The prognostic impact of occult lymph node metastasis in node-negative gastric cancer: a systematic review and meta-analysis

Adherence to Guidelines for Diagnosis, Staging, and Treatment for Gastric Cancer in Italy According to the View of Surgeons and Patients

Background: Despite the strong declining trends in incidence and mortality over the last decades, gastric cancer (GC) is still burdened with high mortality, even in high-income countries. To improve GC prognosis, several guidelines have been increasingly published with indications about the most appropriate GC management. The Italian Society of Digestive System Pathology (SIPAD) and Gastric Cancer Italian Research Group (GIRCG) designed a survey for both surgeons and patients with the purpose of evaluating the degree of application and adherence to guidelines in GC management in Italy. Materials and Methods: Between January and May 2022, a questionnaire has been administered to a sample of Italian surgeons and, in a simplified version, to members of the Patient Association "Vivere Senza Stomaco" (patients surgically treated for GC between 2008 and 2021) to investigate the diagnosis, staging, and treatment issues. Results: The survey has been completed by 125 surgeons and 125 patients. Abdominal CT with gastric hydro-distension before treatment was not widespread in both groups (47% and 42%, respectively). The rate of surgeons stating that they do not usually perform minimally invasive gastrectomy was 15%, but the rate of patients who underwent a minimally invasive approach was 22% (between 2011 and 2022). The percentage of surgeons declaring to perform extended lymphadenectomy (>D2) was 97%, although a limited lymph node dissection rate was observed in about 35% of patients. Conclusions: This survey shows several important discrepancies from surgical attitudes declared by surgeons and real data derived from the reports available to the patients, suggesting heterogeneous management in clinical practice and, thus, a not rigorous adherence to the guidelines.

A 3 M Evaluation Protocol for Examining Lymph Nodes in Cancer Patients: Multi-Modal, Multi-Omics, Multi-Stage Approach

Through meticulous examination of lymph nodes, the stage and severity of cancer can be determined. This information is invaluable for doctors to select the most appropriate treatment plan and predict patient prognosis; however, any oversight in the examination of lymph nodes may lead to cancer metastasis and poor prognosis. In this review, we summarize a significant number of articles supported by statistical data and clinical experience, proposing a standardized evaluation protocol for lymph nodes. This protocol begins with preoperative imaging to assess the presence of lymph node metastasis. Radiomics has replaced the single-modality approach, and deep learning models have been constructed to assist in image analysis with superior performance to that of the human eye. The focus of this review lies in intraoperative lymphadenectomy. Multiple international authorities have recommended specific numbers for lymphadenectomy in various cancers, providing surgeons with clear guidelines. These numbers are calculated by applying various statistical methods and real-world data. In the third chapter, we mention the growing concern about immune impairment caused by lymph node dissection, as the lack of CD8 memory T cells may have a negative impact on postoperative immunotherapy. Both excessive and less lymph node dissection have led to conflicting findings on postoperative immunotherapy. In conclusion, we propose a protocol that can be referenced by surgeons. With the systematic management of lymph nodes, we can control tumor progression with the greatest possible likelihood, optimize the preoperative examination process, reduce intraoperative risks, and improve postoperative quality of life.

PET/CT for Predicting Occult Lymph Node Metastasis in Gastric Cancer

A portion of gastric cancer patients with negative lymph node metastasis at an early stage eventually die from tumor recurrence or advanced metastasis. Occult lymph node metastasis (OLNM] is a potential risk factor for the recurrence and metastasis in these patients, and it is highly important for clinical prognosis. Positron emission tomography (PET)/computed tomography (CT) is used to assess lymph node metastasis in gastric cancer due to its advantages in anatomical and functional imaging and non-invasive nature. Among the major metabolic parameters of PET, the maximum standardized uptake value (SUVmax) is commonly used for examining lymph node status. However, SUVmax is susceptible to interference by a variety of factors. In recent years, the exploration of new PET metabolic parameters, new PET imaging agents and radiomics, has become an active research topic. This paper aims to explore the feasibility and predict the effectiveness of using PET/CT to detect OLNM. The current landscape and future trends of primary metabolic parameters and new imaging agents of PET are reviewed. For gastric cancer patients, the possibility to detect OLNM non-invasively will help guide surgeons to choose the appropriate lymph node dissection area, thereby reducing unnecessary dissections and providing more reasonable, personalized and comprehensive treatments.

Misclassification of nodal stage in gastric cancer: 16 lymph nodes is not enough

Background

In gastric cancer, nodal stage plays an important role. Insufficient lymph node harvesting or incomplete examination may lead to misclassification and affect postoperative strategy and group survival. This study’s objective was to determine the minimum number of examined lymph nodes needed in gastric cancer and compare this to the minimum lymph node count according to the current Union for International Cancer Control (UICC) classification using real world data.

Methods

Based on anatomical data, expected mean lymph node counts and their 95% confidence intervals for complete D2 lymphadenectomy were calculated. Using stochastic analysis, a threshold for correct classification in 95% of cases was determined. Survival data of nodal negative gastric cancer patients was extracted from the Surveillance, Epidemiology, and End Results (SEER)-Database for 2010–2017. Patients reaching at least the calculated theoretical threshold were compared to the minimum threshold according to the current UICC classification.

Results

The expected lymph node count was 30 (95% CI: 28–32; range 17–52), corresponding to a 27 lymph nodes. In nodal negative patients with exactly 16 and at least 27 examined lymph nodes, relative 5 year survival was 79 and 89% in T1/T2 and 39 and 64% T3/T4 gastric cancer, respectively. Theoretically, when only 16 lymph nodes are analyzed, nodal negative staging may be incorrect in up to 47% of cases.

Conclusions

A minimum threshold of 16 examined lymph nodes cannot be justified. Retrospective analysis confirmed systematic misclassification of patients with insufficient lymphadenectomy in nodal negative gastric cancer patients. Correct lymphadenectomy and thorough examination of the surgical specimen is mandatory.

Multi-view learning for lymph node metastasis prediction using tumor and nodal radiomics in gastric cancer

Purpose. This study aims to develop and validate a multi-view learning method by the combination of primary tumor radiomics and lymph node (LN) radiomics for the preoperative prediction of LN status in gastric cancer (GC). Methods. A total of 170 contrast-enhanced abdominal CT images from GC patients were enrolled in this retrospective study. After data preprocessing, two-step feature selection approach including Pearson correlation analysis and supervised feature selection method based on test-time budget (FSBudget) was performed to remove redundance of tumor and LN radiomics features respectively. Two types of discriminative features were then learned by an unsupervised multi-view partial least squares (UMvPLS) for a latent common space on which a logistic regression classifier is trained. Five repeated random hold-out experiments were employed. Results. On 20-dimensional latent common space, area under receiver operating characteristic curve (AUC), precision, accuracy, recall and F1-score are 0.9531 ± 0.0183, 0.9260 ± 0.0184, 0.9136 ± 0.0174, 0.9468 ± 0.0106 and 0.9362 ± 0.0125 for the training cohort respectively, and 0.8984 ± 0.0536, 0.8671 ± 0.0489, 0.8500 ± 0.0599, 0.9118 ± 0.0550 and 0.8882 ± 0.0440 for the validation cohort respectively (reported as mean ± standard deviation). It shows a better discrimination capability than single-view methods, our previous method, and eight baseline methods. When the dimension was reduced to 2, the model not only has effective prediction performance, but also is convenient for data visualization. Conclusions. Our proposed method by integrating radiomics features of primary tumor and LN can be helpful in predicting lymph node metastasis in patients of GC. It shows multi-view learning has great potential for guiding the prognosis and treatment decision-making in GC.

Significance of Lymph Node Metastasis in the Treatment of Gastric Cancer and Current Challenges in Determining the Extent of Metastasis

The stomach exhibits abundant lymphatic flow, and metastasis to lymph nodes is common. In the case of gastric cancer, there is a regularity to the spread of lymph node metastasis, and it does not easily metastasize outside the regional nodes. Furthermore, when its extent is limited, nodal metastasis of gastric cancer can be cured by appropriate lymph node dissection. Therefore, identifying and determining the extent of lymph node metastasis is important for ensuring accurate diagnosis and appropriate surgical treatment in patients with gastric cancer. However, precise detection of lymph node metastasis remains difficult. Most nodal metastases in gastric cancer are microscopic metastases, which often occur in small-sized lymph nodes, and are thus difficult to diagnose both preoperatively and intraoperatively. Preoperative nodal diagnoses are mainly made using computed tomography, although the specificity of this method is low because it is mainly based on the size of the lymph node. Furthermore, peripheral nodal metastases cannot be palpated intraoperatively, nodal harvesting of resected specimens remains difficult, and the number of lymph nodes detected vary greatly depending on the skill of the technician. Based on these findings, gastrectomy with prophylactic lymph node dissection is considered the standard surgical procedure for gastric cancer. In contrast, several groups have examined the value of sentinel node biopsy for accurately evaluating nodal metastasis in patients with early gastric cancer, reporting high sensitivity and accuracy. Sentinel node biopsy is also important for individualizing and optimizing the extent of uniform prophylactic lymph node dissection and determining whether patients are indicated for function-preserving curative gastrectomy, which is superior in preventing post-gastrectomy symptoms and maintaining dietary habits. Notably, advancements in surgical treatment for early gastric cancer are expected to result in individualized surgical strategies with sentinel node biopsy. Chemotherapy for advanced gastric cancer has also progressed, and conversion gastrectomy can now be performed after downstaging, even in cases previously regarded as inoperable. In this review, we discuss the importance of determining lymph node metastasis in the treatment of gastric cancer, the associated difficulties, and the need to investigate strategies that can improve the diagnosis of lymph node metastasis.

Combination of the ratio between metastatic and harvested lymph nodes and negative lymph node count as a prognostic indicator in advanced gastric cancer: a retrospective cohort study

Background

The aim of our study was to examine the impact of the combination of the ratio between metastatic and harvested lymph nodes (RML) and negative lymph node (NLN) count on overall survival (OS) in patients with advanced gastric cancer (GC).

Methods

The clinicopathological data of 2,952 advanced GC patients who received curative resection between 1994 and 2015 were collected. They were divided into four groups according to the RML: 0, 0-0.1, 0.1-0.4, and >0.4. We distinguished survival differences through Kaplan-Meier analysis among the subgroups to investigate the impacts of the RML on OS in advanced GC patients. OS was examined according to clinicopathological variables. Spearman's correlation coefficient was used to assess the relationships between the RML and metastatic lymph node (MLN) count and NLN count.

Results

A total of 1,182 patients were enrolled into the study. The median follow-up time was 39 months (interquartile range 20 to 68 months). The 5-year OS rate of all 1,182 GC patients was 54.4%. Kaplan-Meier survival analysis showed that the median OS declined significantly with increasing RML (5-year survival rate 81.2% vs. 69.1% vs. 42.8% vs. 13.1%, P<0.001). As the NLN count increased, the survival rate of GC patients increased (5-year survival rate 12.8% vs. 25.2% vs. 60.2%, P<0.05). The RML, not NLN count, was identified as an independent factor for OS (P<0.001) through multivariate analysis. Spearman correlation analysis suggested that the RML was positively correlated with the number of MLNs (ρ=0.973, P<0.001) and inversely associated with the NLN count (ρ=-0.513, P<0.001).

Conclusions

The RML is an independent prognostic predictor of OS in advanced GC patients, and the NLN count may serve as a supplementary strategy for the present tumor-node-metastasis (TNM) classification to further improve the prognostic prediction efficiency. The combination of the RML and NLN count should be an important predictor for current clinical applications.

Prognostic significance of Borrmann type combined with vessel invasion status in advanced gastric cancer

BACKGROUND

Borrmann classification (types I-IV) for the detection of advanced gastric cancer has been accepted worldwide, and lymphatic and/or blood vessel invasion (LBVI) status is related to the poor prognosis after gastric cancer.

AIM

To evaluate the significance of Borrmann type combined with LBVI status in predicting the prognosis of advanced gastric cancer.

METHODS

We retrospectively studied the clinicopathological characteristics and long-term survival data of 2604 patients who were diagnosed with advanced gastric adenocarcinoma at Harbin Medical University Cancer Hospital from January 2009 to December 2013. Categorical variables were evaluated by the Pearson’s χ² test, the Kaplan-Meier method was used to identify differences in cumulative survival rates, and the Cox proportional hazards model was used for multivariate prognostic analysis.

RESULTS

A total of 2604 patients were included in this study. The presence of LVBI [LBVI (+)] and Borrmann type (P = 0.001), tumor location (P < 0.001), tumor size (P < 0.001), histological type (P < 0.001), tumor invasion depth (P < 0.001), number of metastatic lymph nodes (P < 0.001), and surgical method (P < 0.001) were significantly correlated with survival. When analyzing the combination of the Borrmann classification and LBVI status, we found that patients with Borrmann type III disease and LBVI (+) had a similar 5-year survival rate to those with Borrmann IV + LBVI (-) (16.4% vs 13.1%, P = 0.065) and those with Borrmann IV + LBVI (+) (16.4% vs 11.2%, P = 0.112). Subgroup analysis showed that the above results were true for any pT stage and any tumor location. Multivariate Cox regression analysis showed that Borrmann classification (P = 0.023), vascular infiltration (P < 0.001), tumor size (P = 0.012), pT stage (P < 0.001), pN stage (P < 0.001), and extent of radical surgery (P < 0.001) were independent prognostic factors for survival.

CONCLUSION

Since patients with Borrmann III disease and LBVI (+) have the same poor prognosis as those with Borrmann IV disease, more attention should be paid to patients with Borrmann III disease and LBVI (+) during diagnosis and treatment, regardless of the pT stage and tumor location, to obtain better survival results.

The clinicopathological characteristics and prognosis of patients with node-positive gastric cancer after curative surgery

BACKGROUND

Lymph node (LN) metastasis is one of the independent prognostic factors of gastric cancer (GC). The difference in survival rates and initial recurrence patterns in patients with node-positive GC with retrieved LN numbers greater than or less than 16 is worthy of further study.

METHODS

A total of 1314 patients with node-positive GC were enrolled. The clinicopathological characteristics, retrieved LN numbers, adjuvant chemotherapy, initial recurrence patterns, and survival differences between serosa-negative and serosa-positive GC were investigated.

RESULTS

For serosa-negative GC, patients with retrieved LN numbers ≥16 were associated with fewer tumor recurrences, locoregional recurrences, distant metastases, and better 5-year overall survival (OS) rates and disease-free survival (DFS) rates. For serosa-positive GC, patients with retrieved LN numbers ≥16 were associated with similar locoregional and distant metastasis and similar 5-year OS and DFS rates compared with those with retrieved LN numbers <16. Retrieved LN numbers fewer than 16 can cause stage migration compared with retrieved LN numbers ≥16. Multivariate analysis showed that both the retrieved LN numbers (≥ or <16) and adjuvant chemotherapy were independent prognostic factors affecting OS in serosa-negative GC, while adjuvant chemotherapy but not the retrieved LN numbers was an independent prognostic factor of OS in serosa-positive GC.

CONCLUSION

For serosa-negative GC, retrieved LN numbers fewer than 16 can cause stage migration, a higher tumor recurrence rate and worse OS and DFS rates compared with patients with retrieved LN numbers ≥16. Due to a high tumor recurrence rate in serosa-positive GC, adjuvant chemotherapy rather than retrieved LN numbers played an important role in improving patient prognosis.

Impact of multisection and immunohistochemistry in lymph node staging of Gastric Carcinoma - Case series

Gastric carcinoma (GC) locoregional recurrence may occur even in cases where the tumor has been completely resected, possibly due to lymph node (LN) micrometastases. It is estimated that in 10% to 30% of cases, LN micrometastases are not detected by a conventional method for histological assessment of LN metastases with hematoxylin-eosin (HE). A cross-sectional study assessed 51 patients with GC by histological evaluation of the LN micrometastases through LN multi sectioning associated with immunohistochemistry analysis with monoclonal antibodies AE1 and AE3. Total gastrectomy was performed in 51% of patients. The total number of resected LN nodes was 1698, with a mean number of resected LN of 33.3 ± 13.2 per surgical specimen, of which 187 had metastasis. After the application of LN multisection and immunohistochemistry, LN micrometastases were found in 45.1% of the cases. LN staging changed in 29.4%, and tumor staging changed in 23.5% of the cases. In patients initially staged as pN0, LN staging and tumor staging changed, both in 19.2% of the cases. In patients initially staged as pN1 or more, LN staging changed in 40.0% of them, and tumor staging changed in 28.0% of the cases. The accuracy of HE for the histological staging of LN tumoral involvement was 76%, which was considered insufficient for CG patients staging. Investigation of LN micrometastasis through LN multisection and immunohistochemistry should be performed, particularly in cases where the presence of blood and lymphatic vessel invasion has been identified after conventional histological analysis, as well as in patients with advanced GC.

The Prognosis Value of Lymphatic Vessel Invasion in pN0 Gastric Cancer Patients with Insufficient Examined Lymph Nodes

OBJECTIVES

To investigate the prognosis value of lymphatic vessel invasion (LVI) in pN0 gastric cancer patients with insufficient examined lymph nodes (ELNs).

METHODS

Clinicopathologic and prognostic data of pN0 gastric cancer patients with insufficient ELNs who underwent radical surgery in our institution were retrospectively studied.

RESULTS

Firstly, we confirmed that less than 16 but not less than 30 ELNs were insufficient ELNs in the present study. Of the 350 pN0 patients with < 16 ELNs, 64 patients (18.29%) had LVI. The overall survival (OS) of patients with LVI was significantly poorer than those without LVI. Multivariate analysis suggested that LVI was one of the independent factors predicting prognosis of pN0 patients with < 16 ELNs. Further analyses suggested that there were similar prognoses between pN0 patients with < 16 ELNs who had LVI and pN1 patients, and between pN0 patients with < 16 ELNs who had no LVI and pN0 patients with ≥ 16 ELNs, respectively. Therefore, we proposed a novel pN classification, in which LVI-positive pN0 gastric cancer with < 16 ELNs was classified as pN1 disease. Two-step multivariate analysis demonstrated that the novel pN classification was more suitable for prognostic assessment than the original one.

CONCLUSIONS

LVI is a powerful and independent prognostic factor for pN0 gastric cancer patients with < 16 ELNs, and node-negative gastric cancer with < 16 ELNs which had LVI should be considered as node-positive disease. LVI is an effective indicator identifying patients stage migration happens to in pN0 patients with < 16 ELNs.

Silencing of Long Non-Coding RNA Colon Cancer-Associated Transcript 2 Inhibits the Growth and Metastasis of Gastric Cancer Through Blocking mTOR Signaling

Purpose

This study aimed to evaluate the specific role of colon cancer-associated transcript 2 (CCAT2) on gastric cancer (GC), and reveal the potential regulatory mechanism relating to mammalian target of rapamycin (mTOR) signaling.

Methods

The expression of CCAT2 was detected in GC tissues and cells by quantitative real-time PCR (qRT-PCR), and its relation with the pathologic characteristics of GC patients was analyzed. HGC-27 and SGC-7901 cells were transfected with siRNA-CCAT2 to silence CCAT2, and HGC-27 cells were then treated with an mTOR agonist Leucine (Leu) to activate mTOR signaling. The cell proliferation was evaluated by cell viability and colony formation. The cell cycle and apoptosis, and the migration and invasion abilities were detected by Flow cytometry, and Transwell assay, respectively. The expression of PCNA (proliferation marker), Snail, N-cadherin, E-cadherin (invasion markers), P53, Caspase-8, Bcl-2 (apoptosis markers), LC3-II/LC3-I, ATG3, p62 (autophagy makers), phosphorylated mTOR (p-mTOR), p-AKT, and p-p70S6K (mTOR signaling markers) were detected by Western blot.

Results

CCAT2 was upregulated in GC tissues and cells, and positively associated with the maximum tumor diameter, lymphatic metastasis, TNM staging, and low overall survival rate (P < 0.05). siRNA-CCAT2 transfection significantly inhibited the viability, colony formation, and migration and invasion abilities, blocked the cell cycle in G0/G1 phase, and promoted the apoptosis and autophagy of SGC-7901 and HGC-27 cells (P < 0.05). In addition, siRNA-CCAT2 transfection significantly upregulated P53, Caspase-8, LC3-II/LC3-I and ATG3, and downregulated PCNA, Bcl-2, p62, p-mTOR, p-AKT and p-p70S6K in SGC-7901 and HGC-27 cells (P < 0.05). siRNA-CCAT2 reversed the tumor-promoting effect of mTOR signaling activation on HGC-27 cells (P < 0.05).

Conclusion

Silencing of CCAT2 inhibited the proliferation, migration and invasion, and promoted the apoptosis and autophagy of GC cells through blocking mTOR signaling.

Development and validation of a nomogram for preoperative prediction of lymph node metastasis in early gastric cancer

Background

The status of lymph nodes in early gastric cancer is critical to make further clinical treatment decision, but the prediction of lymph node metastasis remains difficult before operation. This study aimed to develop a nomogram that contained preoperative factors to predict lymph node metastasis in early gastric cancer patients.

Methods

This study analyzed the clinicopathologic features of 823 early gastric cancer patients who underwent gastrectomy retrospectively, among which 596 patients were recruited in the training cohort and 227 patients in the independent validation cohort. Significant risk factors in univariate analysis were further identified to be independent variables in multivariable logistic regression analysis, which were then incorporated in and presented with a nomogram. And internal and external validation curves were plotted to evaluate the discrimination of the nomogram.

Results

Totally, six independent predictors, including the tumor size, macroscopic features, histology differentiation, P53, carbohydrate antigen 19-9, and computed tomography-reported lymph node status, were enrolled in the nomogram. Both the internal validation in the training cohort and the external validation in the validation cohort showed the nomogram had good discriminations, with a C-index of 0.82 (95%CI, 0.78 to 0.86) and 0.77 (95%CI, 0.60 to 0.94) respectively.

Conclusions

Our study developed a new nomogram which contained the most common and significant preoperative risk factors for lymph node metastasis in patients with early gastric cancer. The nomogram can identify early gastric cancer patients with the high probability of lymph node metastasis and help clinicians make more appropriate decisions in clinical practice.

Negative lymph node count as an independent prognostic factor in stage III patients after curative gastrectomy: A retrospective cohort study based on a multicenter database

OBJECTIVE

To examine the prognostic value of negative lymph node (NLN) count in stage III gastric cancer (GC) patients after curative gastrectomy.

METHODS

The clinicopathological data of 2942 stage III patients who underwent curative gastrectomy between 2001 and 2011 were analyzed. Only patients with ≥16 examined lymph nodes (ELNs) were included. After cut-point survival analysis, the 2942 patients were divided into three subgroups with NLN counts of 0, 1-9, and ≥10. Survival differences among the subgroups were analyzed to assess the effects of NLN count on stage migration and overall survival (OS) in stage III GC patients. Spearman's correlation coefficient was used to assess the relationships between the ELN count and the positive lymph node (PLN) count, the ELN count and the NLN count, and the NLN count and the PLN count.

RESULTS

Survival analyses revealed that the NLN count was significantly associated with OS (P = 0.001) and was an independent predictor (P < 0.01) of prognosis in stage III GC patients. Subgroup analysis showed that the prognostic evaluation accuracy was highest when the NLN count was ≥10 for stage III patients. Stage migrations were mainly detected in the following pathological tumor-node (pTN) subgroups: pT2N3a with 1-9 NLNs and pT2N3b with ≥10 NLNs, and pT3N3a with 1-9 NLNs and pT3N3b with ≥10 NLNs. NLN count was positively correlated with the ELN and the PLN counts for pT2N3 and pT3N3 stage GC patients (r = 0.694 and r = 0.881 for pT2N3 patients; r = 0.685 and r = 0.902 for pT3N3 patients, respectively; P < 0.001). These findings indicate that the NLN count may be a useful prognostic predictor in stage III GC patients.

CONCLUSIONS

The NLN count may improve the prognostic prediction efficiency of the tumor-node-metastasis (TNM) classification for GC, especially for stage III patients, and should be recommended for clinical applications.

Sentinel lymph node detection for gastric cancer: Promise or pitfall?

At present, optimal surgery for gastric cancer is still under debate, especially the extent of lymph node dissection. Gastrectomy with D1/D2 lymphadenectomy is standard treatment for resectable advanced gastric cancer. However, in early gastric cancer without lymph node metastasis, gastrectomy with D1/D2 lymphadenectomy may not be unnecessary, which could increases morbidity and mortality and reduces the quality of life (QOL). Therefore, the concept of sentinel lymph node could be applied in gastric cancer. But due to the complexity of gastric lymphatic drainage, there are still many issues under debate, such as suitable tracers, the method of mapping and collecting and the oncologic safety of sentinel node navigation surgery (SNNS). In addition, skip metastasis and unreliability of intraoperative pathological diagnosis are two main reasons for false negative cases. In this review, we summarize the current status and controversy of sentinel lymph node detection in gastric cancer, attempting to help with practical application. Further, we hold opinion that we should be cautious about performing sentinel lymph node detection in gastric cancer before an accurate and effective method occurs.

The relationship between the number of examined lymph nodes and the efficacy of chemotherapy for gastric cancer

BACKGROUND

The purpose of this research was to investigate the relationship between the number of examined lymph nodes (eLNs) and the prognosis.

METHODS

A retrospective examination of reports and studies carried out at two institutions was conducted. According to TNM stages, the relationship between the number of eLNs and the prognosis was analyzed.

RESULTS

The 5-year disease-specific survival (DSS) of all enrolled patients was 66.3%. A multivariate analysis showed the type of gastrectomy, histologic type, perineural invasion, pT stage, pN stage, chemotherapy and eLNs to be independent prognostic markers. Additionally, with the exception of patients with stage I disease, the 5-year DSS of patients who had < 25 eLNs removed had a higher risk of having a worst prognosis compared to patients who had ≥ 25 eLNs removed. Through this study, a hypothetical TNM staging system was obtained for predicting the prognosis according to the number of eLNs. Chemotherapy was able to improve the prognosis of patients with stage III and < 25 eLNs in stage II.

CONCLUSIONS

Extended lymphadenectomy with a new goal of dissecting 25 LNs for the evaluation of stage II-III cancer cases is recommended. Our hypothetical TNM staging system may be able to stratify the risk more accurately compared to the current AJCC 8th system. Chemotherapy can improve the prognosis in advanced gastric cancer, but its benefit may be affected by the surgical quality.

Comparison of Long-Term Outcomes of Endoscopic Submucosal Dissection and Surgery for Early Gastric Cancer: a Systematic Review and Meta-analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) is an endoscopic alternative to surgical resection of early gastric cancer (EGC). Besides offering both diagnostic and therapeutic capability, it has the benefits of reducing post-operative complications and provides fast recovery and better quality of life compared to surgical resection of neoplastic lesions. However, due to limitations of the procedure, its long-term outcomes are rather controversial.

METHODS

This study has been carried out to investigate the long-term outcomes of ESD which includes the overall survival (OS), disease-free survival (DFS), and recurrence rate. The following databases were used to search for articles published until February 2018: Medline, Cochrane Library, PubMed, Web of Science, and EBSCO.

RESULTS

A total of 13 eligible studies covering 4986 patients were selected for a meta-analysis based on specified inclusion and exclusion criteria. The difference of OS and disease-specific survival (DSS) between ESD and surgical treatment was not statistically significant (RR = 0.90, 95% CI = 0.68-1.19, p = 0.46; RR = 0.40, 95% CI = 0.15-1.03, p = 0.06, respectively). However, DFS in the ESD group was much lower than that in the surgery group (RR = 3.40, 95% CI = 2.39-4.84, p < 0.001). In terms of the treatment after recurrence, the proportion of patients who could receive radical treatment was significantly higher in the ESD than that in the gastrectomy (OR = 5.27, 95% CI = 2.35-11.79, p < 0.001).

CONCLUSIONS

This meta-analysis showed that ESD might be an alternative treatment option to surgery for patients with EGC in Asian countries. But a close surveillance program after ESD is of necessity, considering the higher possibility of tumor recurrence after ESD.

A comparison of the operative outcomes of D1 and D2 gastrectomy performed at a single Western center with multiple surgeons: a retrospective analysis with propensity score matching

BACKGROUND

There has been worldwide debate on lymphadenectomy for gastric cancer, with increasing consensus on performing an extended (D2) resection. There is a paucity of data in Australia. Our aim is to compare overall outcomes between a D1 and D2 lymphadenectomy for gastric cancer in a single specialist unit.

METHODS

We performed a retrospective analysis on patients who underwent a curative primary gastric resection for gastric adenocarcinoma between January 1996 and April 2016, primary outcomes included overall survival (OS) and disease-free survival (DFS). Propensity score matching (PSM) analysis was used to balance covariates between D1/D1+ and D2 groups. Kaplan-Meier survival curves of D1/D1+ versus D2 were constructed and evaluated using the log-rank test with subgroup analyses for pathological node (pN) status. Multiple Cox proportional hazards model was used to determine predictors of overall survival.

RESULTS

Two hundred four patients underwent a gastrectomy, 54 had D1/D1+, and 150 had a D2 lymphadenectomy. After PSM, there were 39 patients in each group, the 10-year OS for D1/D1+ was 52.1 and 76.2% for D2 (p = 0.008), and 10-year DFS was 35% for D1 and 58.1% for D2 (p = 0.058). Subgroup analysis showed that node-negative (N0) patients had improved 5-year OS for D2 (90.9%), compared to D1/D1+ (76.4%) (p = 0.028). There was no difference in operative mortality between the groups (D1 vs D2: 2 vs 0%, p = 0.314), nor in post-operative complications (p = 0.227). Multiple Cox analysis showed advanced tumor stage (stages III and IV), and lymphadenectomy type (D1) and the presence of postoperative complications were independent predictors of poor overall survival.

CONCLUSIONS

D2 lymphadenectomy with spleen and pancreas preservation can be performed safely on patients with gastric adenocarcinoma. Significant improvement in overall survival is observed in patients with N0 disease who underwent D2 lymphadenectomy without increasing operative morbidity or mortality. This paper supports the notion of a global consensus for a D2 lymphadenectomy, particularly in the Western context.

Borrmann Type 1 Cancer is Associated with a High Recurrence Rate in Locally Advanced Gastric Cancer

BACKGROUND

This study aimed to investigate the clinicopathologic characteristics and outcomes of Borrmann type 1 gastric cancer and evaluate its clinical significance in advanced gastric cancer compared with Borrmann types 2 and 3 cancer.

METHODS

Between January 1989 and December 2013, 1949 patients with advanced gastric cancer who underwent curative gastrectomy at our institution were enrolled in the study.

RESULTS

Of the 1949 patients, 59 (3%) exhibited Borrmann type 1 cancer, characterized by a large size, rare serosal invasion, lower lymph node involvement, location in the upper third of the stomach, intestinal type, and differentiated histology. The recurrence rate was higher for Borrmann type 1 than for Borrmann types 2 and 3 cancer. In addition, more than half of the Borrmann type 1 recurrences showed a hematogenous pattern. However, overall survival did not differ significantly among the three cancer types. In the multivariate analysis, Borrmann type 1 cancer, with tumor depth, node metastasis, and vascular invasion, was an independent risk factor associated with recurrence. Particularly, Borrmann type 1 cancer showed a worse prognosis in both overall survival and recurrence-free survival than the other Borrmann types in the upper third of the stomach.

CONCLUSIONS

Borrmann type 1 gastric cancer is associated with a higher recurrence rate than Borrmann types 2 and 3, but not with a difference in the overall survival rate.

Elevated preoperative neutrophil-to-lymphocyte ratio can predict poor survival in early stage gastric cancer patients receiving radical gastrectomy: The Fujian prospective investigation of cancer (FIESTA) study

Aims: This cohort study was conducted to evaluate the prognostic impact of blood-routine parameters before radical gastrectomy on gastric cancer mortality.

Methods: Total 3012 patients with gastric cancer were consecutively enrolled from a mono-center between 2000 and 2010, and the latest follow-up was completed in 2015.

Results: The median follow-up time was 44.05 months. Finally, 1331 out of 3012 gastric cancer patients died from gastric cancer. Per standard deviation increment in neutrophil (hazard ratio or HR=1.08, P<0.001), white blood cell count (HR=1.07, P=0.001), neutrophil-to-lymphocyte ratio or NLR (HR=1.08, P<0.001) and platelet-to-lymphocyte ratio (HR=1.08, P<0.001) was significantly associated with an increased risk of gastric cancer mortality, while that in lymphocyte (HR=0.69, P<0.001), hemoglobin (HR=0.82, P<0.001) and lymphocyte-to-monocyte ratio (HR=0.68, P<0.001) was associated with a reduced risk. Survival tree analysis indicated that in patients with TNM stage I/II, the contrasts of NLR>2.61 with ≤2.61 and NLR>1.87 with ≤1.87 were respectively associated with a 5.21-fold (P=0.004) and 2.36-fold (P=0.001) increased risk of gastric cancer mortality. The effect-size magnitude of NLR was further potentiated in patients with invasion depth T1/T2 (HR=1.73, P=0.001), regional lymph node metastasis N0 (HR=1.60, P<0.001), TNM stage I/II (HR=1.36, P=0.009) and tumor size ≤ 4.5 cm (HR=1.17, P<0.001).

Conclusions: Our findings consolidated the prognostic impact of preoperative NLR on gastric mortality, and demonstrated that elevated preoperative NLR was a robust indicator of poor survival in patients at early stage.

DETECTION OF OCCULT LYMPH NODE TUMOR CELLS IN NODE-NEGATIVE GASTRIC CANCER PATIENTS

BACKGROUND

The presence of lymph nodes metastasis is one of the most important prognostic indicators in gastric cancer. The micrometastases have been studied as prognostic factor in gastric cancer, which are related to decrease overall survival and increased risk of recurrence. However, their identification is limited by conventional methodology, since they can be overlooked after routine staining.

AIM

To investigate the presence of occult tumor cells using cytokeratin (CK) AE1/AE3 immunostaining in gastric cancer patients histologically lymph node negative (pN0) by H&E.

METHODS

Forty patients (T1-T4N0) submitted to a potentially curative gastrectomy with D2 lymphadenectomy were evaluated. The results for metastases, micrometastases and isolated tumor cells were also associated to clinicopathological characteristics and their impact on stage grouping. Tumor deposits within lymph nodes were defined according to the tumor-node-metastases guidelines (7th TNM).

RESULTS

A total of 1439 lymph nodes were obtained (~36 per patient). Tumor cells were detected by immunohistochemistry in 24 lymph nodes from 12 patients (30%). Neoplasic cells were detected as a single or cluster tumor cells. Tumor (p=0.002), venous (p=0.016), lymphatic (p=0.006) and perineural invasions (p=0.04), as well as peritumoral lymphocytic response (p=0.012) were correlated to CK-positive immunostaining tumor cells in originally negative lymph nodes by H&E. The histologic stage of two patients was upstaged from stage IB to stage IIA. Four of the 28 CK-negative patients (14.3%) and three among 12 CK-positive patients (25%) had disease recurrence (p=0.65).

CONCLUSION

The CK-immunostaining is an effective method for detecting occult tumor cells in lymph nodes and may be recommended to precisely determine tumor stage. It may be useful as supplement to H&E routine to provide better pathological staging.

Increasing the Number of Examined Lymph Nodes is a Prerequisite for Improvement in the Accurate Evaluation of Overall Survival of Node-Negative Gastric Cancer Patients

BACKGROUND

This study aims to elucidate whether increasing the number of examined lymph nodes (NELN) is mandatory for the accurate prognosis of node-negative gastric cancer (GC) patients after curative gastrectomy in Eastern countries (China and Japan).

METHODS

The clinicopathological data of 2455 GC patients (including 1137 node-negative cases) were included to demonstrate whether a minimum NELN is inevitable for guaranteeing the accurate prognosis of node-negative GC patients after curative gastrectomy.

RESULTS

Survival analyses revealed that the NELN significantly positively correlated with overall survival (p < 0.001) and was an independent prognostic predictor (hazard ratio 0.447; p = 0.025) of 1137 node-negative GC patients. Stratum analysis within the Kaplan-Meier method showed that sex, tumor size, and extent of lymphadenectomy did not affect the NELN in predicting the prognosis of all node-negative GC patients. Stage migration was mainly detected in the subgroup of node-negative GC Chinese patients who presented considerably lower mean NELN and more advanced staging than patients from Japan. The NELN was identified as the most intensively independent predictor of prognosis of 600 node-negative GC patients from China, with the smallest Akaike information criterion (176.964) and Bayesian information criterion values (194.552). These findings indicate that increasing the NELN is a prerequisite to guaranteeing precise TNM classification.

CONCLUSIONS

The NELN should be considered a mandatory requirement for improving the accuracy of prognostic evaluation of GC patients, especially for advanced-stage patients.

Clinical significance of the anterosuperior lymph nodes along the common hepatic artery identified by sentinel node mapping in patients with gastric cancer

BACKGROUND

The sentinel node (SN) concept is safely applied and validated in early gastric cancer. Gastric lymph nodes are divided into five basins with the main gastric arteries, and the anterosuperior lymph nodes with the common hepatic artery (No. 8a) are classified in the right gastric artery (r-GA) basin. Although No. 8a are considered to have lymphatic flow from the r-GA basin, there might be additional multiple lymphatic flows into No. 8a. The aim of this study is to analyze the lymphatic flows to No. 8a and to investigate the clinical significance of No. 8a as a sentinel node (SN No. 8a).

METHODS

Four hundred and twenty-nine patients with cT1N0 or cT2N0 gastric cancer underwent SN mapping. We used technetium-99 tin colloid solution and blue dye as a tracer.

RESULTS

We detected SN No. 8a in 35 (8.2 %) patients. In these patients, we detected SN No. 8a with SNs that belonged to the left gastric artery (l-GA) basin (66 %), right gastroepiploic artery (r-GEA) basin (54 %), and right gastric artery (r-GA) basin (46 %). In addition, celiac artery lymph nodes were detected as SNs significantly more frequently. Function-preserving surgery was performed significantly less often in patients with SN No. 8a (p =0.018).

CONCLUSIONS

We found that SN No. 8a seemed to have lymphatic flow not only from the r-GA basin, but also from the l-GA basin or r-GEA basin. When SN No. 8a are detected, we should be careful to perform function-preserving surgery, even in SN-negative cases.

Practical intraoperative pathologic evaluation of sentinel lymph nodes during sentinel node navigation surgery in gastric cancer patients - Proposal of the pathologic protocol for the upcoming SENORITA trial

Over the last decade, as the number of patients with early gastric cancer increased and the subsequent survival rate improved, there has been a consistent effort to verify the applicability of the sentinel node concept in gastric cancer in a bid to improve postoperative quality of life in these patients. During sentinel node navigation surgery in gastric cancer patients, intraoperative pathologic examination of the retrieved sentinel nodes plays a critical role in determining the extent of surgery, but the optimal method is still under debate. Currently, a multicenter, phase III clinical trial is underway to compare laparoscopic sentinel basin dissection with stomach preserving surgery and standard laparoscopic gastrectomy in terms of oncologic outcomes in patients with clinical stage T1N0 gastric cancer. Herein, the currently available intraoperative pathologic techniques are reviewed and their clinical significance and applicability are appraised based on the published literature. The proper pathologic examination of the sentinel lymph nodes in an upcoming clinical trial (SENORITA trial) is also proposed here based on this review.

Borrmann type IV gastric cancer should be classified as pT4b disease

BACKGROUND

The impact of macroscopic pathologic features of primary tumor that could be obtained preoperatively on pT classification has not been reported so far. The aim of this study was to investigate the feasibility of incorporation of Borrmann type IV gastric cancer into the pT classification.

MATERIALS AND METHODS

Clinicopathologic and prognostic data of 1622 patients with advanced gastric cancer who underwent radical surgery were retrospectively studied.

RESULTS

Of 1622 patients, 135 (8.32%) patients were classified as having Borrmann type IV gastric cancer. We first confirmed that Borrmann type IV gastric cancer was one of the independent prognostic factors for patients with advanced gastric cancer who underwent radical surgery. Interestingly, we found that overall survival of patients with Borrmann type IV gastric cancer could be clearly distinguished by pN classification and pathological TNM stage but not by pT classification. Importantly, further analysis demonstrated that the prognosis of Borrmann type IV gastric cancers was homogeneous with that of pT4b cancers but poorer than pT2, pT3, pT4a cancers. Therefore, we proposed a novel pT classification in which pT4b disease was defined as cancers that were Borrmann type IV or those that had invaded adjacent structures. Two-step multivariate analysis demonstrated that the novel pT classification was more suitable for prognostic assessment than the original classification.

CONCLUSIONS

Classifying Borrmann type IV gastric cancer as pT4b disease improves pT classification prediction of prognosis in patients with advanced gastric cancer after radical surgery.

CA19-9 serum levels predict micrometastases in patients with gastric cancer

Background

We explored the prognostic value of the up-regulated carbohydrate antigen (CA19-9) in node-negative patients with gastric cancer as a surrogate marker for micrometastases.

Patients and methods

Micrometastases were determined using reverse transcription quantitative polymerase chain reaction (RT-qPCR) for a subgroup of 30 node-negative patients. This group was used to determine the cut-off for preoperative CA19-9 serum levels as a surrogate marker for micrometastases. Then 187 node-negative T1 to T4 patients were selected to validate the predictive value of this CA19-9 threshold.

Results

Patients with micrometastases had significantly higher preoperative CA19-9 serum levels compared to patients without micrometastases (p = 0.046). CA19-9 serum levels were significantly correlated with tumour site, tumour diameter, and perineural invasion. Although not reaching significance, subgroup analysis showed better five-year survival rates for patients with CA19-9 serum levels below the threshold, compared to patients with CA19-9 serum levels above the cut-off. The cumulative survival for T2 to T4 node-negative patients was significantly better with CA19-9 serum levels below the cut-off (p = 0.04).

Conclusions

Preoperative CA19-9 serum levels can be used to predict higher risk for haematogenous spread and micrometastases in node-negative patients. However, CA19-9 serum levels lack the necessary sensitivity and specificity to reliably predict micrometastases.

Low junctional adhesion molecule A expression correlates with poor prognosis in gastric cancer

BACKGROUND

The aberrant expression of junctional adhesion molecule A (JAM-A), which has a close correlation with the development, progression, metastasis, and prognosis of cancer, has been frequently reported. However, neither JAM-A expression nor its correlation with clinicopathologic variables and patient survival has been defined in gastric cancers. Moreover, little is known about the role of JAM-A in gastric cancer progression. We carried out the present study to investigate the prognostic value of JAM-A expression in gastric cancer patients. Furthermore, the biological roles of JAM-A in gastric cancer progression were also investigated.

METHODS

We determined JAM-A expression in 167 primary gastric cancer tissues and 94 matched adjacent non-tumor tissues by immunohistochemistry. Transwell migration assays and matrigel invasion assays were used to explore the role of JAM-A in gastric cancer cells migration and invasion. CCK-8 assays were used to examine the effect of JAM-A on the proliferation of gastric cancer cells.

RESULTS

JAM-A was downregulated in gastric cancer tissues. Low JAM-A expression was significantly associated with tumor size, lymphatic vessel invasion, lymph node metastasis, and TNM stage. Low JAM-A expression was also significantly associated with poor disease-specific survival in gastric cancer patients. Multivariate analysis demonstrated low JAM-A expression as an independent factor predicting poor survival. In addition, JAM-A had the effect on inhibition of gastric cancer cells migration and invasion. However, JAM-A had no significant effects on proliferation of gastric cancer cells.

CONCLUSIONS

Low JAM-A expression correlates with poor clinical outcome and promotes cell migration and invasion in gastric cancer.

Clinical significance of lymph node metastasis in gastric cancer

Gastric cancer, one of the most common malignancies in the world, frequently reveals lymph node, peritoneum, and liver metastases. Most of gastric cancer patients present with lymph node metastasis when they were initially diagnosed or underwent surgical resection, which results in poor prognosis. Both the depth of tumor invasion and lymph node involvement are considered as the most important prognostic predictors of gastric cancer. Although extended lymphadenectomy was not considered a survival benefit procedure and was reported to be associated with high mortality and morbidity in two randomized controlled European trials, it showed significant superiority in terms of lower locoregional recurrence and disease related deaths compared to limited lymphadenectomy in a 15-year follow-up study. Almost all clinical investigators have reached a consensus that the predictive efficiency of the number of metastatic lymph nodes is far better than the extent of lymph node metastasis for the prognosis of gastric cancer worldwide, but other nodal metastatic classifications of gastric cancer have been proposed as alternatives to the number of metastatic lymph nodes for improving the predictive efficiency for patient prognosis. It is still controversial over whether the ratio between metastatic and examined lymph nodes is superior to the number of metastatic lymph nodes in prognostic evaluation of gastric cancer. Besides, the negative lymph node count has been increasingly recognized to be an important factor significantly associated with prognosis of gastric cancer.