Relevance of lymph node metastasis along the superior mesenteric vein in gastric cancer

Surgery Matters: Progress in Surgical Management of Gastric Cancer

OPINION STATEMENT

The surgical treatment of gastric carcinoma has progressed significantly in the past few decades. A major milestone was the establishment of multimodal therapies for locally advanced tumours. Improvements in the technique of endoscopic resection have supplanted surgery in the early stages of many cases of gastric cancer. In cases in which an endoscopic resection is not possible, surgical limited resection procedures for the early stages of carcinoma are an equal alternative to gastrectomy in the field of oncology. Proximal gastrectomy is extensively discussed in this context. Whether proximal gastrectomy leads to a better quality of life and better nutritional well-being than total gastrectomy depends on the reconstruction chosen. The outcome cannot be conclusively assessed at present. For locally advanced stages, total or subtotal gastrectomy with D2 lymphadenectomy is now the global standard. A subtotal gastrectomy requires sufficiently long tumour-free proximal resection margins. Recent data indicate that proximal margins of at least 3 cm for tumours with an expansive growth pattern and at least 5 cm for those with an infiltrative growth pattern are sufficient. The most frequently performed reconstruction worldwide following gastrectomy is the Roux-en-Y reconstruction. However, there is evidence that pouch reconstruction is superior in terms of quality of life and nutritional well-being. Oncological gastric surgery is increasingly being performed laparoscopically. The safety and oncological equivalency were first demonstrated for early carcinomas and then for locally advanced tumours, by cohort studies and RCTs. Some studies suggest that laparoscopic procedures may be advantageous in early postoperative recovery. Robotic gastrectomy is also increasing in use. Preliminary results suggest that robotic gastrectomy may have added value in lymphadenectomy and in the early postoperative course. However, further studies are needed to substantiate these results. There is an ongoing debate about the best treatment option for gastric cancer with oligometastatic disease. Preliminary results indicate that certain patient groups could benefit from resection of the primary tumour and metastases following chemotherapy. However, the exact conditions in which patients may benefit have yet to be confirmed by ongoing trials.

Clinical Significance of Metastasis or Micrometastasis to the Lymph Node Along the Superior Mesenteric Vein in Gastric Carcinoma: A Retrospective Analysis

Background

The validity of lymphadenectomy of the lymph node along the superior mesenteric vein (LN14v) in gastric cancer remains controversial. The study investigated the characteristics and prognosis of gastric cancer with metastasis or micrometastasis to LN14v.

Methods

A retrospective study of 626 patients undergoing radical gastrectomy in our center from January 2003 to December 2015 was analyzed. In total, 303 patients had lymphadenectomy of LN14v, and lymph node micrometastasis was evaluated by immunohistochemical staining for cytokeratin nodes CK8/18. A logistic regression model was applied to confirm the predictive factors of micrometastasis. Survival analysis was performed to evaluate the effect of micrometastasis or metastasis on prognosis.

Results

The metastatic rate of the LN14v lymph node was 15.8%, and the micrometastatic rate was 3.3%. Multivariate analysis showed site, Borrmann classification, postoperative lymph node metastasis (pN), and metastasis in LN6 and LN9 were predictive factors for LN14v micrometastasis or metastasis (P < 0.05). The 5-year survival rate in the positive group (LN14v micrometastasis or metastasis) was 12.4%. The prognosis of patients without LN14v lymph node micrometastasis was better than that of the positive group, whereas the difference between group of LN14v micrometastasis and LN14v metastasis was not obvious. In matched analysis, patients with stage III gastric cancer L/M area, pN2-3, and LN6(+) who underwent lymphadenectomy of LN14v had better survival than those without lymphadenectomy of LN14v.

Conclusion

Lymph node micrometastasis may provide accurate prognostic information for patients with gastric cancer. Moreover, lymphadenectomy of LN14v might improve the survival of patients with stage III gastric cancer of L/M area, pN2-3, and LN6(+).

Current status of extended 'D2 plus' lymphadenectomy in advanced gastric cancer

The extent of lymph node (LN) dissection has been a topic of interest in gastric cancer (GC) surgery. D2 lymphadenectomy is considered the standard surgical procedure for most resectable advanced GC cases. The value and indications of more extended lymphadenectomy than D2 remain unclear. Currently, the controversial stations beyond the D2 range are mainly focused on no. 14v, no. 16a2/b1 and no. 13 LN stations. The metastatic rate of no. 14v LN is relatively high in advanced distal GC, particularly in patients with suspicious no. 6 LN metastasis. D2 plus no. 14v LN dissection may be attributed to improved survival outcomes for patients with obvious no. 6 LN metastasis. Although GC with para-aortic lymph node (PALN) metastases is considered an M1 disease beyond surgical cure, patients with limited PALN metastases may benefit from the treatment strategy of adjuvant chemotherapy followed by D2 plus no. 16a2-b1 LN dissection. In addition, D2 plus no. 13 LN dissection may be an option in a potentially curative gastrectomy for GC with duodenal invasion. The present review discusses the current status and future perspectives of D2 plus lymphadenectomy.

Current status of lymph node dissection in gastric cancer

Gastrectomy with lymph node (LN) dissection has been regarded as the standard surgery for gastric cancer (GC), however, the rational extent of lymphadenectomy remains controversial. Though gastrectomy with extended lymphadenectomy beyond D2 is classified as a non-standard gastrectomy, its clinical significance has been evaluated in many studies. Although hard evidence is lacking, D2 plus superior mesenteric vein (No. 14v) LN dissection is recommended when harbor metastasis to No. 6 nodes is suspected in the lower stomach, and dissection of splenic hilar (No. 10) LN can be performed for advanced GC invading the greater curvature of the upper stomach, and D2 plus posterior surface of the pancreatic head (No. 13) LN dissection may be an option in a potentially curative gastrectomy for cancer invading the duodenum. Prophylactic D2+ para-aortic nodal dissection (PAND) was not routinely recommended for advanced GC patients, but therapeutic D2 plus PAND may offer a chance of cure in selected patients, preoperative chemotherapy was considered as the standard treatment for GC with para-aortic node metastasis. There has been no consensus on the extent of lymphadenectomy for the adenocarcinoma of the esophagogastric junction (AEG) so far. The length of esophageal invasion can be used as a reference point for mediastinal LN metastases, and the distance from the esophagogastric junction to the distal end of the tumor is essential for determining the optimal extent of resection. The quality of lymphadenectomy may influence prognosis in GC patients. Both hospital volume and surgeon volume were important factors for the quality of radical gastrectomy. Centralization of GC surgery may be needed to improve prognosis.

Factors associated with metastasis in superior mesenteric vein lymph node in subtotal gastrectomy for gastric cancer: Retrospective case control study

Objective

The revised Japanese treatment guideline for gastric cancer recommends dissection of the superior mesenteric vein lymph node (No. 14v LN) if there is metastasis in infrapyloric lymph node (No. 6 LN). However, it is still controversial whether LN dissection is necessary. The aim of this study was to investigate the factors associated with metastasis in No. 14v LN.

Methods

Patients who underwent D2 lymphadenectomy between 2003 and 2010 were included. We excluded patients who underwent total gastrectomy, had multiple lesions, or had missing data about the status of metastasis in the LNs that were included in D2 lymphadenectomy. Clinicopathologic characteristics and the metastasis in regional LNs were compared between patients with No. 14v LN metastasis (14v+) and those without (14v−).

Results

Five hundred sixty patients were included in this study. Univariate analysis showed that old age, larger tumor size, tumor location, differentiation, lymphatic invasion, venous invasion, perineural invasion, T classification, and N classification were related to metastasis in No. 14v LN. Multivariate analysis showed differentiation (P=0.027) and N classification (P<0.001) were independent related factors. Metastasis in infrapyloric lymph node (No. 6 LN) and proxiaml splenic lymph node (No. 11p LN) was independently associated with metastasis in No. 14v LN.

Conclusions

Differentiation and N classification were independent factors associated with No. 14v LN metastasis, and No. 6 and No. 11p LN metastasis were independent risk factors for No. 14v LN metastasis.

"D2 plus" lymphadenectomy is associated with improved survival in distal gastric cancer with clinical serosa invasion: a propensity score analysis

The aim of this study was to elucidate the potential impact of “D2 plus” lymphadenectomy on the long-term survival of distal gastric cancer (GC) patients with clinical serosa invasion. A total of 394 distal GC patients with clinical serosa invasion who underwent at least standard D2 lymphadenectomy were enrolled. Patients were categorized into two groups according to the extent of lymphadenectomy: D2 group and “D2 plus” group. Propensity score matching was used to adjust for the differences in baseline characteristics. In the multivariate analysis for the whole study series, extent of lymphadenectomy was an independent prognostic factor for GC patients (P = 0.011). With the strata analysis, the significant prognostic differences between the two groups were only observed in patients at the IIIa-b or N1-3a stages. After matching, patients in “D2 plus” group still demonstrated a significantly higher 5-year overall survival rate than those in D2 group (55.3% versus 43.9%, P = 0.042). The common therapeutic value index of No. 12b, No. 12p, No. 14v and No. 13 LNs was 4.6, which was close to that of No. 5 LN station. In conclusion, “D2 plus” lymphadenectomy may be associated with improved overall survival in distal GC with clinical serosa invasion.

Prognostic significance of 14v-lymph node dissection to D2 dissection for lower-third gastric cancer

BACKGROUND

Radical gastrectomy with D2 lymph node (LN) dissection is the standard surgical procedure for patients with resectable gastric cancer (GC). In the fifteenth edition of the Japanese Classification of Gastric Carcinoma, the 14v LN (LNs along the root of the superior mesenteric vein) was defined as the regional gastric LN. The efficacy of 14v LN dissection during radical distal gastrectomy for lower-third GC remains controversial.

AIM

To analyze whether the addition of 14v LN dissection improved the survival of patients with lower-third GC.

METHODS

The data from 65 patients who underwent 14v LN dissection and 65 patients treated without 14v LN dissection were selected using the propensity score-matched method from our institute database constructed between 2000 and 2012. Overall survival was compared between the groups.

RESULTS

Overall survival was similar between patients with 14v LN metastasis and those with distant metastasis (P = 0.521). Among patients with pathological stage IIIA disease, those who were treated with 14v LN dissection had a significantly higher overall survival than those treated without it (P = 0.020). Multivariate analysis showed that age < 65 years and pT2-3 stage were independent favorable prognostic factors for prolonged overall survival in patients with pathological stage IIIA disease. Patients with No. 1, No. 6, No. 8a, or No. 11p LN metastasis were at higher risk of having 14v LN metastasis.

CONCLUSION

Adding 14v LN dissection to D2 dissection during radical distal gastrectomy may improve the overall survival of patients with pathological stage IIIA lower-third GC.

Is it worthy of adding dissection of the superior mesenteric vein lymph node (14v) to standard D2 gastrectomy for distal gastric cancers with No. 6 lymph node metastasis?

PURPOSE

Radical gastrectomy with D2 lymphadenectomy has been widely recognized as standard surgical procedure for advanced gastric cancer, while the role of No. 14v lymphadenectomy in distal gastric cancer remains controversial.

METHODS

Clinicopathological data of 793 distal gastric cancer patients who underwent at least a radical D2 lymphadenectomy with No. 6 nodes metastasis were retrospectively reviewed.

RESULTS

Fifty patients received No. 14v lymphadenectomy. Patients with No. 14v nodes metastasis (21/50, 42.0%) had poor prognosis. The No. 14v nodes metastasis was not an independent prognostic factor (P = 0.075). In distal gastric cancer patients with No. 6 nodes metastasis, No. 14v lymphadenectomy deteriorated overall survival, what's more, No. 14v lymphadenectomy was an independent risk prognostic factor (hazard ratio: 1.404; 95% confidence interval 1.043-1.889; P = 0.025). There was no significant difference in overall or locoregional and other types of recurrence rate between the 14vD+ and the 14vD- groups. The proportion of complication rate was greater in 14vD+ group (P = 0.001).

CONCLUSION

Extended D2 gastrectomy including No. 14v lymphadenectomy seems to be associated with poor overall survival and increased complication rate of distal gastric cancer patients with No. 6 nodes metastasis.

Therapeutic Value of Lymph Node Dissection Along the Superior Mesenteric Vein and the Posterior Surface of the Pancreatic Head in Gastric Cancer Located in the Lower Third of the Stomach

Background

Therapeutic value of lymph node dissection along the superior mesenteric vein (14v) and the posterior surface of the pancreatic head (13) remains unclear in gastric cancer patients.

Methods

We reviewed 355 patients with advanced gastric cancer in the lower third of the stomach who had undergone gastrectomy at our hospital.

Results

The frequency of lymph node (LN) metastasis was 10.2% and 7.4% in stations 13 and 14v, respectively. The frequency of station 13 metastasis was 26.8% for T3/T4 tumors with group 2 LNs metastasis and 1.4% for all other tumors. The frequency of station 14v metastasis was 22.2% for T3/T4 tumors with group 2 LNs metastasis and 1.8% for all other tumors. The therapeutic values for dissecting LN stations 13 and 14v were 1.9 and 0.9, respectively, similar to the therapeutic value for group 2 LN dissection.

Conclusion

Because metastasis to stations 13 and 14v occurs frequently in patients with T3/T4 gastric cancer located in the lower third of the stomach who also have metastasis to group 2 LNs, stations 13 and 14v should be dissected in these patients.

Risk factors for metastasis to No.14v lymph node and prognostic value of 14v status for gastric cancer patients after surgery

Background

D2 procedure has been accepted as the standard lymphadenectomy for advanced GC, while the role of No.14v lymph node (14v) dissection for distal GC is still controversial.

Methods

A total of 284 GC patients receiving D2 plus 14v dissection in our center were enrolled. Patients were categorized into two groups based on 14v status: positive group (PG) and negative group (NG). Clinicopathological factors correlated with 14v metastasis and prognostic variables were respectively analyzed.

Results

Thirty-five patients (12.3%) had 14v metastasis. Metastasis to No.4d and No.6 lymph node were independent variables affecting 14v metastasis. Patients with positive 14v had a significant lower 3-year overall survival (OS) rate than those without (3-year OS: 42.9% vs. 70.3%, P < 0.001). Multivariable analysis demonstrated that 14v status was an independent prognostic factor for III stage GC (hazard ratio 1.462, 95% confident interval: 1.182-2.309, P = 0.027). The prognosis of 14v positive patients correlated with tumor size and No.6 lymph node status in univariate analysis.

Conclusion

GC patients with No.4d and No.6 lymph node metastasis were more likely to have positive 14v. Status of 14v was an independent prognostic factor for III stage GC. Patients with 14v metastasis usually had a poorer prognosis, while survival in such patients after curative surgery was similar to that of patients staged IIIc without 14v metastasis.

Safety and prognostic impact of prophylactic laparoscopic superior mesenteric vein (No. 14v) lymph node dissection for lower-third gastric cancer: a propensity score-matched case-control study

AIM

To investigate oncologic efficacy of prophylactic laparoscopic superior mesenteric vein (No. 14v) lymph node (LN) dissection for lower-third gastric cancer (LTGC).

METHODS

We retrospectively collected data from 757 patients who underwent laparoscopic-assisted distal gastrectomy for LTGC. Of these patients, 102 underwent 14v LN dissection (14vD+ group), and the remaining 655 patients did not undergo 14v LN dissection (14vD- group). The outcomes were compared using a 1:1 propensity score matching method.

RESULTS

After matching, 93 patients from the 14vD+ group and 93 patients from the 14vD- group with similar clinicopathological characteristics were compared. Before matching, the overall survival (OS) was similar between the two groups (P = 0.742). After matching, the OS was greater in the 14vD+ group (P = 0.025). The status of 14v dissection was not a significant prognostic factor in the survival analyses, both before and after matching. However, a stratified analysis according to the independent factors in the OS showed that the OS in the 14vD+ group was higher than that in the 14vD- group for cT2-3 patients after matching. The forest plot of OS showed that after matching the 14vD+ group had a significantly higher 3-year OS rate than the 14vD- group in cT2-3 patients. The distribution of the therapeutic index demonstrated that the index of 14v LN was similar to those of Nos. 1, 7, 8a, 9, and 11p after matching.

CONCLUSIONS

Adding laparoscopic 14v dissection for laparoscopic-assisted radical distal gastrectomy was safe and might improve the OS for clinically advanced LTGC without serosal invasion.

Five-year Survival Associated with Stage I Gastric Cancer after Resection of Early Recurrence at Nodal Station No. 14v: a Case Report

The role of nodal station No. 14v (along the superior mesenteric vein) in lymphadenectomy for distal gastric cancer remains elusive. A 73-year-old woman underwent endoscopic submucosal dissection for gastric cancer, and was referred to our division for additional surgery because of pathologically non-curative resection. A laparoscopic distal gastrectomy with D1+ dissection was performed, with a final diagnosis of pT1bN1M0, Stage IB (2 nodal metastases to No. 6). Four months post-surgery, abdominal computed tomography revealed a 14-mm solitary nodule along the superior mesenteric vein. The lesion was excised and pathologically identified as a lymph node metastasis. Adjuvant chemotherapy with tegafur-gimeracil-oteracil potassium (S-1) was administered for the metastasis. Presently the patient survives without recurrence, 5.5 years after the second operation. Our findings suggest that there is lymphatic flow from the No. 6 to the No. 14v nodal station. Some patients with a No. 6 metastasis may benefit from a No. 14v lymphadenectomy, even in early-staged disease.

Evaluation of rational extent lymphadenectomy for local advanced gastric cancer

Based upon studies from randomized clinical trials, the extended (D2) lymph node dissection is now recommended as a standard procedure for local advanced gastric cancer worldwide. However, the rational extent lymphadenectomy for local advanced gastric cancer has remained a topic of debate in the past decades. Due to the limitation of low metastatic rate in para-aortic nodes (PAN) in JCOG9501, the clinical benefit of D2+ para-aortic nodal dissection (PAND) for patients with stage T4 and/or stage N3 disease, which is very common in China and other countries except Japan and Korea, cannot be determined. Furthermore, the role of splenectomy for complete resection of No.10 and No.11 nodes has been controversial, and however, the final results from the randomized trial of JCOG0110 have yet to be completed. Gastric cancer with the No.14 and No.13 lymph node metastasis is defined as M1 stage in the current version of the Japanese classification. We propose that D2+No.14v and +No.13 lymphadenectomy may be an option in a potentially curative gastrectomy for tumors with apparent metastasis to the No.6 nodes or infiltrate to duodenum. The examined lymph node and extranodal metastasis are significantly associated with the survival of gastric cancer patients.

Positive impact of adding No.14v lymph node to D2 dissection on survival for distal gastric cancer patients after surgery with curative intent

BACKGROUND

D2 lymphadenectomy has been increasingly regarded as standard surgical procedure for advanced gastric cancer (GC), while the necessity of No.14v lymph node (14v) dissection for distal GC is still controversial.

METHODS

A total of 920 distal GC patients receiving at least a D2 lymph node dissection in Department of Gastric Cancer, Tianjin Medical University Cancer Institute and Hospital were enrolled in this study, of whom, 243 patients also had the 14v dissected. Other 677 patients without 14v dissection were used for comparison.

RESULTS

Forty-five (18.5%) patients had 14v metastasis. There was no significant difference in 3-year overall survival (OS) rate between patients with and without 14v dissection. Following stratified analysis, in TNM stages I, II, IIIa and IV, 14v dissection did not affect 3-year OS; in contrast, patients with 14v dissection had a significant higher 3-year OS than those without in TNM stages IIIb and IIIc. In multivariate analysis, 14v dissection was found to be an independent prognostic factor for GC patients with TNM stage IIIb/IIIc disease [hazard ratio (HR), 1.568; 95% confidence interval (CI): 1.186-2.072; P=0.002]. GC patients with 14v dissection had a significant lower locoregional, especially lymph node, recurrence rate than those without 14v dissection (11.7% vs. 21.1%, P=0.035).

CONCLUSIONS

Adding 14v to D2 lymphadenectomy may be associated with improved 3-year OS for distal GC staged TNM IIIb/IIIc.

Laparoscopic Infrapyloric Area Lymph Node Dissection with No. 14v Enlargement for Advanced Lower Gastric Cancer in Middle Colic Vein Approach

BACKGROUND

We developed a procedure for laparoscopic infrapyloric area lymph node (LN) dissection with No. 14v enlargement, which is complicated for patients with advanced lower gastric cancer (GC) (Xu et al., World J Gastroenterol 13:5133-5138,2007; Masuda et al., Dig Surg 25:351-358,2008; An et al., Br J Surg 98:667-672,2011].

METHODS

From April 2008 to December 2014, 1096 patients with GC underwent laparoscopy-assisted radical distal gastrectomy in our department. According to the Japanese GC treatment guidelines, D2 (+No. 14v) may be beneficial in tumors with apparent metastasis to the No. 6 nodes (Japanese Gastric Cancer Association, Gastric Cancer 14:113-123,2010). Thus, 151 advanced lower GC patients with apparent metastasis to the No. 6 nodes underwent additional No. 14v LN dissection. We dissected infrapyloric area LNs with No. 14v dissection from the left to the right side (i.e., middle colic vein approach).

RESULTS

Mean operation time was 22.8 ± 10.0 min, mean blood loss was 17.1 ± 14.6 ml, and mean times to first flatus, fluid diet, and soft diet were 3.7 ± 1.2 days, 5.0 ± 1.7 days, and 8.4 ± 1.6 days, respectively. A mean of 33.7 ± 11.2 LNs were retrieved, including 3.9 ± 2.7 No. 6 LNs and 2.0 ± 1.6 No. 14v LNs. Of 151 patients, 26 had No. 14v metastasis (17.2%), and 43 (28.5%) were accompanied by an extensive infrapyloric area nodal involvement. The overall postoperative morbidity rate was 10.6% (16 of 151). At a median follow-up of 56 months (range 5-84 months), cumulative 3-year overall survival was 56.0%.

CONCLUSIONS

Although it remains controversial whether prophylactic No. 14v dissection improves survival, laparoscopic infrapyloric area LN dissection using a middle colic vein approach may be safely achieved and is more convenient for advanced lower GC.

Mitogen-activated protein kinase signaling pathway and invasion and metastasis of gastric cancer

The mortality rate of gastric cancer worldwide is as high as 70%, despite the development of novel therapeutic strategies. One reason for the high mortality is the rapid and uninhibited spread of the disease, such that the majority of patients are diagnosed at a stage when efficient therapeutic treatment is not available. Therefore, in-depth research is needed to investigate the mechanism of gastric cancer metastasis and invasion to improve outcomes and provide biomarkers for early diagnosis. The mitogen-activated protein kinase (MAPK) signaling pathway is widely expressed in multicellular organisms, with critical roles in multiple biological processes, such as cell proliferation, death, differentiation, migration, and invasion. The MAPK pathway typically responds to extracellular stimulation. However, the MAPK pathway is often involved in the occurrence and progression of cancer when abnormally regulated. Many studies have researched the relationship between the MAPK signaling pathway and cancer metastasis and invasion, but little is known about the important roles that the MAPK signaling pathway plays in gastric cancer. Based on an analysis of published data, this review aims to summarize the important role that the MAP kinases play in the invasion and metastasis of gastric cancer and attempts to provide potential directions for further research and clinical treatment.

Significant differences in the clinicopathological characteristics and survival of gastric cancer patients from two cancer centers in china and Korea

PURPOSE

To compare the clinicopathological data and long-term survival of gastric cancer patients in China and Korea.

MATERIALS AND METHODS

Patients who had undergone gastrectomy for gastric cancer between 1998 and 2009 in 2 high-volume institutions in both China (n=1,637) and Korea (n=2,231) were retrospectively evaluated. Clinicopathological variables, overall survival (OS), progression-free survival (PFS), and surgery-related complications were assessed for all patients and compared between the 2 institutions.

RESULTS

Chinese patients included in the study were significantly older and had a significantly lower body mass index (BMI) than the Korean patients. Esophagogastric junction tumors were more frequent in Chinese patients. However, the number of patients with stage I gastric cancer, the number of harvested lymph nodes, and the number of total gastrectomies were significantly higher in the Korean population. Korean patients also presented with fewer undifferentiated tumors than Chinese patients. Furthermore, Korean patients had prolonged OS and PFS for stage III cancers only. BMI, tumor-node-metastasis (TNM) stage, tumor invasion, number of positive lymph nodes, and distant metastases were all independent factors affecting OS and PFS.

CONCLUSIONS

Although China and Korea are neighboring Asian countries, the clinicopathological characteristics of Chinese patients are significantly different from those of Korean patients. Korean gastric cancer patients had longer OS and PFS than Chinese patients. Influencing factors included TNM stage, tumor invasion, and lymph node metastasis.

NAIF1 inhibits gastric cancer cells migration and invasion via the MAPK pathways

PURPOSE

Nuclear apoptosis-inducing factor 1 (NAIF1) could induce apoptosis in gastric cancer cells. Previously, we have reported that the expression of NAIF1 protein is down-regulated in gastric cancer tissues compared with the adjacent normal tissues. However, the role of NAIF1 in gastric cancer cells is not fully understood.

METHODS

The effects of NAIF1 on cell viability were evaluated by MTT and colony formation assays. The ability of cellular migration and invasion were analyzed by transwell assays. The expression levels of targeted proteins were determined by western blot. The relative RNA expression levels were analyzed using quantitative polymerase chain reaction assays. Xenograft experiment was employed to determine the anti-tumor ability of NAIF1 in vivo.

RESULTS

The study demonstrates that transient transfection of NAIF1 in gastric cancer cells BGC823 and MKN45 could inhibit the cell proliferation, migration, and invasion of the two gastric cancer cell lines. The tumor size is smaller in NAIF1-overexpressed MKN45 cell xenograft mice than in unexpressed group. Further in-depth analysis reveals that NAIF1 reduces the expression of MMP2 as well as MMP9, and inhibits the activation of FAK, all of which are key molecules involved in regulating cell migration and invasion. In addition, NAIF1 inhibits the expression of c-Jun N-terminal kinase (JNK) by accelerating its degradation through ubiquitin-proteasome pathway. Meanwhile, NAIF1 reduces the mRNA and protein expression of ERK1/2.

CONCLUSIONS

Our study revealed that NAIF1 plays a role in regulating cellular migration and invasion through the MAPK pathways. It could be a therapeutic target for gastric cancer.

Relevance of hepatoduodenal ligament lymph nodes in resectional surgery for gastric cancer

BACKGROUND

Hepatoduodenal lymph node (HDLN) positivity is considered distant metastasis in gastric cancer according to the seventh American Joint Committee on Cancer (AJCC) classification. In contrast, the International Union Against Cancer seventh edition and the Japanese Gastric Cancer Association both consider HDLN as a regional lymph node that can be included in the context of a curative resection. The purpose of this study was to determine whether there was justification for considering HDLN involvement as a distant metastasis for which resectional surgery could not have survival benefit.

METHODS

This study enrolled consecutive patients with gastric cancer having D2 or greater resections, with removal and pathological assessment of the HDLN, between 1989 and 2009. The pathological stage of all patients was determined based on the seventh AJCC criteria, with HDLN included as a regional lymph node.

RESULTS

A total of 1872 patients had their HDLN removed, of whom 68 had a metastatic lymph node in the hepatoduodenal ligament. The 5-year survival rate of these 68 patients was 30 per cent, compared with 47·7 per cent for those with stage III (P < 0·001) and 9·8 per cent for those with stage IV (P = 0·007) HDLN-negative tumours. The 5-year survival rate of 41 patients with HDLN metastasis and no evidence of distant metastasis at any other site was significantly higher than that among 120 patients with stage IV disease without HDLN metastasis (P < 0·001), whereas 5-year survival did not differ between the 41 patients with stage I-III disease with HDLN metastasis and 568 patients with stage III tumours without HDLN metastasis (P = 0·184). HDLN metastasis was not a significant factor for survival in multivariable analysis.

CONCLUSION

It is inappropriate to include the HDLN in the distant metastatic lymph node group in gastric cancer. The seventh AJCC criteria for node grouping should be revised.

Improved survival after adding dissection of the superior mesenteric vein lymph node (14v) to standard D2 gastrectomy for advanced distal gastric cancer

BACKGROUND

Extended lymph node dissection in gastric cancer (D3) was proven to have no survival benefit compared with a D2 dissection, but whether adding the superior mesenteric nodes (No. 14v) to the dissection provides survival benefit for gastric cancer patients remains controversial.

METHODS

From April 2001 to June 2007, 1,661 patients underwent curative resection for middle or lower third gastric cancer. Patients were grouped according to No. 14v lymphadenectomy (14vD+/14vD-). Clinicopathologic characteristics and treatment-related factors were compared between the groups. Overall survival according to the clinical stage (Union for International Cancer Control tumor-node-metastasis staging 6th edition) was analyzed using the Cox proportional hazard model.

RESULTS

The incidence of No. 14v lymph node metastasis was 5.0%. There was no difference in morbidity or mortality between the 14vD+ and the 14vD- groups. The proportion of locoregional recurrence was greater in 14vD- group (P = .018). In clinical stages I and II, 14v lymph node dissection did not affect overall survival; in contrast, 14v lymph node dissection was an independent prognostic factor in patients with clinical stage III/IV gastric cancer (hazard ratio, 0.58; 95% confidence interval, 0.38-0.88; P = .01).

CONCLUSION

Extended D2 gastrectomy including No. 14v lymph node dissection seems to be associated with improved overall survival of patients with clinical stage III/IV gastric cancer in the middle or lower third of the stomach.

Current management and future strategies of gastric cancer

The overall prognosis of gastric cancer has gradually improved over the past decades with growing awareness of potential carcinogens, surveillance programs and early diagnosis, as well as advances in surgical techniques and multimodality treatments. Nevertheless, the outcome of advanced stage disease still remains poor with currently available treatments, and a worldwide consensus on the standard management thereof has not been established. To improve prognosis and quality of life in gastric cancer patients, both standardization and individualization of managements are imperative. Diagnostic tests and surgical procedures need to be further sophisticated and standardized based on more recent evidences from ongoing and future randomized controlled trials, while comprehensive management should be individualized to each patient. Future challenges lie with how to optimize personalized therapies by deciphering biological complexity of gastric cancer and incorporating molecular biomarkers in clinical practice to forecast prognosis and to guide targeted therapeutics in adjunct to current standards of care.