D1 versus D2 lymphadenectomy for gastric cancer

Gastric Cancer: Clinical Features, Screening, Diagnosis, Treatment, and Prevention

The objective of this article is to highlight the clinical features, screening, diagnosis, treatment, and prevention of gastric cancer (GC). Early GC is often asymptomatic leading to frequent delays in diagnosis. Weight loss and persistent abdominal pain are the most common symptoms at initial diagnosis. The diagnosis of GC typically involves a combination of endoscopy, biopsy, and imaging studies. Endoscopic resection techniques are emerging as successful treatment options for early GC. Treatment options for advanced GC include surgery and chemotherapy. The first line chemotherapy for advanced GC consists of doublet therapy with a combination of platinum and fluoropyrimidines. Trastuzumab, a monoclonal antibody, is used in the treatment of human epidermal growth factor 2 positive GCs. Antiangiogenic agents and immunotherapy are also useful in the treatment of GC. Currently there are no GC screening guidelines in the United States, but they exist in other regions where there is increased prevalence of GC. Prevention strategies for GC include Helicobacter pylori eradication and adoption of a healthy diet consisting of fruits and vegetables.

Long-Term Impact of D2 Lymphadenectomy during Gastrectomy for Cancer: Individual Patient Data Meta-Analysis and Restricted Mean Survival Time Estimation

BACKGROUND

Debate exists concerning the impact of D2 vs. D1 lymphadenectomy on long-term oncological outcomes after gastrectomy for cancer.

METHODS

PubMed, MEDLINE, Scopus, and Web of Science were searched and randomized controlled trials (RCTs) analyzing the effect of D2 vs. D1 on survival were included. Overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS) were assessed. Restricted mean survival time difference (RMSTD) and 95% confidence intervals (CI) were used as effect size measures.

RESULTS

Five RCTs (1653 patients) were included. Overall, 805 (48.7%) underwent D2 lymphadenectomy. The RMSTD OS analysis shows that at 60-month follow-up, D2 patients lived 1.8 months (95% CI -4.2, 0.7; p = 0.14) longer on average compared to D1 patients. Similarly, 60-month CSS (1.2 months, 95% CI -3.9, 5.7; p = 0.72) and DFS (0.8 months, 95% CI -1.7, 3.4; p = 0.53) tended to be improved for D2 vs. D1 lymphadenectomy.

CONCLUSIONS

Compared to D1, D2 lymphadenectomy is associated with a clinical trend toward improved OS, CSS, and DFS at 60-month follow-up.

Correlation of Preoperative Anemia Subtypes with Tumor Characteristics, Systemic Inflammation and Immediate Postoperative Outcomes in Gastrointestinal Cancer Patients - A Prospective Observational Study

PURPOSE

Patients with gastrointestinal (GI) malignancies more frequently present with anemia. A large proportion of them exhibit a systemic inflammatory response causing anemia of chronic disease. Although tumor factors play an essential role in determining the prognosis, studies have also reported the role of host factors in the outcome. This study was done to determine the association between systemic inflammation, tumor characteristics, and immediate postoperative outcome among various anemia subgroups.

METHODS

This was a single-center, prospective observational study of patients undergoing treatment for GI cancers. The modified Glasgow Prognostic Score (mGPS) was calculated, and patients were followed up until discharge regarding postoperative complications, length of the hospital, ICU stay, and mortality. The patient demographics, tumor characteristics, systemic inflammation, and postoperative complications were studied among different subtypes of anemia.

RESULTS

A total of 209 patients were analyzed, and a higher prevalence of normocytic anemia (52.63%) and systemic inflammatory response (62.21%) was observed among the study population. Systemic inflammation was significantly associated with a higher nodal stage (p = 0.02) and margin positivity (p = 0.006). Patients with higher mGPS had significantly higher requirements for blood transfusion (p = 0.003), superficial SSI (p = 0.03), and sepsis (p = 0.02); however, other postoperative complications were comparable among patients without an inflammatory response.

CONCLUSION

Higher prevalence of normocytic anemia is observed among patients with gastrointestinal cancer. Normocytic anemia is significantly associated with systemic inflammation with no significant difference in tumor characters and immediate postoperative outcomes.

Development of a deep learning-based model to diagnose mixed-type gastric cancer accurately

OBJECTIVE

The accurate diagnosis of mixed-type gastric cancer from pathology images presents a formidable challenge for pathologists, given its intricate features and resemblance to other subtypes of gastric cancer. Artificial Intelligence has the potential to overcome this hurdle. This study aimed to leverage deep machine learning techniques to establish a precise and efficient diagnostic approach for this cancer type which can also predict the metastatic risk using two software, U-Net and QuPath, which have not been trialled in gastric cancers.

METHODS

A U-Net neural network was trained to recognise, and segment differentiated components from 186 pathology images of mixed-type gastric cancer. Undifferentiated components in the same images were annotated using the open-source pathology imaging software QuPath. The outcomes from U-Net and QuPath were used to calculate the ratios of differentiation/undifferentiated components which were correlated to lymph node metastasis.

RESULTS

The models established by U-Net recognised ∼91% of the regions of interest, with precision, recall, and F1 values of 90.2%, 90.9% and 94.6%, respectively, indicating a high level of accuracy and reliability. Furthermore, the receiver operating characteristic curve analysis showed an area under the cure of 91%, indicating good performance. A bell-curve correlation between the differentiated/undifferentiated ratio and lymphatic metastasis was found (highest risk between 0.683 and 1.03), which is paradigm-shifting.

CONCLUSION

U-Net and QuPath exhibit promising accuracy in the identification of differentiated and undifferentiated components in mixed-type gastric cancer, as well as paradigm-shifting prediction of metastasis. These findings bring us one step closer to their potential clinical application.

Uncovering the Impact of Lymphadenectomy in Advanced Gastric Cancer: A Comprehensive Review

Gastric cancer is a significant health concern worldwide, and lymphadenectomy plays a crucial role in its treatment. However, there is ongoing debate regarding the optimal approach-D1 or D2 lymphadenectomy. This paper aims to synthesize the available evidence by conducting a comprehensive literature review and comparing the advantages and disadvantages of both techniques. The analysis includes studies, clinical trials, and systematic reviews that assess survival outcomes, morbidity, and quality of life. The selected studies revealed different outcomes associated with D1 and D2 lymphadenectomy, including lymph node harvest, disease control, recurrence rates, and overall survival. Postoperative complications also varied between the two techniques. These findings highlight the complex considerations involved in selecting the most suitable lymphadenectomy approach for individual patients. Therefore, the decision requires an individualized assessment that considers the potential benefits and risks of D1 and D2 techniques. A collaborative approach involving interdisciplinary teams is crucial for developing personalized treatment plans that optimize both oncological outcomes and postoperative quality of life.

Prevalence of nodal metastases in the individual lymph node stations for different T-stages in gastric cancer: a systematic review

BACKGROUND

Gastrectomy with lymph node dissection is the cornerstone of curative treatment of gastric cancer. Extent of lymphadenectomy may differ depending on T-stage, as the rate of lymph node metastases may differ. The objective of this systematic review is to investigate and compare the prevalence of nodal metastases in the individual lymph node stations between different T-stages.

METHODS

Data reporting and structure of this systematic review follows the PRISMA checklist. The Medline and PubMed databases were systematically searched. The search included the following Mesh terms: "Stomach Neoplasms", "Lymphatic Metastasis" and "Lymph Node Excision". The primary outcome was the highest prevalence of nodal metastases per T-stage.

RESULTS

The initial search resulted in 175 eligible articles. Five articles met the inclusion criteria and were accordingly analyzed. Concerning the lymph node stations 1 to 7, the lymph nodes along the lesser gastric curvature (station 3) show the highest metastases rate (T1: 5.5%, T2: 21.9%, T3: 41.9%, T4: 71.0%). Concerning the lymph node stations 8 to 20, the lymph nodes around the common hepatic artery (station 8) show the highest metastases rate (T1: 0.8%, T2: 7.9%, T3: 14.0%, T4: 28.2%).

CONCLUSION

An overall low prevalence of nodal metastases in the individual lymph node stations in early, T1 gastric carcinomas and an overall high prevalence in more advanced, T3 and T4 gastric carcinomas endorse a more tailored approach based on the different gastric T-stages. In addition, a less extensive lymphadenectomy seems justified in early T1 carcinoma.

SYNOPSIS

This systematic review provides an overview of the prevalence of nodal metastases for the individual lymph node stations between different T-stages, showing an overall low prevalence in early, T1 gastric carcinomas and an overall high prevalence in the more advanced, T3 and T4 gastric carcinomas.

Preoperative Risk Factors and Prognostic Impact of Postoperative Complications Associated with Total Gastrectomy

INTRODUCTION

We evaluated the risk factors for patients with gastric cancer (GC) undergoing total gastrectomy (TG) that predict postoperative complications, including anastomotic leakage, postoperative pneumonia, and heart disease.

METHODS

We collected 106 patients who received TG for GC between May 2009 and May 2017 at Gunma University Graduate School of Medicine, including clinicopathologic, surgical, postoperative complication, laboratory test, and physiologic test data.

RESULTS

Of 106 patients, 92 (86.8%) had no complications, and 14 (13.2%) had complications. Univariate analyses revealed that a high American Society of Anaesthesiologists physical status (ASA-PS) and neutrophil-lymphocyte ratio (NLR) of ≥3.5 significantly correlated with postoperative complications. Multivariate analyses showed that high ASA-PS was an independent prognostic factor of postoperative complications. The cancer recurrence rate was 34.8% in the noncomplication group and 71.4% in the complication group.

CONCLUSION

Patients with postoperative complications are prone to recurrence and poor prognosis. For patients with high-risk GC with poor ASA-PS and high NLR, more thorough perioperative management is essential.

D2 lymphadenectomy with complete mesogastrium excision vs. conventional D2 gastrectomy for advanced gastric cancer

Background:

The complete mesogastrium excision (CME) based on D2 radical gastrectomy is believed to significantly reduce the local-regional recurrence compared with D2 radical gastrectomy in advanced gastric cancer, and it is widely used in China. This study aimed to explore whether D2 + CME is superior to D2 on surgical outcomes during gastrectomy from Chinese data.

Methods:

Feasible studies comparing the D2 + CME (D2 + CME group) and D2 (D2 group) published up to March 2020 are searched from electronic databases. The data showing surgical and complication outcomes are extracted to be pooled and analyzed.

Results:

Fourteen records including 1352 patients were included. The D2 + CME group had a shorter mean operative time (weighted mean difference [WMD] = —16.72 min, 95% confidence interval [CI]: −26.56 to −6.87 min, P < 0.001), lower mean blood loss (WMD = −39.08 mL, 95% CI: −49.94 to −28.21 mL, P < 0.001), higher mean number of retrieved lymph nodes (WMD = 2.13, 95% CI: 0.58–3.67, P = 0.007), shorter time to first flatus (WMD = −0.31 d, 95% CI: −0.53 to − 0.10 d, P = 0.005), and postoperative hospital days (WMD = −1.09, 95% CI: −1.92 to −0.25, P = 0.010) than the D2 group. Subgroup analysis suggested that the advantages from the D2 + CME group were obvious in traditional open radical gastrectomy, proximal gastrectomy, and distal gastrectomy compared with D2 group. The evaluations of post-operative complications showed that the patients who underwent D2 + CME had a lower incidence of post-operative complications than the patients who underwent D2 surgery alone (relative risk [RR] = 0.65, 95% CI: 0.45–0.87, P = 0.003). The D2 radical gastrectomy plus CME improved 3-year overall survival (OS) (RR = 1.16, 95% CI: 1.02–1.32, P = 0.020) and lowered the local recurrence rate (RR = 0.51, 95% CI: 0.28–0.94, P = 0.030). The patients undergoing laparoscopic surgery or total gastrectomy had more significant advantages compared between D2 + CME and D2 groups in 3-year OS.

Conclusion:

The data from China show that D2 radical gastrectomy plus CME are reliable procedures and safety compared to D2 radical gastrectomy with faster recovery, lower risk, and better prognosis.

Next-Generation Sequencing Analysis of Gastric Cancer Identifies the Leukemia Inhibitory Factor Receptor as a Driving Factor in Gastric Cancer Progression and as a Predictor of Poor Prognosis

Gastric cancer (GC) is the third cause of cancer-related mortality worldwide. Nevertheless, because GC screening programs are not cost-effective, most patients receive diagnosis in the advanced stages, when surgical options are limited. Peritoneal dissemination occurs in approximately one-third of patients with GC at the diagnosis and is a strong predictor of poor outcome. Despite the clinical relevance, biological and molecular mechanisms underlying the development of peritoneal metastasis in GC remain poorly defined. Here, we report results of a high-throughput sequencing of transcriptome expression in paired samples of non-neoplastic and neoplastic gastric samples from 31 patients with GC with or without peritoneal carcinomatosis. The RNA-seq analysis led to the discovery of a group of highly upregulated or downregulated genes, including the leukemia inhibitory factor receptor (LIFR) and one cut domain family member 2 (ONECUT2) that were differentially modulated in patients with peritoneal disease in comparison with patients without peritoneal involvement. Both LIFR and ONECUT2 predicted survival at univariate statistical analysis. LIFR and its major ligand LIF belong to the interleukin-6 (IL-6) cytokine family and have a central role in immune system regulation, carcinogenesis, and dissemination in several human cancers. To confirm the mechanistic role of the LIF/LIFR pathway in promoting GC progression, GC cell lines were challenged in vitro with LIF and a LIFR inhibitor. Among several GC cell lines, MKN45 cells displayed the higher expression of the receptor, and their exposure to LIF promotes a concentration-dependent proliferation and epithelial-mesenchymal transition (EMT), as shown by modulation of relative expression of E-cadherin/vimentin along with JAK and STAT3 phosphorylation and acquisition of a migratory phenotype. Furthermore, exposure to LIF promoted the adhesion of MKN45 cells to the peritoneum in an ex vivo assay. These effects were reversed by the pharmacological blockade of LIFR signaling. Together, these data suggest that LIFR might have a major role in promoting disease progression and peritoneal dissemination in patients with GC and that development of LIF/LIFR inhibitors might have a role in the treatment of GC.

Data Set for Reporting Carcinoma of the Stomach in Gastrectomy

Context.—

A standardized detailed surgical pathology report is the cornerstone of gastric cancer management.

Objective.—

To guide management and prognostication for patients with gastric carcinomas globally, the International Collaboration on Cancer Reporting aimed to produce an evidence-based international pathology reporting data set with a panel of globally recognized expert pathologists and clinicians.

Design.—

Based on published guidelines/data sets for gastric carcinomas, a working draft was developed by the chair of the expert panel of pathologists and clinicians. The draft was then circulated to the panel and discussed in a series of teleconferences and email communications until consensus was achieved. The draft data set was uploaded on the International Collaboration on Cancer Reporting Web site for public comment. The data set was reviewed in consideration of the feedback, and a final version was approved by the panel.

Results.—

This data set was developed for gastrectomy specimens for primary gastric carcinomas, including neuroendocrine carcinomas and mixed neuroendocrine-nonneuroendocrine neoplasms. Well-differentiated neuroendocrine tumors, nonepithelial malignancies, and secondary tumors were excluded from this data set. The final data set contains 15 core (required) elements and 8 noncore (recommended) elements. A commentary is provided for each element.

Conclusions.—

The International Collaboration on Cancer Reporting has published freely available, evidence-based data sets for gastric cancer reporting. Standardized reporting has been shown to improve patient care and facilitates data exchange and analysis for quality assurance, cancer epidemiology, and clinical and basic research.

Comparison of East-Asia and West-Europe cohorts explains disparities in survival outcomes and highlights predictive biomarkers of early gastric cancer aggressiveness

Surgical resection with lymphadenectomy and peri-operative chemotherapy is the universal mainstay for curative treatment of gastric cancer (GC) patients with loco-regional disease. However, GC survival remains asymmetric in West- and East-world regions. We hypothesize this asymmetry derives from differential clinical management. Therefore, we collected chemo-naïve GC patients from Portugal and South-Korea to explore specific immunophenotypic profiles related to disease aggressiveness, and clinicopathological factors potentially explaining associated overall survival (OS) differences. Clinicopathological and survival data were collected from chemo-naïve surgical cohorts from Portugal (West-Europe cohort (WE-C); n=170) and South-Korea (East-Asia cohort (EA-C); n=367), and correlated with immunohistochemical expression profiles of E-cadherin and CD44v6 obtained from consecutive tissue microarrays sections. Survival analysis revealed a subset of 12.4% of WE-C patients, whose tumors concomitantly express E-cadherin_abnormal and CD44v6_very-high, displaying extremely poor OS, even at TNM stages I and II. These WE-C stages I and II patients were particularly aggressive compared to all other, invading deeper into the gastric wall (p=0.032) and more often permeating the vasculature (p=0.018) and nerves (p=0.009). A similar immunophenotypic profile was found in 11.9% of EA-C patients, but unrelated to survival. Stage I and II EA-C patients displaying both biomarkers also permeated more lymphatic vessels (p=0.003), promoting lymph node (LN) metastasis (p=0.019), being diagnosed on average 8-years earlier and submitted to more extensive LN dissection than WE-C. Concomitant E-cadherin_abnormal/CD44v6_very-high expression predicts aggressiveness and poor survival of stage I and II GC submitted to conservative lymphadenectomy.

Treatment Strategies of Gastric Cancer-Molecular Targets for Anti-angiogenic Therapy: a State-of-the-art Review

Purpose

Recent studies have suggested that molecular targets for the anti-angiogenic therapy might constitute a basis for additional therapy in gastric cancer treatment. A vast number of molecules, receptors, pathways, specific interactions, and thus strategies that target gastric cancer angiogenesis specifically have been reported in numerous research articles and clinical trials.

Methods

We conducted a systematic literature review of molecularly targeted treatment strategies in gastric cancer on the following databases—PubMed, Google Scholar, and Scopus—on September 20, 2020. Multiple articles and evaluations were searched for studies reporting newly found and promising molecular anti-angiogenic therapy pathways. Eventually, 39 articles regarding the anti-angiogenic therapy in gastric cancer were included in the final analysis.

Results

As a consequence of the release of the pro-angiogenic molecules from the tumour cells, gastric cancer presents high angiogenic capability. Therefore, potential schemes for future treatment strategies include the decrease of the process ligands as well as the expression of their receptors. Moreover, the increase in the angiogenic inhibitor levels and direct aim for the inner walls of the endothelial cells appear as a promising therapeutic strategy. Beyond that, angiogenesis process inhibition seems to indirectly exaggerate the effects of chemotherapy in the considered patients.

Conclusions

The anti-angiogenic treatment in gastric cancer patients evaluates its significance especially in the early stages of the malignancy. The studies conducted so far show that most of the meaningful angiogenic factors and receptors with the potential molecular pathways should be further evaluated since they could potentially play a substantial role in future therapies.

Isolated brachioradialis metastasis of gastric adenocarcinoma after R0 resection

BACKGROUND

Gastric cancer is the fifth most common cancer worldwide, with an incidence of 6.72 per 100,000 people. Thirty-two percent of gastric cancer patients will live 5 years after diagnosis. Single-site metastasis is noted in 26% of patients with gastric cancer, most commonly in the liver (48%), peritoneum (32%), lung (15%), and bone (12%). Here, a case is presented in which a single skeletal muscle metastasis appeared after appropriate resection and treatment.

CASE PRESENTATION

A 63-year-old man underwent neoadjuvant chemotherapy and a multivisceral en bloc R0 resection. Final pathology showed no evidence of lymph node metastasis with 31 negative lymph nodes. Four months postoperatively, the patient was found to have a rapidly growing biopsy-proven extremity soft tissue gastric metastasis within the brachioradialis muscle. He subsequently underwent metastasectomy and immunotherapy.

CONCLUSION

This case is a rare example of an isolated extremity metastasis of gastric adenocarcinoma in the setting of an R0 resection of the primary tumor and negative nodal disease on final pathology, suggestive of hematogenous spread. We review the biology, workup, and management of gastric cancer and highlight new advancements in the treatment of this aggressive cancer.

Impact of the introduction of formal D2 lymphadenectomy for gastric cancer in a Western setting

Background

Two members from an academic tertiary hospital went to the National Cancer Institute in Tokyo, Japan, to learn how to perform an adequate D2 lymphadenectomy and to then introduce this technique in the surgical care of patients undergoing surgery for gastric cancer at a Western hospital. We aimed to compare the perioperative outcomes and long-term survival of Western patients who underwent gastric resection, performed by these 2 surgeons, before and after the surgeons’ short-course technical training in Japan.

Methods

We conducted a retrospective comparative study of all patients (n = 27 before training and n = 79 after training) who underwent gastric resection for cancer by the same 2 surgeons between September 2007 and December 2017 at the Centre Hospitalier Universitaire de Québec — Université Laval (Québec, Canada). We collected data on patient demographic, clinical, surgical, pathological and treatment characteristics, as well as long-term survival and complications.

Results

In the post-training group, the number of sampled lymph nodes was higher (median 33 v. 14, p < 0.0001), but this increase did not result in a higher number of histologically positive lymph nodes (p = 0.35). The rate of complications was lower in the post-training group (15.2% v. 48.2%, p = 0.002). The hospital stay was shorter in the post-training group (11 [standard deviation (SD) 7] v. 23 [SD 45] d, p = 0.03). The median survival was higher in the post-training group (47 v. 29 mo, p = 0.03).

Conclusion

These results suggest that a short-course technical training in D2 lymphadenectomy, completed in Japan, improved lymph node sampling, decreased postoperative complications and improved survival of patients undergoing surgery for gastric cancer in a Western setting.

Evaluating the benefit of adjuvant radiotherapy after extensive lymph node dissection for gastric cancer: a single-institute retrospective study

Objective:

This study aimed to evaluate whether adjuvant radiotherapy (RT) can improve the treatment outcome of patients with locally advanced gastric cancer who underwent extensive lymph node dissection (ELND).

Materials and Methods:

This retrospective study included patients with gastric cancer pathological stages IIA–IIIC at Taipei Tzu Chi Hospital between 2008 and 2015. Patients (a) aged >80 years, (b) with distant metastasis at diagnosis, (c) with coexisting malignancies, (d) who did not complete the prescribed RT course, and (e) who died 1 month after surgery were excluded. Among 420 patients diagnosed with gastric cancer, 98 were included.

Results:

The median follow-up was 24.5 months. Of 39 patients who underwent adjuvant RT, 38 also received adjuvant chemotherapy (CT). Of 59 patients who did not receive adjuvant RT, only 34 received adjuvant CT. ELND was performed in 67.3% of the patients. The 5-year overall survival (OS) rate was 40%. In the univariate analyses, adjuvant CT regimen, 5-fluorouracil + leucovorin, was associated with worst outcome, while TS-1 was associated with better survival outcome (P = 0.018). The number of involved lymph nodes was strongly related to the OS and disease-free survival (DFS) (P < 0.001). We tried using different numbers of involved lymph nodes as a cutoff point and found that adjuvant RT significantly improved both OS and DFS in patients whose involved lymph nodes were ≥4 (OS, P = 0.017; DFS, P = 0.015). In multivariate analyses, better DFS was associated with negative surgical margin (P = 0.04), earlier disease stage (P = 0.001), adjuvant radiotherapy (P = 0.045), and adjuvant CT regimen TS-1 (P = 0.001).

Conclusion:

Adjuvant RT could improve DFS of patients with locally advanced gastric cancer with or without ELND. When the number of involved lymph nodes is ≥4, adjuvant RT is strongly suggested.

Hereditary Diffuse Gastric Cancer: Approaches to Screening, Surveillance, and Treatment

Hereditary diffuse gastric cancer (HDGC) is a cancer syndrome associated with a significant lifetime risk of diffuse gastric cancer (DGC), a malignancy characterized by late clinical presentation and poor prognosis, as well as lobular breast cancer. HDGC is linked to germline pathogenic variants in the E-cadherin gene (CDH1) that are inherited in an autosomal dominant pattern; however, in many families with DGC clustering, no genetic cause has been identified. This review discusses key elements that allow risk assessment of potential inherited DGC susceptibility. We provide a practical overview of the recommendations for surveillance and treatment of individuals at risk and patients with early disease. The review also outlines future research avenues to improve our understanding of the genetic background and natural history of the disease, the endoscopic detection of early lesions, and the outcome of prophylactic surgery in young individuals.

Leukemia inhibitory factor promotes gastric cancer cell proliferation, migration, and invasion via the LIFR-Hippo-YAP pathway

The long-term outcome of gastric cancer (GC) patients remains unsatisfactory despite some recent improvements. Leukemia inhibitory factor (LIF) is a prognostic biomarker for some solid tumors, however its role in GC remains unknown. In this study, we demonstrated that LIF and LIF receptor (LIFR) are overexpressed in GC tissues and established that a correlation exists between them. LIF and LIFR expression are associated with tumor differentiation, lymphovascular invasion, tumor stage, lymph node metastasis, and pTNM stage, indicating that they may be useful prognostic factors. LIF promoted GC cell proliferation, colony formation, invasion, migration, and tumor growth; it also promoted cell cycle progression and inhibited apoptosis; and knocking out the LIFR gene reversed the effects of LIF. LIF inhibited the activity of the Hippo pathway, resulting in reduced phosphorylation of YAP, increased YAP nuclear translocation, and increased cell proliferation. Finally, silencing YAP mRNA expression suppressed cell proliferation. Overall, the results demonstrate that LIF promotes the malignant biological behavior of GC cells through LIFR-Hippo-YAP signaling. LIF may therefore be a useful biomarker for GC.

Siewert III Adenocarcinoma: Still Searching for the Right Treatment Combination

It remains uncertain whether Siewert III tumors should be treated as esophageal or gastric cancers. Neoadjuvant therapy has been shown to improve survival in both esophageal and gastric trials. Randomized control trials comparing neoadjuvant chemotherapy versus chemoradiation should help define the most optimal treatment regimen. Surgical treatment follows general oncology principals: resect to negative margins with complete lymph node dissection, and, the extent of resection often extends more proximal onto the esophagus in addition to the total/subtotal gastrectomy.

Epigenetic Mechanisms in Gastric Cancer: Potential New Therapeutic Opportunities

Gastric cancer (GC) is one of the deadliest malignancies worldwide. Complex disease heterogeneity, late diagnosis, and suboptimal therapies result in the poor prognosis of patients. Besides genetic alterations and environmental factors, it has been demonstrated that alterations of the epigenetic machinery guide cancer onset and progression, representing a hallmark of gastric malignancies. Moreover, epigenetic mechanisms undergo an intricate crosstalk, and distinct epigenomic profiles can be shaped under different microenvironmental contexts. In this scenario, targeting epigenetic mechanisms could be an interesting therapeutic strategy to overcome gastric cancer heterogeneity, and the efforts conducted to date are delivering promising results. In this review, we summarize the key epigenetic events involved in gastric cancer development. We conclude with a discussion of new promising epigenetic strategies for gastric cancer treatment.

Normal and Abnormal Postoperative Imaging Findings after Gastric Oncologic and Bariatric Surgery

Surgical resection remains the primary choice of treatment and the only potentially curative option for gastric carcinoma, and is increasingly performed laparoscopically. Gastric resection represents a challenging procedure, with a significant morbidity and non-negligible postoperative mortality. The interpretation of imaging after gastric surgery can be challenging due to significant modifications of the normal anatomy. After the surgery, the familiarity with expected imaging appearances is crucial for diagnosis and appropriate management of potentially life-threatening complications in patients who underwent gastric surgery. We review various surgical techniques used in gastric surgery and describe fluoroscopic and cross-sectional imaging appearances of normal postoperative anatomic changes as well as early and late complications after gastric surgery.

Lymph nodes may be a source for immunetherapy in gastric cancer

BACKGROUND

adoptive immunotherapy is a promising cancer therapy. Immune cells are capable of recognizing and destroying cancer cells and represent a powerful strategy, however, this approach remains technically complicated, due to the need to select and isolate immune cells from these, present cancer antigens to those cells, expanding and reinjecting them. Lymph nodes recovered during gastric cancer surgery may represent an option for immunotherapy, since they harbor an enormous amount of immune cells, which have already been presented to cancer antigens. The advantage of selecting only cancer-negative lymph has not been determined yet. The status of immune checkpoints in the immune cells within the lymph nodes was analyzed in order to try to solve this problem.

MATERIALS AND METHODS

Tissue microarrays were constructed and automated immunostaining for PD-1 and PD-L1 was performed on 143 lymph nodes from 70 patients with gastric adenocarcinoma.

RESULTS

In positive nodes, PD-L1 was only positivity in cancer cells (6%) and PD-1 was positive for B lymphocytes (60%), T lymphocytes (70%) and one case in cancer cells (2.5%). In negative nodes, most cases were positive for PD-1 in B (73.1%) and T (71.65%) lymphocytes.

CONCLUSIONS

Expression of PD-1 and PD-L1 in gastric cancer lymph nodes was demonstrated for the first time. PD-1 is expressed in positive and negative nodes, which could activate the PD-1 pathway. Lymphocytes from tumor-free lymph nodes were negative for PD-L1, and this might represent an advantage for selecting these lymph nodes as a potential source of immune cells for adoptive immunotherapy.

Adherence with operative standards in the treatment of gastric cancer in the United States

BACKGROUND

Despite multiple clinical trials and practice guidelines for the treatment of gastric cancer, oncologic outcomes have not improved in the United States. One potential reason could be differences in the quality of surgery as performed in a controlled trial versus in practice.

METHODS

Using the National Cancer Database, rates of adherence with operative standards for gastrectomy for cancer were analyzed. Of the numerous evidence-based operative standards outlined in the manual, two were reliably measured in the NCDB: (1) achieving and R0 resection, and (2) having > 16 lymph nodes examined. Univariable and multivariable Cox proportional hazard modeling and logistic regression were performed.

RESULTS

A total of 28,705 patients with gastric adenocarcinoma who underwent curative-intent gastrectomy during 2004-2014 were identified. Only 36.5% of stage 0/I patients, and 41.8% of stage II/III patients, met minimum standards. Predictors for meeting standards included age < 65, fewer comorbidities, Asian/Pacific Islander race, and treatment at academic and high-volume centers. Patients who met standards had longer OS (stage 0/I: 104.9 versus 66.6 months; stage II/III: 40.6 versus 26.0 months; p < 0.001 for both). Meeting standards was a significant predictor for improved OS for both stage 0/I and II/III patients (HR = 0.665 and HR = 0.747, respectively, p < 0.001 for both).

CONCLUSIONS

For standards that are measurable in the NCDB, adherence is poor. Improved adherence with operative standards may improve survival for gastric cancer patients in the U.S. There is a need for better measuring of, and adherence with, operative standards in gastrectomy for cancer.

Perineural Invasion and Postoperative Adjuvant Chemotherapy Efficacy in Patients With Gastric Cancer

Purpose: There is currently a lack of validated predictors for adjuvant chemotherapy efficacy in patients with gastric cancer (GC). Perineural invasion (PNI) is the process of neoplastic invasion of the nerves, accompanied by tumor microenvironment (TME) changes. TME can determine treatment outcome while the impact of PNI on chemotherapy efficacy remains unknown in GC. We investigated the association between PNI and the efficacy of postoperative adjuvant chemotherapy in patients with resected GC. Methods: Patients who underwent radical resection of stage IB-III GC with or without fluoropyrimidine (FU)-based adjuvant chemotherapy were retrospectively selected from two separate patient cohorts. PNI was confirmed with S100 immunohistochemistry (IHC). Tumor hypoxia and activity of selected pathways were quantified by mRNA-based signature scoring based on publicly available data. A hypoxia biomarker, ERO1A, and a FU resistance biomarker, thymidylate synthase (TS), were assessed by IHC, respectively. Results: Two cohorts included 223 and 599 patients, respectively. Adjuvant chemotherapy significantly improved overall survival (OS) and disease-free survival (DFS) in PNI-positive but not in PNI-negative patients, which was not impacted by stages. Multivariate models showed that adjuvant chemotherapy was an independent predictor for OS and DFS in PNI-positive patients in both cohorts. For TME, PNI-negative tumors were more hypoxic than were PNI-positive tumors, and displayed relative up-regulation of signaling along the pathways that are important in FU metabolism or resistance. Expressions of ERO1A and TS significantly decreased in PNI-positive compared to PNI-negative tumors. Conclusions: PNI might help predict adjuvant chemotherapy benefit in patients with resected GC. Validation in prospective studies is required. Novel treatment strategies need to be developed in PNI-negative patients.

CDH1 (E-Cadherin) Mutation and Gastric Cancer: Genetics, Molecular Mechanisms and Guidelines for Management

Introduction

Germline mutation in CDH1 (E-cadherin) tumor suppressor gene is associated with hereditary diffuse gastric cancer (HDGC) and lobular breast cancers (LBC). E-Cadherin protein is necessary for physiological signaling pathways, such as cell proliferation, maintenance of cell adhesion, cell polarity and epithelial-mesenchymal transition. Dysregulation leads to tumor proliferation, invasion, migration and metastases. We review current perspectives in CDH1 genetics with molecular mechanisms and also discuss management strategies for this aggressive form of gastric cancer.

Methods

Relevant articles from PubMed/Medline and Embase (1994–2019) were searched and collected using the phrases “Hereditary diffuse gastric cancer, Familial gastric cancer, CDH1 mutation, E-Cadherin, Lobular breast cancer, Prophylactic total gastrectomy”.

Results

Current guidelines suggest maintaining a high degree of suspicion of hereditary etiology and recommend testing for CDH1 mutations in patients with familial clustering of HDGC and LBC, especially onset at an early age (before 40 years). In families lacking CDH1 mutations but with high suspicion for hereditary predisposition, testing of CTNNA1 and other closely related HDGC susceptibility genes could be considered. Prophylactic total gastrectomy is recommended for individuals with identified pathogenic germline variants. Endoscopic surveillance with biopsies is recommended for those choosing to delay prophylactic gastrectomy.

Conclusion

Mutation or transcriptional silencing of the CDH1 gene is associated with familial diffuse gastric cancer. Further studies on the expression and the alteration in the proteins in the E-cadherin pathways may serve as biomarkers for early detection; stratify risk and selection of appropriate therapy in these families. Until then prophylactic total gastrectomy is recommended for individuals with CDH1 mutations and family history of diffuse gastric cancer. Endoscopic surveillance and biopsies by experienced gastroenterologists is recommended for those choosing not to have prophylactic gastrectomy and in individuals with CDH1 variants.

A homogenized approach to classify advanced gastric cancer patients with limited and adequate number of pathologically examined lymph nodes

Background

The prognosis of gastric cancer patients with a limited number of pathologically examined lymph nodes (eLN, < 16) is dismal compared to those with adequately eLN (≥ 16), yet they are still classified within the same subgroups using the American Joint Committee on Cancer (AJCC) staging system. We aimed at formulating an easy-to-adopt and clinically reliable stratification approach to homogenize the classification for these two categories of patients.

Methods

Patients staged according to the 8th AJCC pathological nodal (N) and tumor-node-metastasis (TNM) classification were stratified into a Limited and Adequate eLN cohort based on their number of pathologically examined LNs. The statistical differences between the 5-year overall survival (OS) rates of both cohorts were determined and based on which, patients from the Limited eLN cohort were re-classified to a proposed modified nodal (N′) and TNM (TN′M) classification, by matching their survival rates with those of the Adequate eLN cohort. The prognostic performance of the N′ and TN′M classification was then compared to a formulated lymph-node-ratio-based nodal classification, in addition to the 8th AJCC N and TNM classification.

Results

Significant heterogeneous differences in 5-year OS between patients from the Limited and Adequate eLN cohort of the same nodal subgroups were identified (all P < 0.001). However, no significant differences in 5-year OS were observed between the subgroups N0, N1, N2, and N3a of the Limited eLN cohort when compared with N1, N2, N3a, and N3b from the Adequate eLN cohort, respectively (P = 0.853, 0.476, 0.114, and 0.230, respectively). A novel approach was formulated in which only patients from the Limited eLN cohort were re-classified to one higher nodal subgroup, denoted as the N′ classification. This re-classification demonstrated superior stratifying and prognostic ability as compared to the 8th AJCC N and lymph-node-ratio classification (Akaike information criterion values [AIC]: 12,276 vs. 12,358 vs. 12,283, respectively). The TN′M classification also demonstrated superior prognostic ability as compared to the 8th AJCC TNM classification (AIC value: 12,252 vs. 12,312).

Conclusion

The proposed lymph node classification approach provides a clinically practical and reliable technique to homogeneously classify cohorts of gastric cancer patients with limited and adequate number of pathologically examined lymph nodes.

In Patients with Localized and Resectable Gastric Cancer, What is the Optimal Extent of Lymph Node Dissection-D1 Versus D2 Versus D3?

BACKGROUND

Despite advances in the treatment of patients with gastric cancer, the debate over the optimal extent of lymphadenectomy continues.

METHOD

A review of the classification, rationale for, and boundaries of lymphadenectomy is presented. A review of the available literature comparing D1 versus D2 versus D3 lymphadenectomy was performed and included randomized controlled trials, and prospective and retrospective comparative and non-comparative studies.

RESULTS

Earlier studies demonstrated increased morbidity with D2 compared with D1 lymphadenectomy, with no significant survival benefit. More recent studies have demonstrated survival benefit of a pancreas and spleen-sparing D2 lymphadenectomy in patients with advanced, node-positive tumors. Para-aortic/D3 dissections contribute to increased morbidity, with no survival benefit.

CONCLUSIONS

In patients with resectable gastric adenocarcinoma, a D2 lymph node dissection preserving the pancreas and spleen should be considered standard for optimal staging and treatment, provided it is performed by surgeons with sufficient expertise. Extended lymph node dissections beyond D2 should not be routinely performed as it has been shown to have increased morbidity, with no improvement in outcomes. While systemic chemotherapy should be considered standard in patients undergoing D2 lymphadenectomy, the role of adjuvant radiation continues to evolve.

CT-Detected Extramural Vessel Invasion and Regional Lymph Node Involvement in Stage T4a Gastric Cancer for Predicting Progression-Free Survival

OBJECTIVE. This study aimed to investigate the 3-year progression-free survival (PFS) of patients with stage T4a gastric cancer with extramural vessel invasion (EMVI) detected with contrast-enhanced (CE) MDCT. In addition, we investigated the possibility that CT of EMVI could improve clinical nodal (N) staging. MATERIALS AND METHODS. This retrospective study included 143 patients with T4a gastric cancer. Clinical staging was performed with CE-MDCT. All patients underwent radical gastrectomy with extended lymphadenectomy, adjuvant chemotherapy, and conventional follow-up visits. Potential prognostic factors, including CE-MDCT-detected N status, pathologic N status, EMVI detected at CT, tumor location or growth pattern, histologic type or tumor differentiation, and tumor size, were recorded. Survival estimates for PFS were obtained using the Kaplan-Meier product limit for the following patient subgroups: EMVI positive-N positive, EMVI positive-N negative, EMVI negative-N positive, and EMVI negative-N negative. Hazard ratios for 3-year PFS were generated using a Cox proportional hazard regression analysis. RESULTS. The frequency of EMVI detected at CT was 55.9% (80/143). The 3-year PFS rates were 25.0% for the EMVI positive-N positive group, 53.1% for the EMVI positive-N negative group, 75.6% for the EMVI negative-N positive group, and 64.7% for the EMVI negative-N negative group. The EMVI positive-N positive subgroup 3-year PFS rate was significantly lower than that of the other three groups (p < 0.05, log-rank test). Using Cox proportional hazards regression analysis, EMVI positive-N positive status was found to be an independent factor for reduced 3-year PFS, with a hazard ratio of 2.169 (95% CI, 1.300-3.618; p = 0.003). CONCLUSION. EMVI detected at CT, combined with N status detected with CE-MDCT, could be used as a valuable preoperative prognostic factor in patients with T4a gastric cancer.

How many lymph nodes are enough?-defining the extent of lymph node dissection in stage I-III gastric cancer using the National Cancer Database

Background

Surgical resection with lymph node dissection is the primary therapeutic modality for gastric cancer. National Cancer Database (NCDB) was used to determine the extent of lymph nodes (LNs) dissection for gastric cancer.

Methods

The NCDB was queried from 2004-2013 for patients with margin-negative, invasive resected gastric cancer. The optimal number of LNs dissected was determined using a univariate χ² cut-point analysis. Multiple sensitivity analyses were utilized to decrease bias.

Results

A total of 17,851 patients were included. For all patients, the optimal number of LNs needed to be examined was 20+ nodes. When correcting for stage migration (<7 LNs removed), the optimal cut-off value was 20+ LNs. When stratifying by pathologic nodal stage, the cut-off point was 10+ LNs for pN1 and pN2. The 5-year survival was 30.6%±1.6% for 0-9 removed LNs compared to 48.2%±1.2% for 10+ removed LNs (P<0.001) in pN1 disease and 18.3%±1.7% for 0-9 removed LNs compared to 32.6%±1.2% for 10+ removed LNs (P<0.001) in pN2 disease. For pN3 disease, the optimal cut-off point was 20+ LNs; the 5-year survival was 17.2%±1.3% for 0-19 removed LNs compared to 28.5%±1.7% for 20+ removed LNs (P<0.001). Moreover, the outcome was inferior among patients who had >10% positive dissected LNs (P<0.05).

Conclusions

The extent of dissected lymph nodes of 20 or greater lymph nodes was associated with superior survival. Extended LN dissection is to be considered especially in patients with clinical lymphadenopathy.

Evaluation of a multi-slice spiral computed tomography perfusion for the prediction of the recurrence of gastric cancer

AIM

The study aimed to elucidate the value of multislice spiral computed tomography (MSCT) perfusion for the early prediction of gastric cancer (GC) recurrence.

METHODS

MSCT perfusion scans were performed to obtain values pertaining to blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS). Logistic regression analysis was employed to evaluate the risk factors of postoperative recurrence in GC.

RESULTS

The maximum diameter of GC has a positive relationship with PS. The maximum enhancement of GC was positively correlated with BF, blood volume and PS. PS, BF, vascular thrombus and Tumor, Node, Metastasis staging were found to be significant risk factors in relation to the recurrence of GC (p = 0.006, p = 0.002, p < 0.001).

CONCLUSION

MSCT perfusion is strongly correlated with postoperative recurrence of GC, and PS and BF values, vascular thrombus and Tumor, Node, Metastasis staging were discovered as being prominent factors influencing the recurrence of GC.

Extensive Lymph Node Dissection Improves Survival among American Patients with Gastric Adenocarcinoma Treated Surgically: Analysis of the National Cancer Database

INTRODUCTION

The extent of lymphadenectomy in the surgical treatment of gastric cancer is a topic of controversy among surgeons. This study was conducted to analyze the American National Cancer Database (NCDB) and conclude the optimal extent of lymphadenectomy for gastric adenocarcinoma.

METHODS

The NCDB for gastric cancer was utilized. Patients who received at least a partial gastrectomy were included. Patients with metastatic disease, unknown TNM stages, R1/R2 resection, or treated with a palliative intent were excluded. Joinpoint regression was used to identify the extent of lymphadenectomy that reflects the optimal survival. Cox regression analysis and Bayesian information criterion were used to identify significant survival predictors. Kaplan-Meier was applied to study overall survival and stage migration.

RESULTS

40,281 patients of 168,377 met the inclusion criteria. Joinpoint analysis showed that dissection of 29 nodes provides the optimal median survival for the overall population. Regression analysis reported the cutoff ≥29 to have a better fit in the prognostic model than that of ≥15. Dissection of ≥29 nodes in the higher stages provides a comparable overall survival to the immediately lower stage. Nonetheless, the retrieval of ≥15 nodes proved to be adequate for staging without a significant stage migration compared to ≥29 nodes.

CONCLUSION

The extent of lymphadenectomy in gastric adenocarcinoma is a marker of improved resection which reflects in a longer overall survival. Our analysis concludes that the dissection of ≥15 nodes is adequate for staging. However, the dissection of 29 nodes might be needed to provide a significantly improved survival.

Survival Analysis with Extended Lymphadenectomy for Gastric Cancer: Removing Stage Migration from the Equation

The survival benefit of an extended versus standard lymphadenectomy for gastric cancer (GC) is often attributed to upstaging when more lymph nodes (LNs) are removed, i.e., stage migration. An extended lymphadenectomy is defined as 30 or more LNs examined, a surrogate for a D2 dissection. The aim of this study is to examine whether the survival benefit of extended lymphadenectomy persists when stage migration is not possible. The National Cancer Data Base was queried to identify patients with pathologic N3 (pN3, ≥7 positive LNs) gastric adenocarcinoma. Overall survival (OS) was compared by extent of lymphadenectomy (7-14, 15-29, and ≥30 LN) and stratified by T stage. Of 2101 pN3 patients, 419 (19.9%) had 7 to 14 LNs examined, 1164 (55.4%) had 15 to 29 LNs examined, and 518 (24.7%) had ≥30 LNs examined. Unadjusted three-year OS in the entire cohort was 24.6, 27.3, 30.5 per cent for 7 to 14 LNs, 15 to 29 LNs, and ≥30 LNs, respectively (P = 0.003). On adjusted survival analysis by stage for patients with pT1-T2N3 disease, removing ≥30 LNs significantly improved OS compared with removing 7 to 14 LNs (hazard ratio [HR] 2.45, 95% confidence interval = 1.25-4.82, P = 0.009). Extended lymphadenectomy may confer a survival benefit in select patients with pT1N3 and pT2N3 GC, highlighting the importance of the number of LNs examined rather than stage migration on survival. For the majority of the N3 population, pT3-pT4, the extent of lymphadenectomy did not significantly improve the OS.

Evolution in the surgical management of gastric cancer: is extended lymph node dissection back in vogue in the USA?

BACKGROUND

Gastric cancer remains a formidable treatment challenge. For decades, treatment consisted mostly of surgical intervention for this deadly disease. With improvements in the multi-disciplinary management of solid organ malignancies, the approach to this disease is being stepwise refined.

MAIN BODY

One of the prevalent controversies in the surgical management of gastric cancer rests on the need for adequate harvesting of lymph nodes. For decades, lymph node dissection is regarded as a staging technique useful in only upstaging the disease. The adoption of D2 lymphadenectomy has been particularly slow to mature. But with prevailing data from Asia consistently demonstrating a survival benefit from lymphadenectomy, it calls into question the notion of lymphadenectomy as being solely a staging procedure.

CONCLUSIONS

As gastric resection techniques are being better defined in western countries and surgical morbidities lowered on its execution, D2 lymphadenectomy is becoming more accepted as the new standard in the management of gastric cancer.

Clinicopathologic implication of meticulous pathologic examination of regional lymph nodes in gastric cancer patients

BACKGROUND

We aimed to investigate effect of increased number of examined lymph nodes (LNs) to pN category, and compare various N categories in gastric cancer: American Joint Committee on Cancer (AJCC) 7th edition, metastatic LN ratio (MLR), and log odds of positive LNs (LODDS).

METHODS

Four cohorts with a total of 2,309 gastric cancer patients were enrolled. For cohort 1 and 2, prognostic significance of each method by disease-specific survival was analyzed using Akaike and Bayesian information criterion (AIC and BIC).

RESULTS

The total LNs in four cohorts significantly differed [median (range), 28 (6-97) in cohort 1, 37 (8-120) in cohort 2, 48 (7-122) in cohort 3, and 54 (4-221) in cohort 4; p<0.001]. The numbers of negative LNs increased with increase of total LN (p<0.001), but the numbers of metastatic LNs did not increase from cohort 1 to 4. MLR and LODDS in four cohorts had decreasing tendency with increase of total LNs in each pT3 and pT4 category (p<0.001), while the numbers of metastatic LNs did not differ significantly in any pT category (p>0.05). The AIC and BIC varied according to different cut-off values for MLR; model by cut-offs of 0.2 and 0.5 being better for cohort 1, while cut-offs 0.1 and 0.25 was better for cohort 2.

CONCLUSION

Our study showed that the number of metastatic LNs did not increase with maximal pathologic examination of regional LNs. AJCC 7th system is suggested as the simplest method with single cut-off value, but prognostic significance of MLR may be influenced by various cut-offs.

Patterns of Care for Radiotherapy in the Neoadjuvant and Adjuvant Treatment of Gastric Cancer: A Twelve-Year Nationwide Cohort Study in Korea

Purpose

Although Korea has the highest incidence of gastric cancer worldwide and D2-lymphadenectomies are routinely performed, radiotherapy (RT) practice patterns have not been well studied. Therefore, we examined RT usage trends for neoadjuvant/adjuvant patients and identified factors associated with RT. We also examined survival benefits and net medical cost advantages of adding RT.

Materials and Methods

Patients diagnosed with gastric cancer who underwent gastrectomy from 2002-2013 were identified using National Health Insurance Service-National Sample Cohort.

Results

Annually, 30.9 cases per 100,000 population in crude rate underwent gastrectomy in 230 hospitals and 49.8% received neoadjuvant/adjuvant therapy in 182 hospitals. For neoadjuvant/adjuvant patients, postoperative chemo-RT was administered in 4% of cases in 26 hospitals. No significant trends regarding treatment type were observed over time. Having undergone RT was inversely associated with being ≥ 60 years old and having a low income. Having undergone RT was positively related to having a Charlson comorbidity index ≥ 4, hospital location and hospital volume (≥ 2,000 beds). Significant portions of patients treated with RT in this nation (52%) were concentrated in one large-volume hospital. Use of RT linked to increased cost of primary treatment, yet not to reduced overall medical expense. RT did not influence both on overall and disease-specific survivals after adjusting for potential confounders (p > 0.05).

Conclusion

RT was uncommonly utilized as adjuvant or neoadjuvant treatment by physicians in Korea. Despite intrinsic drawback in this data, we did not find either survival benefit or net medical cost advantage by adding RT in adjuvant treatment.

N staging: the role of the pathologist

Gastric cancer is the second cause of cancer-related mortality worldwide. Metastases, including lymph nodes ones, heavily influence the prognosis of this disease. The pathological detection of positive lymph nodes is pivotal for an optimal prognostication and clinical management of affected individuals. Several factors influence the pathological investigation of surgical specimens, ultimately affecting the number of retrieved lymph nodes and, with it, the reliability of N staging. The pathologist plays a central role in optimizing this process. Factors influencing lymph node retrieval and analysis will be herein reviewed, together with the procedures adopted for an optimal pathological analysis of lymph nodes in gastric cancer.

Comparison of different lymph node staging systems in prognosis of gastric cancer: a bi-institutional study from Hungary

Objective

The Union for International Cancer Control (UICC) Node (N) classification is the most common used staging method for the prognosis of gastric cancer. It demands adequate, at least 16 lymph nodes (LNs) to be dissected; therefore different staging systems were invented.

Methods

Between March 2005 and March 2010, 164 patients were evaluated at the Department of General Surgery in the Kenézy Gyula Hospital and at the Department of General, Thoracic and Vascular Surgery in the Kaposi Mór Hospital. The 6th, 7th and 8th UICC N-staging systems, the number of examined LNs, the number of harvested negative LNs, the metastatic lymph node ratio (MLR) and the log odds of positive LNs (LODDS) were determined to measure their 5-year survival rates and to compare them to each other.

Results

The overall 5-year survival rate for all patients was 55.5% with a median overall survival time of 102 months. The tumor stage, gender, UICC N-stages, MLR and the LODDS were significant prognostic factors for the 5-year survival with univariate analysis. The 6th UICC N-stage did not follow the adequate risk in comparing N2 vs. N0 and N3 vs. N0 with multivariate investigation. Comparison of performances of the residual N classifications proved that the LODDS system was first in the prediction of prognosis during the evaluation of all patients and in cases with less than 16 harvested LNs. The MLR gave the best prognostic prediction when adequate (more than or equal to 16) lymphadenectomy was performed.

Conclusions

We suggest the application of LODDS system routinely in western patients and the usage of MLR classification in cases with extended lymphadenectomy.

Applicability of the Proposed Japanese Model for the Classification of Gastric Cancer Location: The "PROTRADIST" Retrospective Study

BACKGROUND

The extension of lymphadenectomy for surgical treatment of gastric cancer remains discordant among European and Japanese surgeons. Kinami et al. (Kinami S, Fujimura T, Ojima E, et al. PTD classification: proposal for a new classification of gastric cancer location based on physiological lymphatic flow. Int. J. Clin. Oncol. 2008;13:320-329) proposed a new experimental classification, the "Proximal zone, Transitional zone, Distal zone" (PTD) classification, based on the physiological lymphatic flow of gastric cancer site. The aim of the present retrospective study is to assess the applicability of PTD Japanese model in gastric cancer patients of our Western surgical department.

METHODS

Two groups of patients with histologically documented adenocarcinoma of the stomach were retrospectively obtained: In the first group were categorized 89 patients with T1a-T1b tumor invasion; and in the second group were 157 patients with T2-T3 category. The data collected were then categorized according to the PTD classification.

RESULTS

In the T1a-T1b group there were no lymph node metastases within the r-GA or r-GEA compartments for tumors located in the P portion, and similarly there were no lymphatic metastases within the l-GEA or p-GA compartments for tumors located in the D portion. On the contrary, in the T2-T3 group the lymph node metastases presented a diffused spreading with no statistical significance between the two classification models.

CONCLUSIONS

Our results show that the PTD classification based on physiological lymphatic flow of the gastric cancer site is a more physiological and clinical version than the Upper, Medium And Lower classification. It represents a valuable and applicable model of cancer location that could be a guide to a tailored surgical approach in Italian patients with neoplasm confined to submucosa. Nevertheless, in order to confirm our findings, larger and prospective studies are needed.

Short- and Long-Term Outcomes After Gastrectomy in Elderly Gastric Cancer Patients

BACKGROUND

The number of elderly patients undergoing gastric cancer surgery has recently increased. We therefore evaluated the short- and long-term outcomes of elderly patients after curative gastrectomy.

METHODS

Overall, 824 patients were included in this retrospective study, which comprised of a non-elderly group (60-64 years; n = 558), an early-elderly group (75-79 years; n = 198), and a late-elderly group (≥80 years; n = 68) who underwent curative gastrectomy for gastric cancer between 2005 and 2009. Postoperative complications, according to the Clavien-Dindo classification, and survival of both elderly groups were compared with the non-elderly group. Postoperative life expectancy of the late-elderly group was compared with the corresponding aged general population.

RESULTS

Overall and severe (grade III or higher) complications in the early-elderly group were comparable with the non-elderly group; however, those in the late-elderly group were significantly more common than in the non-elderly group (p = 0.013 and p = 0.043, respectively). Multivariable analysis revealed that age ≥80 years was an independent risk factor for severe complications (hazard ratio 3.02, 95 % confidence interval 1.12-8.17; p = 0.029), and the disease-specific survivals of both elderly groups were comparable with the non-elderly group in all TNM stages. Postoperative life expectancy of late-elderly patients eliminating death from recurrence was comparable with the corresponding aged general population eliminating death from gastric cancer.

CONCLUSIONS

Gastric cancer surgery in elderly patients aged ≥80 years achieves reasonable long-term survival despite the increased risk of severe complications.

Role of frailty and nutritional status in predicting complications following total gastrectomy with D2 lymphadenectomy in patients with gastric cancer: a prospective study

PURPOSE

This study was performed to determine the association of frailty and nutritional status with postoperative complications after total gastrectomy (TG) with D2 lymphadenectomy in patients with gastric cancer.

METHODS

Patients undergoing TG with D2 lymphadenectomy for gastric cancer between August 2014 and February 2016 were enrolled. Frailty was evaluated by sarcopenia which was diagnosed by a combination of third lumbar vertebra muscle index (L3 MI), handgrip strength, and 6-m usual gait speed. Nutritional status was evaluated by the nutritional risk screening 2002 (NRS 2002) score. Univariate and multivariate analyses evaluating the risk factors for postoperative complications were performed.

RESULTS

A total of 158 patients were analyzed, and 27.2 % developed complications within 30 days of surgery. One patient died within 30 days of the operation. In the univariate analyses, NRS 2002 score ≥3 (OR = 2.468, P = 0.012), sarcopenia (OR = 2.764, P = 0.008), and tumor located at the cardia (OR = 2.072, P = 0.046) were associated with the postoperative complications. Multivariable analysis revealed that sarcopenia (OR = 3.084, P = 0.005) and tumor located at the cardia (OR = 2.347, P = 0.026) were independent predictors of postoperative complications.

CONCLUSIONS

This study showed a significant relationship between postoperative complications and geriatric frailty using sarcopenia in patients with gastric cancer after TG with D2 lymphadenectomy. Frailty should be integrated into preoperative risk assessment and may have implications in preoperative decisionmaking.

Optimal extent of lymphadenectomy for gastric adenocarcinoma: A 7-institution study of the U.S. gastric cancer collaborative

BACKGROUND AND OBJECTIVES

The optimal extent of lymphadenectomy in the treatment of gastric adenocarcinoma is debated. We compared gastrectomy outcomes following limited (D1) or extended (D2) lymphadenectomy.

METHODS

Using the multi-institutional US Gastric Cancer Collaborative database, we reviewed the morbidity, mortality, recurrence, and overall survival (OS) of patients receiving D1 or D2 lymphadenectomies.

RESULTS

Between 2000 and 2012, 266 and 461 patients received a D1 and D2 lymphadenectomy, respectively. ASA class, mean number of comorbidities, grade, and stage were similar between groups. While major morbidity was similar (P = 0.85), mortality was worse for those receiving a D1 lymphadenectomy (4.9% vs. 1.3%, P = 0.004). D2 lymphadenectomy was associated with improved median OS in stage I (4.7 years for D1 vs. not reached for D2, P = 0.003), stage II (3.6 years for D1 vs. 6.3 for D2, P = 0.42), and stage III patients (1.3 years for D1 vs. 2.1 for D2, P = 0.01). After adjusting for predictors of OS, D2 lymphadenectomy remained a significant predictor of improved survival (HR 1.5, 95%CI 1.1-2.0, P = 0.008).

CONCLUSIONS

D2 lymphadenectomy can be performed without increased risk of morbidity and mortality. Additionally, D2 lymphadenectomy is associated with improved survival especially in early stages, and should be considered for gastric adenocarcinoma patients. J. Surg. Oncol. 2016;113:750-755. © 2016 Wiley Periodicals, Inc.

Gastric cancer: Current status of lymph node dissection

D2 procedure has been accepted in Far East as the standard treatment for both early (EGC) and advanced gastric cancer (AGC) for many decades. Recently EGC has been successfully treated with endoscopy by endoscopic mucosal resection or endoscopic submucosal dissection, when restricted or extended Gotoda's criteria can be applied and D1+ surgery is offered only to patients not fitted for less invasive treatment. Furthermore, two randomised controlled trials (RCTs) have been demonstrating the non inferiority of minimally invasive technique as compared to standard open surgery for the treatment of early cases and recently the feasibility of adequate D1+ dissection has been demonstrated also for the robot assisted technique. In case of AGC the debate on the extent of nodal dissection has been open for many decades. While D2 gastrectomy was performed as the standard procedure in eastern countries, mostly based on observational and retrospective studies, in the west the Medical Research Council (MRC), Dutch and Italian RCTs have been conducted to show a survival benefit of D2 over D1 with evidence based medicine. Unfortunately both the MRC and the Dutch trials failed to show a survival benefit after the D2 procedure, mostly due to the significant increase of postoperative morbidity and mortality, which was referred to splenopancreatectomy. Only 15 years after the conclusion of its accrual, the Dutch trial could report a significant decrease of recurrence after D2 procedure. Recently the long term survival analysis of the Italian RCT could demonstrate a benefit for patients with positive nodes treated with D2 gastrectomy without splenopancreatectomy. As nowadays also in western countries D2 procedure can be done safely with pancreas preserving technique and without preventive splenectomy, it has been suggested in several national guidelines as the recommended procedure for patients with AGC.

Clinical significance of lymphadenectomy in patients with gastric cancer

Approximately thirty percent of patients with gastric cancer undergo an avoidable lymph node dissection with a higher rate of postoperative complication. Comparing the D1 and D2 dissections, it was found that there is a significant difference in morbidity, favoured D1 dissection without any difference in overall survival. Subgroup analysis of patients with T3 tumor shows a survival difference favoring D2 lymphadenectomy, and there is a better gastric cancer-related death and non-statistically significant improvement of survival for node-positive disease in patients with D2 dissection. However, the extended lymphadenectomy could improve stage-specific survival owing to the stage migration phenomenon. The deployment of centralization and application of national guidelines could improve the surgical outcomes. The Japanese and European guidelines enclose the D2 lymphadenectomy as the gold standard in R0 resection. In the individualized, stage-adapted gastric cancer surgery the Maruyama computer program (MCP) can estimate lymph node involvement preoperatively with high accuracy and in addition the Maruyama Index less than 5 has a better impact on survival, than D-level guided surgery. For these reasons, the preoperative application of MCP is recommended routinely, with an aim to perform “low Maruyama Index surgery”. The sentinel lymph node biopsy (SNB) may decrease the number of redundant lymphadenectomy intraoperatively with a high detection rate (93.7%) and an accuracy of 92%. More accurate stage-adapted surgery could be performed using the MCP and SNB in parallel fashion in gastric cancer.

The Efficacy of Taxanes- and Oxaliplatin-Based Chemotherapy in the Treatment of Gastric Cancer After D2 Gastrectomy for Different Lauren Types

To investigate the efficacy of Taxanes- and Oxaliplatin-based chemotherapies (TC and OC) in the treatment of gastric cancer patients after D2 gastrectomy with different Lauren types. In this study, 299 patients of gastric adenocarcinoma with D2 lymph node dissection were reviewed between 2007 and 2014. Chemotherapies were classified as Oxaliplatin-based and Taxanes-based regimen. Treatment outcomes were analyzed according to different Lauren types, such as the intestinal type, diffuse type, and mixed type groups, respectively. The disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The log-rank test was used for univariate analysis, and Cox regression was used for multivariate analysis. In diffuse type gastric cancer, the Oxaliplatin-based arm had a longer median DFS and OS compared with Taxanes-based arm (DFS: 47.0 vs 28.6 months, P = 0.04; OS: 51.9 vs 34.5 months, P = 0.048). The chemotherapy regimen was an independent prognostic factor for DFS and OS of diffuse type gastric cancer patients by multivariate analysis (P = 0.01). In the intestinal type, although the DFS and OS of intestinal type patients in TC group were higher than those in OC group (DFS: 53.4 vs 42.4 months; OS: 69.7 vs 57.8 months), there was no statistical significance observed (both P > 0.05). For the mixed type, the 2 different chemotherapy regimens achieved similar median DFS and OS. In a conclusion, the patients of diffuse type were more sensitive to OC, and the intestinal type patients may be benefit from TC. Therefore, it will be of benefit for gastric patients by introducing Lauren classification clinically and to help the choice of chemotherapy regimen for gastric patients after D2 gastrectomy.

Proximal segmentation of the dorsal mesogastrium reveals new anatomical implications for laparoscopic surgery

Generally, the gold standard of radical surgery for gastrointestinal (GI) tumors is en bloc resection of primary lesions and their related tissues. For gastric cancer, the ideal surgical treatment should be D2 radical gastrectomy plus complete mesogastrium excision. Complete mesogastrium excision is rarely done or mentioned since little is known about the mesogastrium and its presence is still with controversy. Topographically, the “mesogastrium” refers to a peri-gastric structure composed of “fascia propria”, enveloping lymph nodes, blood vessels and adipose tissues, which by connecting to the stomach, suspends from the posterior abdominal wall. In this study, by employing video laparoscopy, a number of proximal segments of dorsal mesogastrium were found being extensively scattered around the pancreas. The structure of the mesogastrium was further identified intraoperatively and then confirmed both grossly and histologically after the operation. Our results demonstrated the existence of mesogastrium (gastric mesentery) and its architecture. We suggest for the first time a “Table model” to describe the relationship between the stomach and gastric mesenteries enveloped by fascia propria, which might provide an improvement in the surgical methods for excision of gastric cancer.

Postoperative adjuvant treatment for gastric cancer improves long-term survival after curative resection and D2 lymphadenectomy. Results from a Latin American Center

BACKGROUND

The benefits of adjuvant treatment in the context of a D2 lymph node dissection are controversial. The aim was to investigate the effects of postoperative adjuvant treatment on the survival of patients with a curative resection for gastric cancer and a D2 lymph node dissection.

METHODS

We performed a retrospective cohort study. Patients operated from 1996 to 2013 were selected. We compared long term survival of patients treated with surgery alone and those with surgery plus postoperative adjuvant treatment. A multivariate analysis for survival was applied in every stage.

RESULTS

The study included 580 patients. Two-hundred and four patients received postoperative adjuvant treatment (AD) and 376 patients were treated only with surgery (SU). Patients in the AD group were younger (60 versus 68, p < 0.001), had a lower rate of multiple organ resection (21% versus 39%, p < 0.001) and had less postoperative complications (14% versus 32%, p < 0.001). In the AD group, patients had more advanced disease (stage III; 77% versus 66%, p < 0.001). No difference was found in lymph nodes resected (31 versus 30, p = ns). The median survival with adjuvant treatment was 33 months (39% 5 year survival) and 22 months (31% 5 year survival) for patients without adjuvant treatment (p = 0.003). On multivariate analysis, patients with stage IIIB and IIIC had significantly better overall and disease specific long-term survival with adjuvant treatment.

CONCLUSIONS

These results suggest that there is a long-term survival benefit for patients treated with postoperative adjuvant treatment for stages IIIB and IIIC gastric cancer after D2 lymph node dissection.