Gastric Cancer, Version 3.2016, NCCN Clinical Practice Guidelines in Oncology

Left Gastric Artery Lymph Nodes Should Be Included in D1 Lymph Node Dissection in Gastric Cancer

BACKGROUND

The Japanese Classification of Gastric Carcinoma includes the left gastric artery (#7) lymph nodes (LNs) in the recommended extent of D1 LN dissection, but this recommendation has not been validated in western institutions.

METHODS

We reviewed data from a prospectively maintained database of gastric cancer patients who underwent resection at our academic cancer center and had a separate pathologic assessment of #7 LN in 2005-2016. Risk factors for #7 LN metastases and overall survival were examined by uni- and multivariable analyses.

RESULTS

We identified 173 patients; 114 (66%) were treated with preoperative therapy, most commonly with chemoradiation therapy (47%, 81/173). We identified 22 patients (13%) who had #7 LN metastases, which accounted for 35% (22/63) of node-positive patients. No preoperative factors were associated with #7 LN metastases by univariable analyses. Patients with #7 metastases were not associated with shorter overall survival after adjustment by nodal stage (hazard ratio 1.49, 95% confidence interval 0.67-3.32; p = 0.33).

CONCLUSION

Metastasis to #7 LN station was common in gastric cancer, but the survival impact was not significant after adjustment by nodal stage. We conclude that #7 LNs should be routinely dissected in gastric cancer patients, and this station should be included within the extent of D1 LN dissection.

Curative resectability of gastrointestinal cancer identified from iron deficiency anemia

The present study aimed to clarify the staging and curative resectability of gastrointestinal cancer found through iron deficiency anemia (IDA). An electronic database was used and females >51 and males >18 years old were identified who had been diagnosed with IDA at the internal medicine outpatient clinic of Asahi General Hospital (Chiba, Japan) from 1 April 2010 to 31 March 2012. IDA was defined as a hemoglobin level of <135 g/l for males and <120 g/l for females, combined with a serum ferritin level of <33.71 pmol/l. Of the 472 patients who had been diagnosed with IDA, 347 patients underwent either a gastroscopy and/or colonoscopy, including 120 patients who had undergone both gastroscopy and colonoscopy, 197 patients who only underwent gastroscopy, and 30 patients who only underwent colonoscopy. In total, 125/472 patients diagnosed with IDA did not undergo a gastroscopy or a colonoscopy. From the 50 patients who were diagnosed with cancer as a result of the investigation, 24 patients had gastric cancer and 23 patients had colorectal cancer. Of the gastric cancer patients, 6 patients were stage I, 3 patients stage II, 5 patients were stage III and 9 patients were stage IV. In colorectal cancer, 9 patients were stage II, 8 patients were stage III and 4 patients were stage IV. Curative surgery including endoscopic treatment was performed on 14 gastric cancer patients and 17 colorectal cancer patients of stage III or lower. Malignancies were found in 50 patients with IDA, and curative surgery was performed on >50% of the patients.

Validation of the 8th Edition of the AJCC TNM Staging System for Gastric Cancer using the National Cancer Database

BACKGROUND

The 8th edition AJCC gastric cancer staging manual was refined using Japanese and Korean data from the International Gastric Cancer Association (IGCA). This study evaluated the eighth edition's validity for U.S.

POPULATIONS

METHODS

National Cancer Database (NCDB) was used to obtain data on gastric cancer patients diagnosed from 2004 to 2008 who underwent surgery and to examine differences in stage grouping and survival between AJCC 7th and 8th editions. Discrimination of models derived from NCDB and IGCA data was compared.

RESULTS

Of 12,041 patients, median age was 65, 57.6% were male, median lymph nodes retrieved was 2 (0-76), 30.9% underwent distal/partial gastrectomy, and 49.8% received no adjuvant treatment. The 8th edition differed in that T1-T3 disease was upstaged with N3b, T4aN3a was downstaged from IIIC to IIIB, and T4bN0 and T4aN2 were downstaged from IIIB to IIIA. These changes resulted in increased patients in IIIA (1436 in the 7th edition to 2310 in the 8th) and IIIB (1737-1896) and decreased in IIIC (2100-1067). This also resulted in lower median survival for IIIA (28.7-25.0 months), IIIB (19.6-17.4), IIIC (13.7-11.8). The concordance index for the 8th edition applied to NCDB data was 0.719 [95% confidence interval (CI) 0.703-0.734), which is comparable to that for the 8th edition developed from IGCA data (0.775, 95% CI 0.770-0.780) and the 7th edition applied to NCDB data (0.720, 95% CI 0.704-0.735).

CONCLUSIONS

The 8th edition is valid for U.S. populations, showing clear separation of data with preservation of group order.

Prediction of radiosensitive patients with gastric cancer by developing gene signature

Adjuvant radiotherapy is an important clinical treatment for the majority of gastric cancer, a common cancer. However, radiotherapy is a double-edged sword. It is necessary to develop a method to predict radiosensitive patients who are most likely to benefit from radiotherapy. Using the publicly available data of gastric cancer from The Cancer Genome Atlas (TCGA), we developed a gene signature that predicts radiosensitive patients through estimating a new index, nominal HR (nHR) (HR product of sensitive genes), for each patient. In this study, we provided several results to validate our prediction. Cross-validation results showed that the predicted radiosensitive patients who received radiotherapy had significantly better survival than predicted radiosensitive patients who did not receive radiotherapy. After adjusting for other clinical factors, including age, sex, target therapy, histologic diagnosis, tumor stage, the benefit of radiotherapy on predicted radiosensitive patient remained significant. In addition, predicted radiosensitive patients who received radiotherapy had a significantly reduced rate of disease progression. Taken together, we have obtained a set of genes, to identify radiosensitive patients with gastric cancer. These genes may be potential biomarkers for diagnosis and treatment of gastric cancer, which could give new insight for revealing the underlying mechanism of radiosensitivity of gastric cancer.

Prognostic significance of the total number of harvested lymph nodes for lymph node-negative gastric cancer patients

Background

The relationship between the number of harvested lymph nodes (HLNs) and prognosis of gastric cancer patients without an involvement of lymph nodes has not been well-evaluated. The objective of this study is to further explore this issue.

Methods

We collected data from 399 gastric cancer patients between November 2006 and October 2011. All of them were without metastatic lymph nodes.

Results

Survival analyses showed that statistically significant differences existed in the survival outcomes between the two groups allocated by the total number of HLNs ranging from 16 to 22. Therefore, we adopted 22 as the cut-off value of the total number of HLNs for grouping (group A: HLNs <22; group B: HLNs≥22). The intraoperative and postoperative characteristics, including operative blood loss (P=0.096), operation time (P=0.430), postoperative hospital stay (P=0.142), complications (P=0.552), rate of reoperation (P=0.966) and postoperative mortality (P=1.000), were comparable between the two groups. T-stage-stratified Kaplan–Meier analyses revealed that the 5-year survival rate of patients at the T4 stage was better in group B than in group A (76.9% vs. 58.5%; P=0.004). An analysis of multiple factors elucidated that the total number of HLNs, T stage, operation time and age were independently correlated factors of prognosis.

Conclusions

Regarding gastric cancer patients without the involvement of lymph nodes, an HLN number ≥22 would be helpful in prolonging their overall survival, especially for those at T4 stage. The total number of HLNs was an independent prognostic factor for this population of patients.

Comparative efficacy and safety of Chinese herbal injections combined with the FOLFOX regimen for treating gastric cancer in China: a network meta-analysis

Background

Chinese herbal injections (CHIs) have been proven beneficial to patients with gastric cancer for improving clinical efficacy and relieving adverse reactions (ADRs) of chemotherapy. A network meta-analysis (NMA) was conducted in this study to assess the comparative efficacy and safety of CHIs combined with FOLFOX regimen for treating gastric cancer.

Results

A total of 2316 records were searched, and 81 eligible RCTs involving 15 types of CHIs and 5978 patients were included in the NMA. The results showed that patients who received Shengqifuzheng+ FOLFOX, Compound kushen+ FOLFOX, Huachansu+ FOLFOX, Astragalus+ FOLFOX, Kangai+ FOLFOX, and Lentinan injection + FOLFOX could significantly improve clinical efficacy than using FOLFOX single, and their odds ratios (OR) and 95% confidence intervals (CI)s were 1.57 (1.19,2.09), 2.12 (1.62,2.78),1.72 (1.08,2.80), 3.06 (1.01,8.99), 2.01 (1.52,2.70), and 1.99 (1.20,3.38) respectively. Furthermore, the therapy of Aidi+ FOLFOX, Shenqifuzheng+ FOLFOX, Compound Kushen+ FOLFOX, Huachansu+ FOLFOX, Astragalus polysaccharides+ FOLFOX, Kangai+ FOLFOX, Ginseng polysaccharide+ FOLFOX, Lentinan+ FOLFOX, Xiaoaiping+ FOLFOX, and Shenmai injection + FOLFOX could also achieve a higher performance status compared with FOLFOX regimen alone. Similarly, patients who received CHIs combine with FOLFOX regimen were associated with a significantly decrease the incidence of leucopenia, gastrointestinal reaction and hepatic dysfunction. Cluster analysis demonstrated that Astragalus polysaccharides+ FOLFOX, and Kangai+ FOLFOX seemed optimal therapies in improving clinical efficacy and performance status; Astragalus polysaccharides+ FOLFOX was superior in reducing leucopenia and gastrointestinal reaction; Disodium Cantharidinate and Vitamin B6+ FOLFOX was associated with favorable effects in reducing gastrointestinal reaction and hepatic dysfunction. By contrary, receiving FOLFOX regimen single was proved to rank the worst for these outcomes.

Materials and Methods

A comprehensive literature search was performed in several electronic databases to identify randomized controlled trial (RCTs) regarding CHIs for gastric cancer until January 10, 2017. The quality assessment was accomplished according to the Cochrane risk of bias tool and the methodological section of the CONSORT statement. And a random-effects model NMA was utilized to compare different CHIs combined with FOLFOX regimen with regard to efficacy and safety. Data were analyzed using STATA 12.0 and Win-BUGS 1.4 software.

Conclusions

The results of this NMA suggested that among 15 types of CHIs, Astragalus polysaccharides injection combined with FOLFOX regimen seemed optimal for patients with gastric cancer in improving clinical efficacy and performance status, and relieving ADRs. However, our findings should be confirmed by more prospectively designed, large-sample and multi-center RCTs.

Metformin targets gastric cancer stem cells

Gastric cancer is the third leading cause of cancer-related deaths worldwide and has still a poor prognosis. Therefore, new therapeutic strategies are needed: among them, targeting cancer stem cells (CSCs) could offer new opportunities. The aim of our study was to evaluate the anti-tumoural effect of metformin on gastric cancer in vitro and in vivo and especially, to determine whether this molecule could target the gastric CSCs. Metformin effects were evaluated on the proliferation and tumourigenic properties of the gastric CSCs from patient-derived primary tumour xenografts (PDXs) and cancer cell lines (MKN45, AGS and MKN74) in vitro in conventional 2 dimensional (2D) and in 3 dimensional (3D) culture systems, in which only CSCs are able to form tumourspheres and in mouse xenograft models in vivo. Metformin induced a cell cycle arrest, which decreased cell proliferation in the 2D cultures. In a 3D culture system, metformin decreased the number of tumourspheres, revealing its capacity to target the CSCs. This effect was confirmed by the study of the expression of CSC markers (CD44 and Sox2) and differentiation markers (Kruppel-like factor 4 and MUC5AC), which were decreased or increased in response to metformin, respectively. Finally, in vivo treatment of PDXs with metformin led to a tumour growth delay and decreased the self-renewal ability of the CSCs. These results suggest that the use of metformin could represent an efficient strategy to inhibit tumour growth by targeting gastric CSCs.

Using the National Cancer Database to create a scoring system that identifies patients with early-stage esophageal cancer at risk for nodal metastases

OBJECTIVES

Endoscopic resection is gaining popularity as a treatment for early-stage esophageal adenocarcinoma, particularly for T1a tumors. The goal of this study was to create a scoring system to reflect the risk of nodal metastases in early-stage esophageal adenocarcinoma to be used after endoscopic resection to better individualize treatment.

METHODS

The National Cancer Database was queried for patients with T1a or T1b esophageal adenocarcinoma who underwent esophagectomy. We identified variables affecting nodal metastases using multivariable logistic regression, which we then used to create a scoring system. We stratified the model for T1a or T1b tumors, tested model discrimination, and validated the models by refitting in 1000 bootstrap samples. C-statistics greater than 0.7 were considered relevant.

RESULTS

We identified 1283 patients with T1a or T1b tumors; 146 had nodal metastases (11.4%). Tumor category (pT1a vs pT1b), grade, and size and the presence of angiolymphatic invasion significantly affected the risk of nodal metastases. We assigned points to each variable and added them to get a risk score. In patients with T1a tumors, less than 3% of patients with a risk score of 3 or less had nodal metastases, whereas 16.1% of patients with a risk score of 5 or greater had nodal metastases. In patients with T1b tumors, less than 5% of patients with a risk score of 2 or less had nodal metastases, whereas 41% of patients with a score of 6 or greater had nodal metastases (c-statistic = 0.805).

CONCLUSIONS

The proposed scoring system seems to be useful in discriminating risk of nodal metastases in patients with T1a or T1b esophageal adenocarcinoma and may be useful in directing patients who received endoscopic resection to esophagectomy or careful follow-up.

Therapeutic Outcomes of Endoscopic Resection of Early Gastric Cancer with Undifferentiated-Type Histology: A Korean ESD Registry Database Analysis

Background/Aims

To assess the therapeutic outcomes of endoscopic resection (ER) of early gastric cancer (EGC) with undifferentiated-type histology.

Methods

Cases of ER of EGC with undifferentiated-type histology in the Korean endoscopic submucosal dissection (ESD) registry database were identified and reviewed. The immediate outcomes, including en bloc resection, complete resection, and curative resection rates, and long-term outcomes, including recurrence and survival rates, were extracted and analyzed.

Results

From 2006 to 2015, 275 EGCs with undifferentiated-type histology from 275 patients were identified. The immediate outcomes were as follows: en bloc resection rate: 92.4%; complete resection rate: 80%; and curative resection rate: 36.4%. Compared to patients with lesions that were beyond the expanded indication, those with expanded indication lesions showed better therapeutic outcomes. There was no difference in immediate outcomes between patients with poorly differentiated adenocarcinoma (PDC) and signet ring cell carcinoma (SRC). However, compared to ER of SRC, ER of PDC had a stronger association with submucosal invasion (41.9% vs. 23.6%, p=0.003). With regard to long-term outcomes, there was no difference between lesions with curative and non-curative resections in the recurrence and mortality rates. These rates also did not differ between PDC and SRC (median follow up: 3.96 years).

Conclusions

ER confined to expanded indication lesions can be considered for treatment of EGC with undifferentiated-type histology.

Model to identify early-stage gastric cancers with deep invasion of submucosa based on endoscopy and endoscopic ultrasonography findings

BACKGROUND

Conventional endoscopy and endoscopic ultrasonography (EUS) are used to estimate the invasion depth of early-stage gastric cancers (EGCs), but estimates made by either technique are often inaccurate. We developed a model to determine the invasion depth of EGCs using conventional endoscopy and EUS findings, with pathology results as the reference.

METHODS

We performed a retrospective study of 195 patients (205 lesions) diagnosed with gastric cancers who underwent endoscopy and EUS followed by resection. Based on pathology analyses, lesions (n = 205) were assigned to categories of: mucosa invasion or minute invasion into the submucosal layer less than 500 μm from the muscularis mucosae (M-SM1) or penetration of 500 μm or more (≥SM2). The lesions were randomly assigned to derivation (138 lesions) and validation sets (67 lesions). A depth predictive model was proposed in the derivation set using multivariate logistic regression analyses. The discriminative power of this model was assessed in both sets.

RESULTS

Remarkable redness (OR 5.42; 95% CI 1.32-22.29), abrupt cutting of converging folds (OR 8.58; 95% CI 1.65-44.72), lesions location in the upper third of the stomach (OR 10.26; 95% CI 2.19-48.09), and deep invasion based on EUS findings (OR 16.53; 95% CI 4.48-61.15) significantly associated with ≥SM2 invasion. A model that incorporated these 4 variables discriminated between M-SM1 and ≥SM2 lesions with the area under the ROC curve of 0.865 in the derivation set and 0.797 in the validation set. In the derivation set, a cut-off score of 8 identified lesions as ≥SM2 with 54% sensitivity and 97% specificity. The model correctly predicted the invasion depth 89.86% of lesions; it overestimated the depth of 2.17% of lesions.

CONCLUSIONS

We developed a model to identify EGCs with invasion depth ≥SM2 based on endoscopy and EUS findings. This model might reduce overestimation of gastric tumor depth and prevent unnecessary gastrectomy.

Improvement of atropine on esophagogastric junction observation during sedative esophagogastroduodenoscopy

BACKGROUND AND STUDY AIMS

Although sedation esophagogastroduodenoscopy (EGD) is now widely used, previous research has reported that sedation during EGD exhibits a negative effect on esophagogastric junction (EGJ) exposure. Atropine might improve EGJ exposure, as noted in clinical practice. The aim of this study was to examine whether sedation had a negative effect on EGJ observation in the Chinese population, and whether atropine had some ability to act as an antidote to this unexpected secondary effect of sedation.

PATIENTS AND METHODS

In this cross-sectional study, subjects were divided into the following three groups according to the methods of EGD examination: the non-sedation group, the propofol-fentanyl combined sedation group and the combined sedation with atropine administration group. The EGJ observation was assessed by a key photograph taken with the endoscopic camera 1 cm from the EGJ, which was rated on the following four-degree scale: excellent (score = 4), good (score = 3), fair (score = 2) and poor (score = 1).

RESULTS

The EGJ exposure was better in the sedation group administered atropine (score = 2.64±1.05) than in the sedation group (score = 1.99±1.08, P<0.05) but not as good as in the non-sedation group (score = 3.24±1.12, P<0.05). Reduced detection of EGJ diseases in the sedation group was also found, compared to the non-sedation group (P<0.05). Only the use of atropine (OR = 2.381, 95%CI: 1.297-4.371, P = 0.005) was independently associated with excellent observation of the EGJ during sedation EGD.

CONCLUSIONS

Combined propofol-fentanyl sedation reduces the extent of exposure of the EGJ during EGD and reduces the detection of EGJ diseases. The application of atropine in the sedation endoscopy examination helped to achieve better EGJ observation, but still cannot achieve an equal extent of exposure compared to non-sedation EGD.

Gastric adenocarcinoma

Gastric cancers, with gastric adenocarcinoma (GAC) as the most common histological type, impose a considerable global health burden. Although the screening strategies for early detection have been shown to be successful in Japan and South Korea, they are either not implemented or not feasible in most of the world, leading to late diagnosis in most patients. Helicobacter pylori infection contributes to the development of many endemic GACs, and pre-emptive eradication or early treatment of this bacterial infection might provide effective primary prevention. GACs are phenotypically and genotypically heterogeneous. Localized (clinical stage I) GAC is best treated either endoscopically or with limited surgical resection, but clinical stage II or stage III tumours require multidisciplinary adjunctive approaches in addition to surgery. Although GAC is highly treatable in its early stages, advanced (clinical stage IV) GAC has a median survival of just ∼9-10 months. However, detailed molecular and immune profiling of GAC is yielding promise; early studies with immune checkpoint inhibitors suggest that GAC is amenable to immune modulation. Molecular studies have yielded a vast quantity of new information for potential exploitation. Nevertheless, advances against GACs have lagged compared with other tumours of similar incidence, and more research is necessary to overcome the obstacles to prolong survival.

Gastric Cancer in Southern Europe: High-Risk Disease

Gastric cancer is an aggressive disease. Several risk factors are involved in gastric cancer pathogenesis, likely Helicobacter pylori (H. pylori) infection, genetic factors in hereditary syndromes, lifestyle, and diet. However, well-implemented screening strategies are lacking in most countries, including those in Southern Europe. Nevertheless, gastric cancer outcomes are better in some Southern European countries than in others, likely because of the incidence and distribution of different histologic types. Robotic surgery has been gaining favor as a treatment of early-stage disease, and the need for perioperative chemotherapy or adjuvant chemoradiotherapy (CRT) for locally advanced disease has been debated. In the metastatic setting, trastuzumab in combination with chemotherapy has helped to extend survival compared with chemotherapy alone for HER2-positive disease. This article will describe how gastric cancer is assessed and treated in Southern Europe in an attempt to correlate these approaches from a global perspective.

Omega-3 Fatty Acid Grafted PAMAM-Paclitaxel Conjugate Exhibits Enhanced Anticancer Activity in Upper Gastrointestinal Cancer Cells

Upper Gastrointestinal Cancers (UGCs) are a leading cause of cancer-related deaths worldwide. Paclitaxel (PTX) is frequently used for the treatment of UGCs; however, low bioavailability, reduced solubility, and dose-dependent toxicity impede its therapeutic use. PAMAMG_4.0 -NH₂ -DHA is synthesized by linking amine-terminated fourth-generation poly(amidoamine) (PAMAMG_4.0 -NH₂ ) dendrimers with omega-3 fatty acid docosahexaenoic acid (DHA). Next, PAMAMG_4.0 -NH₂ -DHA-PTX (DHATX) and PAMAMG_4.0 -NH₂ -PTX (PAX) conjugates are synthesized by subsequent covalent binding of PTX with PAMAMG_4.0 -NH₂ -DHA and PAMAMG_4.0 -NH₂ , respectively. ¹ H-NMR and MALDI-TOF analyses are performed to confirm conjugation of DHA to PAMAMG_4.0 -NH₂ and PTX to PAMAMG_4.0 -NH₂ -DHA. The cell viability, clonogenic cell survival, and flow cytometry analyses are used to determine the anticancer activity of PTX, PAX, and DHATX in UGC cell lines. The in vitro data indicate that treatment with DHATX is significantly more potent than PTX or PAX at inhibiting cellular proliferation, suppressing long-term survival, and inducing cell death in UGC cells.

Perspectives of HER2-targeting in gastric and esophageal cancer

INTRODUCTION

The blockade of HER2 signaling has significantly improved the outlook for esophagogastric cancer patients. However, targeting HER2 still remains challenging due to complex biology of this receptor in gastric and esophageal cancers. Areas covered: Here, we review complex HER2 biology, current methods of HER2 testing and tumor heterogeneity of gastroesophageal cancer. Ongoing and completed clinical research data are discussed. Expert opinion: HER2 overexpression is a validated target in gastroesophageal cancer, with therapeutic implications resulting in prolonged survival when inhibited in the front-line setting. With standardized HER2 testing in gastro-esophageal cancer, the ongoing trials are testing newer agents and combinations including combination of anti-HER2 antibodies with immunotherapy. Clonal heterogeneity and emergence of resistance will challenge our approach to treating these patients beyond the frontline settings.

Recent trends of gastric cancer treatment in Turkey

Gastric cancer is the fifth most common type of cancer and is the fourth most common death due to cancer in Turkey. Incidence and mortality rates are one of the highest among European countries. Despite the high rates, management of gastric cancer is still an issue of debate in Turkey and national guidelines have yet to be established. While the treatment plan following the diagnosis of gastric cancer is determined by a multidisciplinary meeting at high-volume centers, the plan in the majority of cases in Turkey is decided based on the decision of an individual physician. The primary goal of the treatment strategy is to obtain the best oncological outcomes and quality of life within the acceptable treatment-related morbidity. Therefore, R0 resection is intended by using standardized surgery with an individualized approach, while avoiding surgery if a curative resection is not possible. In this review, presenting on the recent trends of gastric cancer treatment including surgical, endoscopic, adjuvant/neoadjuvant and conversion treatment options in Turkey are aimed by exploring the institutional approach.

Racial disparities in stage-specific gastric cancer: analysis of results from the Surveillance Epidemiology and End Results (SEER) program database

The incidence of gastric cancer is declining in western countries but continues to represent a serious health problem worldwide, especially in Asia and among Asian Americans. This study aimed to investigate ethnic disparities in stage-specific gastric cancer, including differences in incidence, treatment and survival. The cohort study was analyzed using the data set of patients with gastric cancer registered in the Surveillance, Epidemiology, and End Results (SEER) program from 2004 to 2013. Among 54,165 patients with gastric cancer, 38,308 were whites (70.7%), 7546 were blacks (13.9%), 494 were American Indian/Alaskan Natives (0.9%) and 7817 were Asians/Pacific Islanders (14.4%). Variables were patient demographics, disease characteristics, surgery/radiation treatment, overall survival (OS) and cause specific survival (CSS). Asians/Pacific Islanders demonstrated the highest incidence rates for gastric cancer compared with other groups and had the greatest decline in incidence during the study period (13.03 to 9.28 per 100,000/year), as well as the highest percentage of patients with American Joint Committee on Cancer (AJCC) early stage gastric cancer. There were significant differences between groups in treatment across stages I-IV (all p<0.001); Asians/Pacific Islanders had the highest rate of surgery plus radiation (45.1%). Significant differences were found in OS and CSS between groups (p<0.001); OS was highest among Asians/Pacific Islanders. Multivariate analysis revealed that age, race, grade, stage, location, and second primary cancer were valid prognostic factors for survival. Marked ethnic disparities exist in age-adjusted incidence of primary gastric cancer, with significant differences between races in age, gender, histological type, grade, AJCC stage, location, second cancer, treatment and survival.

Dosimetric Comparison of Three Different Radiotherapy Techniques in Antrum-Located Stomach Cancer

Background: The current optimal radiotherapy (RT) planning technique for stomach cancer is controversial. The design of RT for stomach cancer is difficult and differs according to tumor localization. Dosimetric and clinical studies have been performed in patients with different tumor localizations. This may be the main source of inconsistencies in study results. For this reason, we attempted to find the optimal RT technique for patients with stomach cancer in similar locations. Methods: This study was based on the computed tomography datasets of 20 patients with antrum-located stomach cancer. For each patient, treatments were designed using physical wedge-based conformal RT (WB-CRT), field-in-field intensity-modulated RT (FIF-IMRT), and dynamic intensity-modulated RT (IMRT). The techniques were compared in terms of expected target volume coverage and the dose to organs at risk (OAR) using a dose-volume histogram analysis. Results: FIF-IMRT was the most homogenous technique, with a better homogeneity index than WBCRT (p<0.001) or IMRT (p<0.001). However, IMRT had a better conformity index than WBCRT (p<0.001) or FIF-IMRT (p<0.001). Additionally, all OAR, including the kidneys, liver, and spinal cord, were better protected with IMRT than with WBCRT (p=0.023 to <0.001) or FIF-IMRT (p=0.028 to <0.001). Conclusions: In comparison to FIF-IMRT and WBCRT, IMRT appears to be the most appropriate technique for antrum-located stomach cancer. To establish whether IMRT is superior overall will require clinical studies, taking into account differences in both tumor localization (cardia, body, and antrum) and organ movement in patients with stomach cancer.

Advanced gastric adenocarcinoma: optimizing therapy options

INTRODUCTION

Gastric adenocarcinoma (GAC) is the fifth most common cancer and third leading cause of cancer related mortality worldwide. When localized, cure is achievable with surgery and adjunctive therapies in some patients, however, once advanced, GAC is not a curable condition. Only two targeted agents (trastuzumab and ramucirumab) have been approved and apatinib was approved only in China. Because of the heterogeneous nature of GAC, it is not possible to assess a standard therapeutic approach. Areas covered: In this review, we aimed to describe the optimal systemic therapy regimens for advanced GAC. A literature search was performed to identify all phase II-III studies about advanced GAC from PubMed, clinicaltrials.gov, American Society of Clinical Oncology (ASCO) and European Society for Medical Oncology (ESMO) websites. Expert commentary: A combination of a platinum compound and a fluoropyrimidine is ideal as first line therapy. Trastuzumab should be added if the tumor is HER2 positive. In the second line setting, paclitaxel/ramucirumab is preferred over ramucirumab alone. Recently, two similar molecular classifications for GAC have been proposed. A better understanding of molecular and immune biology of GAC could identify new therapeutic targets.

MACC1 mediates chemotherapy sensitivity of 5-FU and cisplatin via regulating MCT1 expression in gastric cancer

Chemotherapeutic insensitivity is a main obstacle for effective treatment of gastric cancer (GC), the underlying mechanism remains to be investigated. Metastasis-associated in colon cancer-1 (MACC1), a transcription factor highly expressed in GC, is found to be related to chemotherapy sensitivity. Monocarboxylate transporter 1 (MCT1), a plasma membrane protein co-transporting lactate and H⁺, mediates drug sensitivity by regulating lactate metabolism. Targeting MCT1 has recently been regarded as a promising way to treat cancers and MCT1 inhibitor has entered the clinical trial for GC treatment. However, the correlation of these two genes and their combined effects on chemotherapy sensitivity has not been clarified. In this study, we found that MACC1 and MCT1 were both highly expressed in GC and exhibited a positive correlation in clinical samples. Further, we demonstrated that MACC1 could mediate sensitivity of 5-FU and cisplatin in GC cells, and MACC1 mediated MCT1 regulation was closely related to this sensitivity. A MCT1 inhibitor AZD3965 recovered the sensitivity of 5-FU and cisplatin in GC cells which overexpressed MACC1. These results suggested that MACC1 could influence the chemotherapy sensitivity by regulating MCT1 expression, providing new ideas and strategy for GC treatment.

Distal gastrectomy versus total gastrectomy for distal gastric cancer

Even though more than a century later, after the first case of gastrectomy has been successfully performed, the best surgical treatment for distal gastric cancer still remains controversial. Thus, the present study was designed to compare the survival impact of distal (DG) or total gastrectomy (TG) for distal gastric cancer. A total of 1262 distal gastric cancer patients were enrolled in current study including 1157 patients who underwent DG and 157 patients who underwent TG. The postoperative complications and 5-year overall survival were compared between the 2 groups. TG group presented a longer surgical time, a higher volume of intraoperative bleeding, and a larger number of excised lymph nodes (all P < 0.05) compared with the DG group. The postoperative complications were comparable (all P >0.05). The 5-year overall survival rate of DG group was significantly higher than that of TG group (67.6% vs 44.3%, P < 0.001). However, multivariate analysis showed that type of resection was not an independent prognostic factor for distal gastric cancer (P > 0.05). The factor-stratified multivariate analysis showed that only in the subgroup of Tumor-node-metastasis staging system (TNM) stage III (P = 0.049), TG was the independent prognostic factor for poor survival. In conclusion, DG was as feasible as TG; however, TG did not increase the survival rate. DG brought better long-term survival than TG in patients with TNM stage III tumor. We recommended that DG should be the optimal surgical procedure for distal gastric cancer under the premise of negative resection margin.

Gastric Cancer in Southern Europe: High-Risk Disease

Gastric cancer is an aggressive disease. Several risk factors are involved in gastric cancer pathogenesis, likely Helicobacter pylori (H. pylori) infection, genetic factors in hereditary syndromes, lifestyle, and diet. However, well-implemented screening strategies are lacking in most countries, including those in Southern Europe. Nevertheless, gastric cancer outcomes are better in some Southern European countries than in others, likely because of the incidence and distribution of different histologic types. Robotic surgery has been gaining favor as a treatment of early-stage disease, and the need for perioperative chemotherapy or adjuvant chemoradiotherapy (CRT) for locally advanced disease has been debated. In the metastatic setting, trastuzumab in combination with chemotherapy has helped to extend survival compared with chemotherapy alone for HER2-positive disease. This article will describe how gastric cancer is assessed and treated in Southern Europe in an attempt to correlate these approaches from a global perspective.