Regional variation in treatment paradigms for gastric adenocarcinoma has attracted a great deal of interest. Between Asia and the West, major differences have been identified in tumor biology, ...implementation of screening programs, extent of surgical lymphadenectomy, and routine use of neoadjuvant versus adjuvant treatment strategies. Minimally invasive techniques, including both laparoscopic and robotic platforms, have been studied in both regions, with attention to safety, feasibility, and long-term oncologic outcomes. The purpose of this review is to discuss advances in the understanding of the etiology and underlying biology of gastric cancer, as well as the current state of management, focusing on the differences between Asia and the West.
There has been a great deal of interest about varying treatment paradigms of gastric cancer in Eastern and Western countries. Differences in tumor biology, screening initiatives, surgical approach, ...extent of lymphadenectomy, and neoadjuvant versus adjuvant chemotherapy regimens have been studied and documented in the literature. The purpose of this review is to give an updated report on the current status and management differences in the treatment of gastric cancer between Eastern and Western countries.
Preoperative methods to estimate disease-specific survival (DSS) for resectable gastroesophageal (GE) junction and gastric adenocarcinoma are limited. We evaluated the relationship between DSS and ...pretreatment neutrophil to lymphocyte ratio (NLR).
The patient's inflammatory state is thought to be associated with oncologic outcomes, and NLR has been used as a simple and convenient marker for the systemic inflammatory response. Previous studies have suggested that NLR is associated with cancer-specific outcomes.
A retrospective review of a prospectively maintained institutional database was undertaken to identify patients who underwent potentially curative resection for GE junction and gastric adenocarcinoma from 1998 to 2013. Clinicopathologic findings, pretreatment leukocyte values, and follow-up status were recorded. The Kaplan-Meier method was used to estimate DSS, and Cox proportional hazards models were used to evaluate the association between variables and DSS.
We identified 1498 patients who fulfilled our eligibility criteria. Univariate analysis showed that male sex, Caucasian race, increased T and N stage, GE junction location, moderate/poor differentiation, nonintestinal Lauren histology, and vascular and perineural invasion were associated with worse DSS. Elevated NLR was also associated with worse DSS hazard ratio (HR) = 1.11; 95% CI: 1.08-1.14; P < 0.01. On multivariate analysis, pretreatment NLR as a continuous variable was a highly significant independent predictor of DSS. For every unit increase in NLR, the risk of cancer-associated death increases by approximately 10% (HR = 1.10; 95% CI: 1.05-1.13; P < 0.0001).
In patients with resectable GE junction and gastric adenocarcinoma, pretreatment NLR independently predicts DSS. This and other clinical variables can be used in conjunction with cross-sectional imaging and endoscopic ultrasound as part of the preoperative risk stratification process.
The incidence of esophagogastric cancer is rapidly rising, but only a minority of patients derive durable benefit from current therapies. Chemotherapy as well as anti-HER2 and PD-1 antibodies are ...standard treatments. To identify predictive biomarkers of drug sensitivity and mechanisms of resistance, we implemented prospective tumor sequencing of patients with metastatic esophagogastric cancer. There was no association between homologous recombination deficiency defects and response to platinum-based chemotherapy. Patients with microsatellite instability-high tumors were intrinsically resistant to chemotherapy but more likely to achieve durable responses to immunotherapy. The single Epstein-Barr virus-positive patient achieved a durable, complete response to immunotherapy. The level of
amplification as determined by sequencing was predictive of trastuzumab benefit. Selection for a tumor subclone lacking
amplification, deletion of
exon 16, and comutations in the receptor tyrosine kinase, RAS, and PI3K pathways were associated with intrinsic and/or acquired trastuzumab resistance. Prospective genomic profiling can identify patients most likely to derive durable benefit to immunotherapy and trastuzumab and guide strategies to overcome drug resistance.
Clinical application of multiplex sequencing can identify biomarkers of treatment response to contemporary systemic therapies in metastatic esophagogastric cancer. This large prospective analysis sheds light on the biological complexity and the dynamic nature of therapeutic resistance in metastatic esophagogastric cancers.
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To compare disease-specific survival (DSS) between the US and Korea following R0 resection for gastric carcinoma (GC).
Many studies have described decreased 5-year survival after curative gastrectomy ...for GC in the West compared with the East. Although clinicopathological presentations of GC are known to vary widely between Eastern and Western countries, including histology, tumor location, and stage at presentation, it remains unclear whether these factors account for differences in survival.
All patients undergoing curative intent resections (R0) for GC (1995-2005) were evaluated in 2 independent, single-institution prospectively maintained databases from the US (711 patients) and Korea (1646 patients). Patients receiving neoadjuvant chemotherapy were excluded from this analysis. Patient, surgical and pathologic variables were compared. DSS was determined via multivariate analysis using prognostic variables from an internationally validated GC nomogram that estimates the probability of 5- and 9-year survival.
Age and body mass index were significantly higher in US patients. Location of tumors was more often proximal in the United States (39% vs. 9%, P < 0.0001) and distal in Korea (54% vs. 33%, P < 0.0001). Korean patients had more early stage tumors (42% vs. 28% stage Ia, P < 0.0001) with a higher number of lymph nodes identified (97% vs. 79%, >or=15 lymph nodes, P < 0.0001). The 5-year DSS was higher in Korea than in the United States. After multivariate analysis, applying factors used in the nomogram, DSS of Korean GC patients remained significantly better than that of US patients (HR = 1.3, 95% CI; 1.0-1.6, P = 0.008).
This study demonstrates better survival for GC patients in Korea compared with the US as determined by multivariate analysis with a validated gastric cancer nomogram. Multiple possibilities can explain this difference.
Background
While multiple Asian and a few Western retrospective series have demonstrated the feasibility and safety of robotic-assisted gastrectomy for gastric cancer, its reliability for thorough ...resection, especially for locoregional disease, has not yet been firmly established, and reported learning curves vary widely. To support wider implementation of robotic gastrectomy, we evaluated the learning curve for this approach, assessed its oncologic feasibility, and created a selection model predicting the likelihood of conversion to open surgery in a US patient population.
Patients and Methods
We retrospectively reviewed data on all consecutive patients who underwent robotic gastrectomy at a high-volume institution between May 2012 and March 2019.
Results
Of the 220 patients with gastric cancer selected to undergo curative-intent robotic gastrectomy, surgery was completed using robotics in 159 (72.3%). The median number of removed lymph nodes was 28, and ≥ 15 lymph nodes were removed in 94% of procedures. Surgical time decreased steadily over the first 60–80 cases. Complications were generally minor: 7% of patients experienced complications of grade 3 or higher, with an anastomotic leak rate of 2% and mortality rate 0.9%. Factors predicting conversion to open surgery included neoadjuvant chemotherapy, BMI ≥ 31 kg/m
2
, and tumor size ≥ 6 cm.
Conclusions
These findings support the safety and oncologic feasibility of robotic gastrectomy for selected patients with gastric cancer. Proficiency can be achieved by 20 cases and mastery by 60–80 cases. Ideal candidates for this approach are patients with few comorbidities, BMI < 31 kg/m
2
, and tumors < 6 cm.
The goal of a gastric cancer operation is a microscopically negative resection margin and D2 lymphadenectomy. Minimally invasive techniques (laparoscopic and robotic) have been proven to be ...equivalent for oncologic care, yet with faster recovery. Endoscopic mucosal resection can be used for T1a N0 tumor resection. Better understanding of hereditary gastric cancer and molecular subtypes has led to specialized recommendations for MSI-high tumors and patients with pathogenic CDH1 mutations. In the future, surgical management will support minimally invasive approaches and personalized cancer care based on subtype.
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