Different survival outcomes after curative R0-resection for Eastern Asian and European gastric cancer: Results from a propensity score matched analysis comparing a Korean and a German specialized center

Risk of Lymph Node Metastasis in T1b Gastric Cancer: An International Comprehensive Analysis from the Global Gastric Group (G3) Alliance

OBJECTIVE

We sought to define criteria associated with low lymph node metastasis risk in patients with submucosal (pT1b) gastric cancer from 3 Western and 3 Eastern countries.

SUMMARY BACKGROUND DATA

Accurate prediction of lymph node metastasis risk is essential when determining the need for gastrectomy with lymph node dissection following endoscopic resection. Under present guidelines, endoscopic resection is considered definitive treatment if submucosal invasion is only superficial, but this is not routinely assessed.

METHODS

Lymph node metastasis rates were determined for patient groups defined according to tumor pathological characteristics. Clinicopathological predictors of lymph node metastasis were determined by multivariable logistic regression and used to develop a nomogram in a randomly selected subset that was validated in the remainder. Overall survival was compared between Eastern and Western countries.

RESULTS

Lymph node metastasis was found in 701 of 3166 (22.1%) Eastern and 153 of 560 (27.3%) Western patients. Independent predictors of lymph node metastasis were female sex, tumor size, distal stomach location, lymphovascular invasion, and moderate or poor differentiation. Patients fulfilling the National Comprehensive Cancer Network guideline criteria, excluding the requirement that invasion not extend beyond the superficial submucosa, had a lymph node metastasis rate of 8.9% (53/594). Excluding moderately differentiated tumors lowered the rate to 3.4% (10/296). The nomogram's area under the curve was 0.690. Regardless of lymph node status, overall survival was better in Eastern patients.

CONCLUSIONS

The lymph node metastasis rate was lowest in patients with well differentiated tumors that were ≤3 cm and lacked lymphovascular invasion. These criteria may be useful in decisions regarding endoscopic resection as definitive treatment for pT1b gastric cancer.

Impact of postoperative complications on long-term outcomes of patients following surgery for gastric cancer: A systematic review and meta-analysis of 64 follow-up studies

Gastrectomy for cancer is a technically demanding procedure, with postoperative complications (POCs) reported to be in the range of 20%-46%. However, the effect of POCs on long-term survival of gastric cancer patients following surgery is far from conclusive. This systemic review aimed to determine the impact of postoperative complications (POCs) on the long-term survival of patients following surgery for gastric cancer. A systematic electronic search of PubMed and Scopus was performed from inception to June 26, 2018 to identify studies that described the relationship between POCs and long-term survival. Hazard ratios (HRs) for overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival (RFS) from each study were combined using a random-effects model. Sixty-four eligible studies with reported results for 46198 gastric cancer patients were included. A meta-analysis found a statistically significant difference in OS, CSS and RFS between gastric patients with unspecific POCs and no POCs, POCs ≥ Clavien-Dindo grade (CD) 2 and < CD2, major POCs and minor POCs, infectious and non-infectious complications, anastomotic and non-anastomotic complications, and cardiopulmonary and non-cardiopulmonary complications. Subgroup and sensitivity analyses did not significantly change the summary of OS risk estimates between patients with POCs and without POCs. No significant publication bias was observed for the same outcome. The meta-analysis revealed that POCs were associated with worse survival among patients with resected gastric cancer, suggesting that treatment strategies aimed at minimizing POCs may improve oncological outcomes.

Bidirectional chemotherapy combining intraperitoneal docetaxel with intravenous 5-fluorouracil and oxaliplatin for patients with unresectable peritoneal metastasis from gastric cancer: the first study in Western countries

Background

A new treatment using bidirectional intraperitoneal (IP) and intravenous (IV) chemotherapy developed by Asiatic surgeons improves outcomes in patients with synchronous peritoneal metastasis (PM) from gastric cancer (GC).

Methods

We enrolled six consecutive patients with unresectable PM from GC who underwent bidirectional chemotherapy using IP docetaxel and IV FOLFOX or LV5FU2. In one course, IP docetaxel 30 mg/m² was administrated on days 1, 8 and 15, and IV FOLFOX or LV5FU2 was administered on days 1 and 15, followed by 7 days of rest. Before and after a complete bidirectional cycle of three courses, the peritoneal cancer index (PCI) was evaluated by laparoscopy. The primary endpoint was to evaluate the feasibility and safety of bidirectional chemotherapy. Secondary endpoints were overall survival (OS), and the success of the therapeutic strategy was reflected by a decrease of 25% of the initial PCI.

Results

All patients completed one bidirectional cycle. The regimen was well tolerated. The median OS was 13 months [range 5–18], and the 1-year OS rate was 67%. After the first bidirectional cycle, the PCI decrease ≥25% of the initial value in four patients. A major histological response was observed in four patients.

Conclusions

This is the first Western study and confirms the feasibility and safety of bidirectional treatment using IP and IV chemotherapy for patients with unresectable PM from GC, resulting in a 13-month median OS with limited morbidity. The decrease in PCI after one bidirectional cycle is promising.

Prognostic implications of the eighth edition of the union for international cancer control - classification for gastric cancer patients from specialized treatment centers in Germany and Korea: A STOBE-Compliant large-scale cohort study

The validity of the 8th edition of the Union for International Cancer Control (UICC) staging system for gastric cancer has been evaluated only in Asian cohorts and not in European cohorts. The aim of this study was to evaluate the prognostic performance of the 8th edition of the UICC staging system in German and Korean cohorts independently and compare it with that of the 7th edition.A total of 6121 patients (526 from Germany and 5595 from Korea) who underwent upfront surgery for gastric cancer were retrospectively reclassified according to the 8th edition. Survival according to the UICC stages was estimated by the Kaplan-Meier method and compared by log-rank tests. A Cox proportional hazards model was fitted after adjusting for clinicopathological factors, and receiver operating characteristics analysis was conducted.The 8th edition showed significant differences in survival between each adjacent stage in the Korean cohort but not in the German cohort. Multivariate analyses revealed that the 8th edition staging was an independent prognostic factor, and its C-statistics were >0.76 in both German and Korean patients. The results were comparable to those observed with the UICC seventh edition (C-statistics was 0.768 vs 0.767 in the German cohort and 0.789 vs 0.785 in the Korean cohort for the 7th vs the 8th edition).The 8th edition showed prognostic value in predicting the survival of gastric cancer patients in both German and Korean cohorts. However, the predictive ability of the 8th and 7th edition was similar.

Immunotherapy in advanced gastric cancer, is it the future?

The prognosis of advanced gastric cancer remains extremely poor despite the use of standard therapies such as chemotherapy and biological agents. Blocking immune checkpoint especially programmed cell death-1 (PD-1) and its ligand (PD-L1 or B7-H1), has proven efficacy in several solid cancers, and seems to become a potential option in gastric cancer treatment. This review will focus on data describing the immune microenvironment of gastric tumors on which blocking PD-1/PD-L1 axis may have an anti-tumor efficacy. Then, the encouraging results of clinical trials evaluating anti-PD-1/PD-L1-based therapeutic strategy in first or later-line settings will be discuss. Finally, clinical outcomes according to PD-L1 expression, mismatch repair phenotype and other potential predictive biomarkers of anti-tumor response will be described. Altogether, immunotherapy seems promising in advanced gastric cancer in monotherapy or in combining strategies probably for a specific subgroup of patients who need to be better identified.