Validity and necessity of sub-classification of N3 in the 7th UICC TNM stage of gastric cancer

MicroRNA-140-5p inhibits cell proliferation, migration and promotes cell apoptosis in gastric cancer through the negative regulation of THY1-mediated Notch signaling

Studies have highlighted the importance of microRNAs (miRs) in the development of various cancers, including gastric cancer (GC), a commonly occurring malignancy, accompanied by high recurrence and metastasis rate. The aim of the current study was to investigate the role of miR-140-5p in GC. Microarray expression profiles were initially employed to screen the differentially expressed gene related to GC, and the miR regulating the gene was predicted accordingly. The data obtained indicated that thymus cell antigen 1 (THY1) was differentially expressed in GC and confirmed to be a target gene of miR-140-5p. Poorly expressed miR-140-5p and highly expressed THY1 were observed in the GC tissues. SGC-7901 cells were treated with miR-140-5p mimic/inhibitor, siRNA against THY1 and siRNA against Notch1 in order to determine their regulatory roles in GC cell activities. The relationship of miR-140-5p, THY1 and the Notch signaling pathway was subsequently identified. Moreover, cell proliferation, migration, invasion and apoptosis were determined using 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), wound-healing, transwell assay and flow cytometry, respectively. The overexpression of miR-140-5p and silencing of THY1 resulted in a diminished expression of the Notch signaling pathway-related proteins, as well as inhibited proliferation, migration and invasion of GC cells, enhanced expression of pro-apoptotic proteins in addition to elevated apoptosis rate. Taken together, the present study suggests that miR-140-5p directly targets and negatively regulates THY1 expression and inhibits activation of the Notch signaling pathway, whereby the up-regulation of miR-140-5p inhibits development of GC, highlighting the promise of miR-140-5p as a potential target for GC treatment.

Tumour deposits are a significant prognostic factor in gastric cancer - a systematic review and meta-analysis

AIMS

Tumour deposits (TDs) are clusters of cancer cells in the soft tissue that are discontinuous from the primary tumour. In this review we are exploring their relevance for prognosis in patients with gastric cancer.

METHODS AND RESULTS

A literature search was performed to identify studies providing data on TDs and prognosis in gastric cancer patients. Eight papers were included in the meta-analysis, which was carried out in terms of risk ratios (RR) and hazard ratios (HR) with 95% confidence interval (95% CI). Of 7445 patients, 1551 had TDs (20.9%). TDs were associated with a decreased overall survival (OS) in univariate (HR = 2.82, 95% CI = 1.9-4.3) and multivariate analyses (HR = 1.65, 95% CI = 1.3-2.1). TDs were also associated with known prognostic factors such as synchronous metastatic disease (RR = 9.5), invasion depth (RR = 1.8), lymph node metastasis (RR = 1.7), lymphatic invasion (RR = 1.7), vascular invasion (RR = 2.6) and poor differentiation (RR = 1.2).

CONCLUSIONS

We found a strong indication that TDs are independent predictors of prognosis in patients with gastric cancer; hence, TDs should be included in the staging of gastric cancers.

Assessment of the 8th edition of TNM staging system for gastric cancer: the results from the SEER and a single-institution database

AIM

To investigate whether the 8th edition of Tumor, Node, Metastasis (TNM) staging could properly evaluate the prognosis of gastric cancer patients.

METHODS

The prognostic performance between the 7th and 8th edition of TNM staging was compared and clinicopathologic features were analyzed.

RESULTS

The stage shifts in the 8th edition staging resulted in the increased numbers of stage IIIA patients and decreased numbers of stage IIB, stage IIIB and stage IIIC patients. Compared with the previous edition, the 8th edition of TNM staging provided a better prognostic stratification for stage III patients. However, whether it is reasonable to incorporate T4aN2, T4aN3a and T4bN3b into stage IIIA, stage IIIB and stage IIIC respectively, which still need further validation.

CONCLUSION

Despite the obvious superiority, several deficiencies may still exist in the new edition staging. To better provide prognostic information and therapeutic guidance for gastric cancer patients, the TNM staging system should be further improved in the future.

Early postoperative tumor marker responses provide a robust prognostic indicator for N3 stage gastric cancer

The clinical significance of tumor markers after radical gastrectomy has not been well characterized. The purpose of this study is to evaluate the prognostic value of early postoperative tumor marker normalization in N3 stage gastric cancer (GC) patients. A total of 259 N3 stage GC patients with preoperatively elevated carcinoembryonic antigen (CEA, >5 ng/mL) or carbohydrate antigen 19-9 (CA19-9, >37 U/mL) levels underwent radical gastrectomy were analyzed retrospectively. Early postoperative tumor marker response was considered as a normalization of CEA or CA19-9 levels 4 weeks after surgery. The disease-free survival (DFS) and overall survival (OS) were analyzed. N3 stage GC patients were divided into N3a (n = 157) and N3b (n = 102) groups according to the 8th TNM stage system. Early tumor marker response was identified in 96 of 157 N3a patients (61.15%) and 57 of 102 N3b patients (55.88%). In N3 stage GC patients with a tumor marker response, significant increase was observed in both DFS (25.2 months vs 12.5 months, P < .001) and OS (32.5 months vs 18.5 months, P < .001) compared with those without tumor marker response. N3b patients with a tumor marker response showed more favorable DFS (19.2 months vs 13.6 months, P = .019) and OS (25.8 months vs 19.0 months, P = .013) compared with N3a patients lacking a tumor marker response. Multivariate analysis revealed that early tumor marker response was an independent factor for DFS and OS in N3 stage GC, as well as for depth of invasion and metastatic lymph node rate (P < .05). Early postoperative CEA or CA19-9 normalization serves as a strong prognostic indicator in N3 stage GC. Both N3a and N3b patients with increased early postoperative tumor marker levels showed poor outcomes.

The IGCA staging system is more accurate than AJCC7 system in stratifying survival of patients with gastric cancer in stage III

Background

A new staging system recently proposed by the IGCA has demonstrated a better capacity of stratifying different prognoses for gastric cancer than the 7th edition AJCC staging system (AJCC7). The aim of this study was to evaluate the efficacy of the IGCA system in Chinese patients.

Methods

Medical records of patients with gastric cancer who received curative surgery in our center from January 2003 to December 2011 were reviewed retrospectively. All the lesions were staged according to both AJCC7 and IGCA staging systems. Overall survival (OS) of the patients was used as the observation endpoint.

Results

One thousand five hundred twenty-six cases were included in this study. By comparing the AJCC7 system with the IGCA systems, 395 cases were stratified into different stages, most of which were in stage III. The IGCA system could better stratify stage IIIB and IIIC patients (5-year OS, 38.1% vs. 29.0%; P = 0.005) than the AJCC7 system (5-year OS, 38.2% vs. 35.9%; P = 0.148). T3N3bM0, T4aN2M0 and T4aN3bM0 made up 97.5% (385/395) of the stage shift. T3N3bM0, which was stratified to stage IIIB in the AJCC7 system, showed a significant poorer prognosis than T4aN2M0 and T4aN3aM0, which were staged to IIIB and IIIC in the same system. The improper staging was revised in the IGCA staging system.

Conclusions

The IGCA staging system can stratify stage III gastric cancer patients more properly than the AJCC7 system.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3235-3) contains supplementary material, which is available to authorized users.

Risk Factors and Epidemiology of Gastric Cancer in Pakistan

Gastric cancer is the 2nd most common cause of death among all cancers and is the 4th most common cancer in the world. The number of deaths due to gastric cancer is about 800,000 annually. Gastric cancer is more common in men as compared to women and is 3rd most common cancer after colorectal and breast cancers in women. A progressive rise in the incidence rate has been observed in females over the last 5 years. The highest incidence of stomach cancer is in China, South America and Eastern Europe. The incidence of gastric cancer has 20 fold variation worldwide. Global variation is linked by two factors which play important role in developing gastric cancer. One is infection with Helicobacter pylori and the 2nd is diet. South Asia is a region with low risk, despite a high prevalence of H.pylori. Gastric carcinoma is common in southern region of India. Gastric cancer is more readily treated if diagnosed early. This study aims to provide awareness about gastric cancer as well as an updated knowledge about risk factors and epidemiology of gastric cancer in Pakistan.

Expression of C4.4A is a potential independent prognostic factor for patients with gastric cancer

C4.4A, a metastasis-associated gene, encodes a glycolipid-anchored membrane protein which is overexpressed in several human malignancies. However, there are few data available on C4.4A expression and its relationship with progression in gastric cancer. Our study was designed to explore the expression of C4.4A in gastric cancer and to correlate it with clinical outcome. C4.4A expression was studied by quantitative real-time RT-PCR and immunohistochemistry for assessment of correlations with clinicopathological factors. C4.4A mRNA expression was significantly up-regulated in gastric cancer as compared with noncancerous tissue (p<0.05)., being observed in 107 (88.4%) of the 121 gastric cancer cases by immunohistochemistry. We found that the expression of C4.4A mRNA was correlated with size of the tumor, depth of invasion, lymph node metastasis, distant metastasis and TNM stage. Moreover, patients with overexpression of C4.4A has a significantly worse survival (p<0.05). Further multivariable analysis indicated that the expression of C4.4A was an independent prognostic indicator for gastric cancer (p<0.05). In conclusion, overexpression of C4.4A correlates with metastatic potential of gastric cancer and C4.4A could be a novel independent prognostic marker for predicting outcome.

Aberrant expression of the autocrine motility factor receptor correlates with poor prognosis and promotes metastasis in gastric carcinoma

AMFR, autocrine motility factor receptor, also called gp78, is a cell surface cytokine receptor which has a dual role as an E3 ubiquitin ligase in endoplasmic reticulum-associated degradation. AMFR expression is associated with tumor malignancy. We here investigated the clinical significance of AMFR and its role in metastasis and prognosis in gastric cancer. Expression of AMFR, E-cadherin and N-cadherin in cancer tissues and matched adjacent normal tissues from 122 gastric cancer (GC) patients undergoing surgical resection was assessed by immunohistochemistry. Levels of these molecules in 17 cases selected randomly were also analysed by Western blotting. AMFR expression was significantly increased in gastric cancer tissues, and associated with invasion depth and lymph node metastasis. Kaplan-Meier analysis showed AMFR expression correlated with poor overall survival and an increased risk of recurrence in the GC cases. Cox regression analysis suggested AMFR to be an independent predictor for overall and recurrence-free survival. E-cadherin expression was decreased in gastric cancer tissues; conversely, N-cadherin was increased. Expression of AMFR negatively correlated with E-cadherin expression, whereas N-cadherin expression showed a significant positive correlation with AMFR expression. AMFR might be involved in the regulation of epithelial-mesenchymal transition, with aberrant expression correlating with a poor prognosis and promoting invasion and metastasis in GCs.

The rationality of N3 classification in the 7th edition of the International Union Against Cancer TNM staging system for gastric adenocarcinomas: a case-control study

BACKGROUND

The 7th edition of the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) tumor-node-metastasis (TNM) classification system for gastric cancer is more detailed than the 6th edition with respect to tumor depth and lymph node metastasis. The purpose of this study was to evaluate the rationality of the 7th UICC/AJCC TNM classification system, focusing on N3 gastric cancers.

METHODS

A total of 338 patients with N3 gastric cancer who underwent curative resection with ≥ 16 retrieved lymph nodes at two institutions between January 1997 and December 2007 were included in this study. Patients were divided into the N3a (n = 210) and N3b (n = 128) groups. Clinicopathologic characteristics and survival rates were compared between groups.

RESULTS

No difference in clinicopathologic characteristics, including age (p = 0.989), sex (p = 0.382), tumor location (p = 0.124), surgery type (p = 0.909), depth of invasion (p = 0.313), histologic type (p = 0.111), and Lauren classification (p = 0.491), was observed between patients with N3a and N3b gastric cancer. However, overall survival (OS) rates of patients with N3a gastric cancer were greater than that of patients with N3b gastric cancer (5-year OS, 46% vs. 28%; 10-year OS, 33% vs. 19%; both p < 0.001). Five-year survival rates differed significantly between patients with T3N3a and T3N3b (p = 0.006) sub-stages and between those with T4aN3a and T4aN3b (p = 0.004) sub-stages.

CONCLUSIONS

The results of this study support N3 sub-classification for gastric cancers, which warrant differential consideration according to TNM stage.

Anatomic extent of metastatic lymph nodes: still important for gastric cancer prognosis

BACKGROUND

Currently, gastric cancer staging systems do not consider the anatomic extent of metastatic lymph nodes (mLNs) as a prognostic factor. We therefore investigated the prognostic impact of the anatomic extent of mLNs on gastric cancer.

METHODS

The prognoses of 4,043 gastric cancer patients who underwent curative resection were analyzed. Patients with mLNs in lymph node (LN) stations 1-6 (n = 1,980) comprised the perigastric LN-positive (PLN) group, and patients with mLNs in LN stations 7-12 and 14 (n = 2,063) were assigned to the extraperigastric LN-positive (ELN) group. Overall survival was estimated using the Kaplan-Meier method, and hazard ratios (HRs) were calculated by the Cox proportional hazard model.

RESULTS

The ELN group exhibited worse survival than the PLN group (p < 0.001), although there were differences in their clinicopathological features. When patients were stratified according to tumor-node-metastasis stage, the ELN groups had unfavorable prognoses compared with the PLN groups (p < 0.05). There were significant differences in long-term survival when the nodal stage of the current staging systems were subdivided according to anatomic nodal extent (p < 0.05), although there was a strong association between the probability of having extraperigastric mLNs and N classification. In multivariate analysis using age, gender, tumor size, tumor location, histology, T classification, and the extent of mLNs as covariates, presence of extraperigastric mLNs was an independent prognostic factor (HR 1.89, 95 % CI 1.73-2.07), along with age, tumor size, tumor location, and T classification.

CONCLUSIONS

The anatomic extent of mLNs significantly affects patient prognosis. Including the anatomic extent of mLNs in the current staging system may predict gastric cancer prognosis more accurately in patients with the same stage of cancer.