Prognostic value of diffuse versus intestinal histotype in patients with gastric cancer: a systematic review and meta-analysis

Towards Personalization in the Curative Treatment of Gastric Cancer

Gastric cancer is the fifth most common cancer worldwide and has a high mortality rate. In the last decades, treatment strategy has shifted from an exclusive surgical approach to a multidisciplinary strategy. Treatment options for patients with resectable gastric cancer as recommended by different worldwide guidelines, include perioperative chemotherapy, pre- or postoperative chemoradiotherapy and postoperative chemotherapy. Although gastric cancer is a heterogeneous disease with respect to patient-, tumor-, and molecular characteristics, the current standard of care is still according to a one-size-fits-all approach. In this review, we discuss the background of the different treatment strategies in resectable gastric cancer including the current standard, the specific role of radiotherapy, and describe the current areas of research and potential strategies for personalization of therapy.

The clinicopathological characteristics and genetic alterations of gastric cancer patients according to the Lauren classification

ObjectiveThe Lauren classification is an important histological classification of gastric cancer (GC) with different biological behaviors between histological types.BackgroundTo date, there are few reports on the genetic alterations and survival differences between different histological types according to the Lauren classification.MethodsIn total, 433 GC patients undergoing surgery were enrolled. The clinicopathological features, prognoses, and genetic alterations of the different Lauren types were compared.ResultsDiffuse-type GC was associated with a younger age, female predominance, more Borrmann type 3 and 4 tumors, more advanced pathological tumor (T) and node (N) categories, more tumor recurrences (especially peritoneal recurrence), and worse 5-year overall survival and disease-free survival rates than intestinal-type GC and mixed-type GC. Regarding genetic alterations, mixed-type GC was associated with more TP53 mutations than intestinal-type GC and diffuse-type GC. Multivariate analysis demonstrated the following independent prognostic factors: age, Lauren classification, and pathological T and N categories. Regarding mixed-type GC, diffuse-type major tumors were associated with more lymphovascular invasion, a more advanced N category and TNM stage, and fewer PI3K/AKT pathway mutations than intestinal-type major tumors.ConclusionsDiffuse-type GC had unfavorable clinicopathological features and a worse prognosis than intestinal-type GC. For mixed-type GC, the clinicopathological features and genetic alterations were different between intestinal-type major tumors and diffuse-type major tumors.

Diffuse gastric cancer: histologic, molecular, and genetic basis of disease

Diffuse gastric cancer (DGC) is a distinct histopathologic and molecular disease, characterized by mutations in CDH1, RHOA, and others. In addition, DGC is associated with familial syndromes, including hereditary DGC and germline mutation in CDH1. Clinically, this subtype of gastric adenocarcinoma is associated with a poor prognosis and possible resistance to available systemic therapies. An understanding of the genetic and molecular underpinnings of DGC may help inform of its clinical behavior and aid in screening, diagnosis, and response to treatment. In this review, we will review the current histologic, molecular, and genetic landscape of DGC and its relevance to clinical practice.

Biomarkers for Precision Treatment in Gastric Cancer

BACKGROUND

Gastric cancer (GC) is one of the most lethal cancers worldwide. Although GC was historically considered a single entity within the organ of origin, nowadays it is acknowledged that GC represents a heterogeneous disease. Nevertheless, in this field there is still a lack of biomarkers able to guide the choice of the best treatment options for each patient. This review aims to summarize the prognostic and predictive biomarkers evaluated in GC and their role as a guide for treatment for precision medicine.

SUMMARY

Human epidermal growth factor receptor 2 overexpression represents the only predictive molecular biomarker validated in GC, while its prognostic role is still controversial. Microsatellite instability and Epstein-Barr virus status are promising for prediction of the response to immunotherapy. The role of other biomarkers (ctDNA, programmed death ligand 1 [PD-L1], and TMB), as well as the practical application of molecular classifications, requires further evaluation before use in clinical practice. 18-FDG-PET scan could be useful as a predictive tool in non-metastatic GC patients receiving a perioperative approach. Finally, the tumor microenvironment may have an evolving role in the future.

KEY MESSAGES

GC is a heterogeneous disease and targeted approaches are needed. The finding of prognostic and predictive factors is a hot topic in the field of GC personalized medicine.

Disadvantages for non-Hispanic whites in gastric carcinoma survival in Florida

PURPOSE

The prognosis for gastric carcinoma (GC) remains challenging with less than 35% of patients surviving 5 years. GC survival varies greatly by anatomical site, cardia and non-cardia. However, these important differences have not been thoroughly studied in relation to the increasing diversity in US populations such as Florida. In this study we examined, for the first time, the effect of race-ethnicity on risk of death from GC controlling for potential risk factors separately for cardia and non-cardia GCs.

METHODS

Data on GCs diagnosed in Florida from 2005-2016 were obtained from the statewide cancer registry. Age-standardized GC-specific 5-year survival was computed by anatomical site and race-ethnicity. In addition, a competing risk analysis was performed to assess prognostic factors and to estimate subdistribution hazard ratios of death from GC.

RESULTS

Whites had high proportions of cardia GC (43.9%) compared to all racial/ethnic minorities (10.9%, 19.6%, and 13.8% in Blacks, Hispanics, and Asians, respectively; p < .0001). Among 12,302 cases included, there were 7534 deaths from GC and 1179 from other causes. Age standardized GC-specific 5-year survival was significantly lower for Whites (28.0%) compared to Blacks (31.6%), Hispanics (37.6%), and Asians, (39.6%) and significantly lower for cardia GC (25.0%, 95% CI 23.4-26.6) compared to non-cardia GC (37.0%, 95% CI 35.5-38.4). Multivariable competing risk analysis in patients with non-cardia GC showed that Asians (sHR: 0.64, 95% CI 0.51-0.80), Hispanics (sHR 0.71, 95% CI 0.64-0.78), and Blacks (sHR 0.83, 95% CI 0.75-0.92) all had lower risks of death from GC compared to Whites. In patients with cardia GC, only Hispanics had statistically significant lower risk of death from GC than Whites (sHR 0.84, 95% CI 0.74-0.95, p = 0.005).

CONCLUSIONS

The study of racial/ethnic survival disparities in patients with GC in Florida reveals Whites as the most disadvantaged group. Whites are more afflicted by cardia GC, which is associated with higher risk of death than non-cardia GC. However, even within non-cardia GC, Whites had higher risk of death than the other racial-ethnic groups. Commonly assessed survival determinants do not adequately explain these unusual disparities; thus, further investigation is warranted.

Analysis of the Incidence and Survival of Gastric Cancer Based on the Lauren Classification: A Large Population-Based Study Using SEER

Background: Limited evidence exists on the incidence of gastric cancer (GC), and contradictory results exist for the prognosis of GC based on the Lauren classification. We analyzed the incidence and survival of GC based on the Lauren classification. Methods: The Surveillance, Epidemiology, and End Results (SEER) database from 1975 through 2015 was used to identify all patients with surgically resected, histologically diagnosed intestinal or diffused-type GC. Propensity score matching was used to analyze the association between the Lauren classification type and prognosis. Results: The trend of total GC incidence showed an obvious decrease (APC = -1.51, 95% CI: -2.31 to -1.01) as well as that of the intestinal type (APC = -1.43, 95% CI: -2.01 to -1.12). However, we found that the relative incidence of the diffused type was increased (APC = 0.6, 95% CI: 0.41-0.82). The trend of the total incidence of GC (APC = -1.31, 95% CI: -1.91 to -1.03) and that of the intestinal type (APC = -1.11, 95% CI: -1.53 to -0.98) was decreased in 40-49-year-olds, but that of the diffused type was increased (APC = 1.5, 95% CI: 1.2-1.72). We found that trends in GC incidence exhibited a similar pattern in the regional and distant stages and showed a decrease from 1975 through 2015. However, the incidence rate of the local stage was increased, with an APC of 0.5 (95% CI: 0.3-0.7). We identified 15,989 GC cases from the SEER database, including 13,852 intestinal-type and 2,138 diffused-type cases. The 1,336 intestinal-type cases were matched with 1,336 diffused-type cases using propensity score matching (PSM), and patients with the diffused type had a better prognosis than patients with the intestinal type (HR = 0.56, 95% CI: 0.45-0.78). However, we found that patients with diffused-type GC had worse survival than patients with intestinal-type GC in the cohort from Renji Hospital (P < 0.001). Conclusion: The total incidence of GC and that of the intestinal-type GC decreased, but the incidence of diffused-type GC increased in 40-49-year-olds. Diffused types of GCs may have a different prognosis compared to intestinal-type GCs in different patient cohorts. Nevertheless, these results should be interpreted with caution in assessing the prognosis in combination with other factors.

A cohort study and meta-analysis of the evidence for consideration of Lauren subtype when prescribing adjuvant or palliative chemotherapy for gastric cancer

Background

The association between the survival or efficacy of chemotherapy and the Lauren subtype of gastric cancer (GC) remains unclear. We aimed to clarify whether patients with different Lauren subtypes have different survival after treatment with systemic chemotherapy: intestinal gastric cancer (IGC) patients survived better than patients with mixed type gastric cancer (MGC) or diffuse gastric cancer (DGC) after treatment with systemic chemotherapy.

Patients & methods

Relevant studies for the meta-analysis were identified through searching Pubmed, Embase, Cochrane and Ovid up to March 2020. We also included our own prospectively collected cohort of patients that were followed over a 10-year period. Sub-group and sensitivity analyses were also performed.

Results

In our prospective cohort, the overall survival (OS) of IGC patients receiving systemic chemotherapy (chemoIGC) [median OS 5.01 years, interquartile range (IQR) 2.63-6.71] was significantly higher than that of DGC patients receiving the same chemotherapy (chemoDGC) (median OS 1.33 years, IQR 0.78-3.33, p = 0.0001). After adjusting for age, gender and cancer stage, there was a significant difference in OS in patients treated with chemotherapy based on the Lauren classification of GC {hazard ratio (HR) for OS of the IGC versus DGC 0.33, [95% confidence interval (CI), 0.17-0.65; p < 0.001]}. In the IGC patients, the adjusted HR associated with chemotherapy was 0.26 (95% CI, 0.12-0.56; p = 0.001), whereas the association was 0.64 (95% CI, 0.30-1.33; p = 0.23) in the DGC patient group.In our meta-analysis, 33 studies comprising 10,246 patients treated with systemic chemotherapy (chemoIGC n = 4888, chemoDGC n = 5358) met all the selection criteria. While we accounted for much of the heterogeneity in these studies, we found that chemoIGC patients showed significantly improved OS [HR, 0.76 (95% CI, 0.71-0.82); p < 0.00001] when compared with similarly treated chemoDGC patients.

Conclusion

Our results support the consideration of Lauren subtype when prescribing systemic chemotherapy for GC, particularly for MGC or DGC, which may not benefit from chemotherapy. Lauren classification should be considered to stratify chemotherapy regimens to GC patients in future clinical trials, with particular relevance to MGC or DGC, which is more difficult to treat with current regimens.

The diffuse-type gastric cancer epidemiology enigma

Background

Intestinal and diffuse gastric adenocarcinomas differ in clinical, epidemiological and molecular features. However, most of the concepts related to the intestinal-type are translated to gastric adenocarcinoma in general; thus, the peculiarities of the diffuse-type are underappreciated.

Results

Besides its growing importance, there are many gaps about the diffuse-type carcinogenesis and, as a result, its epidemiologic and pathogenetic features remain poorly understood.

Conclusions

Alternative hypotheses to explain these features are discussed, including the role of the gastric microbiota, medical therapies, and modifications in the stomach’s microenvironment.

Treatment of Locally Advanced Gastric Cancer (LAGC): Back to Lauren's Classification in Pan-Cancer Analysis Era?

Background: Guidelines recommend a perioperative approach in patients with stage II/III gastric cancer, but in real-life many patients receive immediate surgery followed by adjuvant chemotherapy (aCT). Although histologic subtypes may have different response to CT, no study has explored the influence of histotype on the efficacy of perioperative CT (pCT) or aCT. Materials and methods: The objective of the study was to evaluate the impact of clinicopathological features and histology (intestinal or diffuse) on survival according to strategy (pCT vs. aCT). The primary endpoint was overall survival (OS) and the secondary endpoint was event-free survival (EFS). Results: Out of 203 patients affected by LAGC, 83 received pCT and 120 aCT. At multivariate, histology and LVI in pCT cohort and positive resection margin in the aCT influenced both OS and EFS. No difference in EFS and OS was observed in relation to strategy. However, in the intestinal-type of pCT cohort survival outcomes were significantly higher compared to the aCT cohort, whereas in the diffuse-type were significantly worse in patients receiving pCT compared to those receiving aCT. Conclusions: Although retrospective and small-sized, this study suggests that the benefit of pCT might be limited to the intestinal-type. This hypothesis needs to be confirmed in prospective series.

Claudin-6 is a single prognostic marker and functions as a tumor-promoting gene in a subgroup of intestinal type gastric cancer

BACKGROUND

We aimed to identify novel tumor-promoting drivers highly expressed in gastric cancer (GC) that contribute to worsened prognosis in affected patients.

METHODS

Genes whose expression was increased and correlated with worse prognosis in GC were screened using datasets from the Cancer Genome Atlas and Gene Expression Omnibus. We examined Claudin-6 (CLDN6) immunoreactivity in GC tissues and the effect of CLDN6 on cellular functions in GC cell lines. The mechanisms underlying GC-promoting function of CLDN6 were also investigated.

RESULTS

CLDN6 was identified as a gene overexpressed in GC tumors as compared with adjacent non-tumorous tissues and whose increased expression was positively correlated with worse overall survival of GC patients, particularly those with Lauren's intestinal type GC, in data from multiple publicly available datasets. Additionally, membranous CLDN6 immunoreactivity detected in intestinal type GC tumors was correlated with worse overall survival. In CLDN6-expressing GC cells, silencing of CLDN6 inhibited cell proliferation and migration/invasion abilities, possibly via suppressing transcription of YAP1 and its downstream transcriptional targets at least in part.

CONCLUSIONS

This study identified CLDN6 as a GC-promoting gene, suggesting that CLDN6 to be a possible single prognostic marker and promising therapeutic target for a subset of GC patients.

Hybrid Argon Plasma Coagulation for Treatment of Gastric Intestinal Metaplasia

Hybrid argon plasma coagulation (HybridAPC® [HAPC]) is an evolution of the standard argon plasma coagulation (APC) technology, where the application of APC is preceded by high-pressure needleless submucosal injection. APC is indicated for the ablation of benign and dysplastic mucosal lesions, such as vascular malformations or Barrett's mucosa. HAPC offers safety and efficacy advantages over standard APC because the submucosal injection acts as a heat sink that disperses energy. This ensures that the underlying muscularis propria remains unaffected, and only the mucosal layer is coagulated in its entirety. An 81-year-old Hispanic male was found to have a 1.2-cm mucosal nodule along the incisura of the stomach. Pathology of the biopsy specimen revealed high-grade dysplasia, and he subsequently underwent endoscopic ultrasound examination, which confirmed the presence of an isolated gastric nodule with no deep invasion of the muscularis propria, consistent with a uT1N0Mx endosonographic staging. He then underwent endoscopic submucosal dissection of the lesion. Pathology of the excised specimen confirmed the presence of multifocal high-grade dysplasia, arising in the background of extensive intestinal metaplasia. The deep margin was clear; however, the lateral resection margins showed focal involvement of intestinal metaplasia with low-grade dysplasia. Surveillance endoscopy confirmed the persistence of diffuse intestinal metaplasia. He was then treated with widespread HAPC due to the presence of underlying diffuse intestinal metaplasia in the stomach. HAPC is an effective and efficient treatment modality for mucosal lesions. In one series of 50 patients, 96% achieved complete macroscopic remission of Barrett's mucosa after a median of 3.5 APC sessions, and 85% achieved complete histological remission. HAPC is a promising therapeutic modality as a thermal injury is targeted, and the depth of injury is contained. This provides immediate procedural efficacy and safety benefits, and reduces subsequent complications when compared with standard APC. We anticipate that the applications of HAPC will continue to grow, as this modality is adopted into common procedural parlance. This case appears to be the first to describe the use of HAPC for definitive treatment of diffuse intestinal metaplasia.

Gastric Cancer with Radiographically Occult Metastatic Disease: Biology, Challenges, and Diagnostic Approaches

Gastric adenocarcinoma is an aggressive cancer that demonstrates heterogeneous biology depending on patient ethnicity, tumor location, tumor type, and genetic profile. It remains the third leading cause of cancer deaths worldwide and was estimated to result in 782,000 deaths in 2018. Challenges exist in accurately assessing the disease burden, as available radiological staging often underestimates metastatic disease. This diagnostic handicap, along with the poor understanding of the heterogeneous biology of gastric cancer, has hindered the development of effective therapeutic solutions and thus halted improvement in patient outcomes over the last few decades. The management of occult peritoneal disease is complicated, as most patients are understaged by standard imaging studies and therefore thought to have local diseases. In this article, we systematically review recent literature on the limitations that are associated with standard radiographic staging, discuss recent molecular biology advances to better identify and diagnose occult peritoneal disease, and propose possible management strategies to approach this complicated clinical problem.

Oligometastatic Gastroesophageal Adenocarcinoma: Molecular Pathophysiology and Current Therapeutic Approach

Gastric and esophageal cancers are dreaded malignancies, with a majority of patients presenting in either a locally advanced or metastatic state. Global incidences are rising and the overall prognosis remains poor. The concept of oligometastasis has been established for other tumor entities and is also proposed for upper gastrointestinal tract cancers. This review article explores metastasis mechanisms on the molecular level, specific to esophageal and gastric adenocarcinoma. Existing data and recent studies that deal with upper gastrointestinal tumors in the oligometastatic state are reviewed. Furthermore, current therapeutic targets in gastroesophageal cancers are presented and discussed. Finally, a perspective about future diagnostic and therapeutic strategies is given.

Histo- and immunohistochemistry-based estimation of the TCGA and ACRG molecular subtypes for gastric carcinoma and their prognostic significance: A single-institution study

Gastric cancers comprise molecularly heterogeneous diseases; four molecular subtypes were identified in the cancer genome atlas (TCGA) study, with implications in patient management. In our efforts to devise a clinically feasible means of subtyping, we devised an algorithm based on histology and five stains available in most academic pathology laboratories. This algorithm was used to subtype our cohort of 107 gastric cancer patients from a single institution (St. Michael’s Hospital, Toronto, Canada), which was divided into 3 cases of EBV-positive, 23 of MSI, 27 of GS and 54 of CIN tumours. 87% of the tumours with diffuse histology were classified as GS subtype, which was notable for younger age. Examining for characteristic molecular features, aberrant p53 immunostaining was seen most frequently in the CIN subtype (43% in CIN vs. 6% in others), whereas ARID1A loss was rarely seen (6% vs. 35% in others). HER2 overexpression was seen exclusively in CIN tumours (17% of CIN tumours). PD-L1 positivity was seen predominantly in the EBV and MSI tumours. As with the TCGA study, no survival differences were seen between the subtypes. A similar strategy was employed to approximate the Asian Cancer Research Group (ACRG) molecular subtyping, with the addition of p53 IHC to the algorithm. We observed rates of ARID1A loss and HER2 overexpression that were comparable to the ACRG study. In summary, our algorithm allowed for clinically feasible means of subtyping gastric carcinoma that recapitulated the key molecular features reported in the large scale studies.

Signet ring cell carcinoma and poorly differentiated adenocarcinoma in a gastric hyperplastic polyp with lymphatic invasion: A case report

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Gastric hyperplastic polyps can turn into adenocarcinoma.

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Very rarely they change into poorly differentiated adenocarcinoma.

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There have been no reports of these polyps transformed into poorly differentiated adenocarcinoma with lymphatic invasion.

Introduction

Gastric hyperplastic polyps are common stomach lesion and these polyps are generally benign. However, they can undergo malignant transformation. Most reported cases of malignant transformation of gastric hyperplastic polyps have been to well or moderately differentiated adenocarcinoma, and those transformed into poorly differentiated adenocarcinoma are extremely rare. No case has been reported that has changed to diffuse type adenocarcinoma with lymphatic invasion.

Presentation of case

A 48-year-old woman presented with worsening anemia. A polyp was seen in the gastric cardia seven years prior to presentation. Helicobacter pylori infection was also found at that time. She underwent upper gastrointestinal endoscopy and biopsy of the polyp revealed signet ring cell carcinoma. Total gastrectomy was performed due to concern about possible invasion into the submucosal layer and there was no evidence of distant metastases. Histologic examination revealed both poorly differentiated adenocarcinoma and signet ring cell carcinoma surrounded by hyperplastic epithelium at the head of the polyp. Lymphatic invasion was also found, and malignant cells were limited to the mucosa.

Discussion

Gastric hyperplastic polyps are commonly associated with chronic gastritis which is related to Helicobacter pylori infections. Gastric hyperplastic polyps are generally benign and rarely undergo malignant transformation to adenocarcinoma with differentiated histology. The gastric hyperplastic polyp in this patient transformed to poorly differentiated adenocarcinoma with lymphatic invasion.

Conclusion

Even small polyps may become poorly differentiated adenocarcinoma with invasion, so close follow-up or endoscopic resection are recommended as well as eradication of Helico Pylori infection when appropriate.

Predictive value of WHO classification for PD-L1 and Her2/Neu expression and distinct associations with protein expression based classification in gastric carcinoma

The Cancer Genome Atlas data on gastric carcinoma has identified four biologic pathways as potential drivers of gastric carcinogenesis and suggested targeted therapies based on the genomic alterations underscoring each subset. The correlation between morphology, biologic groups and their corresponding biomarkers has been eluded in several previous studies; however, a comprehensive analysis in consideration of the recent advancements has not been performed. In this study we explored the predictive value of morphology for biomarker expression and its association with protein expression based classification of gastric carcinoma. Four hundred eighty six gastric carcinomas which had been classified into protein expression-based groups formed the case cohort. Upon analysis, we found a low positive predictive value of an individual morphologic pattern for biomarker-expression, indicating that an individual morphologic pattern alone cannot predict PD-L1, Her2/neu expression and EBV- or MSI-gastric cancer. A combination approach targeting the test in certain WHO patterns can be employed for maximizing the positive predictive values. These include, PD-L1 testing in tubular, carcinoma with lymphoid stroma, undifferentiated and poorly cohesive patterns and Her2/neu testing in tubular, mixed, papillary, mucinous and solid patterns. The predictive values and morphologic associations presented here have the potential to select patients for personalized therapy.

Quality of Life in Vietnamese Gastric Cancer Patients

Background

Gastric cancer (GC) is one of the leading causes of cancer-related death in Vietnam. Research on health-related quality of life of Vietnamese gastric cancer patients is still in its infancy.

Aim

To assess the health-related quality of life (HRQOL) of GC patients using the 15D instrument.

Materials and Method

182 Vietnamese gastric cancer patients were selected to be interviewed and their HRQOL was assessed using the generic 15D questionnaire. Tables regarding history, disease characteristics, and HRQOL of participants were formulated according to genders using STATA 12.0.

Results

The average age of the participants was 60.8 ± 11.6. The average time from diagnosis to the date of interview was 14.8 ± 8.4 months. The health-related quality of life (HRQOL) index score of gastric cancer patients using the 15D instrument was 0.92 ± 0.08, in which the "sexual activity" dimension had the lowest score of 0.66. Also, our study found several factors affecting HRQOL, including age, occupation, education, disease stage, treatment, and time from the date of diagnosis.

Conclusion

The 15D instrument was a suitable tool to assess Vietnamese gastric cancer patients' quality of life. Findings from the study suggest the importance of frequently measuring personal functioning and performance of GC patients as parts of QOL assessment during clinical examination. It also implies the needs for more focused policies on raising the overall quality of life of patients such as encouragement of periodical HQROL assessment and acknowledging HRQOL as a treatment/intervention goal besides the 5-year survival rate.

Prognostic and Predictive Factors for the Curative Treatment of Esophageal and Gastric Cancer in Randomized Controlled Trials: A Systematic Review and Meta-Analysis

BACKGROUND

An overview of promising prognostic variables and predictive subgroups concerning the curative treatment of esophageal and gastric cancer from randomized controlled trials (RCTs) is lacking. Therefore, we conducted a systematic review and meta-analysis.

METHODS

PubMed, EMBASE, CENTRAL, and ASCO/ESMO conferences were searched up to March 2019 for RCTs on the curative treatment of esophageal or gastric cancer with data on prognostic and/or predictive factors for overall survival. Prognostic factors were deemed potentially clinically relevant according to the following criteria; (1) statistically significant (p < 0.05) in a multivariate analysis, (2) reported in at least 250 patients, and (3) p < 0.05, in ≥ 33% of the total number of patients in RCTs reporting this factor. Predictive factors were potentially clinically-relevant if (1) the p-value for interaction between subgroups was <0.20 and (2) the hazard ratio in one of the subgroups was significant (p < 0.05).

RESULTS

For gastric cancer, 39 RCTs were identified (n = 13,530 patients) and, for esophageal cancer, 33 RCTs were identified (n = 8618 patients). In total, we identified 23 potentially clinically relevant prognostic factors for gastric cancer and 16 for esophageal cancer. There were 15 potentially clinically relevant predictive factors for gastric cancer and 10 for esophageal cancer.

CONCLUSION

The identified prognostic and predictive factors can be included and analyzed in future RCTs and be of guidance for nomograms. Further validation should be performed in large patient cohorts.

Perioperative Treatment in Resectable Gastric Cancer: Current Perspectives and Future Directions

Gastric cancer (GC) is the fifth-most common cancer worldwide and an important cause of cancer-related-death. The growing knowledge of its molecular pathogenesis has shown that GC is not a single entity, but a constellation of different diseases, each with its own molecular and clinical characteristics. Currently, surgery represents the only curative approach for localized GC, but only 20% of patients (pts) showed resectable disease at diagnosis and, even in case of curative resection, the prognosis remains poor due to the high rate of disease relapse. In this context, multimodal perioperative approaches were developed in western and eastern countries in order to decrease relapse rates and improve survival. However, there is little consensus about the optimal treatment for non-metastatic GC. In this review, we summarize the current status and future developments of perioperative chemotherapy in resectable GC, attempting to find clear answers to the real problems in clinical practice.

Diverse Expression of IL-32 in Diffuse and Intestinal Types of Gastric Cancer

Introduction

Gastric cancer (GC) represents one of the most common cancers worldwide, frequently diagnosed at advanced stages with poor prognosis, indicating on need for new diagnostic and prognostic markers. The aim of the study was to determine the expression of IL-32, proinflammatory and angiogenic mediators, in patients with diffuse and intestinal gastric cancer and the relationship with clinicopathological aspects.

Material and Methods

The tissue samples of diffuse and intestinal types of tumor of 70 patients with gastric cancer were analyzed. Expression of IL-32, VEGF, IL-17, and CD31 was measured by immunohistochemistry.

Results

IL-32 expression was significantly lower in tissue samples from patients with diffuse type of gastric cancer that is also a severe and more progressive form (TNM stages III and IV, poor histological differentiation, and higher nuclear grade III). Expression of IL-17 was also decreased in patients with diffuse type of gastric cancer. Microvascular density was diminished in diffuse type of gastric cancer.

Conclusions

Downregulated expression of IL-32 in tumor tissue of patients with diffuse type of gastric cancer may implicate on its role in limiting ongoing proinflammatory and proangiogenic processes. This emphasizes on unrecognized role of IL-32 in biology of diffuse type of gastric cancer.

Acetylcholine induces stem cell properties of gastric cancer cells of diffuse type

Gastric cancer is the third leading cause of cancer-related death worldwide, but the mechanisms of gastric carcinogenesis are not completely understood. Recently, the role of cholinergic neuronal pathways in promoting this process has been demonstrated. Our aim was to extend these studies and to evaluate, using an in vitro model of tumorspheres, the effect of acetylcholine on human gastric cancer cells, and the role of acetylcholine receptors and of the nitric oxide pathway, in this effect. The gastric cancer cell line MKN-45 of the diffuse type of gastric cancer was cultured in the presence of acetylcholine, or different agonists or inhibitors of muscarinic and nicotinic acetylcholine receptors, or nitric oxide donor or inhibitor of the nitric oxide pathway, and the number and size of tumorspheres were assessed. The expression of cancer stem cell markers (CD44 and aldehyde dehydrogenase) was also evaluated by immunofluorescence and quantitative reverse transcription polymerase chain reaction. We showed that acetylcholine increased both the number and size of tumorspheres and that this effect was reproduced with both muscarinic and nicotinic acetylcholine receptors agonists and was inhibited by both receptor antagonists. The nitric oxide donor stimulated the tumorsphere formation, while the nitric oxide synthesis inhibitor inhibited the stimulatory effect of acetylcholine. Moreover, acetylcholine increased the expression of stem cell markers on gastric cancer cells. These results indicate that acetylcholine induces the stem cell properties of gastric cancer cells and both muscarinic and nicotinic receptors and a nitrergic pathway might be involved in this effect.

Circulating microRNA-22-3p Predicts the Malignant Progression of Precancerous Gastric Lesions from Intestinal Metaplasia to Early Adenocarcinoma

BACKGROUND

Gastric cancer has a poor outcome and identifying useful biomarkers from peripheral blood or tissue could allow its early detection, or potentially precancerous changes, thus improving the curative rates. MicroRNAs (miRNAs) have been shown to offer great potential in cancer diagnosis and prediction.

AIM

Here, we investigated the role of plasma miRNAs in the natural course of gastric cancer, from intestinal metaplasia to early cancer. The findings were used to understand whether patients at a high risk of malignancy could be given appropriate interventions in the early disease process, such as using endoscopic submucosal dissection to treat gastric dysplasia or early gastric cancer.

METHODS

Participants were divided into healthy control, intestinal metaplasia (IM), and dysplasia/early cancer (pT1a/b) groups. Microarray was used to select potential markers in tissue.

RESULTS

Quantitative real-time polymerase chain reaction data showed circulating miRNA-22-3p had significantly different expression in patients with precancerous lesions or gastric adenocarcinoma. The areas under the curve of incomplete IM versus healthy control, low-grade/high-grade dysplasia, early gastric cancer, and GED were 0.8080, 0.8040, 0.8494, and 0.8095, respectively (all P values < 0.05).

CONCLUSIONS

Circulating miRNA-22-3p could be a potential biomarker for gastric precancerous dysplasia and early cancer detection.

Towards precision medicine: linking genetic and cellular heterogeneity in gastric cancer

Molecular and cellular heterogeneity are phenomena that are revolutionizing oncology research and becoming critical to the idea of personalized medicine. Recent comprehensive molecular profiling has identified molecular subtypes of gastric cancer (GC) and linked them to clinical information. Moreover, GC stem cells (gCSCs) have been identified and found to be responsible for GC initiation and progression, Helicobacter pylori oncogenic action and therapy resistance. Addressing molecular heterogeneity is critical for achieving an optimal therapeutic approach against GC as well as targeting gCSCs. In this review, we outline the implications of molecular and cellular heterogeneity in the treatment of GC and we summarize the clinical impact of the most important regulators of gCSCs.

Molecular biomarkers in gastro-esophageal cancer: recent developments, current trends and future directions

Gastro-esophageal adenocarcinomas (GEA) represent a severe global health burden and despite improvements in the multimodality treatment of these malignancies the prognosis of patients remains poor. HER2 overexpression/amplification has been the first predictive biomarker approved in clinical practice to guide patient selection for targeted treatment with trastuzumab in advanced gastric and gastro-esophageal junction cancers. More recently, immunotherapy has been approved for the treatment of GEA and PD-L1 expression is now a biomarker required for the administration of pembrolizumab in these diseases. Significant progress has been made in recent years in dissecting the genomic makeup of GEA in order to identify distinct molecular subtypes linked to distinct patterns of molecular alterations. GEA have been found to be highly heterogeneous malignances, representing a challenge for biomarkers discovery and targeted treatment development. The current review focuses on an overview of established and novel promising biomarkers in GEA, covering recent molecular classifications from TCGA and ACRG. Main elements of molecular heterogeneity are discussed, as well as emerging mechanisms of primary and secondary resistance to HER2 targeted treatment and recent biomarker-driven trials. Future perspectives on the role of epigenetics, miRNA/lncRNA and liquid biopsy, and patient-derived xenograft models as a new platform for molecular-targeted drug discovery in GEA are presented. Our knowledge on the genomic landscape of GEA continues to evolve, uncovering the high heterogeneity and deep complexity of these tumors. The availability of new technologies and the identification of promising novel biomarker will be critical to optimize targeted treatment development in a setting where therapeutic options are currently lacking. Nevertheless, clinical validation of novel biomarkers and treatment strategies still represents an issue.