Lymphadenectomy for gastric adenocarcinoma: should west meet east?

Development of a reliable surgical quality assurance tool for gastrectomy in oncological trials

BACKGROUND

Despite its recognized importance, there is currently no reliable tool for surgical quality assurance (SQA) of gastrectomy in surgical oncology. The aim of this study was to develop an SQA tool for gastrectomy and to apply this tool within the ADDICT Trial in order to assess the extent and completeness of lymphadenectomy.

METHODS

The operative steps for D1+ and D2 gastrectomy have been previously described in the literature and ADDICT trial manual. Two researchers also performed fieldwork in the UK and Japan to document key operative steps through photographs and semi-structured interviews with expert surgeons. This provided the steps that were used as the framework for the SQA tool. Sixty-two photographic cases from the ADDICT Trial were rated by three independent surgeons. Generalizability (G) theory determined inter-rater reliability. D-studies examined the effect of varying the number of assessors and photographic series they rated. Chi-square assessed intra-rater reliability, comparing how the individual assessor's responses corresponded to their global rating for extent of lymphadenectomy.

RESULTS

The tool comprised 20 items, including 19 anatomical landmarks and a global rating score. Overall reliability had G-coefficient of 0.557. Internal consistency was measured with a Cronbach's alpha score of 0.869 and Chi-square confirmed intra-rater reliability for each assessor as < 0.05.

CONCLUSIONS

A photographic surgical quality assurance tool is presented for gastrectomy. Using this tool, the assessor can reliably determine not only the quality but also the extent of the lymphadenectomy performed based on remaining anatomy rather than the excised specimen.

Uncovering the Impact of Lymphadenectomy in Advanced Gastric Cancer: A Comprehensive Review

Gastric cancer is a significant health concern worldwide, and lymphadenectomy plays a crucial role in its treatment. However, there is ongoing debate regarding the optimal approach-D1 or D2 lymphadenectomy. This paper aims to synthesize the available evidence by conducting a comprehensive literature review and comparing the advantages and disadvantages of both techniques. The analysis includes studies, clinical trials, and systematic reviews that assess survival outcomes, morbidity, and quality of life. The selected studies revealed different outcomes associated with D1 and D2 lymphadenectomy, including lymph node harvest, disease control, recurrence rates, and overall survival. Postoperative complications also varied between the two techniques. These findings highlight the complex considerations involved in selecting the most suitable lymphadenectomy approach for individual patients. Therefore, the decision requires an individualized assessment that considers the potential benefits and risks of D1 and D2 techniques. A collaborative approach involving interdisciplinary teams is crucial for developing personalized treatment plans that optimize both oncological outcomes and postoperative quality of life.

Significance of nodal dissection and nodal positivity in gastric cancer

Lymphadenectomy is a central component of surgery for gastric cancer. However, controversies over the optimal extent of lymphadenectomy in gastric cancer surgery have persisted for several decades. In Eastern countries where the incidence of gastric cancer is high, surgeons have performed extensive lymphadenectomy (D2 lymphadenectomy) with low morbidity and mortality, while most Western surgeons have advocated for more limited lymphadenectomies according to the results of Dutch trial and MRC trial. Initially, these trials had failed to show survival benefit of D2 procedure and instead, found pancreaticosplenectomy performed as part of the D2 procedure associated with high incidence of morbidity and mortality. Subsequently, superiority of D2 lymphadenectomy on survival was demonstrated based on updated results. Moreover, spleen and pancreas preserving D2 lymphadenectomy are being performed safely in Western countries. Today, there is an international consensus on performing D2 lymphadenectomy as the standard procedure for advanced gastric cancer and is widely accepted as the standard procedure for gastric cancer surgery. The significance of the extent of lymphadenectomy is intimately associated with the prognostic importance of nodal metastases as the most powerful indicator of recurrence and survival for patients after curative gastrectomy. Maruyama computer program could be used to estimate the risk of lymph node metastasis in each nodal station. The Maruyama Index could be used to assess the adequacy of lymphadenectomy in gastric cancer. Positive lymph node ratio is calculated as the ratio of positive lymph nodes to all harvested lymph nodes, which might be a more precise predictor of prognosis than the absolute number of positive lymph nodes. While D2 lymphadenectomy enables the accurate staging of the disease, reduces the incidence of locoregional recurrences and thus contribute to an improved overall survival; performing lymphadenectomy beyond D2 is unlikely to improve survival. Therapeutic D2+ lymphadenectomy for advanced gastric cancer requires further evaluations, especially for patients receiving neo-adjuvant or conversion treatments.

Comparing prognostic values of the 7th and 8th editions of the American Joint Committee on Cancer TNM staging system for gastric cancer

Background and Aim:

Our aim was to compare the prognostic value of the American Joint Committee on Cancer (AJCC) 7th and 8th editions staging systems for patients with gastric cancer in China.

Methods:

A total of 1326 gastric cancer patients diagnosed between 2008 and 2012 were included. The discriminative ability of the AJCC 8th and 7th editions was compared using the Harrell’s concordance index (C-index).

Results:

There are two main modifications in the 8th edition. (i) pN3 staging was divided into pN3a and pN3b. The gastric cancer patients with pN3a experienced significantly better overall survival compared with those with pN3b (5-year overall survival: 34.5% vs. 15.6%, P < 0.001) (stratified by pT: pT3: 5-year overall survival: 33.9% vs. 13.2%, P < 0.001; pT4a: 32.8% vs. 16.9%, P = 0.056; pT4b: 17.0% vs. 11.1%, P = 0.048). (ii) Subgroup staging adjustments. The subgroup staging adjustments (T3N3bM0 (IIIB→IIIC), T4aN3aM0 (IIIC→IIIB), T4bN0M0 (IIIB→IIIA), and T4bN2M0 (IIIC→IIIB)) resulted in more gastric cancer patients being accurately staged. Furthermore, the C-index value of the 8th edition tumor node metastasis (TNM) staging system was significantly higher than that of the AJCC 7th TNM staging system to predict the survival of gastric cancer patients (0.701 vs. 0.685, P < 0.001).

Conclusions:

The 8th edition of the TNM staging system is superior to the 7th edition staging system for prediction of survival of gastric cancer patients in China.

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.

A meta-analysis of comparison of proximal gastrectomy with double-tract reconstruction and total gastrectomy for proximal early gastric cancer

Background

In theory, proximal gastrectomy with double-tract reconstruction (PG-DT) was superior to total gastrectomy (TG) in hematologic and nutritional outcomes. However, its clinical effects in proximal early gastric cancer (EGC) have been controversial.

Methods

The purpose of this study was to investigate the outcomes of laparoscopic proximal gastrectomy with double-tract reconstruction (LPG-DT) for proximal EGC. For this systematic review and meta-analysis, we searched for articles published before December of 2018 in the following databases: PubMed, Web of Science, EBSCO, Medline, and Cochrane Library.

Results

The results showed no significant difference in the anastomotic stenosis (OR = 0.91, 95%CI = 0.33–2.50, p = 0.85) and reflux esophagitis (OR = 1.87, 95%CI = 0.62–5.65, p = 0.27) between LPG-DT and laparoscopic total gastrectomy (LTG). The vitamin B12 supplementation rate in the LPG-DT group was lower than the LTG group (OR = 0.06, 95%Cl = 0.01–0.59, p = 0.02).

Conclusions

Due to comparable clinical effect, PG-DT is comparable to TG for patients with proximal EGC. In addition, LPG-DT not only appears superior to TG in terms of preventing vitamin B12 deficiency, but also does not increase the risk of anastomotic stricture and reflux esophagitis.

Electronic supplementary material

The online version of this article (10.1186/s12893-019-0584-7) contains supplementary material, which is available to authorized users.

Implication of lymph node staging in migration and different treatment strategies for stage T2N0M0 and T1N1M0 resected gastric cancer: a SEER population analysis

PURPOSE

The purpose of this study was to explore the differences between stage T2N0M0 and stage T1N1M0 gastric cancer (GC) and to identify the necessity of adjuvant treatment (AT) for these stages.

METHODS

Between years 2004 and 2015, 1971 stage IB GC patients who underwent radical surgery were recruited using the Surveillance, Epidemiology and End Results database. We conducted univariate/multivariate analyses, the propensity score matching and evaluated gastric cancer-specific survival (GCSS) and overall survival (OS) with the log-rank test.

RESULTS

T1N1M0 had a significantly worse survival than T2N0M0 in both GCSS and OS before and after the propensity score matching. Examined lymph nodes (ELN) ≤ 15 and T1N1M0 were independent risk factors for worse GCSS and OS in stage IB GC. The absence of adjuvant chemotherapy (CT) was an independent risk factor for worse GCSS and OS in T1N1M0 but not in T2N0M0. AT demonstrated similar GCSS and OS with surgery alone (SA) for T2N0M0 but better survival for T1N1M0. Compared to CT and adjuvant chemoradiotherapy (CRT) group, SA demonstrated significantly worse GCSS and OS for T1N1M0. There was no significant difference between CT and CRT in both T2N0M0 and T1N1M0 stages. T2N0M0 had a better survival than T1N1M0 in ELN ≤ 15 subgroup. However, similar survival was demonstrated in ELN > 15 subgroup.

CONCLUSIONS

T2N0M0 GC has a better survival rate than T1N1M0 GC when ELN are ≤ 15. Moreover, T2N0M0 GC may not benefit from AT. T1N1M0 GC requires CT but not adjuvant radiotherapy.

Prognostic Value of the Number of Lymph Nodes Examined in Patients with Node-Negative Gastric Cancer

BACKGROUND

Our aim was to evaluate the prognostic value of the number of lymph nodes examined (eLNs) in patients with node-negative gastric cancer (GC) and further to adjust the American Joint Committee on Cancer (AJCC) 8th staging system based on the number of eLNs.

METHODS

Node-negative GC patients diagnosed during 1988-2015 from the Surveillance, Epidemiology, and End Results (SEER) database were included. On the basis of a primary cohort of 4159 node-negative GC patients, we built the adjusted AJCC 8th staging system, which was then internally validated by a bootstrap method, and externally validated with an independent cohort of 5565 node-negative GC patients.

RESULTS

The median number of eLNs was 10. For the training set, the optimal eLNs thresholds were determined to be 9 for node-negative GC patients. The adjusted AJCC 8th staging system for node-negative GC patients based on the number of eLNs had a significantly higher Harrell's concordance index than the initial AJCC 8th staging system (C-index, 0.635 versus 0.616; P < 0.001). Thus, the adjusted AJCC 8th staging system had superior prognostic stratification. Similar results were found in the validation set.

CONCLUSIONS

For node-negative GC patients in the United States, the adjusted AJCC 8th staging system based on the number of eLNs predicted survival more accurately and discriminatively.

The survival benefit of palliative gastrectomy and/or metastasectomy in gastric cancer patients with synchronous metastasis: a population-based study using propensity score matching and coarsened exact matching

Introduction: Palliative surgeries were controversial for asymptomatic metastatic gastric cancer (mGC) patients. This study was aimed to evaluate survival benefit of palliative surgeries to gastric and/or metastatic tumors in mGC patients based on U.S population.

Materials and Methods: A total of 8345 gastric cancer patients diagnosed with synchronous distal metastasis between 2004 to 2013 from the Surveillance, Epidemiology, and End Results Program (SEER) database were divided into four groups according to surgery strategies: surgeries to both primary and metastatic tumors (SPM), gastrectomy only (GO), metastasectomy only (MO) and no surgery performed (NS). Their clinicopathological characteristics and overall survival (OS) were analyzed before and after propensity score matching (PSM) and coarsened exact matching (CEM).

Results: The median OS of SPM and GO patients was both significantly higher than NS patients (11 months vs. 8 months vs. 5 months; P<0.001, respectively) while that of MO was not (6 months vs. 5 months; P= 0.286). In comparisons between surgery strategies, survival benefit was similar between SPM and GO groups (P=0.389) and both showed significantly better survival than MO patients (P<0.001). All surgery strategies were proved to be favorable prognostic factors over non-surgical treatment (Hazard ratio (HR) for SPM: 0.60, P<0.001; HR for GO: 0.62, P<0.001; HR for MO: 0.91, P=0.046). Similar results were obtained after matching by PSM and CEM except that prognostic impact of MO deteriorated.

Conclusions: Gastrectomy plus metastasectomy or gastrectomy alone could be adopted as a choice of improving survival in the U.S population. Metastasectomy alone is not generally recommended.

Different lymph node staging systems for patients with adenocarcinoma of esophagogastric junction

OBJECTIVE

In addition to the traditional TNM N staging system, lymph node ratio (LNR) and log odds of metastatic lymph nodes (LODDS) staging methods were developed in cancers. This study aimed to examine their relative prognostic performance in patients with adenocarcinoma of the esophagogastric junction (AEG).

PATIENTS AND METHODS

Patients who underwent surgical resection for AEG were identified from the Surveillance, Epidemiology, and End Results (SEER) Program and the First Affiliated Hospital of Xi'an Jiaotong University as the training and validation sets, respectively. The Akaike's Information Criterion (AIC), Harrell's C statistic, and ROC curves were utilized for comparison.

RESULTS

A total of 735 patients were involved in the training set. LODDS and LNR staging systems had better prognostic performance than the TNM N staging systems (when considered as a categorical variable: C index = 0.728 and 0.712 vs 0.671; AIC: 6247.537 and 6265.996 vs 6320.045; AUC: 0.762 and 0.719 vs 0.692. For the continuous model: C index = 0.675 and 0.686 vs 0.658; AIC = 6243.740 and 6261.027 vs 6355.077; AUC = 0.778 and 0.733 vs 0.693). In the validation set of 183 patients, the TNM N staging scheme outperformed the LODDS and LNR staging systems (C index = 0.788 vs 0.779 and 0.767; AIC = 1014.702 vs 1026.899 and 1025.288; AUC = 0.806 vs 0.787 and 0.791) when considered a categorical variable. However, when considered a continuous variable, the LODDS and LNR staging systems were better than the TNM N staging system (C index = 0.724 and 0.733 vs 0.747; AIC = 1018.075 and 1025.803 vs 1026.085; AUC = 0.811 and 0.810 vs 0.806).

CONCLUSIONS

The LNR and LODDS staging schemes could be considered new options for prognostic prediction of AEG with respect to lymph node status, especially when considered as continuous variables.

Prognostic and predictive value of metastatic lymph node ratio in stage III gastric cancer after D2 nodal dissection

Introduction

This study is to evaluate the prognostic and predictive value of metastatic lymph node ratio (MLR) in stage III gastric cancer following radical D2 dissection.

Methods

87 patients who underwent radical resection with D2 lymphadenectomy were retrospectively evaluated. The median age was 60 with a 2:1 ratio of male/female. Of these 87 patients, 83 underwent total gastrectomy, the remaining 4 underwent subtotal gastrectomy and 57 patients received adjuvant chemotherapy with fluoropyrimidines. Indexes of lymph node involvement and other clinicopathological data were analyzed. Survival was determined by the Kaplan-Meier method and log-rank test. Multivariate analysis was performed using the Cox proportional hazards model.

Results

Median total retrieved lymph node number was 35 (range: 10-104) with median metastatic lymph node amount of eight (range: 0-71). Median survival time was 31.7 months with a 3-year survival rate of 36.4%. Patients were divided into four groups according to MLR: MLR0, 0; MLR1, <0.1; MLR2, 0.1-0.25; MLR3, >0.25. After median follow-up of 31 months, median OS rates of MLR0 to MLR3 were 37.1m, 35.9m, 31.5m and 20.8m, respectively (p=0.013). Median OS rates were significantly different among subgroups: 39.3m and 36.5m were obtained for low subgroups (MLR<0.24) with or without adjuvant chemotherapy, respectively; 22.9m and 12.2m were found in high subgroups (MLR>0.24) with and without chemotherapy, respectively (p=0.002). Finally, MLR constituted an independent prognostic factor in multivariable analysis.

Conclusions

After R0 resection with D2 lymphadenectomy for stage III gastric cancer, MLR constitutes an effective prognostic indicator. Patients with high MLR may benefit the most from adjuvant chemotherapy.

Evolution in the surgical management of gastric cancer: is extended lymph node dissection back in vogue in the USA?

BACKGROUND

Gastric cancer remains a formidable treatment challenge. For decades, treatment consisted mostly of surgical intervention for this deadly disease. With improvements in the multi-disciplinary management of solid organ malignancies, the approach to this disease is being stepwise refined.

MAIN BODY

One of the prevalent controversies in the surgical management of gastric cancer rests on the need for adequate harvesting of lymph nodes. For decades, lymph node dissection is regarded as a staging technique useful in only upstaging the disease. The adoption of D2 lymphadenectomy has been particularly slow to mature. But with prevailing data from Asia consistently demonstrating a survival benefit from lymphadenectomy, it calls into question the notion of lymphadenectomy as being solely a staging procedure.

CONCLUSIONS

As gastric resection techniques are being better defined in western countries and surgical morbidities lowered on its execution, D2 lymphadenectomy is becoming more accepted as the new standard in the management of gastric cancer.

Gastric cancer treatment: similarity and difference between China and Korea

Chinese populations have many demographic similarities to Korean populations. However, the long-term survival rates of gastric cancer patients in China are still not satisfactory when compared with Korea, especially for the advanced cases. In this article, we discuss about the similarity and difference of gastric cancer treatment in terms of screening, surgical approach, stomach resection, digestive tract reconstruction, lymphadenectomy, harvested lymph nodes, operative morbidity and mortality, postoperative chemotherapy as well as follow-up between China and Korea. Given that a variety of factors ranging from tumor characteristics to different treatment strategies are seen between the two countries, the reasons accounting for the differences in survival should be focused and the corresponding strategy should be considered and finally promote to improve the prognosis of gastric cancer.

East Versus West: Differences in Surgical Management in Asia Compared with Europe and North America

In recent decades, there has been considerable worldwide progress in the treatment of gastric cancer. Gastrectomy with a modified D2 lymphadenectomy (sparing the distal pancreas and spleen) has increasingly gained acceptance as a preferable standard surgical approach among surgeons in the East and the West. Despite growing consensus significant differences still exist in surgical techniques in clinical trials and clinical practices secondary to variations in epidemiology, clinicopathologic features, and surgical outcomes among geographic regions. In addition, Western physicians tend to prefer adjuvant chemotherapy and radiotherapy after surgery instead of using S-1 chemotherapy, as is the preference in the East.

Changing Trends in Gastric Cancer Surgery

Gastric cancer is one of the most common causes of cancer-related death. It requires multimodal treatment and surgery is the most effective treatment modality. Radical surgery includes total or subtotal gastrectomy with lymph node dissection. The extent of lymphadenectomy still remains controversial. Eastern surgeons have performed D2 or more extended lymphadenectomy while their Western colleagues have performed more limited lymph node dissection. However, the trend has been changing in favour of D2 lymph node dissection in both hemispheres. Currently, D2 is the recommended type of lymphadenectomy in experienced centres in the west. In Japan, D2 lymph node dissection is the standard surgical approach. More extensive lymphadenectomy than D2 has not been found to be associated with improved survival and generally is not performed. Bursectomy and splenectomy are additional controversial issues in surgical performance, and trends regarding them will be discussed. The performance of bursectomy is controversial and there is no clear evidence of its clinical benefit. However, a trend toward better survival in patients with serosal invasion has been reported. Routine splenectomy as a part of lymph node dissection has largely been abandoned, although splenectomy is recommended in selected cases. Minimally invasive surgery has gained wide popularity and indications for minimally invasive procedures have been expanding due to increasing experience and improving technology. Neoadjuvant therapy has been shown to have beneficial effects and seems necessary to provide a survival benefit. Diagnostic laparoscopy should be kept in mind prior to treatment.

Report from the 17th Annual Western Canadian Gastrointestinal Cancer Consensus Conference; Edmonton, Alberta; 11-12 September 2015

The 17th annual Western Canadian Gastrointestinal Cancer Consensus Conference (wcgccc) was held in Edmonton, Alberta, 11-12 September 2015. The wcgccc is an interactive multidisciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of gastric cancer.

Strategies to improve treatment outcome in gastric cancer: a retrospective analysis of patients from two high-volume hospitals in Korea and China

China has high incidence of gastric cancer (GC). However, the treatment outcomes of China were unsatisfactory compared to those of Korea. We performed this study to compare tumour characteristics, treatment parameters, and survival outcomes of GC patients between Korea and China based on the databases of two high-volume hospitals, with the aim of identifying indicators of GC prognosis. Data of patients undergoing gastrectomy for GC from 2006 to 2010 were analysed retrospectively. Subgroup survival analyses, stratified by clinicopathologic factors and multivariable analyses, were performed. The interactive roles of chemotherapy and D2 lymphadenectomy for overall survival were also investigated. Among 1365 Chinese and 4981 Korean patients, the proportion of early cancer detection in Chinese patients was much lower relative to that of Korean patients. There were no significant differences between countries in terms of surgical morbidity and mortality. The overall 5-year survival rates were 54.3% and 81.4%; when stratified by clinicopathologic factors, the survival were generally statistically higher in Korean patients. Gender, age, T stage, N stage, extent of lymphadenectomy, radicality of surgery, resection type, and chemotherapy were independently associated with survival in patients without metastasis. Survival rates for stage II and III GC differed significantly between the two countries, but this difference was eliminated among patients who underwent D2 lymphadenectomy or received chemotherapy. These treatments were given to patients with advanced-stage diagnoses (approximately 20% and 80% of patients, respectively). Treatment type was selected as independent prognostic factors in stage I-III and D2/D2+, with chemotherapy resulting in the best prognosis. Many differences in GC tumour characteristics exist between two countries. Early cancer detection and standardized treatment in Korea contribute to superior survival rates. Promotion of an early screening program, training and dissemination of standard D2 lymphadenectomy, and appropriate applications of chemotherapy would improve survival outcomes.

Comparison of laparoscopic versus open gastrectomy for advanced gastric cancer: an updated meta-analysis

BACKGROUND

Laparoscopic gastrectomy (LG) has been used as an alternative to open gastrectomy (OG) to treat early gastric cancer. However, the use of LG for advanced gastric cancer (AGC) has been in debate.

METHODS

Literature retrieval was performed by searching PubMed, EMBASE, and the Cochrane library up to July 2014. Potential studies comparing the surgical effects between LG with OG were evaluated and data were extracted accordingly. Meta-analysis was carried out using RevMan. The pooled risk ratio and weighted mean difference (WMD) with 95 % confidence interval (95 % CI) were calculated.

RESULTS

Overall, 26 studies were included in this meta-analysis. LG had some advantages over OG, including shorter hospitalization (WMD, -3.63, 95 % CI, -4.66 to -2.60; P < 0.01), less blood loss (WMD, -161.37, 95 % CI, -192.55 to -130.18; P < 0.01), faster bowel recovery (WMD, -0.78, 95 % CI, -1.05 to -0.50; P < 0.01), and earlier ambulation (WMD, -0.95, 95 % CI, -1.47 to -0.44; P < 0.01). In terms of surgical and oncological safety, LG could achieve similar lymph nodes (WMD, -0.49, 95 % CI, -1.78 to 0.81; P = 0.46), a lower complication rate [odds ratio (OR), 0.71, 95 % CI, 0.59 to 0.87; P < 0.01], and overall survival (OS) and disease-free survival (DFS) comparable to OG.

CONCLUSIONS

For AGCs, LG appeared comparable with OG in short- and long-term results. Although more time was needed to perform LG, it had some advantages over OG in achieving faster postoperative recovery. Ongoing trials and future studies could help to clarify this controversial issue.

Training in Laparoscopic Gastric Cancer Surgery in the Western World: Current Educational Practices, Challenges, and Potential Opportunities at a Large University Centre

OBJECTIVE

The purpose of this study was to explore and understand how surgeons distribute tasks during a laparoscopic gastrectomy for gastric cancer in an academic teaching environment.

DESIGN

An anonymous, cross-sectional, census survey was used to poll trainees' and staff members' opinions pertaining to laparoscopic gastrectomy.

SETTING

Academic and community tertiary teaching hospitals, affiliated with the University of Toronto.

PARTICIPANTS

All surgeons, within the Department of General Surgery at the University of Toronto, who practice laparoscopic gastrectomy for gastric cancer, were invited to participate. All general surgery residents, postgraduate year 1-5, minimally invasive surgery and surgical oncology fellows at the University of Toronto were invited to participate. Overall response rate was 74.35% (n = 87/117).

RESULTS

The results suggested that trainees do not routinely perform the major operative steps. Trainees agreed with faculty in this regard; however, there was a statistically significant difference in opinions, related to the degree of the perceived active operating of the trainees. There was also a difference in opinion, between trainees and faculty, regarding the common reasons for takeover.

CONCLUSIONS

The present survey highlights that current level of active exposure of surgical trainees to laparoscopic gastric surgery might be insufficient. A lack of role clarity may further hinder an optimal educational experience during these cases. Adopting a stepwise approach, with task deconstruction, could optimize training. Additional training modalities may be required to ensure technical proficiency is acquired before independent practice.

Prognostic Performance of Different Lymph Node Staging Systems After Curative Intent Resection for Gastric Adenocarcinoma

OBJECTIVE

To compare the prognostic performance of American Joint Committee on Cancer/International Union Against Cancer seventh N stage relative to lymph node ratio (LNR), log odds of metastatic lymph nodes (LODDS), and N score in gastric adenocarcinoma.

BACKGROUND

Metastatic disease to the regional LN basin is a strong predictor of worse long-term outcome following curative intent resection of gastric adenocarcinoma.

METHODS

A total of 804 patients who underwent surgical resection of gastric adenocarcinoma were identified from a multi-institutional database. The relative discriminative abilities of the different LN staging/scoring systems were assessed using the Akaike's Information Criterion (AIC) and the Harrell's concordance index (c statistic).

RESULTS

Of the 804 patients, 333 (41.4%) had no lymph node metastasis, whereas 471 (58.6%) had lymph node metastasis. Patients with ≥N1 disease had an increased risk of death (hazards ratio = 2.09, 95% confidence interval: 1.68-2.61; P < 0.001]. When assessed using categorical cutoff values, LNR had a somewhat better prognostic performance (C index: 0.630; AIC: 4321.9) than the American Joint Committee on Cancer seventh edition (C index: 0.615; AIC: 4341.9), LODDS (C index: 0.615; AIC: 4323.4), or N score (C index: 0.620; AIC: 4324.6). When LN status was modeled as a continuous variable, the LODDS staging system (C index: 0.636; AIC: 4304.0) outperformed other staging/scoring systems including the N score (C index: 0.632; AIC: 4308.4) and LNR (C index: 0.631; AIC: 4225.8). Among patients with LNR scores of 0 or 1, there was a residual heterogeneity of outcomes that was better stratified and characterized by the LODDS.

CONCLUSIONS

When assessed as a categorical variable, LNR was the most powerful manner to stratify patients on the basis of LN status. LODDS was a better predicator of survival when LN status was modeled as a continuous variable, especially among those patients with either very low or high LNR.

Race Influences Stage-specific Survival in Gastric Cancer

Gastric adenocarcinoma studies show improved survival for Asians but have not reported stage-specific overall survival (OS) or disease-specific survival (DSS) by race. The Surveillance, Epidemiology and End Results database was queried for cases of gastric adenocarcinoma between 1998 and 2008. We evaluated OS and DSS by race and stage. Number of assessed lymph nodes was compared among surgical patients. Of 49,058 patients with complete staging data, 35,300 were white, 7709 were Asian, and 6049 were black. Asians had significantly better OS for all stages ( P < 0.001) and significantly better DSS for Stages I ( P < 0.0001) and II ( P = 0.0006). As compared with blacks, whites had significantly better DSS for Stages I ( P < 0.0001), II ( P = 0.0055), III ( P = 0.0165), and IV ( P < 0.0001). Among the 28,133 (57%) surgical patients, average number of evaluated lymph nodes was highest for Asians ( P < 0.0001). Among surgical patients with 15 or more nodes evaluated, DSS was worse in blacks with Stage I disease ( P < 0.05). Blacks with gastric adenocarcinoma have a worse DSS, which disappears when surgical treatment includes adequate lymphadenectomy. Race-associated survival differences for gastric adenocarcinoma might simply reflect variations in surgical staging techniques and socioeconomic factors.

Personalized Surgery for Gastric Adenocarcinoma: A Meta-analysis of D1 versus D2 Lymphadenectomy

BACKGROUND

The recent publication of 5-year survival data for the Italian Gastric Cancer Study Group (IGCSG) D1 versus D2 lymphadenectomy for gastric cancer trial adds important data for analysis of whether a D2 lymphadenectomy improves survival.

METHODS

Systematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1985 to February 1, 2014. Meta-analyses were performed using RevMan version 5 software. Long-term outcomes were analyzed. Subgroup analyses of T and N stage were performed.

RESULTS

Outcomes of four randomized, controlled trials involving 1,599 patients (823 D1: 776 D2) enrolled from 1982 to 2005 were included for qualitative analysis and quantitative meta-analysis. Despite the addition of long-term survival data from the IGCSG, 5-year overall and nodal status survival was similar between D1 and D2 trials. However, subgroup analysis revealed a survival benefit for T3 patients (odds ratio 1.64, 95 % confidence interval 1.01-2.67) and a trend for survival benefit for advanced nodal stage (odds ratio 1.36, 95 % confidence interval 0.98-1.87) with D2 compared with D1 lymphadenectomy.

CONCLUSIONS

As recent studies have demonstrated comparable short-term surgical outcomes for both D1 and D2 lymphadenectomies, consideration should be made for more extensive lymph node dissection among patients with advanced stage.

Problems faced by evidence-based medicine in evaluating lymphadenectomy for gastric cancer

Gastric cancer surgical management differs between Eastern Asia and Western countries. Extended lymphadenectomy (D2) is the standard of care in Japan and South Korea since decades, while the majority of United States patients receive at most a limited lymphadenectomy (D1). United States and Northern Europe are considered the scientific leaders in medicine and evidence-based procedures are the cornerstone of their clinical practice. However, surgeons in Eastern Asia are more experienced, as there are more new cases of gastric cancer in Japan (107898 in 2012) than in the entire European Union (81592), or in South Korea (31269) than in the entire United States (21155). For quite a long time evidence-based medicine (EBM) did not solve the question whether D2 improves long-term prognosis with respect to D1. Indeed, eastern surgeons were reluctant to perform D1 even in the frame of a clinical trial, as their patients had a very good prognosis after D2. Evidence-based surgical indications provided by Western trials were questioned, as surgical procedures could not be properly standardized. In the present study we analyzed indications about the optimal extension of lymphadenectomy in gastric cancer according to current scientific literature (2008-2012) and surgical guidelines. We searched PubMed for papers using the key words “lymphadenectomy or D1 or D2” AND “gastric cancer” from 2008 to 2012. Moreover, we reviewed national guidelines for gastric cancer management. The support to D2 lymphadenectomy increased progressively from 2008 to 2012: since 2010 papers supporting D2 have achieved a higher overall impact factor than the other papers. Till 2011, D2 was the procedure of choice according to experts’ opinion, while three meta-analyses found no survival advantage after D2 with respect to D1. In 2012-2013, however, two meta-analyses reported that D2 improves prognosis with respect to D1. D2 lymphadenectomy was proposed as the standard of care for advanced gastric cancer by Japanese National Guidelines since 1981 and was adopted as the standard procedure by the Italian Research Group for Gastric Cancer since the Nineties. D2 is now indicated as the standard of surgical treatment with curative intent by the German, British and ESMO-ESSO-ESTRO guidelines. At variance American NCCN guidelines recommend a D1⁺ or a modified D2 lymph node dissection. In conclusion, D2 lymphadenectomy, originally developed by Eastern surgeons, is now becoming the procedure of choice also in the West. In gastric cancer surgery EBM is lagging behind national guidelines, rather than preceding and orienting them. To eliminate this lag, EBM should value to a larger extent Eastern Asian literature and should evaluate not only the quality of the study design but also the quality of surgical procedures.

BMI and lymph node ratio may predict clinical outcomes of gastric cancer

AIM

BMI and the lymph node (LN) ratio can affect short- and long-term outcomes of patients with gastric cancer.

PATIENTS & METHODS

This study includes 104 consecutive patients with gastric adenocarcinoma who underwent curative gastrectomy divided in two groups: overweight group (group A) and normal weight group (group B).

RESULTS

We found that 53.4% of our patients were overweight (group A). The overall rate of postoperative complications was 16.3%, while mortality was 1%. Statistical analyses revealed that postoperative morbidity was significantly higher in group A (p < 0.05). Long-term survival was significantly higher in group B. Cox regression showed a statistically significant correlation between higher BMI and poor long-term survival after curative gastrectomy. Multivariate analysis has identified age and the LN ratios as independent prognostic factors of survival.

CONCLUSION

In this retrospective analysis, BMI and LN ratio were independently associated with survival in patients with gastric cancer. Further studies are needed to confirm our findings.

Prognostic significance of splenectomy for patients with gastric adenocarcinoma undergoing total gastrectomy: a retrospective cohort study

BACKGROUND

The addition of splenectomy to a D2 gastrectomy in patients with gastric adenocarcinoma (GA) has remained controversial. This study aimed to assess the impact of splenectomy on the overall survival of patients undergoing total gastrectomy for GA.

METHODS

This was a retrospective review of 463 GA patients (excluding positive resection margins and pathologic spleen invasion) undergoing curative total gastrectomy with (TS) and without splenectomy (T) between 1994 and 2008. Clinicopathologic factors affecting the prognosis of these patients were collected prospectively and analyzed.

RESULTS

Two hundred and ninety one patients had T and 172 patients underwent TS. Patient clinicopathological characteristics were comparable between the 2 groups except for tumor size. There were no significant differences in postoperative morbidity and mortality between T and TS groups. Patients in the T group had similar 3- and 5-year survival rates compared with those in the TS groups (p = 0.181). The addition of splenectomy to a total gastrectomy did not impact on the overall survival rates in patients with GA in terms of depth of tumor invasion and nodal metastasis.

CONCLUSIONS

The addition of splenectomy is not associated with survival advantage in GA patients undergoing total gastrectomy.

Ratio of metastatic to examined lymph nodes, a helpful staging system and independent prognostic factor of esophagogastric junction cancer

BACKGROUND

The incidence of the esophagogastric junction cancer is growing rapidly. The purpose of this study is to clarify the outcome of the ratio between metastatic and examined lymph nodes in esophagogastric junction cancer patients with or without 7 examined lymph nodes.

METHODS

A total of 3,481 patients who underwent operation are identified from the Surveillance, Epidemiology, and End Results database. Different lymph nodes resected groups are analyzed to test the lymph nodes ratio factor.

RESULTS

There are 2522 patients with 7 or more lymph nodes resected and 959 patients with less than 7 lymph nodes resected. Lymph nodes ratio and lymph node involvement are independent prognostic factors. But the lymph nodes ratio categories have a better prognostic value than the lymph node involvement categories. Compared with lymph node involvement categories, lymph nodes ratio categories represent patients with more homogeneous overall survival rate.

CONCLUSIONS

This study defines that the lymph nodes ratio is an independent prognostic factor for esophagogastric junction cancer. The lymph nodes ratio can prevent stage migration and may be a helpful system to predict the prognosis of esophagogastric junction cancer patients.

Noncurative gastrectomy for gastric adenocarcinoma should only be performed in highly selected patients

BACKGROUND

The benefit of surgical resection in patients with incurable gastric adenocarcinoma is controversial.

METHODS

A total of 289 patients who presented with advanced or metastatic gastric cancer from 1995 to 2010 were retrospectively reviewed.

RESULTS

Ten patients (3.5 %) required emergent surgery at presentation and were excluded from further analyses. Patients who underwent nonemergent surgery at presentation (n = 110, 38.1 %) received either gastric resection (group A, n = 46, 42 %) or surgery without resection (group B, n = 64, 58 %). Procedures in group A included distal gastrectomy (n = 25, 54 %), total gastrectomy (n = 17, 37 %), and proximal/esophagogastrectomy (n = 4, 9 %). Procedures in group B included laparoscopy (n = 17, 27 %), open exploration (n = 25, 39 %), gastrostomy and/or jejunostomy tube (n = 12, 19 %), and gastrojejunostomy (n = 10, 16 %). Group A required a stay in the intensive care unit or additional invasive procedure significantly more often than group B (15 vs. 2 %, p = 0.009). Four patients in group A (8.7 %) and three patients in group B (4.7 %) died within 30 days of surgery (p = 0.45). When the 110 patients who underwent nonemergent surgery (groups A and B) were compared to nonoperatively managed patients (group C, n = 169, 58 %), median overall survival did not significantly differ (8.6 vs. 9.2 vs. 7.7 months; p > 0.05). Three patients in group B (4.7 %) and three in group C (1.8 %) ultimately required an operation for their primary tumor.

CONCLUSIONS

Patients with gastric adenocarcinoma who present with advanced or metastatic disease not amenable to curative resection infrequently require emergent surgery. Noncurative resection is associated with significant perioperative morbidity and mortality as well as limited overall survival, and should therefore be performed judiciously.

Bursectomy in gastric cancer surgery: surgical technique and operative safety

Although there is little evidence that bursectomy has clinical benefit, its continuing practice imposes evaluation of bursectomy-related adverse effects, especially pancreatic fistula and intestinal obstruction. The aims of this study were to provide a detailed description of the technique of bursectomy as standardized by the authors and determine if extended surgery for gastric cancer with additional bursectomy can be performed safely in Western population. A total of 72 consecutive patients of median age 76.4 years and mean ASA score grade 2.1, who submitted to D2 or D2+ gastrectomy with additional bursectomy for gastric adenocarcinoma, were prospectively studied. Bursectomy was associated with a median additional operative time of 41 min and a median additional blood loss of 65 ml. The post-operative morbidity rate was 19.4 %. Among various adverse events, pancreatic fistula was observed in three patients (4.2 %) and intestinal obstruction was observed in eight patients (11.1 %) including two cases of delayed gastric emptying, one case of afferent loop syndrome, one case of early postoperative adhesions and four cases of prolonged postoperative ileus. The in-hospital mortality rate was 1.4 %. D2 or D2+ gastrectomy with additional bursectomy can be safely performed in Western patients. Although the incidence of pancreatic fistula that we reported was low, the incidence of bursectomy-related intestinal obstruction was high and should always be kept in mind when performing extended surgery for gastric cancer.

Comparison of a lymph node ratio-based staging system with the 7th AJCC system for gastric cancer: analysis of 18,043 patients from the SEER database

OBJECTIVES

The American Joint Committee on Cancer (AJCC) staging system for gastric cancer bases N status on absolute number of metastatic nodes, regardless of the number of examined nodes. We examined a modified staging system utilizing node ratio (Nr), the ratio of metastatic to examined nodes.

METHODS

A total of 18,043 gastric cancer patients who underwent gastrectomy were identified from the US Surveillance, Epidemiology, and End Results (SEER) database. A training set was divided into 5 Nr groups, and a TNrM staging system was constructed. Median survival and overall survival, based on 7th edition AJCC and TNrM staging systems, were compared, and the analysis was repeated in a validation set.

RESULTS

Median examined nodes were 10 to 11. For the training set, overall survival for all 5 AJCC N categories was significantly different when subgrouped into 15 or fewer versus more than 15 examined nodes, but overall survival was similar regardless of the number of examined nodes in 4 of 5 Nr categories. Seven AJCC stages had statistically different overall survival between subgroups, whereas only 1 TNrM stage had statistically different overall survival between subgroups. When misclassification was defined as any subgroup in which median survival fell outside the 95% confidence interval of the group's overall median survival, AJCC staging misclassified 57% of patients and TNrM staging misclassified only 12%. Similar results were found in the validation set.

CONCLUSIONS

The AJCC system classifies SEER gastric cancer patients into stages in which subgroups often have wide variations in survival. For patients undergoing limited lymph node analysis, the proposed TNrM system may predict survival more accurately.

Varying lymphadenectomies for gastric adenocarcinoma in the East compared with the west: effect on outcomes

There are notable differences in surgical approaches to gastric adenocarcinoma throughout the world, particularly in terms of the extent of lymphadenectomy (LAD). In high-incidence countries such as Japan and South Korea, more extensive (e.g., D2) lymphadenectomies are standard, and these surgeries are generally done by experienced surgeons with low morbidity and mortality. In countries such as the United States, where the incidence of gastric adenocarcinoma is 10-fold lower, the majority of patients are treated at nonreferral centers with less extensive (e.g., D1 or D0) lymphadenectomy. There is little disagreement among gastric cancer (GC) experts that the minimum lymphadenectomy that should be performed for gastric adenocarcinoma should be at least a D1 lymphadenectomy, and many of these experts recommend a D2 lymphadenectomy. More extensive lymphadenectomies provide better staging of patient disease and likely reduce locoregional recurrence rates. Two large, prospective randomized trials performed in the United Kingdom and the Netherlands in the 1990s failed to demonstrate a survival benefit of D2 over D1 lymphadenectomy, but these trials have been criticized for inadequate surgical training and high surgical morbidity and mortality rates (10% to 13%) in the D2 group. More recent studies have demonstrated that Western surgeons can be trained to perform D2 lymphadenectomies on Western patients with low morbidity and mortality. The 15-year follow-up of the Netherlands trial now demonstrates an improved disease-specific survival and locoregional recurrence in the D2 group. Retrospective analyses and one prospective, randomized trial suggest that there may be a survival benefit to more extensive lymphadenectomies when performed safely, but this assertion requires further validation.

Operating room to bench for gastric cancer

Gastric cancer is the most common cancer in Korea, with an age-standardized rate of 61.2 in males and 23.9 in females (in 2007), one of the highest in the world. Using a large gastric tissue depository and the extensive clinical experience gained from gastric cancer surgery, we work as a 'translational researcher' to apply basic research tools and results to the clinical field. We are also interested in providing answers to the questions in the operating room using the methods of basic research. I would like to introduce our research activities in this review paper.

Comparative study of complete and partial omentectomy in radical subtotal gastrectomy for early gastric cancer

PURPOSE

Curative surgery for patients with advanced or even early gastric cancer can be defined as resection of the stomach and dissection of the first and second level lymph nodes, including the greater omentum. The aim of this study was to evaluate the short- and long- term outcomes of partial omentectomy (PO) as compared with complete omentectomy (CO).

MATERIALS AND METHODS

Seventeen consecutive open distal gastrectomies with POs were initially performed between February and July in 2006. The patients' clinicopathologic data and post-operative outcomes were retrospectively compared with 20 patients who underwent open distal gastrectomies with COs for early gastric cancer in 2005.

RESULTS

The operation time in PO group was significantly shorter than that in CO group (142.4 minutes vs. 165.0 minutes, p=0.018). The serum albumin concentration on the first post-operative day in PO group was significantly higher than CO group (3.8 g/dL vs. 3.5 g/dL, p=0.018). Three postoperative minor complications were successfully managed with conservative treatment. Median follow-up period between PO and CO was 38.1 and 37.7 months. All patients were alive without recurrence until December 30, 2009.

CONCLUSION

PO during open radical distal gastrectomy can be considered a more useful procedure than CO for treating early gastric cancer. To document the long-term technical and oncologic safety of this procedure, a large-scale prospective randomized trial will be needed.

Gastric cancer surgery: an American perspective on the current options and standards

Gastric cancer is prevalent globally, particularly in Asian countries such as Japan and Korea. While the prevalence of gastric cancer is not nearly as high in the United States (U.S.) as in Asia, the treatment armamentarium differs widely between regions. The role of surgery for gastric cancer in the U.S. has changed drastically over the last decade. While the natural history of gastric cancer seen in the U.S. markedly differs from that seen in Asia, the U.S. experience with endoscopic and minimally invasive techniques is beginning to parallel those seen in Japan and Korea. Minimally invasive surgery has truly come into the forefront of our surgical armamentarium, and its role, along with robotic and endoscopic approaches, remains to be defined as standard of care. At present, minimally invasive approaches appear to offer oncologically equivalent outcomes compared with standard open gastrectomy when performed by experienced surgeons. Extended lymphadenectomy does not appear to offer benefit with improved survival in our patient population, although sufficient lymph node sampling is imperative for adequate staging. Despite aggressive approaches to surgical resection for cure, the U.S. population tends to present with more advanced disease and have a worse prognosis than our Asian counterparts. Palliation with resection and possibly stent placement should be offered for improved quality of life in late-stage disease.

Changing clinical and pathological features of gastric cancer over time

BACKGROUND

The aim of the present multicentre observational study was to evaluate potential changes in clinical and pathological features of patients with gastric cancer (GC) treated in a 15-year interval.

METHODS

A centralized prospective database including clinical, surgical, pathological and follow-up data from 2822 patients who had resection of a primary GC was analysed. The analysis focused on three periods: 1991-1995 (period 1), 1996-2000 (period 2) and 2001-2005 (period 3). Surgical procedure, pathological classification and follow-up were standardized among centres.

RESULTS

The number of resections decreased from 1024 in period 1 to 955 and 843 in periods 2 and 3 respectively. More advanced stages and a smaller number of intestinal-type tumours of the distal third were observed over time. Five-year survival rates after R0 resection (2320 patients) did not change over time (overall: 56·6 and 51·2 per cent in periods 1 and 3; disease-free: 66·8 and 61·1 per cent respectively). Decreases in survival in more recent years were related particularly to more advanced stage, distal tumours and tumours in women. Multivariable analysis showed a lower probability of overall and disease-free survival in the most recent interval: hazard ratio 1·22 (95 per cent confidence interval 1·06 to 1·40) and 1·29 (1·06 to 1·58) respectively compared with period 1. Recurrent tumours were more frequently peritoneal rather than locoregional.

CONCLUSION

Overall and disease-free survival rates after R0 resection of GC were unchanged over time.

High accuracy of multislices computed tomography (MSCT) for para-aortic lymph node metastases from gastric cancer: a prospective single-center study

BACKGROUND

The purpose of this study is to analyze the diagnostic accuracy of MSCT in the identification of para-aortic lymph node metastases from gastric cancer.

METHODS

A total of 92 consecutive patients with primary gastric cancer were prospectively submitted to preoperative MSCT staging according to a standard protocol in the period 2003-2010. All diagnostic procedures were performed by dedicated radiologists who were unaware of the final pathological nodal status. Subsequently all patients underwent potentially curative (R0) resection with extended lymphadenectomy plus para-aortic nodal dissection. Lymph node mapping in different stations and retrieval of single lymph nodes were performed by the surgeon on the fresh specimen and then submitted for pathological examination. Clinical, radiological, and pathological data were prospectively stored on database.

RESULTS

A median number of 47 (range: 18-114) total lymph nodes and 7 (range: 3-29) para-aortic lymph nodes were removed. In 13 of 92 included patients (14%), histological examination demonstrated para-aortic nodal metastases; MSCT was correctly positive in 11 of these cases (sensitivity: 85%). In 79 patients para-aortic nodes were not involved, and MSCT resulted correctly negative in 75 of these patients (specificity: 95%). Positive (PPV) and negative (NPV) predictive values were 73 and 97%, with a global accuracy of 93%.

CONCLUSIONS

MSCT performed according to a standard protocol by dedicated radiologists demonstrated high accuracy in preoperative identification of para-aortic nodal metastases from gastric cancer. These results may be useful in planning surgical approach or during clinical staging before neoadjuvant chemotherapy.

Gastric Cancer Working Group report

EPIDEMIOLOGY

Gastric cancer is the second most common cancer in Asia, more than half of the world's gastric cancer cases arise in Eastern Asia, and the majority of Asia's cases still occur in the distal part of the stomach.

ETIOLOGY AND PREVENTION

The etiology of gastric cancer consists of genetic susceptibility, Helicobacter pylori infection and environmental risk factors. Helicobacter pylori eradication treatment, consumption of fresh vegetables and fruits and use of aspirin and non-steroidal anti-inflammatory drugs seem to reduce the risk of gastric cancer.

ENDOSCOPY AND DIAGNOSIS

Screening for gastric cancer is cost-effective in countries with high incidence. Risk stratification may increase the cost-effectiveness of screening in populations at moderate risk. Endoscopic resection is curative in a subset of patients with early cancer.

SURGERY AND ADJUVANT TREATMENT

R0 resection with D2 lymph node dissection has produced the best survival data. Some kind of post-operative adjuvant chemotherapy including S-1 is recommended after D2 surgery.

CHEMOTHERAPY FOR ADVANCED GASTRIC CANCER

As chemotherapy for gastric cancer, fluorouracils plus platinum are the most widely accepted first-line regimens, whereas taxanes or irinotecan are mostly used in second- and third-line settings. Differences in the approval and medical insurance systems may influence the status of these regimens. Trastuzumab in combination with fluorouracils/platinum will be a standard regimen for HER2-positive gastric cancer. Many new targeting agents are currently under investigation, and Asian countries are playing important roles in investigation and development of new and better treatments for this malignancy.

New metastatic lymph node ratio system reduces stage migration in patients undergoing D1 lymphadenectomy for gastric adenocarcinoma

BACKGROUND

The American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) staging system for gastric cancer incorporates the absolute number of metastatic lymph nodes (N status) and is optimally used when >or=15 nodes are examined. The ratio of metastatic to examined nodes (N ratio) is an effective prognostic tool, but has not been examined in Western patients undergoing primarily D1 lymphadenectomy.

METHODS

Two hundred and fifty seven patients with gastric adenocarcinoma who underwent gastric resection between 1995 and 2005 at our institution were examined. Novel N ratio intervals were determined using the best cutoff approach (Nr0: N ratio = 0 and >or=15 nodes examined; Nr1: 0 <or= N ratio <or= 0.3; Nr2: 0.3 < N ratio <or= 0.7; and Nr3: N ratio > 0.7). Overall survival was examined according to N status and N ratio.

RESULTS

83% of patients underwent D1 lymphadenectomy with a median of 14 lymph nodes examined. Overall survival stratified by N status was significantly different in patients with <15 nodes examined compared with those with >or=15 nodes examined. When we stratified by N ratio intervals, there was no significant difference in overall survival in patients with <15 versus >or= 15 nodes examined. On multivariate analysis, N ratio but not N status was retained as an independent prognostic factor.

CONCLUSIONS

The use of N status for staging patients undergoing primarily D1 lymphadenectomy results in significant stage migration due to varying numbers of nodes examined. Use of N ratio reduces stage migration and may be a more reliable method of staging these patients.