The clinical significance and risk factors of solitary lymph node metastasis in gastric cancer

Development and validation of a novel nomogram to predict overall survival in gastric cancer with lymph node metastasis

Gastric cancer (GC) with lymph node metastasis (LNM) at diagnosis is associated with a unstable prognosis and indefinite survival times. The aim of the present study was to construct and validate a model for the Overall survival (OS) estimation for patients with LNM. The nomogram was constructed to predict the OS for LNM-positive GC using the primary group of 836 patients and validated using an independent cohort of 411 patients. Factors in the nomogram were identified by multivariate Cox hazard analysis. The predictive capability of nomogram was evaluated by calibration analysis and decision curve analysis. Multivariate analysis suggested that eight pre-treatment characteristics were used for developing the nomogram. In the primary cohort, the C-index for OS prediction was 0.788 (95% CI: 0.753-0.823), while in validation cohort, the C-index for OS prediction was 0.769 (95% CI: 0. 720-0.818). The calibration plot for the probability of OS and decision curve analyses showed an optimal agreement. Based on the nomogram, we could divided patients into three groups: low-risk group, middle-risk group and a high-risk group(p <0.001).Taken together, we have provided an easy-to-used and accurate tool for predicting OS, furthermore could be used for risk stratification of OS of LNM-positive GC patients.

Prognostic Significance of Solitary Lymphnode Metastasis and Micrometastasis in Gastric Cancer

Gastric cancer (GC) used to be one of the most common malignancies in the world and still is the second leading cause of malignancy-related death in the Far East. The most significant factors that were found to be associated with the clinical outcome in patients with non-metastatic (M₀) gastric cancer is tumor's depth of invasion, the presence and the extend of lymphnode involvement, as well as the histological type according to Lauren (intestinal or diffuse). Although it is generally accepted that D2 gastrectomy is the procedure of choice to achieve adequate oncologic excision, there are quite many concerns for its use in patients with early gastric cancer (EGC), where N_o or N₁ specimens are frequently reported. The last two decades, with the evolvement of cancer cell detection techniques, the attend of the medical community is focused on GC patients with solitary lymphnode metastasis (SLN) or micrometastasis (mM). There is a discussion whether SLN should be attributed as the “real” sentinel node (SN) and its projection on patients' survival. The aim of this study is to review the recent literature and attempt to clarify the clinical significance of SLN in gastric cancer.

Label-free imaging for T staging of gastric carcinoma by multiphoton microscopy

Gastric cancer is one of the most common malignancies worldwide. The accurate diagnosis of tumor invasion depth is critical for therapeutic strategy and prognosis. Without fluorescent labelling, multiphoton microscopy (MPM) imaging could directly reveal tissue architecture based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG). In this study, we aimed to explore the feasibility of MPM imaging to assess the gastric tumor morphology and infiltration. Unstained slides of 18 fresh gastric tissues with different T staging were examined by multiphoton microscopy. Morphological and quantitative analyses were both conducted. The nuclear area was defined as the area of nuclear boundary. Collagen content was defined as the ratio of SHG pixels to all pixels. Gastric normal and tumor tissues under different T stages visually presented with cellular and subcellular features on fluorescent imaging. The nuclear areas of normal and cancerous cells were 32.01 ± 2.89 and 58.41 ± 6.06 μm2 (P < 0.001), respectively. Collagen content was quantified as 0.087 ± 0.012 in normal mucosa but 0.020 ± 0.007 in cancerous mucosa (P < 0.001). All results were in accord with the paired H&E-stained slides. Our findings suggested the convincing potential of MPM for judging T staging of gastric cancer. Without staining intervention, TPEF and SHG of MPM imaging could objectively and quantitatively indicate the subcellular and molecular changes during carcinogenesis. With the advancement of deep penetration, self-focus imaging and three-dimensional (3D) visualization, label-free MPM imaging compacted with endoscopy could be further introduced to realize the real-time in vivo assessment of tumor invasion clinically.

Clinical significance of the long noncoding RNA RP11-19P22.6-001 in gastric cancer

BACKGROUND

Long non-coding RNAs (lncRNAs) play roles in carcinogenesis; however, the significance of most lncRNAs in gastric cancer is unclear.

OBJECTIVE

To explore the diagnostic value of the long noncoding RNA RP11-19P22.6-001 in gastric cancer.

METHODS

RP11-19P22.6-001 levels in gastric cancer tissues and paired non-tumor tissues were analyzed by quantitative reverse transcription-polymerase chain reaction. Since RP11-19P22.6-001 acts in cis to regulate nitric oxide synthase 2 (NOS2), we also analyzed NOS2 expression and its correlation with gastric cancer. Finally, to analyze the potential diagnostic values of RP11-19P22.6-001, a receiver operating characteristic (ROC) curve was constructed.

RESULTS

RP11-19P22.6-001 expression was significantly downregulated in 70.91% (78/110) of gastric cancer tissues compared to that of adjacent normal tissues. However, NOS2 was upregulated in 75.45% (83/110) of gastric cancer tissues. RP11-19P22.6-001 expression levels were associated with invasion, lymph node metastasis, and TNM stage. The areas under the ROC curves (AUC) were 0.662 and 0.671 for RP11-19P22.6-001 and NOS2, respectively. More importantly, the combined use of these parameters increased the AUC to 0.704.

CONCLUSIONS

RP11-19P22.6-001 and NOS2 may be new biomarkers for the diagnosis and prognosis of gastric cancer. The combined use of lncRNAs and their target genes may be a promising method to increase the diagnostic value of lncRNAs in cancer.

α-Actinin-4 promotes metastasis in gastric cancer

Metastasis increases the mortality rate of gastric cancer, which is the third leading cause of cancer-associated deaths worldwide. This study aims to identify the genes promoting metastasis of gastric cancer (GC). A human cell motility PCR array was used to analyze a pair of tumor and non-tumor tissue samples from a patient with stage IV GC (T3N3M1). Expression of the dysregulated genes was then evaluated in GC tissue samples (n=10) and cell lines (n=6) via qPCR. Expression of α-actinin-4 (ACTN4) was validated in a larger sample size (n=47) by qPCR, western blot and immunohistochemistry. Knockdown of ACTN4 with specific siRNAs was performed in GC cells, and adhesion assays, transwell invasion assays and migration assays were used to evaluate the function of these cells. Expression of potential targets of ACTN4 were then evaluated by qPCR. Thirty upregulated genes (greater than twofold) were revealed by the PCR array. We focused on ACTN4 because it was upregulated in 6 out of 10 pairs of tissue samples and 5 out of 6 GC cell lines. Further study indicated that ACTN4 was upregulated in 22/32 pairs of tissue samples at stage III &IV (P=0.0069). Knockdown of ACTN4 in GC cells showed no significant effect on cell proliferation, but significantly increased cell-matrix adhesion, as well as reduced migration and invasion of AGS, MKN7 and NCI-N87 cells. We found that NF-κB was downregulated in GC with the knockdown of ACTN4. In conclusion, this is the first study to indicate that ACTN4 is significantly upregulated in patients with metastatic GC. ACTN4 reduces cell adhesion and enhances migration and invasion of GC cells and may therefore be a novel therapeutic target for GC.

Value and impact factors of multidetector computed tomography in diagnosis of preoperative lymph node metastasis in gastric cancer: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Multidetector computed tomography (MDCT) exhibited wide ranges of sensitivities and specificities for lymph node assessment of gastric cancer (GC) in several individual studies. This present meta-analysis was carried out to evaluate the value of MDCT in diagnosis of preoperative lymph node metastasis (LNM) and to explore the impact factors that might explain the heterogeneity of its diagnostic accuracy in GC.

METHODS

A comprehensive search was conducted to collect all the relevant studies about the value of MDCT in assessing LNM of GC within the PubMed, Cochrane library and Embase databases up to Feb 2, 2016. Two investigators independently screened the studies, extracted data, and evaluated the quality of included studies. The sensitivity, specificity, and area under ROC curve (AUC) were pooled to estimate the overall accuracy of MDCT. Meta-regression and subgroup analysis were carried out to identify the possible factors influencing the heterogeneity of the accuracy.

RESULTS

A total of 27 studies with 6519 subjects were finally included. Overall, the pooled sensitivity, specificity, and AUC were 0.67 (95% CI: 0.56-0.77), 0.86 (95% CI: 0.81-0.90), and 0.86 (95% CI: 0.83-0.89), respectively. Meta-regression revealed that MDCT section thickness, proportion of serosal invasion, and publication year were the main significant impact factors in sensitivity, and MDCT section thickness, multiplanar reformation (MPR), and reference standard were the main significant impact factors in specificity. After the included studies were divided into 2 groups (Group A: studies with proportion of serosa-invasive GC subjects ≥50%; Group B: studies with proportion of serosa-invasive GC subjects <50%), the pooled sensitivity in Group A was significantly higher than in Group B (0.84 [95% CI: 0.75-0.90] vs 0.55 [95% CI: 0.41-0.68], P < .01). For early gastric cancer (EGC), the pooled sensitivity, specificity, and AUC were 0.34 (95% CI: 0.15-0.61), 0.91 (95% CI: 0.84-0.95), and 0.83 (95% CI: 0.80-0.86), respectively.

CONCLUSION

To summarize, MDCT tends to be adequate to assess preoperative LNM in serosa-invasive GC, but insufficient for non-serosa-invasive GC (particularly for EGC) owing to its low sensitivity. Proportion of serosa-invasive GC subjects, MDCT section thickness, MPR, and reference standard are the main factors influencing its diagnostic accuracy.

Overexpression of carboxypeptidase A4 (CPA4) is associated with poor prognosis in patients with gastric cancer

CarboxypeptidaseA4 (CPA4) is a zinc-containing exopeptidases, and its aberrant expression has been implicated in cancer development and progression. However, few studies have investigated the association between CPA4 over-expression and clinical significance in gastric cancer (GC). In this study, we employed immunohistochemistry to evaluate the expression of CPA4 in gastric cancer tissues, and found that elevated CPA4 expression was detected in 64% (n=100) of primary GCs, but was weak or no staining in the normal mucosa. Clinical relevance analysis showed that positive staining for CPA4 was significantly associated with Tumor size, Stage, Lymph node metastasis, Depth of invasion and Distant metastasis. As tumor markers p53 and Ki67 are closely associated with tumor progression, we further analyzed the correlations between CPA4 levels and these two factors. We found that abnormal expression of CPA4 was positively associated with Ki67 (P=0.002) and reversely correlated with p53 (P=0.035) in GC. In Kaplan-Meier survival analysis, high levels of CPA4 were significantly associated with unfavorable survival in GC patients (P<0.001). Multivariate Cox regression model showed that high expression of CPA4 was an independent prognostic factor for GC patients. In conclusion, our results suggested that CPA4 was highly expressed in gastric cancer tissues. Overexpression of CPA4 can be used as an independent poor prognostic factor in gastric cancer.

Sentinel node biopsy using blue dye and technetium99 in advanced gastric cancer: anatomical drainage and clinical application

Lymph node metastases are an independent prognosis factor in gastric carcinoma (GC) patients. Radical lymphadenectomy can improve survival but it can also increase surgical morbidity. As a principle, sentinel node (SN) navigation surgery can avoid unnecessary lymphadenectomy without compromising prognosis. In this pilot study, 24 patients with untreated GC were initially screened for SN navigation surgery, of which 12 were eligible. Five patients had T2 tumors, 5 had T3 tumors and 2 had T1 tumors. In 33% of cases, tumor diameter was greater than 5.0 cm. Three hundred and eighty-seven lymph nodes were excised with a median of 32.3 per patient. The SN navigation surgery was feasible in all patients, with a median of 4.5 SNs per patient. The detection success rate was 100%. All the SNs were located in N1 and N2 nodal level. In 70.9% of cases, the SNs were located at lymphatic chains 6 and 7. The SN sensitivity for nodal staging was 91.6%, with 8.3% of false negative. In 4 patients who were initially staged as N0, the SNs were submitted to multisection analyses and immunohistochemistry, confirming the N0 stage, without micrometastases. In one case initially staged as negative for nodal metastases based on SN analyses, metastases in lymph nodes other than SN were found, resulting in a 20% skip metastases incidence. This surgery is a reproducible procedure with 100% detection rate of SN. Tumor size, GC location and obesity were factors that imposed some limitations regarding SN identification. Results from nodal multisection histology and immunohistochemistry analysis did not change initial nodal staging.

The predictive factors for lymph node metastasis in early gastric cancer: A clinical study

Objective:

To detect the clinicopathological factors associated with lymph node metastases in early gastric cancer.

Methods:

We retrospectively evaluated the distribution of metastatic nodes in 198 patients with early gastric cancer treated in our hospital between May 2008 and January 2015, the clinicopathological factors including age, gender, tumor location, tumor size, macroscopic type, depth of invasion, histological type and venous invasion were studied, and the relationship between various parameters and lymph node metastases was analyzed.

Results:

In this study, one hundred and ninety-eight patients with early gastric cancer were included, and lymph node metastasis was detected in 28 patients. Univariate analysis revealed a close relationship between tumor size, depth of invasion, histological type, venous invasion, local ulceration and lymph node metastases. Multivariate analysis revealed that the five factors were independent risk factors for lymph node metastases.

Conclusion:

The clinicopathological parameters including tumor size, depth of invasion, local ulceration, histological type and venous invasion are closely correlated with lymph node metastases, should be paid high attention in early gastric cancer patients.

Risk factors associated with splenic hilar lymph node metastasis in patients with advanced gastric cancer in northwest China

There are plenty of risk factors associated with splenic hilar lymph node metastasis (SHLNM) in patients with advanced gastric cancer (AGC). Whereas, their main influencing factors have not reached a consensus yet. The aim of the study is to investigate the related clinicopathological factors influencing SHLNM in AGC. A retrospective study was performed to investigate 150 patients who underwent D2 curative partial or total gastrectomy for gastric carcinoma from January 2007 to November 2012. Clinicopathological factors were analyzed by univariate and multivariate analysis. A total of 10.7% (16/150) of the patients had SHLNM. The overall ratio of metastatic lymph node (positive lymph nodes/lymph nodes harvested) in the splenic hilum was 17.5% (38/217). Univariate analysis results showed SHLNM was related with depth of invasion, tumor grade, tumor size, tumor location and Bormann type, with significant difference (P<0.05); Multivariate analysis demonstrated that SHLNM was related with depth of invasion and tumor size, with significant difference (P<0.05). Consequently, depth of invasion, tumor grade, tumor size, tumor location and Bormann type were associated with SHLNM in AGC, meanwhile depth of invasion and tumor size are independent risk factors. Preoperative predicting risk factors of SHLNM greatly benefits making more rational surgical scheme of treating AGC.