this study. As the initial treatment, 150 patients received chemotherapy (Initial-Cx), and 563 patients underwent surgery (Initial-Sx). Initial-Cx regimens were cisplatin plus S1/docetaxel plus cisplatin plus S1/others (n = 90/37/23). Both overall survival (OS) and progression-free survival (PFS) were similar between the Initial-Cx and Initial-Sx groups (median OS 24.8 and 24.0 months, HR 1.07, 95% CI 0.87-1.3; median PFS 14.9 and 13.9 months, HR 1.04, 95% CI 0.85-1.27). The 5-year OS rates were 22.3% in the Initial-Cx group and 21.5% in the Initial-Sx group.

CONCLUSIONS

Although, the preoperative chemotherapy did not show a survival benefit for GC patients with CY1 and/or P1a, initial-Cx showed favorable survival in patients who converted to P0 and CY0.

Progress and controversy in treatment of gastric cancer patients with positive peritoneal lavage cytology

Gastric cancer is one of the most common malignant tumors in China, and peritoneal metastasis is common in patients with gastric cancer. Positive peritoneal lavage cytology indicates a special type of distant metastasis of gastric cancer, and its therapeutic principle is still unclear. At present, the cornerstone treatment for advanced gastric cancer is radical surgery combined with postoperative adjuvant chemotherapy, and conversion therapy is very important for gastric cancer patients with positive peritoneal lavage cytology. Negative conversion of peritoneal lavage can effectively improve the prognosis. Intraperitoneal hyperthermic perfusion chemotherapy and intraoperative intraperitoneal lavage provide new ideas for the treatment of such patients, which can effectively kill free cancer cells in the abdominal cavity. At present, most clinical studies on the principles of treatment of gastric cancer patients with positive peritoneal lavage cytology are retrospective with a small sample size. We recommend to conduct multidisciplinary MDT discussions and develop individualized treatment plans for these patients, and encourage them to participate in relevant clinical trials.

Docetaxel plus S-1 versus cisplatin plus S-1 in unresectable gastric cancer without measurable lesions: a randomized phase II trial (HERBIS-3)

BACKGROUND

Cisplatin plus S-1 (CS) is the standard first-line chemotherapy for advanced gastric cancer (AGC) in Japan. A previous phase III trial showed that docetaxel plus S-1 (DS) was effective for AGC without measurable lesions, but no studies have compared these two regimens.

METHODS

Eligible patients had unresectable or recurrent HER2-negative AGC without measurable lesions. Patients were randomized to DS (docetaxel 40 mg/m² on day 1, S-1 80-120 mg on days 1-14, every 3 weeks) or CS (cisplatin 60 mg/m² on day 8, S-1 80-120 mg on days 1-21, every 5 weeks). The primary endpoint was overall survival (OS).

RESULTS

All patients had unresectable primary disease. Sixty-one patients were randomly assigned to DS (n = 30) or CS (n = 31). One CS patient was ineligible due to HER2 positivity. The median number of cycles was 9.5 (range 2-49) with DS and 5.5 (range 1-10) with CS. There were no treatment-related deaths. The most common grade 3-4 non-hematological toxicity was fatigue (7% with DS, 13% with CS), followed by anorexia (3% with DS, 10% with CS) and diarrhea (3% with DS, 10% with CS). The 2-year OS rates were 43.3% with DS and 30.0% with CS (log-rank P = 0.113), with a hazard ratio of 0.617 (95% confidence interval 0.337-1.128), indicating non-inferiority of DS to CS with respect to OS (P < 0.001).

CONCLUSIONS

DS showed slightly but nonsignificantly less toxicity and higher efficacy than CS for AGC without measurable lesions. DS should be further investigated in phase III trials.

Impact of metabolism-related mutations on the heart rate of gastric cancer patients after peritoneal lavage

BACKGROUND

During surgery for gastric cancer, peritoneal lavage using warm distilled water can cause temporary hemodynamic changes.

AIM

To examine the associations between changes in heart rate and single nucleotide polymorphisms (SNPs).

METHODS

This was a prospective observational study of patients with gastric cancer who underwent gastrectomy and peritoneal hypotonic lavage at the Third Affiliated Hospital of Soochow University from March 2018 to March 2019. Related SNPs were selected, and the verified exons were analyzed. Heart rate and blood pressure (BP) were measured before and after lavage. The patients were grouped as heart rate change ≥ 30% vs < 30%. Comparison and regression analyses of the selected SNPs were performed between the two groups.

RESULTS

According to the inclusion/exclusion criteria, 194 patients were included in the analysis. Of these patients, 138 were male, with a mean age of 65.9 ± 0.8 years, and 56 were female, with a mean age of 65.0 ± 1.3 years. Heart rate dropped by 0%-10% in 65 participants, by 10%-15% in 29, by 15%-20% in 23, by 20%-50% in 39, by 50%-100% in four, six had a cardiac arrest, and 28 had an increase in heart rate. Considering the possible impact of exonic SNPs on the phenotypes, TEP1 (rs938886), TEP1 (rs1713449), and RECQL5 (rs820196) were analyzed. The haplotype analysis suggested that the haplotypes CTT [odds ratio (OR) = 2.018, 95% confidence interval (CI): 1.012-4.025, P = 0.0430] and GCC (OR = 2.293, 95%CI: 1.174-4.477, P = 0.0131) of TEP1 (rs938886), TEP1 (rs1713449), and RECQL5 (rs820196) increased the risk of a drop in heart rate > 30%.

CONCLUSION

The TEP1 (rs938886), TEP1 (rs1713449), and RECQL5 (rs820196) SNPs were associated with changes in heart rate ≥ 30% during intraperitoneal lavage using distilled water after gastrectomy for gastric cancer.

Current status of conversion surgery for stage IV gastric cancer

Palliative chemotherapy with best supportive care is a mainstay for patients with gastric cancer (GC) and distant metastasis. However, with advances in GC chemotherapy, multimodal treatment, including perioperative chemotherapy plus conversion surgery, has attracted attention as a new strategy to improve the outcome of patients with stage IV disease. Conversion surgery is defined as surgical treatment aimed at R0 resection after a good response to induction chemotherapy for tumors originally considered unresectable or marginally resectable for technical and/or oncological reasons. Various biological characteristics differ, depending on each metastatic condition in stage IV GC. The main metastatic pathways of GC can be divided into three categories: lymphatic, hematogenous, and peritoneal. In each category, considerable historical data on conversion surgery have demonstrated the benefits of individualized approaches. However, owing to the diversity of these conditions, a common definition, including the choice of induction chemotherapy, optimal timing of resection, and eligibility for conversion surgery, has not been established among surgical oncologists. Thus, we explore the current and future treatment options by reviewing the literature on this controversial topic comprehensively.

Survival outcomes and prognostic indicators for gastric cancer patients with positive peritoneal wash cytology but no peritoneal metastasis after radical gastrectomy

BACKGROUND

Positive peritoneal wash cytology with no peritoneal metastasis (CY1P0) is a special type of distant gastric cancer metastasis, which describes a patient with positive peritoneal lavage cytology, but no definitive peritoneal metastasis, and there are no widely accepted treatment guidelines. We enrolled 48 primary CY1P0 gastric cancer patients treated by radical gastrectomy in this study. Our study illustrated the efficacy of radical gastrectomy for CY1P0 gastric cancer patients, and suggested that the pathological N factor and vascular invasion were significant independent risk factors for overall survival (OS).

AIM

To assess the survival of CY1P0 gastric cancer patient post-radical gastrectomy, and to identify factors associated with long-term prognosis.

METHODS

Our study included 48 patients with primary CY1P0 gastric cancer who had radical gastrectomies at the Cancer Hospital, Chinese Academy of Medical Sciences, Beijing, China between 2013 and 2018. R0 resection was achieved in all 48 patients. Twelve patients received neoadjuvant chemotherapy. Thirty patients received adjuvant chemotherapy and four received adjuvant chemoradiotherapy. OS statistics were available for 48 patients. Follow-up continued through March 2020. Univariate and multivariate analyses were performed using a Cox proportional hazards model to identify prognostic factors.

RESULTS

Median OS was 22.0 mo (95% confidence interval: 13.366-30.634 mo) post-surgery. Univariate analyses demonstrated that tumor site (P = 0.021), pathological N factor (P = 0.001), pathological T factor (P = 0.028), vascular invasion (P = 0.046), and the level of CA199 prior to initiating therapy (P = 0.002) were significant risk factors for OS. Multivariate analyses demonstrated that pathological N factor (P = 0.001) and vascular invasion (P = 0.031) were significant independent risk factors for OS.

CONCLUSION

This study suggested that radical gastrectomy may be efficient for CY1P0 gastric cancer patient post-radical gastrectomy and the pathological N factor and vascular invasion are significant independent risk factors for OS.

Do liver metastases from gastric cancer contraindicate aggressive surgical resection? A 14-year single-center experience

BACKGROUND

Advanced gastric cancer (GC) with liver metastasis is often characterized by multiple and bilobular metastases and may also be associated with extrahepatic metastatic lesions. Hence, many physicians consider that radical surgeries are contraindicated for liver metastases from GC (LMGC). According to the 2017 Japanese treatment guideline for GC, a smaller number of liver metastases without unresectable factors may be an indication for liver resection (LR) with curability. The actual 5-year overall survival (OS) rate ranges from 0 to 0.37.

AIM

To present the institutional indications for LR for LMGC and identify important factors for prognostic outcomes.

METHODS

In total, 30 patients underwent LR for LMGC during a 14-year period, and we evaluated the clinical, surgical, and oncological findings. In all patients, radical surgery with intentional lymphadenectomy was performed for the primary GC. The median follow-up duration after the initial LR was 33.7 mo, and three patients with no recurrence died of causes unrelated to the LMGC. The OS and recurrence-free survival rates after the initial LR were assessed.

RESULTS

Seventeen patients had metachronous LMGC. The initial LR achieved curability in 29 patients. Perioperative chemotherapy was introduced in 23 patients. The median greatest LMGC dimension was 30 mm, and the median number of LMGC was two. Twenty-two patients had unilobular LMGC. The 5-year OS and recurrence-free survival rates were 0.48 and 0.28, respectively. The median survival duration and recurrence-free duration after the initial LR were 16.8 and 8.6 mo, respectively. Twenty-one patients developed recurrence after the initial LR. Additional surgeries for recurrence were performed in nine patients, and these surgeries clearly prolonged the patients' survival. Pathological serosal invasion was an independent predictor of a poor prognostic outcome after the initial LR. Aggressive LR may be indicated for carefully selected patients with LMGC.

CONCLUSION

Our results of LR for LMGC seem acceptable. Additional surgeries for recurrence after the initial LR might prolong OS. Pathological serosal invasion is important for poor prognostic outcomes.

Prognostic benefit of conversion surgery for HER2 positive stage IV gastric cancer; a case series study of eleven patients treated with trastuzumab-based chemotherapy

BACKGROUND

Since the ToGA trial, trastuzumab-based chemotherapy is the standard treatment for HER2 positive stage IV gastric cancer. However, it is not yet clear whether surgical resection after trastuzumab-based chemotherapy (conversion surgery) can improve survival of HER2 positive stage IV gastric cancer. The purpose of this study is to evaluate the prognostic benefit of conversion surgery in HER2 positive stage IV gastric cancer patients.

CASE PRESENTATION

We retrospectively investigated the medical records of the patients with HER2 positive (IHC3(+) or IHC2(+)/FISH(+)) stage IV gastric cancer treated with trastuzumab-based chemotherapy as the first line treatment. Overall survival (OS) was compared between patients with conversion surgery and without. Eleven HER2 positive stage IV gastric cancer patients treated with trastuzumab-based chemotherapy as the first line treatment were evaluated. Response rate was 63.6%, and 6 of 11 patients could receive conversion surgery. R0 resection was achieved in four patients. In Kaplan-Meier analysis, patients who received conversion surgery showed significantly better OS than those without surgery (3-year survival rate, 66.7% vs. 20%, P = 0.03). The median OS of patients who achieved R0 resection is 51.8 months.

CONCLUSIONS

Conversion surgery might have a survival benefit for HER2 positive stage IV gastric cancer patients. If curative surgery is technically possible, conversion surgery could be a treatment option for HER2 positive stage IV gastric cancer.

Biomarker analysis to predict the pathological response to neoadjuvant chemotherapy in locally advanced gastric cancer: An exploratory biomarker study of COMPASS, a randomized phase II trial

Background: The findings of COMPASS, a randomized phase II study, suggested that the regimens and courses of neoadjuvant chemotherapy (NAC) for locally advanced gastric cancer (GC) did not affect the pathological response. However, pathological complete response was achieved in 10% patients who received four courses of either S-1/cisplatin or paclitaxel/cisplatin. We hypothesized that if relevant biomarkers could be used to predict the suitable NAC regimen before treatment initiation, further improvements could be ensured in the outcomes of locally advanced GC.

Materials and Methods: mRNA extraction, real-time polymerase chain reaction, and immunohistochemical analyses were performed using endoscopic biopsy specimens of primary tumors, collected prior to NAC, to determine the clinically relevant biomarkers.

Results: TIMP1, DSG2, RRM1, MUC2, EGFR, ZDHHC14, and CLDN18.2 were identified as biomarker candidates, since their expression was significantly associated with the pathological responses to each NAC regimen. Furthermore, TIMP1 and DSG2 were identified as predictive biomarkers of the pathological response to each NAC regimen.

Conclusions: The effective prediction of the pathological response to NAC regimens in locally advanced GC using biomarkers identified from endoscopic biopsy specimens indicates the possibility of personalizing NAC based on biomarker analysis.

Conversion therapy for peritoneal lavage cytology-positive type 4 and large type 3 gastric cancer patients selected as candidates for R0 resection by diagnostic staging laparoscopy

BACKGROUND

The long-term outcomes of type 4 and large type 3 gastric cancer patients with positive peritoneal lavage cytology (CY1) remain unsatisfying. We evaluated our treatment strategy of conversion therapy for CY1 patients without peritoneal dissemination (P0).

METHODS

Diagnostic staging laparoscopy (DSL) was performed before treatment. Chemotherapy was applied for DSL-diagnosed P0CY1. The re-evaluation of peritoneal metastasis by staging laparoscopy (re-SL) was performed when a response to chemotherapy was identified by gastroscopy and/or CT. Gastrectomy with radical lymphadenectomy was applied as conversion therapy when peritoneal lavage cytology-negative (CY0) and P0 were diagnosed with re-SL, with the aim of achieving R0 resection. Chemotherapy was continued as palliative treatment in patients for whom re-SL was not applicable or when re-SL did not confirm P0CY0. The long-term outcomes were retrospectively evaluated.

RESULTS

Between 2009 and 2015, 214 patients with type 4 and large type 3 gastric cancer underwent DSL in the Cancer Institute Hospital. Thirty-nine patients were initially diagnosed with P0CY1. Seven patients received palliative gastrectomy first due to outlet obstruction or other reasons. Thirty-two patients received chemotherapy first. Among them, 13 patients underwent gastrectomy as conversion therapy and 19 were treated with palliative chemotherapy. The 3-year survival rate of patients who underwent conversion therapy, palliative chemotherapy and palliative gastrectomy was 76.9% [95% confidence interval (CI) 47.8-92.4%], 10.5% (95% CI 1.9-42.3%), and 0%, respectively.

CONCLUSION

Conversion therapy might be a promising treatment for P0CY1 type 4 and large type 3 gastric cancer patients. Re-SL was useful for selecting candidates for R0 resection.

Conversion Surgery for Stage IV Gastric Cancer

The prognosis of stage IV gastric cancer (GC) is poor, with palliative chemotherapy remaining the main therapeutic option. Studies increasingly indicate that patients with unresectable stage IV GC, who undergo gastrectomy with radical intention after responding to several regimens of combined chemotherapy, can achieve good survival outcomes. Thus, surgery aiming at radical resection for unresectable stage IV GC after combined chemotherapy has received increasing attention in recent years. This novel therapeutic strategy was defined as conversion surgery in patients with unresectable stage IV GC and it can associate with significant improved survival when R0 resection can be achieved. Despite the recent advances in conversion surgery for patients with unresectable stage IV GC, selection criteria for combination chemotherapy regimens, indications for conversion surgery, optimal timing to surgery, and postoperative chemotherapy all remain controversial. This article reviews the current state of conversion surgery for unresectable stage IV GC.

Randomized clinical trial of extensive intraoperative peritoneal lavage versus standard treatment for resectable advanced gastric cancer (CCOG 1102 trial)

BACKGROUND

A survival benefit of extensive intraoperative peritoneal lavage (EIPL) has been reported in patients with gastric cancer with positive peritoneal cytology. The hypothesis of this study was that EIPL may reduce peritoneal recurrence in patients with advanced gastric cancer who undergo surgery with curative intent.

METHODS

This was an open-label, multi-institutional, randomized, phase 3 trial to assess the effects of EIPL versus standard treatment after curative gastrectomy for resectable gastric cancer of T3 status or above. The primary endpoint was disease-free survival (DFS); secondary endpoints were overall survival, peritoneal recurrence-free survival and incidence of adverse events.

RESULTS

Between July 2011 and January 2014, 314 patients were enrolled from 15 institutions and 295 patients were analysed (145 and 150 in the EIPL and no-EIPL groups respectively). The 3-year DFS rate was 63·9 (95 per cent c.i. 55·5 to 71·2) per cent in the EIPL group and 59·7 (51·3 to 67·1) per cent in the control group (hazard ratio (HR) 0·81, 95 per cent c.i. 0·57 to 1·16; P = 0·249). The 3-year overall survival rate was 75·0 (67·1 to 81·3) per cent in the EIPL group and 73·7 (65·9 to 80·1) per cent in the control group (HR 0·91, 0·60 to 1·37; P = 0·634). Peritoneal recurrence-free survival was not significantly different between the two groups (HR 0·92, 0·62 to 1·36; P = 0·676). No intraoperative complications related to EIPL were observed.

CONCLUSION

EIPL did not improve survival or peritoneal recurrence in patients who underwent gastrectomy for advanced gastric cancer. Registration number: 000005907 (http://www.umin.ac.jp/ctr/index.htm).

Proposal of a New TNM Classification for Gastric Cancer: Focusing on pN3b and Cytology-Positive (CY1) Disease

Purpose

Gastric cancer with lymph node metastasis (LNM) more than 15 (N3b) was defined as stage IV until the 6th AJCC system. However, it has been reclassified as a localized disease (stage IIb or III) since the 7th system. The aim of this study is to demonstrate that the survival of N3b is comparable to cytology-only positive (CY1-only) stage IV and to propose a new TNM system interpreting N3b as an eligibility criterion for receiving more intensive chemotherapy regimens.

Materials and Methods

1,430 patients who underwent gastric cancer surgery at Seoul National University Hospital from 2007 to 2012 were retrospectively analyzed. The 5-year survival rate (5YSR) and 3-year recurrence-free survival (RFS) were evaluated according to the 7th and 8th systems, as well as a new categorization based on N-classification; N0-2 (LNM<7), N3a (LNM 7–15), or N3b (LNM>15).

Results

The survival of N3b is comparable to that of CY1-only stage IV (log rank test, P=0.671) and is distinct from that of grossly stage IV (log rank test, P<0.001). The survival of the remaining stage IIIc (T4bN3a) was comparable to those of N3b and CY1-only stage IV. Most N3b patients had significantly shorter 3-year RFS and mean RFS than those with IIb–IIIc, as if N3b itself was a higher TNM stage.

Conclusions

In terms of survival, T4bN3a, N3b, and CY1-only stage IV were unified as stage IVa, while grossly stage IV was defined as stage IVb. N3b can be regarded as an eligibility criterion for undergoing more intensive chemotherapy regimens.

Efficacy of Postoperative Chemotherapy After Resection that Leaves No Macroscopically Visible Disease of Gastric Cancer with Positive Peritoneal Lavage Cytology (CY1) or Localized Peritoneum Metastasis (P1a): A Multicenter Retrospective Study

BACKGROUND

Gastric cancer (GC) patients with positive peritoneal lavage cytology (CY1) and/or localized peritoneum metastasis (P1a) are defined as stage IV in the 15th edition of the Japanese Classification of Gastric Cancer. In Japan, the most common treatment for patients with CY1 and/or P1a is gastrectomy followed by postoperative chemotherapy.

PATIENTS AND METHODS

Subjects in this multi-institutional retrospective study were GC patients with CY1 and/or P1a who received surgical resection that leaves no macroscopically visible disease. Patients were selected from 34 institutions in Japan between 2007 and 2012. Selection criteria included adenocarcinoma, no distant metastasis except CY1 and P1a, and no prior treatment for GC before surgery.

RESULTS

Among 824 patients registered, 506 were identified as eligible, with a background of P0CY1, P1aCY0, or P1aCY1 (72.5%, 16.0%, and 11.5% of subjects, respectively). Sixty-two patients had not received postoperative chemotherapy (no-Cx), whereas 444 patients had received postoperative chemotherapy: S-1 monotherapy (S-1; n = 267, 52.7%), cisplatin plus S-1 (CS; n = 114, 22.5%), and others (n = 63, 12.6%). Overall survival (OS) was 29.5, 24.7, 25.4 and 9.9 months in the S-1, CS, 'others', and no-Cx groups, respectively [CS vs. S-1: hazard ratio (HR) 1.15, 95% confidence interval (CI) 0.89-1.50; p = 0.275]. In multivariate analysis, OS was similar between the S-1 and CS groups (CS vs. S-1: HR 1.19, 95% CI 0.92-1.55; p = 0.18).

CONCLUSIONS

Postoperative chemotherapy after gastrectomy that leaves no macroscopically visible disease may have some survival benefits for GC patients with CY1 and/or P1a. In contrast, S-1 plus cisplatin seems to have no additional benefit over S-1 treatment alone.

Curative-Intent Surgery for Stage IV Advanced Gastric Cancer: Who Can Undergo Surgery and What Are the Prognostic Factors for Long-Term Survival?

BACKGROUND

A retrospective study was performed to evaluate the predictive factors for performing curative-intent surgery and prognostic factors for long-term survival of patients undergoing surgery for stage IV gastric cancer.

PATIENTS AND METHODS

Between 2001 and 2017, 271 patients with stage IV gastric cancer with distant metastasis who underwent systemic chemotherapy were enrolled. Logistic regression analysis was performed to evaluate predictive factors for curative-intent surgery. Cox proportional hazards regression model was applied for patients who were subsequently treated with curative-intent surgery to identify prognostic factors for long-term survival.

RESULTS

Curative-intent surgery was performed in 48 patients (17.7%). Median survival time was significantly longer in the surgery group than in the nonsurgery group (53 vs. 11 months, p < 0.0001). R0 resection was performed in 35 patients (72.9%). The three-year overall survival (OS) rates of the R0, R1, and R2 surgery groups were 75.4%, 33.3%, and 25.0%, respectively (p = 0.0002). Logistic regression analysis revealed that lymphogenous distant metastasis alone (odds ratio = 3.276, p = 0.004), positive lavage cytology alone (6.394, 0.014), doublet or triplet chemotherapy (4.064, 0.034), and high Glasgow prognostic score (0.276, 0.001) were independent predictive factors for performing curative-intent surgery. Among patients undergoing surgery, the Cox proportional hazards regression model for OS showed that R0 surgery was an independent prognostic factor for favorable OS (hazard ratio 0.188, p = 0.022).

CONCLUSIONS

Patients with lymphogenous distant metastasis alone, P0CY1 alone, good immunonutritional status, and doublet/triplet chemotherapy are candidates for performing effective curative-intent surgery. R0 surgery is crucial for improving long-term survival after surgery.

Is curative gastrectomy justified for gastric cancer with cytology positive as the only stage IV factor?

AIMS

The prognosis of patients with gastric cancer and stage IV factors is poor. However, several recent studies have identified that curative surgery followed by S-1 chemotherapy for cytology positive (CY1) only patients contributed to a better prognosis. This study was designed to compare the prognosis between curative and palliative gastrectomy followed by chemotherapy in CY1 only stage IV gastric cancer.

METHODS

Between 2001 and 2016, 1507 patients underwent gastrectomy for gastric cancer. Of these, 51 consecutive patients with only CY1 factor who underwent gastrectomy followed by chemotherapy were enrolled in this study.

RESULTS

(1) Twenty three (45%) patients underwent curative D2 or D2+ gastrectomy, and the remaining 28 (55%) patients underwent palliative gastrectomy, followed by S-1 based or another historical recommended chemotherapy postoperatively. (2) Compared with patients undergoing palliative gastrectomy, patients undergoing curative gastrectomy had a significantly better prognosis (P = 0.042; median survival time: curative vs. palliative, 22.6 months vs. 11.8 months) and a lower incidence of recurrences (P = 0.091). Two- and five-year overall survival rates of patients following curative gastrectomy were 48.2% and 18.2%, respectively. A multivariate analysis showed that venous invasion [P = 0.006; hazard ratio (HR), 3.70 (95% CI: 1.27-9.43)] and curative gastrectomy [P < 0.005; HR, 0.28 (95% CI: 0.12-0.87)] were independent prognostic factors.

CONCLUSION

Curative gastrectomy followed by chemotherapy might be justified to improve the prognosis of patients with only CY1 Stage IV gastric cancer.

Aggressive Graphic/Surgical R0 Resection and Jejunal Interposition with Preservation of Mesojejunal Autonomic Nerves in Patients with Stage IV Esophagogastric Junction Adenocarcinoma: A Report of 3 Cases

BACKGROUND Three patients with stage IV esophagogastric junction cancer (EGJC) underwent extended resection to achieve a graphic/surgical R0 status (no visible remnant of viable tumor in imaging/surgical findings) and adjuvant chemotherapy from the early postoperative period. We also introduced use of our digestive reconstruction technique in these patients. CASE REPORT We used jejunal interposition for digestive reconstruction, which involved end-to-end jejunojejunostomy with a biofragmentable anastomosis ring. The mesojejunal autonomic nerves of the lifted jejunum were preserved. The first adenocarcinoma involved the perilesional lymph nodes (LNs). Graphic/surgical R0 resection was completed by para-aortic LN dissection. The diagnosis (Japanese Classification of Gastric Carcinoma) was stage IV [pM1(LYM)]. Adjuvant chemotherapy began on postoperative day (POD) 11. The second adenocarcinoma was accompanied by a solitary lung metastasis. Intraoperative cytology of ascitic fluid was positive, and cisplatin was intraperitoneally administered. Adjuvant chemotherapy began on POD 10. The solitary lung metastasis was then resected, and graphic/surgical R0 resection was achieved. The diagnosis was stage IV [pM1(PUL) and CY1]. The third adenocarcinoma was accompanied by multiple liver metastases and metastatic regional LNs. The diagnosis was stage IV [H1]. Systemic chemotherapy was repeated. Only a solitary liver metastasis remained and was treated by radiofrequency ablation. Conversion surgery was conducted, achieving graphic/surgical R0 resection. Systemic chemotherapy was continued from POD 10. CONCLUSIONS For patients with stage IV EGJC, extended resection to achieve a graphic/surgical R0 status is still controversial, and systemic chemotherapy is important. The results of the present study suggest that our physiological reconstruction technique does not affect the efficacy of other therapies, such as adjuvant chemotherapy.

The Chinese Society of Clinical Oncology (CSCO): clinical guidelines for the diagnosis and treatment of gastric cancer

China is one of the countries with the highest incidence of gastric cancer. There are differences in epidemiological characteristics, clinicopathological features, tumor biological characteristics, treatment patterns, and drug selection between gastric cancer patients from the Eastern and Western countries. Non-Chinese guidelines cannot specifically reflect the diagnosis and treatment characteristics for the Chinese gastric cancer patients. The Chinese Society of Clinical Oncology (CSCO) arranged for a panel of senior experts specializing in all sub-specialties of gastric cancer to compile, discuss, and revise the guidelines on the diagnosis and treatment of gastric cancer based on the findings of evidence-based medicine in China and abroad. By referring to the opinions of industry experts, taking into account of regional differences, giving full consideration to the accessibility of diagnosis and treatment resources, these experts have conducted experts' consensus judgement on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes. This guideline uses tables and is complemented by explanatory and descriptive notes covering the diagnosis, comprehensive treatment, and follow-up visits for gastric cancer.

A single-institution retrospective analysis of gastric carcinoma with positive peritoneal lavage cytology and without serosal invasion: A case series

BACKGROUND AND OBJECTIVES

Peritoneal dissemination of gastric cancer is often associated with serosal infiltration. The aim of this study was to evaluate the clinical importance of peritoneal lavage cytology in patients with gastric carcinoma without serosal invasion. The incidence and impact on prognosis of positive cytology were analyzed.

METHODS

Of 2768 patients with gastric cancer, outcomes and pathological characteristics of 973 patients were reviewed retrospectively. All patients underwent peritoneal lavage at laparotomy for curative or palliative resection of gastric cancer between 1999 and 2017. Among these, 479 who underwent surgery from January 1999 to March 2012 were also reviewed to analyze 5-year survival.

RESULTS

Of 973 patients enrolled, 338 (35%) did not have serosal invasion, and peritoneal cytology was positive in 4/338 (1.2%). Of these four patients, one had submucosal invasion and three had muscularis propria invasion. Of 635 patients with serosal invasion, peritoneal cytology was positive in 74/635 (12%). Of 479 patients reviewed for survival, cytology was positive in 32/479, with 3/32 (9%) surviving for five years, and cytology was negative in 447 patients with 266/447 (60%) surviving for five years.

CONCLUSIONS

Cytologic evaluation should be routinely performed in patients with early-stage gastric cancer.

Recent advances in the management of gastric adenocarcinoma patients

Gastric adenocarcinoma (GAC) is one of the most aggressive malignancies and has a dismal prognosis. Therefore, multimodality therapies to include surgery, chemotherapy, targeted therapy, immunotherapy, and radiation therapy are needed to provide advantage. For locally advanced GAC (>cT1B), the emerging strategies have included preoperative chemotherapy, postoperative adjuvant chemotherapy, and (occasionally) postoperative chemoradiation in various regions. Several novel therapies have been assessed in clinical trials, but only trastuzumab and ramucirumab (alone and in combination with paclitaxel) have shown overall survival advantage. Pembrolizumab has been approved by the US Food and Drug Administration on the basis of response rate only for patients with microsatellite instability (MSI-H) or if PD-L1 expression is positive (≥1% labeling index in tumor/immune cells in the presence of at least 100 tumor cells in the specimen). Nivolumab has been approved in Japan on the basis of a randomized trial showing significant survival advantage for patients who received nivolumab compared with placebo in the third or later lines of therapy. The cure rate of patients with localized GAC in the West is only about 40% and that for metastatic cancer is very poor (only 2-3%). At this stage, much more target discovery is needed through molecular profiling. Personalized therapy of patients with GAC remains a challenge.

Prognostic significance of peritoneal lavage cytology in staging gastric cancer: systematic review and meta-analysis

BACKGROUND

Peritoneal cytology has been used as a part of the cancer staging of gastric cancer patients. The primary aim of this systematic review was to evaluate the value of peritoneal cytology as part of the staging of gastric cancer and survival prediction. The second aim was to establish if positive cytology may be modified by neoadjuvant therapy, to improve prognosis.

METHODS

An electronic literature search was performed using Embase, Medline, Web of Science, and Cochrane library databases up to January 2016. The logarithm of the hazard ratio (HR) with 95% confidence intervals (CI) was used as the primary summary statistic. Comparative studies were used, and the outcome measure was survival in three groups: (1) positive versus negative cytology at staging laparoscopy immediately preceding surgery; (2) effect of neoadjuvant therapy on cytology and survival; and (3) positive cytology in the absence of macroscopic peritoneal disease was compared with obvious macroscopic peritoneal disease.

RESULTS

Pooled analysis demonstrated that positive cytology was associated with significantly reduced overall survival (HR, 3.46; 95% CI, 2.77-4.31; P < 0.0001). Interestingly, negative cytology following neoadjuvant chemotherapy was associated with significantly improved overall survival (HR, 0.42; 95% CI, 0.31-0.57; P < 0.0001). The absence of macroscopic peritoneal disease with positive cytology was associated with significantly improved overall survival (HR, 0.64; 95% CI, 0.56-0.73; P < 0.0001).

CONCLUSION

This study suggests that patients with initial positive cytology may have a good prognosis following neoadjuvant treatment if the cytology results change to negative after treatment.

Will molecular target agents enable the multidisciplinary treatment in stage IV gastric cancer?

A detailed molecular characterization of gastric cancer has been revealed by global initiatives and a number of new molecular agents are under investigation. Currently only trastuzumab, a monoclonal antibody for human epidermal growth factor receptor 2 (HER2), is clinically used for HER2 positive advanced gastric cancer patients and ramucirumab, a monoclonal antibody directed against the extracellular ligand-binding domain of vascular endothelial growth factor receptor (VEGFR)2, can be used in second line. However, despite the progress in gastric cancer treatment, the prognosis of stage IV gastric cancer patients remains dismal. To achieve a remarkable improvement in the prognosis of patients, a multidisciplinary treatment approach with the help of effective molecular target agents should be considered. So far the role of multidisciplinary treatment for stage IV gastric cancer is still uncertain due to limited available data and absence of long-lasting tumor control with systemic therapy. Herein, an overview of the latest developments of molecular targeted agents for gastric cancer in advanced stages, in the perioperative setting and in oligometastatic disease is provided. The possibility of a multidisciplinary strategy using molecular target agents and surgery for stage IV gastric cancer is also assessed.

The survival and prognosticators of peritoneal cytology-positive gastric cancer patients who received upfront gastrectomy and subsequent S-1 chemotherapy

BACKGROUND

Upfront surgery and subsequent S-1 chemotherapy is frequently selected for peritoneal cytology-positive (CY1) gastric cancer patients without other distant metastases (CY1-only). The objective of this study was to confirm the efficacy of this strategy in clinical practice and to identify the risk factors associated with survival.

METHODS

Overall survival (OS) and recurrence-free survival (RFS) were examined in 36 CY1-only patients who underwent macroscopic curative resection followed by postoperative S-1 chemotherapy between January 2000 and June 2015. Univariate and multivariate analyses were performed using a Cox proportional hazards model to identify risk factors.

RESULTS

The median OS was 22.3 months (95% confidence interval 18.7-31.0). When the OS was compared by a log-rank test, significant differences were observed in the status of lymph node metastasis of pathological N3b (pN3b). Moreover, the univariate and multivariate analyses demonstrated that the status of pN3b was a significant independent risk factor for OS and RFS. The median OS in patients with pathological N0-N3a (pN0-N3a) was 31.0 months, while that in patients with pN3b was 18.2 months (P = 0.002). The median RFS in patients with pN0-N3a was 16.4 months, while that in patients with pN3b was 7.9 months (P = 0.007).

CONCLUSIONS

The present study confirmed the efficacy of postoperative S-1 chemotherapy for CY1-only gastric cancer patients who received upfront surgery. This strategy might be recommended as clinical practice for patients with CY1 disease but a more effective treatment should be established for CY1-positive patients, especially for those who are diagnosed with CY1 and pN3b disease.

Long-term survival and prognosis associated with conversion surgery in patients with metastatic gastric cancer

In gastric cancer, primary systemic chemotherapy is the standard approach for the management of patients with initially unresectable metastasis, and it occasionally leads to a reduction in the size of the lesion, which facilitates surgical resection. The aim of this study was to examine the prognosis of patients who were able to undergo complete resection following chemotherapy. A total of 10 patients who underwent radical surgery for stage IV primary gastric cancer after chemotherapy between 2009 and 2015 at the Department of Surgery of Hokkaido Social Work Association Obihiro Hospital (Obihiro, Japan) were retrospectively investigated. Three regimens were used (S-1, n=1; S-1 + cisplatin, n=8; and S-1 + docetaxel, n=1). The mean time from chemotherapy to surgery was 210 days. One total gastrectomy + splenectomy + colectomy, one total gastrectomy + splenectomy, four total gastrectomies and three distal gastrectomies were performed. There were two cases of pancreatic fistula formation postoperatively. All the patients survived for >1 year. Of the 10 patients, 5 survived without recurrence. The median survival time was 871.1 days after diagnosis. Therefore, curative resection after chemotherapy is associated with a better prognosis in stage IV gastric cancer patients.

Prognostic role of gastrectomy in patients with gastric cancer with positive peritoneal cytology

This retrospective study identified the optimal treatment strategy for patients with gastric cancer with positive peritoneal cytology. We analyzed clinicopathologic and survival data for 54 patients who had undergone gastrectomy and/or chemotherapy for treatment of gastric cancer with positive peritoneal cytology with (n = 40) or without (n = 14) metastatic disease. The median overall survival did not differ significantly between patients with gastric cancer with positive peritoneal cytology with and without metastatic disease (19 versus 13 months, respectively). Among 14 clinicopathologic variables, the lack of gastrectomy was the only significant independent unfavorable factor for survival (odds ratio, 1.64; 95% confidence interval, 1.04-2.57; P = 0.03). The median overall survival significantly differed among patients who had undergone gastrectomy plus chemotherapy, chemotherapy alone, and gastrectomy alone (25, 10, and 17 months, respectively; P < 0.01). Gastrectomy may be optimal for patients with (gastric cancer with positive peritoneal cytology), considering its favorable prognostic effect with respect to perioperative chemotherapy.

Tumor Infiltrative Pattern Predicts Sites of Recurrence After Curative Gastrectomy for Stages 2 and 3 Gastric Cancer

BACKGROUND

In East Asia, the tumor infiltrative pattern (INF) has been routinely evaluated by hematoxylin and eosin-stained sections as a pathologic characteristic of surgically resected specimens.

METHODS

The infiltrative pattern of gastric cancer (GC) has been histopathologically classified as INFa (expansive growth), INFb (intermediate type) and INFc (infiltrative growth) according to the Japanese Classification of Gastric Carcinoma. The prognostic value and characteristics of the disease recurrence pattern for each INF type were assessed in 785 patients with various stages of GC and also in 243 patients with stages 2 and 3 GC.

RESULTS

Comparison of the overall survival experienced by patients independently of stage showed that INF was significantly associated with prognosis. Specifically, peritoneal metastasis was present in 91 % of stage 4 patients in the INFc group, whereas hepatic metastasis was present in 39 % of stage 4 patients in the INFa and INFb group. After curative gastrectomy of patients with stages 2 or 3 GC, INF was not significantly associated with survival. The prevalence of peritoneal recurrence was significantly higher in the INFc group than in the INFa and INFb group, whereas the prevalence of hepatic recurrence was significantly higher in the INFa and INFb group than in the INFc group. Multivariate analysis identified INFc as an independent risk factor for peritoneal recurrence after curative gastrectomy. The association of the INF type with the incidence of peritoneal recurrence was observed with all disease stages regardless whether the patient was given adjuvant chemotherapy or not.

CONCLUSIONS

Evaluation of the INF type shows promise for its role as a predictor of postoperative recurrence sites in patients with GC.

Is conversion therapy possible in stage IV gastric cancer: the proposal of new biological categories of classification

Conversion therapy for gastric cancer (GC) has been the subject of much recent attention. It is defined as a surgical treatment aiming at an R0 resection after chemotherapy for tumors that were originally unresectable or marginally resectable for technical and/or oncological reasons. However, the indications for resection remain to be clarified. In the present review, we focus on the biology and heterogeneous characteristics of stage IV GC and propose new categories of classification. Stage IV GC patients can be divided based on the absence (categories 1 and 2) or presence (categories 3 and 4) of macroscopically detectable peritoneal dissemination, which has a different biological outcome compared to hematological metastasis. Category 1 is defined oncologically as stage IV but the metastasis is technically resectable. Category 2 includes a marginally resectable metastasis or patients for whom the operation would not necessarily be the best choice. Category 3 includes a potentially unresectable metastasis of peritoneal dissemination that is only macroscopically detectable. Category 4 includes noncurable metastasis with peritoneal and other organ metastasis. The indications for conversion therapy might include the patients from category 2, some patients from category 3 and a very small number of patients from category 4. The longer survival can be expected for patients corresponding to categories 1, 2 and, to a lesser extent, 3, while the treatment of other patients focuses on "care." The provision of conversion therapy for stage IV GC patients might be one of the main roles of surgical oncologists in the near future.

Postoperative adjuvant chemotherapy with S-1 alters recurrence patterns and prognostic factors among patients with stage II/III gastric cancer: A propensity score matching analysis

BACKGROUND

A phase 3 evidence indicates that S-1 adjuvant is beneficial among East Asian patients with stage II/III gastric cancer (GC). However, little is known about the changes in prognostic factors and recurrence patterns after it has become widespread as a standard of care. The present study compared prognostic factors of patients with stage II/III GC treated with or without S-1 adjuvant with formulate appropriate risk stratification strategies.

METHODS

We enrolled 171 patients with stage II/III GC, 92 patients who underwent gastrectomy alone, and 79 patients treated with S-1 adjuvant. To balance more strictly the essential variables including stage of progression, we conducted propensity score analysis and 70 pairs of patients were generated from each group. Prognostic factors were compared between the groups and initial recurrence patterns were investigated to explore reasons for the change.

RESULTS

In concordance with the previous phase 3 trial, overall and recurrence-free survival were better for the S-1 adjuvant group. In the surgery alone group, carcinoembryonic antigen ≥ 5 ng/mL, total gastrectomy, vessel invasion, pT4, and stage 3 were identified as significant prognostic factors. In striking contrast, macroscopic tumor size ≥ 50 mm was the only significant prognostic factor for the S-1 adjuvant group. The lower overall recurrence rate of the S-1 adjuvant group was attributable mainly to a significant decrease of peritoneal recurrence.

CONCLUSION

Prognostic factors changed substantially after implementation of S-1 adjuvant treatment. Macroscopic tumor size should be considered for patient stratification and selection of treatment options for patients with stage II/III GC.

Circulating Tumor Cells as an Independent Predictor of Survival in Advanced Gastric Cancer

BACKGROUND

When the indication for surgery of highly advanced gastric cancer is considered, careful selection of the patients is important. In addition to tumor-node-metastasis factors and peritoneal lavage cytology (CY), which are important predictors of prognosis, detection of circulating tumor cells (CTCs) could be another potential marker.

METHODS

This study prospectively evaluated CTCs using a semi-automated immunomagnetic separation system (CellSearch) for 136 patients with advanced gastric cancer to determine the frequency of CTC positivity. For 123 patients who also had their CY evaluated, the significance of both CTC and CY, was investigated as a potential biomarker to predict progression-free survival (PFS) or to monitor the therapeutic effect.

RESULTS

In 25 patients (18.4 %), CTCs were positive. Positive CTC counts were more common for tumors with diffuse histologic type and distant metastasis. The PFS of CTC-positive patients was significantly shorter than that of CTC-negative patients (hazard ratio 2.03; P = 0.016). A multivariate analysis of 123 patients showed that CTC and CY as well as performance status and macroscopic distant metastasis were independent factors for PFS. When both CTC and CY were converted to negative values by therapeutic interventions, long-term PFS was achieved.

CONCLUSIONS

Detection of CTCs was an independent predictor of a shorter PFS in advanced gastric cancer. For selecting patients who require intensive treatment, CTCs could be a valuable biomarker. The combined status of CTC and CY would be useful in selecting patients for radical surgery. Further investigation with a larger number of patients is necessary to establish the importance of CTCs.