Surgical treatment results of intestinal and diffuse type gastric cancer. Implications for a differentiated therapeutic approach?

Chinese national clinical practice guidelines on the prevention, diagnosis, and treatment of early gastric cancer

BACKGROUND

Gastric cancer is one of the most common malignant tumors in the digestive system in China. Few comprehensive practice guidelines for early gastric cancer in China are currently available. Therefore, we created the Chinese national clinical practice guideline for the prevention, diagnosis, and treatment of early gastric cancer.

METHODS

This clinical practice guideline (CPG) was developed in accordance with the World Health Organization's recommended process and with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) in assessing evidence quality. We used the Evidence to Decision framework to formulate clinical recommendations to minimize bias and increase transparency in the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and the Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guidelines to ensure completeness and transparency of the CPG.

RESULTS

This CPG contains 40 recommendations regarding the prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer based on available clinical studies and guidelines. We provide recommendations for the timing of Helicobacter pylori eradication, screening populations for early gastric cancer, indications for endoscopic resection and surgical gastrectomy, follow-up interval after treatment, and other recommendations.

CONCLUSIONS

This CPG can lead to optimum care for patients and populations by providing up-to-date medical information. We intend this CPG for widespread adoption to increase the standard of prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer; thereby, contributing to improving national health care and patient quality of life.

Effect of preoperative chemotherapy on the histopathological classification of gastric cancer

BACKGROUND

In the era of individualized gastric cancer (GC) treatment, accurate determination of histological subtype becomes increasingly relevant. As yet, it is unclear whether preoperative chemotherapy may affect the histological subtype. The aim of this study was to assess concordance in histological subtype between pretreatment biopsies and surgical resection specimens before and after the introduction of perioperative treatment.

METHODS

Histological subtype was centrally determined in paired GC biopsies and surgical resection specimens of patients treated with either surgery alone (SA) in the Dutch D1/D2 study or with preoperative chemotherapy (CT) in the CRITICS trial. The histological subtype as determined in the resection specimen was considered the gold standard. Concordance rates and sensitivity and specificity of intestinal, diffuse, mixed, and "other" subtypes of GC were analyzed.

RESULTS

In total, 105 and 515 pairs of GC biopsies and resection specimens of patients treated in the SA and CT cohorts, respectively, were included. Overall concordance in the histological subtype was 72% in the SA and 74% in the CT cohort and substantially higher in the diffuse subtype (83% and 86%) compared to the intestinal (70% and 74%), mixed (21% and 33%) and "other" subtypes (54% and 54%). In the SA cohort, sensitivities and specificities were 0.88 and 0.71 in the intestinal, 0.67 and 0.93 in the diffuse, 0.20 and 0.98 in the mixed, and 0.50 and 0.93 in the "other" subtypes, respectively.

CONCLUSION

Our results suggest that accurate determination of histological subtype on gastric cancer biopsies is suboptimal but that the impact of preoperative chemotherapy on histological subtype is negligible.

A Retrospective Analysis of the Lauren Classification in the Choice of XELOX or SOX as an Adjuvant Chemotherapy for Gastric Cancer

BACKGROUND

We aim to retrospectively explore the guiding value of the Lauren classification for patients who have undergone D2 gastrectomy to choose oxaliplatin plus capecitabine (XELOX) or oxaliplatin plus S-1 (SOX) as a further systemic treatment after the operation.

METHODS

We collected data of 406 patients with stage III gastric cancer(GC)after radical D2 resection and regularly received XELOX or SOX adjuvant treatment after surgery and followed them for at least five years. According to the Lauren classification, we separated patients out into intestinal type (IT) GC together with non-intestinal type(NIT) GC. According to the chemotherapy regimen, we separated patients into the SOX group together with the XELOX group.

RESULTS

Among non-intestinal type patients, the 3-year DFS rates in the SOX group and the XELOX group were 72.5%, respectively; 54.5% (P=0.037); The 5-year OS rates were 66.8% and 51.8% respectively (P=0.038), both of which were statistically significant.

CONCLUSION

The patients of non-intestinal type GC may benefit from the SOX regimen. Differences were counted without being statistically significant with intestinal-type GC in the SOX or XELOX groups.

Incidence, clinicopathological characteristics, and therapeutic strategy for gastric cancer patients with metastasis to the central nervous system

AIM

This study aimed to analyze the clinicopathologic features and treatment outcomes of central nervous system (CNS) metastasis from gastric cancer.

METHODS

A total of 419 patients diagnosed with unresectable advanced or recurrent gastric cancer at Kochi Medical School between January 2007 and December 2021 were evaluated. Data of patients were reviewed, and clinicopathological information and survival outcomes of those with CNS metastases were compared to patients without CNS metastases.

RESULTS

In total, 12/419 (2.9%) patients (median age: 66.5 years [range, 41-82 years]) were diagnosed with CNS metastasis from gastric cancer. Eleven had diffuse-type gastric cancer which was significantly more common than in those without CNS metastasis (91% vs. 61%, p = .034). Human epidermal growth factor receptor 2 status was positive in one of the 12 patients. The median survival time was significantly lower for patients with CNS metastasis than for those without CNS metastasis (1.8 months vs. 11.4 months, p < .001). The median survival time for patients who underwent surgical resection, radiation, or chemotherapy for CNS metastasis was significantly higher than those who received only best supportive care (3.5 months vs. .6 months; p = .007).

CONCLUSIONS

CNS metastasis was found in 2.9% (12/419) of patients with unresectable advanced or recurrent gastric cancer. Diffuse-type histology was a risk factor for CNS metastasis. Multidisciplinary treatment, including surgical resection, radiation treatment, or chemotherapy, for CNS metastasis from gastric cancer may benefit selected patients.

Impact of positive microscopic resection margins (R1) after gastrectomy in diffuse-type gastric cancer

INTRODUCTION

Diffuse-type gastric cancer (DTGC) is associated with poor outcome. Surgical resection margin status (R) is an important prognostic factor, but its exact impact on DTGC patients remains unknown. The aim of this study was to assess the prognostic value of microscopically positive margins (R1) after gastrectomy on survival and tumour recurrence in DTGC patients.

METHODS

All consecutive DTGC patients from two tertiary centers who underwent curative oncologic gastrectomy from 2005 to 2018 were analyzed. The primary endpoint was overall survival (OS) for R0 versus R1 patients. Secondary endpoints included disease-free survival (DFS), recurrence patterns as well as the overall survival benefit of chemotherapy in this DTGC patient cohort.

RESULTS

Overall, 108 patients were analysed, 88 with R0 and 20 with R1 resection. Patients with negative lymph nodes and negative margins (pN0R0) had the best OS (median 102 months, 95% CI 1-207), whereas pN + R0 patients had better median OS than pN + R1 patients (36 months 95% CI 13-59, versus 7 months, 95% CI 1-13, p < 0.001). Similar findings were observed for DFS. Perioperative chemotherapy offered a median OS of 46 months (95% CI 24-68) versus 9 months (95% CI 1-25) after upfront surgery (p = 0.022). R1 patients presented more often early recurrence (< 12 postoperative months, 30% vs 8%, p = 0.002), however, no differences were observed in recurrence location.

CONCLUSION

DTGC patients with microscopically positive margins (R1) presented poorer OS and DFS, and early tumour recurrence in the present series. R0 resection should be obtained whenever possible, even if other adverse biological features are present.

Oncological impact of unexpected horizontal tumor spread in gastric cancer that requires total gastrectomy

BACKGROUND

Gastric cancer often exhibits discrepancies between the gross and pathological tumor boundaries, and the degree of discrepancy may be a tumor characteristic. However, whether these discrepancies influence oncological outcomes remains unclear.

METHODS

The data of patients who underwent total gastrectomy for gastric cancer from 2005 to 2018 were collected. A new parameter, ΔPM, which corresponds to the length of the discrepancy between the gross and pathological proximal boundaries, was calculated and the patients were divided into two groups: patients with long ΔPM and those with short ΔPM. Oncological outcomes were compared between the two groups.

RESULTS

A length of 8 mm was determined as the cutoff value for long or short ΔPM. Tumor size, growth pattern, pathological type, depth, and esophageal invasion were associated with ΔPM > 8 mm. Overall survival of the ΔPM > 8 mm group was significantly worse than that of the ΔPM ≤ 8 mm group (5-year overall survival: 58% vs 78%; p < 0.0001). Multivariate analysis revealed that ΔPM > 8 mm was an independent risk factor for poor survival and peritoneal metastasis. The likelihood ratio test revealed a significant interaction between pT status and ΔPM (p = 0.0007). Circumferential involvement and gross esophageal invasion were poorer survival factors in the ΔPM > 8 mm group.

CONCLUSIONS

ΔPM > 8 mm is related to several clinicopathological characteristics and is an independent risk factor for poorer survival and peritoneal metastasis but not local recurrence. ΔPM > 8 mm combined with circumferential involvement or esophageal invasion is associated with relatively poor survival outcomes.

Sleep Duration and Stress Level in the Risk of Gastric Cancer: A Pooled Analysis of Case-Control Studies in the Stomach Cancer Pooling (StoP) Project

The association between sleep and stress and cancer is underinvestigated. We evaluated these factors in association with gastric cancer (GC). Five case-control studies from the Stomach Cancer Pooling (StoP) Project were included. We calculated the odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) for sleep duration and stress level in association with GC through multiple logistic regression models adjusted for several lifestyle factors. The analysis included 1293 cases and 4439 controls, 215 cardia and 919 noncardia GC, and 353 diffuse and 619 intestinal types. Sleep duration of ≥9 h was associated with GC (OR =1.57, 95% CI = 1.23-2.00) compared to 8 h. This was confirmed when stratifying by subsite (noncardia OR = 1.59, 95% CI = 1.22-2.08, and cardia OR = 1.63, 95% CI = 0.97-2.72) and histological type (diffuse OR = 1.65, 95% CI = 1.14-2.40 and intestinal OR = 1.24, 95% CI = 0.91-1.67). Stress was associated with GC (OR = 1.33, 95% CI = 1.18-1.50, continuous). This relationship was selectively related to noncardia GC (OR = 1.28, 95% 1.12-1.46, continuous). The risk of diffuse (OR = 1.32, 95% CI = 1.11-1.58) and intestinal type (OR = 1.23, 95% CI = 1.07-1.42) were higher when stress was reported. Results for the association between increasing level of stress and GC were heterogeneous by smoking and socioeconomic status (p for heterogeneity = 0.02 and <0.001, respectively). In conclusion, long sleep duration (≥9 h) was associated with GC and its subtype categories. Stress linearly increased the risk of GC and was related to noncardia GC.

Exploring potential molecular resistance and clonal evolution in advanced HER2-positive gastric cancer under trastuzumab therapy

HER2-positive gastric cancer (GC) makes up 15-20% of all GC incidences, and targeted therapy with trastuzumab is the standard of treatment. However, the mechanisms of resistance to trastuzumab are still not fully understood and presents a significant challenge in clinical practice. In this study, whole exome sequencing (WES) was performed on paired tumor tissues before trastuzumab treatment (at baseline) and at progressive disease (PD) in 23 GC patients. Clinicopathological and molecular features that may be associated with primary and/or acquired resistance to trastuzumab were identified. Lauren classification of intestinal type was associated with a more prolonged progression-free survival (PFS) than diffuse type (HR = 0.29, P = 0.019). Patients with low tumor mutation burden (TMB) showed significantly worse PFS, while high chromosome instability (CIN) was correlated with prolonged OS (HR = 0.27; P = 0.044). Patients who responded to treatment had a higher CIN than nonresponders, and a positive trend towards increasing CIN was observed as response improved (P = 0.019). In our cohort, the most common genes to acquire mutations are AURKA, MYC, STK11, and LRP6 with four patients each. We also discovered an association between clonal branching pattern and survival, with an extensive clonal branching pattern being more closely related to a shorter PFS than other branching patterns (HR = 4.71; P = 0.008). We identified potential molecular and clinical factors that provide insight regarding potential association to trastuzumab resistance in advanced HER2-positive GC patients.

RhoA G17E/Vav1 Signaling Induces Cancer Invasion via Matrix Metalloproteinase-9 in Gastric Cancer

BACKGROUND

RAS homolog family member A (RhoA), a member of the Rho family of small GTPases, and Vav1, a guanine nucleotide exchange factor for Rho family GTPases, have been reported to activate pathways related to the actin cytoskeleton and regulation of cell shape, attachment, and motility. The interaction between these molecules in lymphoma is involved in malignant signaling, but its function in epithelial malignancy is unknown. Here, we investigated the malignant signal of mutant RhoA in gastric cancer and demonstrated the potential of RhoA G17E/Vav1 as a therapeutic target for diffuse gastric cancer.

METHODS

The RhoA mutants R5W, G17E, and Y42C were retrovirally transduced into the gastric cancer cell line MKN74. The stably transduced cells were used for morphology, proliferation, and migration/invasion assays in vitro. MKN74 cells stably transduced with ectopic wild-type RhoA and mutant RhoA (G17E) were used in a peritoneal xenograft assay.

RESULTS

The RhoA mutations G17E and Y42C induced morphological changes in MKN74. G17E induced Vav1 expression at the mRNA and protein levels and promoted the migration and invasion of MKN74. An RNA interference assay of Vav1 revealed that RhoA G17E enhanced cancer cell invasion via Vav1. Furthermore, immunoprecipitation revealed that Vav1 and RhoA G17E specifically bind and function together through matrix metalloproteinase -9. In a peritoneal xenograft model of nude mice, RhoA G17E promoted peritoneal dissemination, whereas Vav1 knockdown suppressed it.

CONCLUSION

Overall, our findings indicate that RhoA G17E is associated with Vav1 and promoted cancer invasion via matrix metalloproteinase -9 in gastric cancer cells. Thus, RhoA G17E/Vav1 signaling in diffuse gastric cancer may be a useful therapeutic target.

Prevention and treatment of a positive proximal margin after gastrectomy for cardia cancer

A tumour-positive proximal margin (PPM) after extended gastrectomy for oesophagogastric junction (OGJ) adenocarcinoma is observed in approximately 2-20% of patients. Although a PPM is an unfavourable prognostic factor, the clinical relevance remains unclear as it may reflect poor tumour biology. This narrative review analyses the most relevant literature on PPM after gastrectomy for OGJ cancers. Awareness of the risk factors and possible measures that can be taken to reduce the risk of PPM are important. In patients with a PPM, surgical and non-surgical treatments are available but the effectiveness remains unclear.

Hereditary Diffuse Gastric Cancer: A 2022 Update

Gastric cancer is ranked fifth among the most commonly diagnosed cancers, and is the fourth leading cause of cancer-related deaths worldwide. The majority of gastric cancers are sporadic, while only a small percentage, less than 1%, are hereditary. Hereditary diffuse gastric cancer (HDGC) is a rare malignancy, characterized by early-onset, highly-penetrant autosomal dominant inheritance mainly of the germline alterations in the E-cadherin gene (CDH1) and β-catenin (CTNNA1). In the present study, we provide an overview on the molecular basis of HDGC and outline the essential elements of genetic counseling and surveillance. We further provide a practical summary of current guidelines on clinical management and treatment of individuals at risk and patients with early disease.

Clinicopathological differences, risk factors and prognostic scores for western patients with intestinal and diffuse-type gastric cancer

BACKGROUND

In the molecular era, the Laurén system is still a cost-effective and widely implemented classification for gastric cancer (GC) and it has been recently associated with clinical, histological and molecular features of these tumors. Despite recent advances in the understanding of the molecular biology of GC, there is a need to develop new prognostic tools for patient stratification in clinical practice. Thus, the identification of easily available prognostic factors in patients with intestinal and diffuse-type tumors can significantly improve risk assessment and patient stratification in GC.

AIM

To identify clinicopathological differences, risk factors, and to develop cost-effective prognostic scores for patients with intestinal and diffuse-type GC.

METHODS

Retrospective study of all patients undergoing surgery for GC at a tertiary referral center from 2001 to 2019. 286 cases met inclusion criteria (intestinal: 190, diffuse: 96). Clinical data and gross findings were collected. All specimens were reviewed by two independent pathologists and a detailed protocol for histologic evaluation was followed. Five tissue microarrays (TMAs) were constructed and sections of the TMA block were immunostained for HERCEPTEST, MSH2, MSH6, MLH1 and PMS2. Statistical analyses were performed and prognostic scores were developed based on hazard ratios.

RESULTS

Intestinal and diffuse-type GC showed different epidemiological, clinicopathological and prognostic features. Diffuse tumors were significantly associated with younger age, less symptomatology, flat morphology, deeper invasion, perineural infiltration, advanced stage at diagnosis, administration of adjuvant therapy and poorer prognosis. Intestinal lesions were fungoid or polypoid, showed necrosis, desmoplasia, microsatellite instability and HERCEPTEST positivity and were diagnosed at earlier stages. Tumor depth, desmoplasia, macroscopic type and lymph node involvement were independently related to the Laurén subtype. Furthermore, intestinal and diffuse GC were associated with different risk factors for progression and death. Vascular invasion, perineural infiltration and growth pattern were important prognostic factors in intestinal-type GC. On the contrary, tumor size and necrosis were significant prognosticators in diffuse-type GC. Our recurrence and cancer-specific death scores for patients with intestinal and diffuse-type GC showed an excellent patient stratification into three (diffuse GC) or four (intestinal) prognostic groups.

CONCLUSION

Our findings support that Laurén subtypes represent different clinicopathological and biological entities. The development of specific prognostic scores is a useful and cost-effective strategy to improve risk assessment in GC.

Multimodal treatment in oligometastatic gastric cancer

Gastric cancer is generally diagnosed at an advanced stage, especially in countries without screening programs. Previously, the metastatic stage was synonymous with palliative management, and surgical indications were only for symptomatic relief. However, this therapeutic option is associated with poor prognosis. A subgroup of patients with limited metastatic disease could benefit from intensive treatment. A combination of chemotherapy, immunotherapy, and targeted therapy could help either maintain a resectable state for oligometastatic disease or diminish the metastasis size to obtain a complete resection configuration. This latter strategy is known as conversion therapy and has growing evidence with favorable outcomes. Oncosurgical approach of metastatic disease could prolong survival in selected patients. The challenge for the surgeon and oncologist is to identify these specific patients to offer the best multimodal management. We review in this article the actual evidence for the treatment of oligometastatic gastric cancer with curative intent.

Risk factors and oncological impact of positive resection margins in gastrectomy for cancer: are they salvaged by an additional resection?

BACKGROUND

The situation of positive resection margins (PRMs) varies notably between Western and Asian countries. In the West, PRMs are associated with advanced disease and R1, whereas in Asia, PRMs are also considered in early disease because stomach preservation was recently prioritized. Furthermore, PRMs are usually resected to obtain R0. However, the oncological impact of PRMs and additional resection remains unclear. The aim of this study is to evaluate the oncological impact of PRMs in laparoscopic gastrectomy (LG) for clinical stage (cStage) I gastric cancer.

METHODS

A total of 2121 patients who underwent LG for cStage I gastric cancer between 2007 and 2015 were enrolled. Survival outcomes were compared between patients with PRMs (group P) and those without (group N). Furthermore, prognostic factors were analyzed using multivariate analysis.

RESULTS

Twenty-seven patients (1.3%) had PRMs. Patients in group P had upper and more advanced disease, and the 5-year relapse-free survival (RFS) rate was worse in group P compared with group N (76.3% vs. 95.1%, P = 0.003). The 5-year RFS of patients with pT2 or deeper (pT2-4) disease in group P was significantly worse than that of patients in group N (66.7% vs. 89.5%, P = 0.030) although that of patients with pT1 was not. Likelihood ratio tests showed that there was a significant interaction between pT status and PRM (P = 0.005).

CONCLUSION

PRM in cStage I gastric cancer is associated with advanced upper disease. It remains an independent prognostic factor in pT2-4 disease even after an additional resection to obtain R0.

Quantitative difference of oral pathogen between individuals with gastric cancer and individuals without cancer

The loss of teeth and lack of oral hygiene have been associated with the risk of developing gastric cancer (GC) in several populations evidenced in epidemiological studies. In this study, we quantitatively compared the proportion of oral pathogens in individuals with gastric cancer and individuals without cancer in a referral hospital in the city of Belém, Brazil. This study evaluated 192 patients with GC and 192 patients without cancer. Periodontal clinical examination was performed, and all individuals were submitted to the collection of salivary and dental biofilms. When comparing the median periodontal indexes in the gastric and cancer-free groups, it was statistically significant (p < 0.001) in the gastric cancer group compared to the probing depth of the periodontal pocket. Levels of bacterial DNA were observed in saliva and dental plaque, with a statistically significant difference (p < 0.001) between individuals with cancer and without neoplasia in all the bacteria surveyed. Significant relationships (p < 0.001) between biological agents and GC have been found in bacterial species that cause high rates of periodontal pathology and caries. The results suggest a different quantitative association in the presence of oral pathogens between individuals without cancer and patients with GC. As noted, it cannot be said that the bacteria present in the oral cavity increase the risk of gastric cancer or are aggravating factors of the disease. However, it is worth mentioning that, as it is part of the digestive system, the lack of care for the oral cavity can negatively affect the treatment of patients with gastric cancer.

Grossing of Gastrointestinal Specimens: Best Practices and Current Controversies

The proper handling of the gross specimen is imperative, as it is the most important first step in providing excellent patient care. Our diagnoses depend on the correct description and submission of tissue sections for histologic analysis. A logical and problem-solving approach to handling the gross specimen is presented.

Diagnostic and therapeutic potencies of miR-18a-5p in mixed-type gastric adenocarcinoma

Mixed-type gastric adenocarcinoma (by Lauren Classification) has poor clinical outcomes with few targeted treatment options. The primary objective of this study was to find the prognostic factors, accurate treatment approaches, and effective postoperative adjuvant therapy strategies for patients with mixed-type gastric adenocarcinoma (GA). A microRNA sequencing data set and the corresponding clinical parameters of patients with gastric cancer were obtained from The Cancer Genome Atlas. Differentially expressed microRNAs (DEMs) of diffuse- and intestinal-type GA were, respectively, determined. Kaplan-Meier and log-rank tests were subsequently carried out to evaluate the prognostic relevance of each DEM. To study the common factors between diffuse- and intestinal-type GA, a pathway enrichment analysis was performed on the target genes of identified DEMs using the PANTHER database. After data preprocessing, we analyzed a total of 230 samples from 210 patients with GA. Eighty-six DEMs in diffuse-type GA samples and 59 DEMs in intestinal-type GA samples were, respectively, identified (p  2.0). The Kaplan-Meier survival method further screened out six prognosis-related DEMs for diffuse-type GA and seven prognosis-related DEMs for intestinal-type GA (p < 0.05). MiR-18a-5p was found to be the only common prognosis-related DEM between diffuse- and intestinal-type GA. The common signaling pathways further revealed that target genes of miR-18a-5p are involved in mixed-type GA progression. This study suggests that miR-18a-5p acts as a potential target for treatment, and common signal pathways provide a rich basis to seek reliable and effective molecular targets for the diagnosis, clinical treatment, and postoperative adjuvant therapy strategy of mixed-type GA.

Genetic Gastric Cancer Risk Syndromes

Purpose of review

Gastric cancer is a leading cause of cancer death in the world. Between 1% and 3% of cases are associated with specific genetic cancer risk syndromes. The purpose of this article is to review the latest insights, as well as gaps in knowledge, regarding some of the most common hereditary gastric cancer syndromes: hereditary diffuse gastric cancer (HDGC), gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS), Lynch syndrome, the adenomatous polyposis syndromes, and the hamartomatous polyposis syndromes.

Recent findings

Patients carrying pathogenic variants in CDH1, but not meeting clinical criteria for HDGC, are increasingly being identified thanks to multigene panel testing; their absence from previous analyses overestimated gastric cancer penetrance. GAPPS is a recently described hereditary gastric cancer syndrome associated with specific point mutations in the promoter 1B region of the APC gene.

Summary

Risk of gastric cancer is highest among carriers of pathogenic variants in CDH1, with cumulative incidences approximately 40% and 30% for men and women, respectively. Mutations associated with Lynch syndrome and adenomatous polyposis syndromes confer greatest risk for gastric cancer in East Asian populations. Risk of gastric cancer in GAPPS and hamartomatous polyposis syndromes is difficult to estimate due to their rarity, but mutation status likely determines risk. Future research is needed to more precisely define risk of gastric cancer in these syndromes, so strategies for screening and prophylactic gastrectomy can be optimized.

A population-based study on intestinal and diffuse type adenocarcinoma of the oesophagus and stomach in the Netherlands between 1989 and 2015

AIM

To investigate the nationwide time trends in incidence and survival of oesophageal and gastric adenocarcinomas according to the Laurén classification (intestinal, diffuse and mixed type).

METHODS

All patients diagnosed in the Netherlands with oesophageal or gastric adenocarcinoma between 1989 and 2015 were included. A syntax was developed to determine the histological subtype based on pathology reports as archived in the Dutch pathology registry. These reports were linked to individual data from the Netherlands Cancer Registry. Relative survival was used to assess survival.

RESULTS

The histological subtype could be determined in 18.691 (84.1%) oesophageal and in 32.312 (83.5%) gastric adenocarcinomas. Among these, 79% were intestinal and 21% diffuse type in oesophageal cancers, compared to 55% intestinal and 44% diffuse type in gastric cancers. Relative median survival of intestinal type tumours was longer than that of diffuse type tumours, that is, 12.1 versus 9.4 months for oesophageal carcinomas, and 10.1 versus 7.6 months for gastric carcinomas, respectively. Between 1989 and 2015, the relative median survival of non-metastatic intestinal and diffuse type oesophageal adenocarcinoma improved from 12.0 to 30.0 months, and from 12.0 to 19.2 months, respectively. The same was true for intestinal type gastric carcinoma (from 22.8 to 27.6 months) but for diffuse type gastric carcinoma, the increase was less (from 16.8 to 18.0 months).

CONCLUSION

In this nationwide study, histological subtypes of oesophageal and gastric adenocarcinomas differed in incidence and survival times. These findings may call for a differentiated treatment approach.

GEFT protein expression in digestive tract malignant tumors and its clinical significance

Guanine nucleotide exchange factor T (GEFT), a member of the Rho guanine nucleotide exchange factor family, is expressed in a variety of tumors. In the present study, the expression and clinical significance of GEFT in malignant digestive tract tumors was assessed. Tumor and adjacent control samples from 180 patients were tested. Positive GEFT expression rates were 80, 83.33 and 86.67% in esophageal squamous carcinoma (ESCC), gastric carcinoma (GC) and colorectal cancer (CRC), respectively. GEFT expression was associated with diffuse type carcinoma according to the Lauren classification (χ²=12.525, P=0.002) and tumor-node-metastasis (TNM) stages III/IV (χ²=4.033, P=0.045) in GC, and with vessel carcinoma embolus (χ²=7.890, P=0.005) and lymph node metastasis (χ²=5.455, P=0.020) in CRC, but was not associated with other clinicopathological parameters. Patients with high levels of GEFT protein expression had a less favorable outcome compared with patients with low levels of GEFT expression in patients with CRC (χ²=3.876, P=0.049). However, a significant association was not found between GEFT expression and overall survival in patients with ESCC (χ²=0.040, P=0.842) or GC (χ²=0.501, P=0.479). The rate of human epidermal growth factor receptor 2 upregulation in patients with GC was 13.33% and it was associated with nerve invasion (χ²=4.005, P=0.045) and TNM stages III/IV (χ²=5.600, P=0.018). Mismatch repair protein (MMRP) defect was observed in six cases, and the KRAS mutation rate was 26.67% in patients with CRC. GEFT expression was significantly correlated with MMRP (r=-0.285, P=0.027) and KRAS mutation in patients with CRC (r=0.697, P<0.001). These findings revealed frequent GEFT upregulation in malignant digestive tract tumors, which may have promoted tumor development. GEFT expression in CRC may be associated with microsatellite instability and KRAS mutation status, suggesting that GEFT may be a potential therapeutic target for patients with CRC.

Prognostic value and association of Lauren classification with VEGF and VEGFR-2 expression in gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors in the world. As anti-angiogenic therapy shows efficacy in the treatment of GC, but only works in certain patients, the identification of potential beneficiaries are urgently required in order to apply appropriate treatments. The Lauren classification demonstrates numerous differences in etiology, epidemiology and pathology; however, the association between Lauren classification and pro-angiogenic factors remains unclear. The present study aimed to investigate the clinicopathological factors associated with Lauren classification and the prognostic significance of Lauren classification and vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) expression in GC. Paraffin-embedded GC tissues and clinical information of 255 patients with GC were collected. The clinicopathological factors associated with Lauren classification were evaluated by Logistic regression analysis. Kaplan-Meier survival and Cox regression analyses were used to examine the prognostic significance of Lauren classification and of VEGF and VEGFR-2 expression in patients with GC. The results demonstrated that there was no association between Lauren classification and VEGF and VEGFR-2 expression. Furthermore, results from survival analysis demonstrated that Lauren classification (P=0.001) and Tumor-Node-Metastasis stage (stage II, P=0.002; stage III, P<0.001) were independent prognostic factors in GC. Following subgroup analysis based on Tumor-Node-Metastasis stage, Lauren classification was demonstrated to be an independent prognostic factor in patients with stage III GC (P=0.010) but not in patients with stage I or II GC. Furthermore, VEGFR-2 overexpression was an independent predictor of survival in intestinal-type GC (P=0.040) but not in diffuse-type GC. Taken together, these results indicate that Lauren classification may serve as an independent prognostic factor for patients with GC. In addition, although the expression of VEGF and VEGFR-2 was not associated with Lauren classification, VEGFR-2 overexpression may be considered as an independent prognostic factor in intestinal-type GC.

Population-Based Study on Risk Factors for Tumor-Positive Resection Margins in Patients with Gastric Cancer

Background

Radical gastrectomy is the cornerstone of the treatment of locally advanced gastric cancer. This study was designed to evaluate factors associated with a tumor-positive resection margin after gastrectomy and to evaluate the influence of hospital volume.

Methods

In this Dutch cohort study, patients with junctional or gastric cancer who underwent curative gastrectomy between 2011 and 2017 were included. The primary outcome was incomplete tumor removal after the operation defined as the microscopic presence of tumor cells at the resection margin. The association of patient and disease characteristics with incomplete tumor removal was tested with multivariable regression analysis. The association of annual hospital volume with incomplete tumor removal was tested and adjusted for the patient- and disease characteristics.

Results

In total, 2799 patients were included. Incomplete tumor removal was seen in 265 (9.5%) patients. Factors associated with incomplete tumor removal were: tumor located in the entire stomach (odds ratio (OR) [95% confidence interval (CI): 3.38 [1.91–5.96] reference: gastroesophageal junction), cT3, cT4, cTx (1.75 [1.20–2.56], 2.63 [1.47–4.70], 1.60 [1.03–2.48], reference: cT0-2), pN+ (2.73 [1.96–3.80], reference: pN−), and diffuse and unknown histological subtype (3.15 [2.14–4.46] and 2.05 [1.34–3.13], reference: intestinal). Unknown differentiation grade was associated with complete tumor removal (0.50 [0.30–0.83], reference: poor/undifferentiated). Compared with a hospital volume of < 20 resections/year, 20–39, and > 39 resections were associated with lower probability for incomplete tumor removal (OR 0.56 [0.42–0.76] and 0.34 [0.18–0.64]).

Conclusions

Tumor location, cT, pN, histological subtype, and tumor differentiation are associated with incomplete tumor removal. The association of incomplete tumor removal with an annual hospital volume of < 20 resections may underline the need for further centralization of gastric cancer care in the Netherlands.

Electronic supplementary material

The online version of this article (10.1245/s10434-019-07381-0) contains supplementary material, which is available to authorized users.

Intestinal and diffuse gastric cancer: a retrospective study comparing primary sites

OBJECTIVE

We assessed differences in primary sites and spread patterns of the intestinal and diffuse subtypes of gastric carcinoma. We also compared survival outcomes based on spread patterns.

MATERIALS AND METHODS

For this retrospective IRB-approved study, our institutional imaging database was mined for patients with gastric cancer. We included 99 treatment-naïve patients. Patient demographics, pathologic data, tumor classification, primary tumor site, and metastasis sites were recorded. Pearson's chi-squared test was used to correlate tumor pathology with metastatic sites. Kaplan-Meier survival curves were compared between baseline metastatic types. A heat map was created based on the relative frequencies of metastatic sites for each primary tumor site.

RESULTS

Of the 99 patients, 66 patients had intestinal and 33 had diffuse gastric carcinoma. The intestinal subtype was significantly associated with hepatic metastases (p < 0.001). Diffuse subtype was associated with peritoneal metastases, including omental metastases (p < 0.006), gastrosplenic ligament involvement (p < 0.004), and mesocolonic implants (p < 0.008). Patients with primary gastric tumors occurring at the greater curvature had longer overall survival than those with primary sites at the antrum, GE junction and lesser curvature (p = 0.0015). Patients with peritoneal metastases had a significantly shorter overall survival than patients without peritoneal metastases (p < 0.001). Patients without mesocolon, gastrohepatic ligament, and gastrosplenic ligament involvement had a better survival (p = 0.005, p = 0.0002, and p = 0.0005, respectively). Presence of hepatic metastases had no effect on survival (p = 0.16).

CONCLUSION

Recognizing distinctive spread patterns for intestinal versus diffuse gastric carcinoma can aid radiologists in diagnosis and guide clinical management.

Nectin1 expression is frequently decreased in gastric cancers

Gastric cancer (GC) is rich in many different histological types, but how the histological pattern is defined remains to be proved. The relation between GC histological types and the expression of nectin1, which is one of the cell adhesion molecules that composes adherens junction, has not been reported. According to a publicly available database of 406 GC patients, the median overall survival of Nectin1 high expression patients was 55.4 months and that of low expression patients was 25.6 months (P = 0.0246). Using surgically or endoscopically resected GC samples, nectin1 expression was analyzed by immunohistochemistry. Nectin1 expressed at adherens junction in all the normal epithelial cells. However, nectin1 expressed not at adherens junction but at apical membrane in epithelial cells in intestinal metaplasia. The expression pattern of nectin1 in intestinal type GC resembled to intestinal metaplasia. In order to analyze the difference in nectin1 expression between GC histological types, a total of 116 intestinal type GC and 33 diffuse type GC. The expression of necitin1 in diffuse type GC (3.0%) was remarkably decreased compared to that in intestinal type GC (65.5%) (P < 0.0001). In conclusion, this is the first report showing an association between nectin1 expression and histological subtypes of GC.

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

BACKGROUND

There are two distinct types of gastric carcinoma (GC), intestinal, more frequently sporadic and linked to environmental factors, and diffuse (undifferentiated) that is highly metastatic and characterized by rapid disease progression and a poor prognosis. However, there are many conflicting data in the literature concerning the association between histology and prognosis in GC. This meta-analysis was performed to provide demonstration if histology according to Lauren classification is associated with different prognosis in patients with GC.

METHODS

We searched PubMed, the Cochrane Library, SCOPUS, Web of Science, CINAHL, and EMBASE for all eligible studies. The combined hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) in terms of overall survival (OS) were evaluated.

RESULTS

A total of 73 published studies including 61,468 patients with GC were included in this meta-analysis. Our analysis indicates that GC patients with diffuse-type histology have a worst prognosis than those with intestinal subgroup in all studies (HR 1.23; 95% CI, 1.17-1.29; P<0.0001), in both loco-regional confined (HR 1.21; 95% CI, 1.12-1.30; P<0.0001) and advanced disease (HR 1.25; 95% CI, 1.046-1.50; P=0.014), in Asiatic (HR 1.2; 95% CI, 1.14-1.27; P<0.0001) and Western patients (HR 1.3; 95% CI, 1.19-1.41; P<0.0001), and in those not exposed (HR 1.15; 95% CI, 1.07-1.24; P<0.0001) or exposed (HR 1.27; 95% CI, 1.17-1.37; P<0.0001) to (neo)adjuvant therapy.

CONCLUSIONS

Our results indicated that histology might be a useful prognostic marker for both early and advanced GC patients, with intestinal-type associated with a better outcome. This information could be used for stratification purpose in future clinical trials.

Droplet-based microtumor model to assess cell-ECM interactions and drug resistance of gastric cancer cells

Gastric cancer (GC) is a common aggressive malignant tumor with high incidence and mortality worldwide. GC is classified into intestinal and diffuse types according to the histo-morphological features. Because of distinctly different clinico-pathological features, new cancer therapy strategies and in vitro preclinical models for the two pathological variants of GC is necessary. Since extracellular matrix (ECM) influence the biological behavior of tumor cells, we hypothesized that GC might be more similarly modeled in 3D with matrix rather than in 2D. Herein, we developed a microfluidic-based a three-dimensional (3D) in vitro gastric cancer model, with subsequent drug resistance assay. AGS (intestinal type) and Hs746T (diffuse type) gastric cancer cell lines were encapsulated in collagen beads with high cellular viability. AGS exhibited an aggregation pattern with expansive growth, whereas Hs746T showed single-cell-level infiltration. Importantly, in microtumor models, epithelial-mesenchymal transition (EMT) and metastatic genes were upregulated, whereas E-cadherin was downregulated. Expression of ß-catenin was decreased in drug-resistant cells, and chemosensitivity toward the anticancer drug (5-FU) was observed in microtumors. These results suggest that in vitro microtumor models may represent a biologically relevant platform for studying gastric cancer cell biology and tumorigenesis, and for accelerating the development of novel therapeutic targets.

Trop2 is overexpressed in gastric cancer and predicts poor prognosis

The cell surface protein Trop2 is overexpressed in a variety of human cancers. Trop2 expression increases tumor development and metastasis and reduces patient survival. However, little is known about the role of Trop2 expression and its prognostic value in gastric cancer (GC), particularly in Chinese populations. We analyzed Trop2 expression in GC tissues collected from Chinese GC patients. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry on tissue microarrays were performed to assess levels of Trop2 mRNA and protein in GC, and correlations between Trop2 expression and clinical characteristics and prognosis were analyzed. Trop2 expression was higher in GC tissues than in neighboring non-tumor tissues. Increased Trop2 protein levels in GC were associated with increased differentiation, tumor node metastasis stage, tumor size, lymph node metastasis, distant metastasis, and H. pylori infection. GC patients with high Trop2 expression also had poor overall survival rates. These data suggest Trop2 is a useful prognostic biomarker for GC.

Challenge and thought on treatment of diffuse gastric cancer

Diffuse gastric cancer, which has a high degree of malignancy and is metastasis-prone, is a pathological type of Lauren classification. The incidence of diffuse gastric cancer shows an increasing trend in China, and it greatly threatens the human health. There have been many studies on diffuse gastric cancer, and its treatment and prognosis have been improved to some extent. In this paper, we systematically describe diffuse gastric cancer with regard to its epidemiology, diagnosis, biological behavior, and factors affecting the treatment and prognosis, and discuss problems and disputes in current diagnosis and treatment, with an aim to provide convenience for the further research and help for clinical work.

Lauren classification and individualized chemotherapy in gastric cancer

Gastric cancer is one of the most common malignancies worldwide. During the last 50 years, the histological classification of gastric carcinoma has been largely based on Lauren's criteria, in which gastric cancer is classified into two major histological subtypes, namely intestinal type and diffuse type adenocarcinoma. This classification was introduced in 1965, and remains currently widely accepted and employed, since it constitutes a simple and robust classification approach. The two histological subtypes of gastric cancer proposed by the Lauren classification exhibit a number of distinct clinical and molecular characteristics, including histogenesis, cell differentiation, epidemiology, etiology, carcinogenesis, biological behaviors and prognosis. Gastric cancer exhibits varied sensitivity to chemotherapy drugs and significant heterogeneity; therefore, the disease may be a target for individualized therapy. The Lauren classification may provide the basis for individualized treatment for advanced gastric cancer, which is increasingly gaining attention in the scientific field. However, few studies have investigated individualized treatment that is guided by pathological classification. The aim of the current review is to analyze the two major histological subtypes of gastric cancer, as proposed by the Lauren classification, and to discuss the implications of this for personalized chemotherapy.

Hereditary diffuse gastric cancer: updated clinical guidelines with an emphasis on germline CDH1 mutation carriers

Germline CDH1 mutations confer a high lifetime risk of developing diffuse gastric (DGC) and lobular breast cancer (LBC). A multidisciplinary workshop was organised to discuss genetic testing, surgery, surveillance strategies, pathology reporting and the patient's perspective on multiple aspects, including diet post gastrectomy. The updated guidelines include revised CDH1 testing criteria (taking into account first-degree and second-degree relatives): (1) families with two or more patients with gastric cancer at any age, one confirmed DGC; (2) individuals with DGC before the age of 40 and (3) families with diagnoses of both DGC and LBC (one diagnosis before the age of 50). Additionally, CDH1 testing could be considered in patients with bilateral or familial LBC before the age of 50, patients with DGC and cleft lip/palate, and those with precursor lesions for signet ring cell carcinoma. Given the high mortality associated with invasive disease, prophylactic total gastrectomy at a centre of expertise is advised for individuals with pathogenic CDH1 mutations. Breast cancer surveillance with annual breast MRI starting at age 30 for women with a CDH1 mutation is recommended. Standardised endoscopic surveillance in experienced centres is recommended for those opting not to have gastrectomy at the current time, those with CDH1 variants of uncertain significance and those that fulfil hereditary DGC criteria without germline CDH1 mutations. Expert histopathological confirmation of (early) signet ring cell carcinoma is recommended. The impact of gastrectomy and mastectomy should not be underestimated; these can have severe consequences on a psychological, physiological and metabolic level. Nutritional problems should be carefully monitored.

Does adjuvant chemoradiotherapy improve the prognosis of gastric cancer after an r1 resection? Results from a dutch cohort study

OBJECTIVE

The aim of this study was to investigate the impact of adjuvant chemoradiotherapy (CRT) on survival of non-metastatic gastric cancer patients who had undergone an R1 resection.

METHODS

We compared the survival of patients after an R1 gastric cancer resection from the population-based Netherlands Cancer Registry who did not receive adjuvant CRT (no-CRT group) with the survival of resected patients who had been treated with adjuvant CRT (CRT group) at our institute. Patients who had a resection between 2002 and 2011 were included. CRT consisted of radiotherapy (45 Gy) combined with concurrent cisplatin- or 5-fluorouracil-based chemotherapy. The impact of CRT treatment on overall survival was assessed using multivariable Cox regression and stratified propensity score analysis.

RESULTS

A series of 409 gastric cancer patients who had undergone an R1 resection were studied (no-CRT, N = 369; CRT, N = 40). In the no-CRT group, median age was higher (70 vs. 57 years; p < 0.001) and the percentage of patients with diffuse-type tumors was lower (43 vs. 80 %; p < 0.001). There were no significant differences in pathological T- and N-classification. There was a significant difference in median overall survival between the no-CRT and CRT group (13 vs. 24 months; p = 0.003). In a multivariable analysis, adjuvant CRT was an independent prognostic factor for improved overall survival (hazard ratio 0.54; 95 % confidence interval 0.35-0.84). This effect of CRT was further supported by propensity score analysis.

CONCLUSIONS

Adjuvant CRT was associated with an improved survival in patients who had undergone an R1 resection for gastric cancer.

Recurrent gain-of-function mutations of RHOA in diffuse-type gastric carcinoma

Diffuse-type gastric carcinoma (DGC) is characterized by a highly malignant phenotype with prominent infiltration and stromal induction. We performed whole-exome sequencing on 30 DGC cases and found recurrent RHOA nonsynonymous mutations. With validation sequencing of an additional 57 cases, RHOA mutation was observed in 25.3% (22/87) of DGCs, with mutational hotspots affecting the Tyr42, Arg5 and Gly17 residues in RHOA protein. These positions are highly conserved among RHO family members, and Tyr42 and Arg5 are located outside the guanine nucleotide-binding pocket. Several lines of functional evidence indicated that mutant RHOA works in a gain-of-function manner. Comparison of mutational profiles for the major gastric cancer subtypes showed that RHOA mutations occur specifically in DGCs, the majority of which were histopathologically characterized by the presence of poorly differentiated adenocarcinomas together with more differentiated components in the gastric mucosa. Our findings identify a potential therapeutic target for this poor-prognosis subtype of gastric cancer with no available molecularly targeted drugs.