Surgical treatment variation in a prospective, randomized trial of chemoradiotherapy in gastric cancer: the effect of undertreatment

Feasibility of Regional Lymphadenectomy for Stomach-Preserving Surgery in Early Gastric Cancer Omitting Sentinel Node Navigation: A Post Hoc Analysis of the SENORITA Trial

BACKGROUND

Sentinel node navigation (SNN) has been known as the effective treatment for stomach-preserving surgery in early gastric cancer; however, SNN presents several technical difficulties in real practice.

OBJECTIVE

This study aimed to evaluate the feasibility of regional lymphadenectomy omitting SNN, using the post hoc analysis of a randomized controlled trial.

METHODS

Using data from the SENORITA trial that compared laparoscopic standard gastrectomy with lymphadenectomy and laparoscopic SNN, 237 patients who underwent SNN were included in this study. Tumor location was divided into longitudinal and circumferential directions. According to the location of the tumor, the presence or absence of lymph node (LN) metastases between sentinel and non-sentinel basins were analyzed. Proposed regional LN stations were defined as the closest area to the primary tumor. Sensitivities, specificities, positive predictive values, and negative predictive values (NPV) of SNN and regional lymphadenectomy were compared.

RESULTS

Metastasis to non-sentinel basins with tumor-free in sentinel basins was observed in one patient (0.4%). The rate of LN metastasis to non-regional LN stations without regional LN metastasis was 2.5% (6/237). The sensitivity and NPV of SNN were found to be significantly higher than those of regional lymphadenectomy (96.8% vs. 80.6% [p = 0.016] and 99.5% vs. 97.2% [p = 0.021], respectively).

CONCLUSIONS

This study showed that regional lymphadenectomy for stomach-preserving surgery, omitting SNN, was insufficient; therefore, SNN is required in stomach-preserving surgery.

A combined approach for individualized lymphadenectomy in gastric cancer patients

Introduction: Gastric cancer ranks as the fifth most common cancer globally. The presence of lymph node metastasis is a significant prognostic factor influencing survival. Postoperative morbidity and nodal staging accuracy are heavily affected by the extent of lymph node dissection. Our study aimed to explore the potential integration of two contemporary methods, sentinel node navigation surgery (SNNS) and the Maruyama Computer Program (MCP), to improve the accuracy of nodal staging. Materials and methods: We conducted a prospective data collection involving patients with gastric adenocarcinoma from 2008 to 2018 at the Department of Surgery, University of Debrecen, Hungary. Data from 100 consecutive patients were collected. The primary and secondary endpoints included evaluating the rate of node-negative patients and the diagnostic accuracy of our combined approach. Results: Sentinel node mapping was successful in 97 out of 100 patients. We found that using the threshold value of the Maruyama Index (MI) ≥ 28, all metastatic stations of sentinel-node-negative patients could be identified. Our method achieved 100% sensitivity and negative predictive value, with a specificity of 60.42% (95% CI = 46.31%-72.98%). Discussion: The combined application of SNNS and MCP has proven to be an effective diagnostic technique in the synergistic approach for identifying metastasis-positive lymph node stations. Despite its limitations, this combination may assist clinicians in customizing lymphadenectomy for gastric cancer patients.

Optimal extent of lymph node dissection in gastric cancer

Gastric cancer still remains a major cause of cancer-related deaths globally. Stage-adapted, individualized treatment is crucial to achieving optimal oncological outcomes. Postoperative morbidity and accurate nodal staging are heavily influenced by the extent of lymph node dissection. On one hand, insufficient lymphadenectomy may result in understaging and undertreatment of a patient, on the other hand, unnecessary lymph node dissection may result in a higher rate of postoperative complications. Approximately one-third of patients with gastric cancer undergoes an avoidable lymph node dissection. Many of the recent treatment updates in the management of gastric cancer have a major influence on both surgical and oncological approaches. Currently, a wide range of endoscopic, minimally invasive, and hybrid surgical techniques are available. The concept of sentinel node biopsy and utilization of the Maruyama Computer Program are significant components of stage-adapted gastric cancer surgery. Likewise, centralization and application of national guidelines, widespread use of neoadjuvant therapy, and the stage migration phenomenon are serious concerns to be discussed. Our goal is to review the available surgical strategies for gastric cancer, with a primary focus on lymphadenectomy.

Comparison of 4 lymph node staging systems for the prognostic prediction of esophagogastric junction adenocarcinoma with ≤15 retrieved lymph nodes

BACKGROUND

Directly applying the 8th American Joint Committee on Cancer (AJCC) Tumor Node Metastasis (TNM) staging system to evaluate the prognosis of patients with esophagogastric junction adenocarcinoma (AEG) might lead to under-staging, when insufficient lymph nodes were retrieved during surgery. The prognostic value of 4 lymph nodes staging systems, 8th AJCC TNM N stage, lymph node ratio (LNR), log odds of positive lymph nodes (LODDS), and negative lymph nodes (NLN), in AEG patients having ≤15 retrieved lymph nodes were compared.

METHODS

869 AEG patients diagnosed between 2004 and 2012 with ≤15 retrieved lymph nodes were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression analyses were conducted to assess the association of cancer-specific survival (CSS) and overall survival (OS) with 8th AJCC TNM N stage, LNR, LODDS, and NLN respectively. Predictive survival ability was assessed and compared using linear trend χ2 score, likelihood ratio (LR) test, Akaike information criterion (AIC), Harrell concordance index (C-index), and Receiver Operative Curve (ROC).

RESULTS

The N stage, LNR, LODDS, and NLN were all independent prognostic predictors for CSS and OS in multivariate Cox models. Comparatively, LODDS demonstrated higher linear trend χ2 score, LR test score, C-index and integrated area under the curve (iAUC) value, and lower AIC in CSS compared to the other three systems. Moreover, for patients without regional lymph node metastasis, NLN showed higher C-index and lower AIC.

CONCLUSIONS

LODDS showed better predictive performance than N, LNR, and NLN among patients with node-positive patients while NLN performed better in node-negative patients. A combination of LODDS and NLN has the potential to provide more prognostic information than the current AJCC TNM classification.

Surgical Treatment for Gastric Cancer

Surgery is an essential component of curative-intent treatment strategies for gastric cancer. However, the care of each patient with gastric cancer must be individualized based on patient and tumor characteristics. It is important that all physicians who will be caring for patient with gastric cancer understand the current best practices of surgical management to provide patients with the highest quality of care. This article aims to provide this information while acknowledging areas of surgical management that are still controversial.

Surgical Management of Gastric Cancer: A Systematic Review

Gastric cancer is the fifth most common cancer worldwide, and it is responsible for 7.7% of all cancer deaths. Despite advances in the field of oncology, where radiotherapy, neo and adjuvant chemotherapy may improve the outcome, the only treatment with curative intent is represented by surgery as part of a multimodal therapy. Two concepts may be adopted in appropriate cases, neoadjuvant treatment before gastrectomy (G) or primary surgical resection followed by chemotherapy. Such an approach, combined with early detection and better screening, has led to a decrease in the overall incidence of gastric cancer. Unfortunately, malignant tumors of the stomach are often diagnosed in locally advanced or metastatic stages when the median overall survival remains poor. Surgical care in these cases must be provided by a multidisciplinary team in a high-volume center. Important surgical aspects such as optimum resection margins, surgical technique, and number of harvested lymph nodes are important factors for patient outcomes. The standardization of surgical treatment of gastric cancer in accordance with the patient’s profile is of decisive importance for a better outcome. This review aims to summarize the current standards in the surgical treatment of gastric cancer.

Chemoradiotherapy or chemotherapy as adjuvant treatment for resected gastric cancer: should we use selection criteria?

Background

The management of gastric adenocarcinoma is essentially based on surgery followed by adjuvant treatment. Adjuvant chemotherapy (CT) as well as chemoradiotherapy (CTRT) have proven their effectiveness in survival outcomes compared to surgery alone. However, there is little data comparing the two adjuvant approaches. This study aimed to compare the prognosis and survival outcomes of patients with gastric adenocarcinoma operated and treated by adjuvant radio-chemotherapy or chemotherapy.

Materials and methods

We retrospectively evaluated 80 patients with locally advanced gastric cancer (LGC) who received adjuvant treatment. We compared survival outcomes and patterns of recurrence of 53 patients treated by CTRT and those of 27 patients treated by CT.

Results

After a median follow-up of 38.48 months, CTRT resulted in a significant improvement of the 5-year PFS (60.9% vs. 36%, p = 0.03) and the 5-year OS (55.9% vs. 33%, p = 0.015) compared to adjuvant CT. The 5-year OS was significantly increased by adjuvant CTRT (p = 0.046) in patients with lymph node metastasis, and particularly those with advanced pN stage (p = 0.0078) and high lymph node ratio (LNR) exceeding 25% (p = 0.012). Also, there was a significant improvement of the PFS of patients classified pN2-N3 (p = 0.022) with a high LNR (p = 0.018). CTRT was also associated with improved OS and PFS in patients with lymphovascular and perineural invasion (LVI and PNI) compared to chemotherapy.

Conclusion

There is a particular survival benefit of adding radiotherapy to chemotherapy in patients with selected criteria such as lymph node involvement, high LNR LVI, and PNI.

Challenges to quality assurance of surgical interventions in clinical oncology trials: A systematic review

Where surgery forms the primary curative modality in surgical oncology trials the quality of this intervention has the potential to directly influence outcomes. Many trials however lack a robust framework to ensure surgical quality. We aim to report existing published challenges to quality assurance of surgical interventions within oncological trials. A systematic on-line literature search of Embase and Medline identified 34 relevant studies, including 19 RCTs, 11 further analyses of the primary RCTs, and 4 trial protocols. Inclusion criteria: oncological RCTs with a surgical intervention and/or associated publications relevant to the research question; 'Challenges to quality assurance of surgery in clinical oncology trials'. Selected articles were assessed by two reviewers to identify reported challenges to quality assurance of surgical intervention within these trials. Reported challenges to surgical quality could be classified as those affecting credentialing, standardisation and monitoring of surgical interventions. Constraints of using case volume for credentialing surgeons; inter-centre variation in the definition and execution of interventions; insufficient training, and monitoring of surgical quality, were the most commonly encountered challenges within each of these three domains. Findings confirmed an inadequacy in the implementation and reporting of effective surgical quality assurance measures. The surgical community should enable implementation of agreed upon mitigating strategies to overcome challenges to surgical quality in oncology trials.

Impact of surgical resection rate on survival in gastric cancer: nationwide study

Background

There are marked geographical variations in the proportion of patients undergoing resection for gastric cancer. This study investigated the impact of resection rate on survival.

Methods

All patients with potentially curable gastric cancer between 2006 and 2017 were identified from the Swedish National Register of Oesophageal and Gastric Cancer. The annual resection rate was calculated for each county per year. Resection rates in all counties for all years were grouped into tertiles and classified as low, intermediate or high. Survival was analysed using the Cox proportional hazards model.

Results

A total of 3465 patients were diagnosed with potentially curable gastric cancer, and 1934 (55.8 per cent) were resected. Resection rates in the low (1261 patients), intermediate (1141) and high (1063) tertiles were 0–50.0, 50.1–62.5 and 62.6–100 per cent respectively. The multivariable Cox analysis revealed better survival for patients diagnosed in counties during years with an intermediate versus low resection rate (hazard ratio (HR) 0.81, 95 per cent c.i. 0.74 to 0.90; P < 0.001) and high versus low resection rate (HR 0.80, 0.73 to 0.88; P < 0.001).

Conclusion

This national register study showed large regional variation in resection rates for gastric cancer. A higher resection rate appeared to be beneficial with regard to overall survival for the entire population.

Challenges surrounding postoperative adjuvant chemotherapy for T2N0 gastric cancer

Determining the requirement for adjuvant chemotherapy in patients with stage IB gastric cancer (GC), and particularly for those with stage T2N0 (muscularis propria) disease, remains challenging. Patients with stage II/III disease benefit from postoperative adjuvant therapy; however, the randomized trials examining whether such therapy affords any survival benefit to patients with T2N0 disease are not sufficient. Current evidence suggests that not all patients with T2N0 disease should undergo such treatment, but only those with a high risk. To date, a number of retrospective studies have attempted to identify factors that are predictive of increased risk in an effort to guide adjuvant therapy-related clinical decision making. The National Comprehensive Cancer Network and the Chinese Society of Clinical Oncology have published guidelines regarding factors associated with increased patient risk. As a result, treatment decisions for patients with stage T2N0 disease are currently determined on an individualized basis, in light of risk factors and the potential benefits of treatment. The present review surveyed current evidence related to the treatment of patients with high-risk GC and highlighted the potential avenues for future investigated.

Prognostic value of a new staging system based on the retrieved number and metastatic rate of LNs in gastric cancer with ≤15 retrieved LNs

OBJECTIVE

To investigate a reasonable lymph node (N) staging system for gastric cancer patients with ≤15 retrieved lymph nodes (LNs).

METHODS

The clinicopathological and follow-up data of patients with ≤15 LNs were obtained from the US Surveillance, Epidemiology, and End Results (SEER) database to analyze the impact of the number of retrieved LNs and metastatic status on the prognosis. In addition, external validation was achieved with data from two medical centers in China.

RESULTS

A total of 18,139 gastric cancer patients with 1-15 retrieved LNs from the SEER database were enrolled and randomly divided into the training group and the internal validation group. A new LN staging system, mNr staging (mNr0-4; 5 stages), was established according to the number of retrieved LNs and the metastatic rate. Compared with the TNM and TNrM staging systems (established by Wang J; misclassification rates of 50.4% and 62.5%, respectively), the mTNrM staging system had a lower misclassification rate (23.4%). Furthermore, there was a significant difference in the 5-year overall survival (OS) rate between the mTNrM staging subgroups (p < 0.05); however, no significant difference was found in the 5-year OS rate of partial adjacent stages in the TNM (8th edition) and TNrM (p > 0.05) staging systems. Similar results were obtained in the external validation cohort.

CONCLUSION

mNr and mTNrM staging systems can efficiently distinguish a survival difference in patients who undergo gastrectomy with ≤15 retrieved LNs, with more accurate predictions of the 5-year OS rate of patients compared with the TNM and TNrM staging systems.

Current status of adjuvant chemotherapy for gastric cancer

Although radical gastrectomy is a standard treatment for advanced gastric cancer, recurrence remains high. After several large-scale controlled studies have shown the beneficial effects of adjuvant chemotherapy, that treatment emerged as a standard option for advanced gastric cancer after gastrectomy. However, various guidelines from different countries have suggested different adjuvant chemotherapies. Understanding the differences between guidelines is very important for investigating further therapeutic strategies. Fortunately, because there are many ongoing studies about new regimens for adjuvant treatment, it is expected that patients with gastric cancer after surgery will have better outcome.

Surgicopathological Quality Control and Protocol Adherence to Lymphadenectomy in the CRITICS Gastric Cancer Trial

OBJECTIVE

The purpose of this study was to evaluate surgicopathological quality and protocol adherence for lymphadenectomy in the CRITICS trial.

SUMMARY OF BACKGROUND DATA

Surgical quality assurance is a key element in multimodal studies for gastric cancer. In the multicenter CRITICS trial (ChemoRadiotherapy after Induction chemotherapy In Cancer of the Stomach), patients with resectable gastric cancer were randomized for preoperative chemotherapy, followed by gastrectomy with a D1+ lymphadenectomy (removal of stations 1 to 9 and 11), followed by either chemotherapy or chemoradiotherapy.

METHODS

Surgicopathological compliance was defined as removal of ≥15 lymph nodes. Surgical compliance was defined as removal of the indicated lymph node stations. Surgical contamination was defined as removal of lymph node stations that should be left in situ. The Maruyama Index (MI, lower is better), which has proven to be an indicator of surgical quality and is strongly associated with survival, was analyzed.

RESULTS

Between 2007 and 2015, 788 patients were randomized, of whom 636 patients underwent a gastrectomy with curative intent. Surgicopathological compliance occurred in 72.8% (n = 460) of the patients and improved from 55.0% (2007) to 90.0% (2015). Surgical compliance occurred in 41.1% (n = 256). Surgical contamination occurred in 59.6% (n = 371). Median MI was 1 (range 0 to 136).

CONCLUSION

Surgical quality in the CRITICS trial was excellent, with a MI of 1. Surgicopathological compliance improved over the years. This might be explained by the quality assurance program within the study and centralization of gastric cancer surgery in the Netherlands.

Blast from the past: Perioperative use of the Maruyama computer program for prediction of lymph node involvement in the surgical treatment of gastric cancer following neoadjuvant chemotherapy

BACKGROUND

Surgical quality assurance is a key element of gastric cancer treatment. The Maruyama Computer Program (MCP) allows to predict lymph node involvement in stations no. 1-16. The aim of the current study was to evaluate the accuracy of the MCP predictions in GC patients treated with neoadjuvant chemotherapy (nCTH) followed by gastrectomy with adequate lymphadenectomy.

METHODS

101 patients who underwent preoperative nCTH followed by D2 gastrectomy with curative intent were analysed. The response to nCTH was measured using the tumour regression grade system.

RESULTS

Test sensitivity, specificity, PPV, NPV and accuracy of the MCP were 92%, 33%, 41%, 89%, and 53%, respectively. In patients with response to nCTH, number of false positive (FP) results was significantly higher than in patients who did not respond to nCTH both in the N1 (56.3% vs 28.9%, p < 0.0001) and in the N2 (59% vs 41%, p < 0.0001) trier. The risk for FP results was 6 times higher in N1 (OR = 6.50, 95%CI: 3.91-10.82,; p < 0.0001) and N2 (OR = 5.84, 95%CI: 2.85-11.96; p < 0.0001) triers. In patients with intestinal type GC, the risk for FP results was 4 times higher than in other histologic types of GC in both N1 (OR = 4.23, 95%CI: 2.58-6.95; p < 0.0001) and N2 (OR = 4.23, 95%CI: 2.02-9.62; p = 0.0002) triers.

CONCLUSIONS

MCP predictions in the GC patients treated with nCTH have low specificity due to significantly high number of FP results. Noticeably low accuracy level of predictions indicate a need for new prediction models, based on Laurén classification, since it may provide some information on expected regression grade.

In Patients with Localized and Resectable Gastric Cancer, What is the Optimal Extent of Lymph Node Dissection-D1 Versus D2 Versus D3?

BACKGROUND

Despite advances in the treatment of patients with gastric cancer, the debate over the optimal extent of lymphadenectomy continues.

METHOD

A review of the classification, rationale for, and boundaries of lymphadenectomy is presented. A review of the available literature comparing D1 versus D2 versus D3 lymphadenectomy was performed and included randomized controlled trials, and prospective and retrospective comparative and non-comparative studies.

RESULTS

Earlier studies demonstrated increased morbidity with D2 compared with D1 lymphadenectomy, with no significant survival benefit. More recent studies have demonstrated survival benefit of a pancreas and spleen-sparing D2 lymphadenectomy in patients with advanced, node-positive tumors. Para-aortic/D3 dissections contribute to increased morbidity, with no survival benefit.

CONCLUSIONS

In patients with resectable gastric adenocarcinoma, a D2 lymph node dissection preserving the pancreas and spleen should be considered standard for optimal staging and treatment, provided it is performed by surgeons with sufficient expertise. Extended lymph node dissections beyond D2 should not be routinely performed as it has been shown to have increased morbidity, with no improvement in outcomes. While systemic chemotherapy should be considered standard in patients undergoing D2 lymphadenectomy, the role of adjuvant radiation continues to evolve.

Prognostic and Predictive Factors for the Curative Treatment of Esophageal and Gastric Cancer in Randomized Controlled Trials: A Systematic Review and Meta-Analysis

BACKGROUND

An overview of promising prognostic variables and predictive subgroups concerning the curative treatment of esophageal and gastric cancer from randomized controlled trials (RCTs) is lacking. Therefore, we conducted a systematic review and meta-analysis.

METHODS

PubMed, EMBASE, CENTRAL, and ASCO/ESMO conferences were searched up to March 2019 for RCTs on the curative treatment of esophageal or gastric cancer with data on prognostic and/or predictive factors for overall survival. Prognostic factors were deemed potentially clinically relevant according to the following criteria; (1) statistically significant (p < 0.05) in a multivariate analysis, (2) reported in at least 250 patients, and (3) p < 0.05, in ≥ 33% of the total number of patients in RCTs reporting this factor. Predictive factors were potentially clinically-relevant if (1) the p-value for interaction between subgroups was <0.20 and (2) the hazard ratio in one of the subgroups was significant (p < 0.05).

RESULTS

For gastric cancer, 39 RCTs were identified (n = 13,530 patients) and, for esophageal cancer, 33 RCTs were identified (n = 8618 patients). In total, we identified 23 potentially clinically relevant prognostic factors for gastric cancer and 16 for esophageal cancer. There were 15 potentially clinically relevant predictive factors for gastric cancer and 10 for esophageal cancer.

CONCLUSION

The identified prognostic and predictive factors can be included and analyzed in future RCTs and be of guidance for nomograms. Further validation should be performed in large patient cohorts.

Surgical Compliance and Outcomes in Gastric Cancer: a population-based cohort study

Background: Surgical resection is one of curative treatment for gastric cancer (GC), however, a set of patients show poor surgical compliance in the USA. We aimed to identify the risk factors associated with surgical compliance and investigate the difference in survival.

Methods: GC patients diagnosed between 1973 and 2014 were identified from the Surveillance Epidemiology and End Results (SEER) databases. Based on different surgical compliance and treatment regimen, patients were classified into three subgroups: surgical compliance group, surgical noncompliance group, and non-surgical group. Multivariable Logistic regression analysis was adopted to identify the factors related to surgical compliance; Multivariable Cox regression was used to investigate the prognostic factors. Overall survival (OS) and cancer-specific survival (CSS) were analyzed using the Kaplan-Meier estimator method.

Results: Of 79374 GC patients who were recommended for surgical therapy, 15201(19.2%) cases did not perform surgery. Poor compliance of surgery was related to old age, American Indian/Alaska Native race, poor grading/late staging, single/widowed status, lower socioeconomic status and earlier time of diagnosis. As expected, GC patients of surgical compliance group showed significantly more favorable survival than the other two groups (P<0.0001); notably, the outcome of surgical noncompliance group came close to that of non-surgical group.

Conclusion: GC patients of poor surgical compliance demonstrated adverse survival, which was comparable to that of non-surgical patients. The poor surgical compliance was associated with older age, American Indian/Alaska Native race, poor tissue differentiation/advanced stage of tumor, single/widowed status, lower socioeconomic status and earlier time of diagnosis.

Association between hospital volume and quality of gastric cancer surgery in the CRITICS trial

BACKGROUND

Studies investigating the association between hospital volume and quality of gastric cancer surgery are lacking. In the present study, the effect of hospital volume on quality of gastric cancer surgery was evaluated by analysing data from the CRITICS (ChemoRadiotherapy after Induction chemotherapy In Cancer of the Stomach) trial.

METHODS

Patients who underwent gastrectomy with curative intent in the Netherlands were selected from the CRITICS trial database. Annual hospital volume of participating centres was derived from the Netherlands Cancer Registry. Hospital volume was categorized into very low (1-10 gastrectomies per year per institution), low (11-20), medium (21-30) and high (31 or more), and linked to the CRITICS database. Quality of surgery was analysed by surgicopathological compliance (removal of at least 15 lymph nodes), surgical compliance (removal of indicated lymph node stations) and the Maruyama Index. Postoperative morbidity and mortality were also compared between hospital categories.

RESULTS

Between 2007 and 2015, 788 patients were included in the CRITICS study, of whom 494 were analysed. Surgicopathological compliance was higher (86·7 versus 50·4 per cent; P < 0·001), surgical compliance was greater (52·9 versus 19·8 per cent; P < 0·001) and median Maruyama Index was lower (0 versus 6; P = 0·006) in high-volume hospitals compared with very low-volume hospitals. There was no statistically significant difference in postoperative complications or mortality between the hospital volume categories.

CONCLUSION

Surgery performed in high-volume hospitals was associated with better surgical quality than surgery carried out in lower-volume hospitals.

Impact of upfront randomization for postoperative treatment on quality of surgery in the CRITICS gastric cancer trial

BACKGROUND

Preoperative randomization for postoperative treatment might affect quality of surgery. In the CRITICS trial (ChemoRadiotherapy after Induction chemotherapy In Cancer of the Stomach), patients were randomized before treatment to receive chemotherapy prior to a D1 + gastrectomy (removal of lymph node station (LNS) 1-9 + 11), followed by either chemotherapy (CT) or chemoradiotherapy (CRT). In this analysis, the influence of upfront randomization on the quality of surgery was evaluated.

METHODS

Quality of surgery was analyzed in both study arms using surgicopathological compliance (removal of ≥ 15 lymph nodes), surgical compliance (removal of the indicated LNS), and surgical contamination (removal of LNS that should be left in situ). Furthermore, the 'Maruyama Index of Unresected disease' (MI) was evaluated in both study arms, and validated with overall survival.

RESULTS

Between 2007 and 2015, 788 patients with gastric cancer were included in the CRITICS study of which 636 patients were operated with curative intent. No difference was observed between the CT and CRT group regarding surgicopathological compliance (74.8% vs 70.9%, P = 0.324), surgical compliance (43.2% vs 39.2%, P = 0.381), and surgical contamination (59.4% vs 59.9%, P = 0.567). Median MI was 1 in both groups (range CT 0-88 and CRT 0-136, P = 0.700). A MI below 5 was associated with better overall survival (CT: P = 0.009 and CRT: P = 0.013).

CONCLUSION

Surgical quality parameters were similar in both study arms in the CRITICS gastric cancer trial, indicating that upfront randomization for postoperative treatment had no impact on the quality of surgery. A Maruyama Index below five was associated with better overall survival.

Necessity of adjuvant concurrent chemo-radiotherapy in D2-resected LN-positive gastric cancer

BACKGROUND AND PURPOSE

To investigate the role of adjuvant concurrent chemo-radiotherapy (CCRT) by analyzing the outcomes of adjuvant CCRT versus chemotherapy alone (CA) in patients with D2-resected gastric cancer with lymph node (LN) metastasis.

MATERIALS AND METHODS

Patients with gastric cancer from the institutional registry who underwent curative D2 and R0 resection from December 2004 to January 2013 followed by adjuvant CCRT or CA and demonstrated pathologically confirmed LN metastasis without distant metastasis were included in the study.

RESULTS

A total of 1633 patients were included (909 patients in the adjuvant CCRT group and 724 patients in the CA group), and median follow-up was 65.4 months (range, 3.9-141.7 months). There was a significant difference in age (p < 0.0001), Lauren's classification (p = 0.02), number of LN metastases (p < 0.0001), and pN stage (p < 0.0001) between the CCRT and CA groups. During follow-up, recurrence was detected in 419 (25.7%) of patients overall, 236 (26.0%) in the CCRT group, and 183 (25.3%) in the CA group. Recurrence-free survival (RFS) was not significantly different between the CCRT and CA groups in univariable analysis (p = 0.92). After adjustment, pT/pN stage and perineural invasion showed statistical significance in multivariable Cox regression analysis; however, RFS was significantly higher in the CCRT group (p = 0.03, hazard ratio 0.801, 95% confidence interval 0.658-0.975).

CONCLUSIONS

The adjusted RFS was significantly higher in the CCRT group than the CA group in patients with D2 resected LN metastatic gastric cancer.

CURRENT STATUS OF THE MULTIDISCIPLINARY TREATMENT OF GASTRIC ADENOCARCINOMA

Background:

The complexity of the management of gastric cancer requires a multidisciplinary evaluation of patients with this tumor. Several treatments have been employed, associated to the surgical resection.

Objective:

To review the available therapeutic alternatives for the treatment of gastric adenocarcinoma.

Methods:

A review of selected articles on multidisciplinary treatment of gastric adenocarcinoma in the Pubmed and Medline databases between 2000 and 2017 was carried out. The following headings were related: stomach cancer, treatment, chemotherapy and radiotherapy.

Results:

There are several valid alternatives, with good results for the treatment of gastric cancer: chemoradiotherapy or chemotherapy in the adjuvant scenario; perioperative chemotherapy; and chemoradiotherapy after neoadjuvance with isolated chemotherapy.

Conclusion:

Current evidences suggest that combined multidisciplinary treatment is superior to surgery alone. However, the optimal treatment regimen is not yet established, and depends on a number of factors, especially the type of surgical resection employed. Therefore, the therapeutic decision should be made by a multidisciplinary team, assessing patient’s personal characteristics, biology of the tumor, residual disease, risks and side effects.

Underutilization of Treatment for Regional Gastric Cancer Among the Elderly in the USA

BACKGROUND

In the USA, a quarter of elderly patients do not receive any treatment for regional gastric cancer, which results in poorer outcomes. We sought to identify factors associated with undertreatment of regional gastric cancer in this population, as well as to assess overall survival in the undertreated population.

METHODS

Elderly patients (aged ≥ 65 years) diagnosed with regional gastric cancer between 2001 and 2009 were identified from the Surveillance Epidemiology and End Results (SEER)-Medicare linked databases. Treatment was defined as receiving any medical or surgical therapy for gastric cancer. Logistic regression analysis was used to identify factors associated with failure to receive treatment. Overall survival was analyzed using the Kaplan-Meier method and Cox proportional hazard model.

RESULTS

Of 5972 patients with regional gastric cancer, 1586 (26.5%) received no treatment. Median age was 78 years; 56.1% of patients were men. On multivariable analysis, the factors strongly associated with lack of therapy were age ≥ 80 years, black race, lower education level, and diagnosis before 2007. As expected, patients who received therapy had better overall survival (log-rank test, p < 0.001). Specifically, median survival and 5-year survival were 16.5 months and 20.5% for treated patients, compared with 9.1 months and 19.0% for untreated patients.

CONCLUSIONS

Elderly patients with gastric cancer have better overall 5-year survival after receiving treatment for their cancer. Disparities in the use of treatment for curable cancers are associated with older age, black race, lower educational level, and diagnosis before 2007.

Is the 8th Edition of the AJCC TNM Staging System Sufficiently Reasonable for All Patients with Noncardia Gastric Cancer? A 12,549-Patient International Database Study

BACKGROUND

The aim of this work is to compare the prognostic ability between the 7th and 8th editions of the American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) classification for gastric cancer (GC).

METHODS

A total of 10,194 noncardia GC patients were identified from the Surveillance, Epidemiology, and End Results database from 1988 to 2008. Concordance index (C-index), bayesian information criterion (BIC), and time-dependent receiver operating characteristic (t-ROC) analyses were used. External validation was performed using a dataset (n = 2355) derived from Fujian Medical University Union Hospital.

RESULTS

Overall survival for all five AJCC N categories differed significantly when patients were subgrouped into ≤ 15 versus >15 examined lymph nodes (eLNs). The prognostic ability of the 8th edition (C-index 0.716) was not improved over the 7th edition (C-index 0.716). Subgroup analysis showed superior performance of the 8th over the 7th edition in patients with > 15 eLNs (C-index 0.742 vs. 0.735); however, the two editions showed similar performance for patients with ≤ 15 eLNs (C-index 0.713 vs. 0.713). The BIC and t-ROC analyses were consistent. To better predict the prognosis of patients with ≤ 15 eLNs, we established a novel prognostic model based on independent prognostic factors (C-index 0.735). BIC analysis showed that this new model was better than the 7th and 8th editions. Similar results were obtained from the validation set.

CONCLUSIONS

The 8th edition of the AJCC TNM classification shows better prognostic ability than the 7th edition in noncardia GC patients with > 15 eLNs, but no improvement was found in patients with ≤ 15 eLNs; therefore, a novel prognostic model is proposed.

Efficacy of Adjuvant S-1 Versus XELOX Chemotherapy for Patients with Gastric Cancer After D2 Lymph Node Dissection: A Retrospective, Multi-Center Observational Study

BACKGROUND

After curative resection of gastric cancer with D2 lymph node dissection, postoperative adjuvant chemotherapy with S-1 or capecitabine plus oxaliplatin (XELOX) is considered to be standard therapy in Eastern countries. This study aimed to compare the efficacies of adjuvant S-1 and XELOX chemotherapy for gastric cancer patients after D2 dissection based on disease-free survival (DFS).

METHODS

This retrospective observational study was conducted at 29 tertiary hospitals in Korea. Of 1898 patients who underwent curative resection and received adjuvant chemotherapy for gastric cancer between February 2012 and December 2013, 1088 patients who met the eligibility criteria were enrolled in the study. After propensity score-matching, the 3-year disease-free survival rate (DFS) was used to compare efficacies directly between adjuvant XELOX and S-1 chemotherapies for patients with stage 2 or 3 gastric cancer after D2 gastrectomy.

RESULTS

The 3-year DFS rates for the S-1 and XELOX groups did not differ significantly among disease stages 2A, 2B, and 3A (all p > 0.05). However, the survival rates for the S-1 group were significantly lower than for the XELOX group for stage 3B (65.8% vs. 68.6%; p = 0.019) and stage 3C (48.4% vs. 66.7%; p = 0.002) gastric cancer. The hazard ratios (HRs) of S-1 chemotherapy for recurrence compared with XELOX for stages 3B and 3C were respectively 2.030 [95% confidence interval (CI), 1.110-3.715; p = 0.022] and 2.732 (95% CI 1.427-5.234; p = 0.002).

CONCLUSIONS

Adjuvant XELOX chemotherapy was more effective than S-1 for patients with stage 3B or 3C gastric cancer after D2 lymph node dissection.

Comparison of changes in renal function with dosimetric parameters in gastric cancer patients treated with adjuvant chemoradiotherapy

PURPOSE

Our objective was to analyze kidney damage using glomerular filtration rate (GFR) and dynamic renal scintigraphy (DRS) compared with dose volume histogram (DVH) parameters in gastric cancer patients.

MATERIALS AND METHODS

Twenty-two gastric cancer patients treated with postoperative chemoradiotherapy were retrospectively evaluated. Student's t test was used to compare pre- and posttreatment GFR and creatinine values. The relative contribution of the left and right kidney in DRS results was expressed as left-to-right ratio (L/R), and the percentage of initial and control participation ratio difference was calculated. Spearman's correlation analysis was used to compare the percentage difference of L/R ratio with DVH parameters of each kidney.

RESULTS

In DRS analysis, decrease in left kidney cortical function was observed in one patient. V5-V10 of the left and bilateral kidneys were significantly associated with GFR decline. None of the DVH parameter was significantly associated with L/R ratio. However, the V15 and D_mean of the bilateral kidney were significantly correlated with greater decrease in L/R ratio in seven patients whose posttreatment DRS period was > 12 months.

CONCLUSIONS

Decline in renal function, even with current renal constraints, was observed. Minimization of V5, V10, and V15 and mean dose (D_mean) to the kidney should be considered.

Perioperative chemotherapy for resectable gastric cancer - what is the evidence?

The UK MAGIC trial published in 2006 was the first RCT to identify improved long-term survival rates using preoperative chemotherapy for resectable gastric or gastroesophageal cancer. Overnight, the treatment regimen impacted European guidelines. However, the majority of patients underwent limited lymph node dissection, and analyses of the rates of curative resection, downsizing and downstaging were not by intention to treat, rightfully raising concerns about their validity. For the subset of true gastric cancers, meta-analyses may even question the claims of improved long-term survival rates by present-day regimens. A rhetorical question can be posed as to whether downstaging and improved survival rates by preoperative (radio)-chemotherapy for cancers of the distal esophagus or gastric cardia, has confounded our conclusions on the (lack of) effect of present-day regimens of perioperative chemotherapy for true gastric cancers, let alone in a situation with proper lymph node dissection. At present, a plea can be made to move one step back and revert to an RCT with a surgery alone arm. Inclusion criteria and analyses of future RCTs must stratify on tumor location and the Lauren type and embrace the newly developed scheme of sub-classification of gastric cancers based on extensive molecular profiling as reported in the seminal Cancer Genome Atlas Study.

Extent of lymphadenectomy has no impact on postoperative complications after gastric cancer surgery in Sweden

Objective

Curative gastric cancer surgery entails removal of the primary tumor with adequate margins including regional lymph nodes. European randomized controlled trials with recruitment in the 1990’s reported increased morbidity and mortality for D2 compared to D1. Here, we examined the extent of lymphadenectomy during gastric cancer surgery and the associated risk for postoperative complications and mortality using the strengths of a population-based study.

Methods

A prospective nationwide study conducted within the National Register of Esophageal and Gastric Cancer. All patients in Sweden from 2006 to 2013 who underwent gastric cancer resections with curative intent were included. Patients were categorized into D0, D1, or D1+/D2, and analyzed regarding postoperative morbidity and mortality using multivariable logistic regression.

Results

In total, 349 (31.7%) patients had a D0, 494 (44.9%) D1, and 258 (23.4%) D1+/D2 lymphadenectomy. The 30-d postoperative complication rates were 25.5%, 25.1% and 32.2% (D0, D1 and D1+/D2, respectively), and 90-d mortality rates were 8.3%, 4.3% and 5.8%. After adjustment for confounders, in multivariable analysis, there were no significant differences in risk for postoperative complications between the lymphadenectomy groups. For 90-d mortality, there was a lower risk for D1 vs. D0.

Conclusions

The majority of gastric cancer resections in Sweden have included only a limited lymphadenectomy (D0 and D1). More extensive lymphadenectomy (D1+/D2) seemed to have no impact on postoperative morbidity or mortality.

Applicability of the Proposed Japanese Model for the Classification of Gastric Cancer Location: The "PROTRADIST" Retrospective Study

BACKGROUND

The extension of lymphadenectomy for surgical treatment of gastric cancer remains discordant among European and Japanese surgeons. Kinami et al. (Kinami S, Fujimura T, Ojima E, et al. PTD classification: proposal for a new classification of gastric cancer location based on physiological lymphatic flow. Int. J. Clin. Oncol. 2008;13:320-329) proposed a new experimental classification, the "Proximal zone, Transitional zone, Distal zone" (PTD) classification, based on the physiological lymphatic flow of gastric cancer site. The aim of the present retrospective study is to assess the applicability of PTD Japanese model in gastric cancer patients of our Western surgical department.

METHODS

Two groups of patients with histologically documented adenocarcinoma of the stomach were retrospectively obtained: In the first group were categorized 89 patients with T1a-T1b tumor invasion; and in the second group were 157 patients with T2-T3 category. The data collected were then categorized according to the PTD classification.

RESULTS

In the T1a-T1b group there were no lymph node metastases within the r-GA or r-GEA compartments for tumors located in the P portion, and similarly there were no lymphatic metastases within the l-GEA or p-GA compartments for tumors located in the D portion. On the contrary, in the T2-T3 group the lymph node metastases presented a diffused spreading with no statistical significance between the two classification models.

CONCLUSIONS

Our results show that the PTD classification based on physiological lymphatic flow of the gastric cancer site is a more physiological and clinical version than the Upper, Medium And Lower classification. It represents a valuable and applicable model of cancer location that could be a guide to a tailored surgical approach in Italian patients with neoplasm confined to submucosa. Nevertheless, in order to confirm our findings, larger and prospective studies are needed.

Influence of Total Lymph Node Count on Staging and Survival After Gastrectomy for Gastric Cancer: An Analysis From a Two-Institution Database in China

BACKGROUND

Although current guidelines suggest that 16 or more lymph nodes (LNs) are required for the appropriate staging of gastric cancer, the effect that the minimum number of examined LNs (eLNs) in the different types of gastrectomy has on survival remains unclear.

METHODS

This study retrospectively analyzed 2662 patients who underwent curative gastrectomy with D2 lymphadenectomy for gastric cancer at Fujian Medical University Union Hospital from January 2000 to December 2010 and randomly divided them into development (70 %, n = 1863) and validation (30 %, n = 799) data sets. An additional external validation was performed using the data set (n = 285) collected during the same period from the Sun Yat-sen University Cancer Center in Guangzhou, China. A hypothetical tumor-node-metastasis (TNM) classification (hTNM) was proposed based on eLNs and survival.

RESULTS

The mean numbers of nodes removed during radical distal and total gastrectomy were respectively 26 ± 9.6 and 29 ± 10.7 (p < 0.01). The optimal LN-count thresholds were determined to be 16 for patients who underwent curative distal gastrectomy and 21 for patients who underwent total gastrectomy. The hTNM staging system had higher linear trend and likelihood ratio χ ² scores and lower Akaike information criterion (AIC) values than the seventh American Joint Committee on Cancer (AJCC) TNM classification. Thus, the hTNM staging system exhibited superior prognostic stratification. Similar results were found in the two validation data sets.

CONCLUSION

A harvest of at least 21 LNs may represent a superior threshold for radical total gastrectomy (RTG) and could yield a better prognosis. For patients undergoing RTG, the hTNM staging system may predict survival more accurately and discriminatively. However, a validation from a Western institution is warranted.

Recent insights in the therapeutic management of patients with gastric cancer

Gastric cancer remains frequent and one of the most lethal malignancies worldwide. In this article, we aimed to comprehensively review recent insights in the therapeutic management of gastric cancer, with focus on the surgical and perioperative management of resectable forms, and the latest advances regarding advanced diseases. Surgical improvements comprise the use of laparoscopic surgery including staging laparoscopy, a better definition of nodal dissection, and the development of hyperthermic intraperitoneal chemotherapy. The best individualized perioperative management should be assessed before curative-intent surgery for all patients and can consists in perioperative chemotherapy, adjuvant chemo-radiation therapy or adjuvant chemotherapy alone. The optimal timing and sequence of chemotherapy and radiation therapy with respect to surgery should be further explored. Patients with advanced gastric cancer have a poor prognosis. Nevertheless, they can benefit from doublet or triplet chemotherapy combination, including trastuzumab in HER2-positive patients. Upon progression, second-line therapy can be considered in patients with good performance status. Although anti-HER2 (trastuzumab) and anti-VEGFR (ramucirumab) may yield survival benefit, anti-EGFR and anti-HGFR therapies have failed to improve outcomes. Nevertheless, combination regimens containing cytotoxic drugs and targeted therapies should be further evaluated; keeping in mind that gastric cancer biology is different between Asia and the Western countries.

Alternative staging of regional lymph nodes in gastric cancer

The TNM pN stage based on the number of metastatic lymph nodes is an independent prognostic factor in gastric cancer. Many studies have highlighted the phenomenon of stage migration and problems in comparing groups of patients with different numbers of total lymph nodes harvested within TNM staging. The current version of UICC/AJCC and JGCA TNM classifications postulates a minimal number of 16 lymph nodes as the base for N stage determination. Alternative systems such as lymph node ratio (LNR), positive to negative lymph node ratio (PNLNR), and LOGODDS (or LODDS), were implemented to increase the quality of LN assessment. These methods have reached the background in the literature, but to date no standard approach according to the cut-offs for the stages has been implemented. LOGODDS is the method that most reflects the number of harvested lymph nodes. The rationale for alternative staging methods, their correlations, and limitations are presented.

The Essentials of Locoregional Control in the Treatment of Gastric Cancer

Gastric cancer is the fourth most frequent cancer in the world. For curative treatment and local control of gastric cancer, surgery is essential. The extent of the lymph node dissection is still under debate. Only one available trial showed significantly increased overall survival, whereas in all other randomised trials no significant difference could be found.

As surgery alone often is not sufficient in the curative treatment in gastric cancer, different (neo)adjuvant treatment strategies have extensively been studied. The recently published MAGIC trial showed downstaging, downsizing and an improved overall survival for patients treated with perioperative chemotherapy, compared to surgery alone (difference 13%, p = 0.009). The INT 0116 trial on the other hand, demonstrated the benefit of postoperative chemoradiotherapy compared to surgery alone for patients with a curative resection of gastric cancer. However, the quality of resections in this trial was poor, illustrating the importance of standardisation by quality control. This could be done by the Maruyama index, which quantifies the likelihood of unresected disease.

In the Netherlands, the CRITICS trial has recently been launched, which will be a quality controlled trial comparing postoperative chemoradiotherapy and chemotherapy on survival and/or locoregional control in patients who receive neoadjuvant chemotherapy followed by a D1+ gastric resection.

Surgical management of advanced gastric cancer: An evolving issue

Worldwide, gastric cancer represents the fifth most common cancer and the third leading cause of cancer deaths. Although the overall 5-year survival for resectable disease was more than 70% in Japan due to the implementation of screening programs resulting in detection of disease at earlier stages, in Western countries more than two thirds of gastric cancers are usually diagnosed in advanced stages reporting a 5-year survival rate of only 25.7%. Anyway surgical resection with extended lymph node dissection remains the only curative therapy for non-metastatic advanced gastric cancer, while neoadjuvant and adjuvant chemotherapies can improve the outcomes aimed at the reduction of recurrence and extension of survival. High-quality research and advances in technologies have contributed to well define the oncological outcomes and have stimulated many clinical studies testing multimodality managements in the advanced disease setting. This review article aims to outline and discuss open issues in current surgical management of advanced gastric cancer.

Quality control of lymph node dissection in the Dutch Gastric Cancer Trial

BACKGROUND

Current guidelines indicate that D2 resection is the standard of care for patients with locally advanced gastric cancer. To assess the impact of quality assurance of lymph node removal, non-compliance and contamination in the D1 and D2 study arms of the Dutch Gastric Cancer Trial were investigated with respect to recurrence and survival.

METHODS

The location and numbers of lymph nodes detected at pathological investigation in the Dutch Gastric Cancer Trial were compared according to the guidelines of the Japanese Research Society for the study of Gastric Cancer. Non-compliance was defined as inadequate removal of lymph node stations. Contamination was defined as lymph nodes removed outside the intended level of resection. The dissection groups D1 and D2 were divided into non-compliance, compliance and contamination categories. Long-term overall survival was calculated for minor (2 or fewer lymph nodes) and major (more than 2 lymph nodes) non-compliance and contamination in the D1 and D2 group, using Kaplan-Meier plots.

RESULTS

Some 1078 patients were included, of whom 711 with potentially curative surgical resections were evaluated. Overall non-compliance was 80·5 per cent in the D1 and 81·6 per cent in the D2 group. Major non-compliance occurred in 15·3 per cent of the D1 and 26·0 per cent of the D2 group. Major contamination hardly occurred. Overall 15-year survival rates in the randomized groups were 21·2 per cent (D1) and 29·0 per cent (D2) (P = 0·351). After exclusion of patients with major non-compliance and/or major contamination, survival rates were 23·2 per cent (319 patients) and 32·6 per cent (245) respectively (P = 0·261). Where there was major non-compliance, survival rates in the D1 (58 patients) and D2 (86) groups were 10 and 17 per cent respectively (P = 0·302). Survival in the D2 compliant + contaminated group (139 patients) was significantly better than that in the D1 group without contamination (282): 35·7 versus 19·9 per cent (P = 0·041). In the D2 group, there was a significant difference in survival between contaminated (95 patients) and non-contaminated (236) groups: 39 versus 25·1 per cent (P = 0·041).

CONCLUSION

Non-compliance in the D2 dissection group may have obscured a significant difference in survival between the randomized groups. A D2 dissection with contamination was associated with the best survival, suggesting that extended D2 lymph node dissections improve survival.

Optimal management of resectable gastric adenocarcinoma

The worldwide incidence of gastric adenocarcinoma has rapidly declined in the past century, but gastric cancer remains the fifth most common malignancy in the world. Approximately half of all cases of gastric cancer are diagnosed in Eastern Asia. In this review, we provide an overview of the landmark studies investigating neoadjuvant and adjuvant therapies in resectable gastric cancer and highlight ongoing efforts to define optimal population-adapted management strategies.

Surgical management of gastric cancer: the East vs. West perspective

Gastric cancer is a unique malignancy, with definite geographic differences in incidence, pathology, treatment and outcome. While the incidence has been declining in the Western hemisphere, steady rates have been reported in Eastern countries, particularly South Korea and Japan. One of the most profound differences between the East and West centers around treatment strategies, with Western clinicians routinely adopting a neoadjuvant approach, prior to surgical resection. Eastern clinicians, however, favor primary surgical therapy and have pioneered many of the techniques currently used worldwide. From endoscopic therapies to minimally-invasive surgery, including laparoscopic and robotic techniques, the Eastern surgeons have studied their techniques with high-volumes of patients. Western surgeons, practicing in systems where gastric cancer care is not centralized, typically have performed less aggressive surgical resections, although generally see more advanced diseases. In the era where global care is becoming more standardized, however, the differences in surgical practice have lessened. This review compares the surgical techniques and outcomes for gastric cancer practiced in the East with those standard in the West.

Subtotal gastrectomy for gastric cancer

Although a steady decline in the incidence and mortality rates of gastric carcinoma has been observed in the last century worldwide, the absolute number of new cases/year is increasing because of the aging of the population. So far, surgical resection with curative intent has been the only treatment providing hope for cure; therefore, gastric cancer surgery has become a specialized field in digestive surgery. Gastrectomy with lymph node (LN) dissection for cancer patients remains a challenging procedure which requires skilled, well-trained surgeons who are very familiar with the fast-evolving oncological principles of gastric cancer surgery. As a matter of fact, the extent of gastric resection and LN dissection depends on the size of the disease and gastric cancer surgery has become a patient and “disease-tailored” surgery, ranging from endoscopic resection to laparoscopic assisted gastrectomy and conventional extended multivisceral resections. LN metastases are the most important prognostic factor in patients that undergo curative resection. LN dissection remains the most challenging part of the operation due to the location of LN stations around major retroperitoneal vessels and adjacent organs, which are not routinely included in the resected specimen and need to be preserved in order to avoid dangerous intra- and postoperative complications. Hence, the surgeon is the most important non-TMN prognostic factor in gastric cancer. Subtotal gastrectomy is the treatment of choice for middle and distal-third gastric cancer as it provides similar survival rates and better functional outcome compared to total gastrectomy, especially in early-stage disease with favorable prognosis. Nonetheless, the resection range for middle-third gastric cancer cases and the extent of LN dissection at early stages remains controversial. Due to the necessity of a more extended procedure at advanced stages and the trend for more conservative treatments in early gastric cancer, the indication for conventional subtotal gastrectomy depends on multiple variables. This review aims to clarify and define the actual landmarks of this procedure and the role it plays compared to the whole range of new and old treatment methods.

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.

What make differences in the outcome of adjuvant treatments for resected gastric cancer?

After a long history of Dark Age of adjuvant chemotherapy for gastric cancer, definite evidences of survival benefit from adjuvant treatment have been reported since 2000s. These survival benefits are likely attributed to something new approach different from pervious studies. In 2001, South West Oncology Group INT0116 trial yielded survival benefit in curatively resected gastric cancer patients with postoperative chemoradiotherapy [5-fluorouracil (5-FU) + Leucovorin + radiotherapy], followed by positive result by MAGIC Trial, employing peri-operative(pre- and postoperative chemotherapy with Epirubicin, cisplatin (CDDP), 5-fluorouracil (ECF) regimen in patients with curative resection. A novel drug [S1: ACTS-GC (Adjuvant chemotherapy trial of TS-1 for gastric cancer) in 2007], or new drug combination chemotherapys [CDDP + 5-FU: FNCLCC/FFCD (Federation Nationale des Centres de Lutte contre le cancer/Federation Francophone de Cancerologie Digestive) in 2011, Capecitabine + Oxaliplatin: CLASSIC in 2012] also produced positive results in terms of improved prognosis. Neoadjuvant or perioperative chemotherapy, novel anti-cancer drugs, and chemoradiotherapy might be the key words to develop further improvement in the adjuvant treatment of resectable gastric cancer. Moreover, it is not new but still true to stress the importance of D2 surgery as the baseline treatment in order to minimize the amount of residual tumor after surgery.

Morbidity and mortality associated with gastrectomy for gastric cancer

BACKGROUND

Surgery alone is often inadequate for advanced-stage gastric cancer. Surgical complications may delay adjuvant therapy. Understanding these complications is needed for multidisciplinary planning.

MATERIAL AND METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was queried for patients who underwent gastrectomy for malignancy (ICD-9 code 151.x) from 2005 to 2010. Thirty-day mortality and morbidity were evaluated.

RESULTS

Overall, 2,580 patients underwent gastrectomy for malignancy, divided as total gastrectomy 999 (38.7 %) and partial gastrectomy 1,581 (61.3 %). Overall, serious morbidity occurred in 23.6 %, and the 30-day mortality was 4.1 %. Patients receiving a total gastrectomy were younger and healthier than those receiving a partial gastrectomy for the following measured criteria: age, diabetes, chronic obstructive pulmonary disease and hypertension. Serious morbidity and mortality were significantly higher in the total gastrectomy group than the partial gastrectomy group (29.3 vs. 19.9 %, p < 0.001; and 5.4 vs. 3.4 %, p < 0.015, respectively). The inclusion of additional procedures increased the risk of mortality for the following: splenectomy (odds ratio [OR] 2.8; p < 0.001), pancreatectomy (OR 3.5; p = 0.001), colectomy (OR 3.6; p < 0.001), enterectomy (OR 2.7; p = 0.030), esophagectomy (OR 3.5; p = 0.035). Abdominal lymphadenectomy was not associated with increased morbidity (OR 1.1; p = 0.41); rather, it was associated with decreased mortality (OR 0.468; p = 0.028).

CONCLUSIONS

Gastrectomy for cancer as currently practiced carries significant morbidity and mortality. Inclusion of additional major procedures increases these risks. The addition of lymphadenectomy was not associated with increased morbidity or mortality. Strategies are needed to optimize surgical outcomes to ensure delivery of multimodality therapy for advanced-stage disease.

Retrospective analysis of adjuvant chemotherapy for curatively resected gastric cancer

AIM: To determine the efficacy of adjuvant chemotherapy for gastric cancer in clinical practice, a retrospective analysis was conducted in a high-volume Chinese cancer center.

METHODS: Between November 1995 and June 2007, a total of 423 gastric or esophagogastric adenocarcinoma patients who did (Arm A, n = 300) or did not (Arm S, n = 123) receive radical gastrectomy followed by postoperative chemotherapy were enrolled in this retrospective analysis. In Arm A, monotherapy(fluoropyrimidines, n = 25), doublet (platinum/fluoropyrimidines, n = 164), or triplet regimens [docetaxel/cisplatin/5FU (DCF), or modified DCF, epirubicin/cisplatin/5FU (ECF) or modified ECF, etoposide/cisplatin/FU, n = 111] were administered. Disease-free survival (DFS) and overall survival (OS) were compared between the two arms. A subgroup analysis was carried out in Arm A. A multivariate analysis of prognostic factors was conducted.

RESULTS: Stage I, II and III cancers accounted for 9.7%, 35.7% and 54.6% of the cases, respectively, according to the American Joint Committee on Cancer (AJCC) staging system, 7^th edition. Only 178 (42.1%) patients had more than 15 lymph nodes harvested. Hazard ratio estimates for Arm A compared with Arm S were 0.47 (P < 0.001) for OS and 0.59 (P < 0.001) for DFS. The 5-year OS rate was 52% in Arm A vs 36% in Arm S (P = 0.01); the adverse events in Arm A were mild and easily controlled. Ultimately, 73 patients (26.5%) who received doublet or triplet regimens switched to monotherapy with fluoropyrimidines. The OS and DFS did not differ between monotherapy and the combination regimens, however, both were statistically improved in the subgroup of patients who were switched to monotherapy with fluoropyrimidines after doublet or triplet regimens as well as patients who received ≥ 8 cycles of chemotherapy.

CONCLUSION: In clinical practice, platinum/fluoropyrimidines with adequate treatment duration is recommended for stage II/III gastric cancer patients accordingto the 7^th edition of the AJCC staging system after curative gastrectomyeven with limited lymphadenectomy.

Adjuvant treatment for gastric cancer: chemotherapy versus radiation

Gastric cancer is among the leading causes of cancer death worldwide. Surgery is the only curative modality, but mortality remains high because a significant number of patients have recurrence after complete surgical resection. Chemotherapy, radiation, and chemoradiotherapy have all been studied in an attempt to reduce the risk for relapse and improve survival. There is no globally accepted standard of care for resectable gastric cancer, and treatment strategies vary across the world. Postoperative chemoradiation with 5-fluorouracil/leucovorin is most commonly practiced in the United States; however, recent clinical trials from Asia have shown benefit of adjuvant chemotherapy alone and have questioned the role of radiation. In this review, we examine the current literature on adjuvant treatment of gastric cancer and discuss the roles of radiation and chemotherapy, particularly in light of these new data and their applicability to the Western population. We highlight some of the ongoing and planned clinical trials in resectable gastric cancer and identify future directions as well as areas where further research is needed.

Lymph node dissection in resectable advanced gastric cancer

The extent of surgery for gastric cancer has been debated since Billroth performed his first gastrectomy in 1881. This review gives an overview of the available literature on the extent of gastrectomy and lymphadenectomy for advanced resectable gastric cancer. Subtotal gastrectomy is associated with lower morbidity and mortality compared with total gastrectomy, without compromising long-term survival. However, a positive resection margin decreases the chance of curation. Frozen section examination may prevent this. For poorly differentiated singlet ring cell tumors, there may be an argument to perform a total gastrectomy in all cases. In 1981, the Japanese Research Society for the Study of Gastric Cancer provided guidelines for the standardization of surgical treatment and pathological evaluation of gastric cancer. Since then, D2 lymph node dissections have become the standard of care in Japan. Because of the superior stage-specific survival rates in Japan, a D2 dissection was evaluated in several Western randomized controlled trials, but no survival benefit was found for a D2 over a D1 dissection. This might be explained by the increased mortality in the D2 dissection groups which might be the result of a standard pancreaticosplenectomy and low experience with D2 dissections. Adding the removal of the para-aortic nodes to a D2 dissection does not further improve survival. The removal of lymph node stations 10 and 11 by splenectomy showed an increased morbidity, no survival benefit, and a very poor prognosis if lymph nodes were affected. Therefore, pancreaticosplenectomy should only be performed in cases of tumor invasion into these organs. A D2 dissection without routine splenectomy and pancreatic tail resection in experienced hands should be considered standard of care for advanced resectable gastric cancer, both in Asian and in Western patients. Centralization and auditing may further improve outcomes after gastrectomy.

(Neo)-adjuvant chemo(-radio) therapy for adenocarcinomas of the gastroesophageal junction and the stomach in the West

Worldwide, the treatment of adenocarcinomas of the gastroesophageal junction and stomach has changed over the past decades. It is no longer surgery alone. Nowadays, most patients undergo surgery plus pre- and/or postoperative therapies. However, there are still marked differences in surgical procedures between the East and the West which might influence the surgical prognosis and thereby also the choice of perioperative treatment strategies. In the East, with its more extended surgical procedures, including standard D2 dissections, the current treatment philosophy is primary surgery followed by adjuvant chemotherapy. Neoadjuvant approaches are restricted to really advanced tumors, and perioperative chemoradiation is not routinely used (at least to date). This clearly differs from treatment strategies currently recommended in Western countries. In Europe and North America, pre- plus postoperative chemotherapy has become the recommended treatment for locally more advanced tumors, and preoperative chemoradiation is increasingly administered to patients with adenocarcinomas of the gastroesophageal junction (Siewert type I/II). However, the role of postoperative chemotherapy (despite its increasing use) is still under discussion in the West (especially Europe) and not generally recommended/accepted as a standard treatment. Postoperative chemoradiation, which is one standard treatment in North America, is only regarded as a treatment option for patients after 'inadequate surgery' (i.e. <D2 dissection) in many European countries.

D2 lymphadenectomy with surgical ex vivo dissection into node stations for gastric adenocarcinoma can be performed safely in Western patients and ensures optimal staging

BACKGROUND

The AJCC recommends examination of >16 nodes to stage gastric adenocarcinoma. D2 lymphadenectomy (LAD) followed by surgical ex vivo dissection (SEVD) into nodal stations is standard at many high-volume Asian centers, but potential increases in morbidity and mortality have slowed adoption of D2 LAD in some Western centers.

METHODS

A total of 331 patients with gastric adenocarcinoma who underwent surgical resection at one Western institution from 1995 to 2010 were examined.

RESULTS

Median age of patients was 69 years old, 65% were male, and 84% were white. D1 LAD was performed in 285 patients (86%) and D2 LAD in 46 patients (14%), with SEVD being performed in 17 patients (37%) in the D2 group. D2 LAD with or without SEVD was performed much more commonly between 2006 and 2010. For the D1, D2 without SEVD, and D2 with SEVD groups, the median number of examined nodes and percentage with >16 examined nodes were 16 and 51%, 27 and 93%, and 40 and 100%, respectively. Major complications occurred in 16% of the D1 group and 17% of the D2 group (p>0.05), and 30-day mortality was 3% for the D1 group and 0% for the D2 group. D2 LAD was a positive prognostic factor for overall survival on univariate (p=0.027) and multivariate analyses (p=0.005), but there were several possible confounding variables.

CONCLUSIONS

D2 LAD at our Western institution was performed with low morbidity and no mortality. Optimal staging occurred after D2 LAD combined with SEVD, where a median of 40 nodes were examined and all patients had >16 examined nodes.

Can adjuvant chemoradiotherapy replace extended lymph node dissection in gastric cancer?

Surgical resection remains the essential part in the curative treatment of gastric cancer. However, with surgery only, long-term survival is poor (5-year survival <25 % in Europe). Randomized studies, which compared limited (D1) lymph node dissection with more extended (D2) resections in the Western world, failed to show a survival benefit for more extensive surgery. A substantial increase in survival was found with perioperative chemotherapy in the MAGIC study. In addition, the SWOG/Intergroup 0116 study showed that postoperative chemoradiotherapy (CRT) prolonged 5-year overall survival compared to surgery only. However, it has been argued that surgical undertreatment undermined survival in this trial. In a randomized Korean study, patients with advanced stage gastric cancer who received postoperative CRT had better outcome after a D2 dissection. At our institute phase I-II studies with adjuvant cisplatin and capecitabine-based CRT have been performed in over 120 patients with resected gastric cancer. Retrospective comparison of patients treated in these studies with those that had surgery only in the D1D2 study, demonstrated that postoperative CRT was associated with better outcome, especially after D1 or a R1 resection. For daily practice, it remains unclear whether patients after optimal (D2) gastric surgery will benefit from postoperative CRT. This is currently being tested in prospective randomized phase III trials (CRITICS; TOPGEAR).

Effect of adjuvant chemoradiotherapy on overall survival of gastric cancer patients submitted to D2 lymphadenectomy

BACKGROUND

Adjuvant chemoradiotherapy (CRT) is the standard treatment in Western countries for gastric cancer patients submitted to curative resection. However, the role of adjuvant CRT in gastric cancer treated with D2 lymphadenectomy has not been well defined.

METHODS

We conducted a retrospective study in patients with stage II to IV gastric adenocarcinoma with no distant metastases, who underwent curative resection with D2 lymphadenectomy between January 2002 and December 2007. The present study compared the 3-year overall survival of two treatments (adjuvant CRT according to the INT 0116 trial versus resection alone). Survival curves were estimated by the Kaplan-Meier method and compared with a log-rank test. Multivariate analysis of prognostic factors was performed by the Cox proportional hazards model.

RESULTS

A total of 185 patients were included, 104 patients (56 %) received adjuvant CRT and 81 received resection alone. The 3-year overall survival was 64.4 % in the CRT group and 61.7 % in the resection-alone group (p: 0.415). However, according to the Cox proportional hazards model, adjuvant CRT was a prognostic factor for 3-year overall survival (hazard ratio [HR] 0.46, 95 % confidence interval [CI] 0.26-0.82, p: 0.008).

CONCLUSIONS

In the present study, adjuvant CRT was associated with a lower risk of death over a 3-year period in gastric cancer patients treated with D2 lymphadenectomy.

Neoadjuvant or adjuvant therapy for resectable gastric cancer: a systematic review and practice guideline for North America

BACKGROUND

Gastric cancer is a global health problem accounting for 10% of all new cancer cases and 12% of all cancer deaths worldwide. Many clinical trials and meta-analyses have explored the value of neoadjuvant or adjuvant chemotherapy and radiation therapy in gastric cancer; however, these studies have produced conflicting results. The purpose of this guidance document was to determine whether patients with resectable gastric cancer should receive neoadjuvant or adjuvant therapy in addition to surgery. Outcomes of interest were overall survival, disease-free survival, and adverse events.

METHODS

A systematic review was undertaken to inform recommendations regarding neoadjuvant and adjuvant therapy in resectable gastric cancer in Ontario, Canada. MEDLINE and EMBASE databases, as well as American Society of Clinical Oncology (ASCO) annual meeting proceedings and American Society for Therapeutic Radiology and Oncology (ASTRO) proceedings were systematically searched from 2002 to 2010. Oral fluoropyrimidine trials were excluded owing to the unavailability of these agents in North America.

RESULTS

Overall, 22 randomized controlled trials (RCTs), 13 meta-analyses, and two secondary analyses were included. The systematic review informed the development of a clinical practice guideline with the following recommendations. Postoperative 5-fluorouracil-based chemoradiotherapy based on the Macdonald approach or perioperative ECF (epirubicin, cisplatin, fluorouracil) chemotherapy based on the Cunningham/MAGIC (Medical Research Council Adjuvant Gastric Infusional Chemotherapy) approach are both acceptable standards of care in North America. Choice of treatment should be made on a case-by-case basis. Adjuvant chemotherapy is a reasonable option for those patients for whom the Macdonald and MAGIC protocols are contraindicated. All patients with resectable gastric cancer should undergo a pretreatment multidisciplinary assessment to determine the best plan of care.

CONCLUSIONS

Overall survival in patients with resectable gastric cancer is significantly improved with the use of either postoperative chemoradiation (Macdonald approach) or perioperative ECF (MAGIC protocol).