From twilight to starlight? Debating the role of chemoradiotherapy in gastric cancer in the D2 dissection era

Patients affected by resectable locally advanced gastric cancer (GC) should receive perioperative chemotherapy as a standard of care. However, an additional benefit of adjuvant chemoradiation (CRT) has been negated by modern trials in the era of extended surgical dissection, and CRT is currently only considered on an individual basis in case of suboptimal resection. However, the dismal prognosis of GC and the modest treatment completion rates of perioperative chemotherapy have pushed to reconsider CRT, particularly as a preoperative treatment, in light of modern treatment techniques, advances in the understanding of the immune landscape and development of targeted agents. The aim of this review is to critically assess the historical role of CRT, the limitations of current evidence and to debate its potential role in an integrated neoadjuvant strategy for patients with resectable GC.

Adjuvant Concurrent Chemoradiotherapy (CRT) plus Docetaxel-Cisplatin-Fluorouracil (DCF) versus CRT plus Fluorouracil-Folinic Acid (FUFA) in Stage III Gastric Cancer

INTRODUCTION

Adjuvant chemoradiotherapy (CRT) is the optimal management strategy in resectable gastric cancer. There is a debate about the efficacy of more aggressive CRT plus chemotherapy regimens in adjuvant setting. This study aimed to compare the efficacy of adjuvant CRT plus docetaxel-cisplatin-fluorouracil (DCF) versus CRT plus fluorouracil-folinic acid (FUFA) in stage III gastric cancer.

METHODS

Patients with a diagnosis of stage III gastric cancer treated with adjuvant therapy after curative resection were analyzed. Patients' disease characteristics and impacts of the regimens on median disease-free survival (DFS) and median overall survival (OS) were analyzed retrospectively.

RESULTS

One hundred sixty-one patients (102 in FUFA arm and 59 in DCF arm) with a median age of 56.0 (29-79) were evaluated. In the DCF arm, there were more renal toxicities (31.6% vs 6.4% P < 0.001), emergency department admissions (64.9% vs 23.7%, P < 0.001), and dose reductions/treatment modifications in the DCF arm (51.6% vs 37.2, P < 0.001). The median follow-up was 23 months (1-124) in the FUFA arm and 26.0 months (1-77) in the DCF arm. The median DFS was 25.0 months (%95 CI, 12.7-37.2) in the DCF arm and 17.0 months (%95 CI, 2.6-31.3) in the FUFA arm, P = 0.66. The median OS was 28.0 months (%95 CI, 17.0-38.9) in the DCF arm and 25.0 months (%95 CI, 11.9-36.0) in the FUFA arm, P = 0.70.

CONCLUSION

In conclusion, when compared with FUFA regimen, more aggressive therapy with DCF was more toxic and did not improve OS in adjuvant setting of stage III gastric cancer.

Development and validation of nomogram models to predict radiotherapy or chemotherapy benefit in stage III/IV gastric adenocarcinoma with surgery

Objectives

The advanced gastric adenocarcinoma (GAC) patients (stage III/IV) with surgery may have inconsistent prognoses due to different demographic and clinicopathological factors. In this retrospective study, we developed clinical prediction models for estimating the overall survival (OS) and cancer-specific survival (CSS) in advanced GAC patients with surgery.

Methods

A retrospective analysis was conducted using the Surveillance, Epidemiology, and End Results (SEER) database. The total population from 2004 to 2015 was divided into four levels according to age, of which 179 were younger than 45 years old, 695 were 45-59 years old, 1064 were 60-74 years old, and 708 were older than 75 years old. There were 1,712 men and 934 women. Univariate and multivariate Cox regression analyses were performed to identify prognostic factors for OS and CSS. Nomograms were constructed to predict the 1-, 3-, and 5-year OS and CSS. The models' calibration and discrimination efficiency were validated. Discrimination and accuracy were evaluated using the consistency index, area under the receiver operating characteristic curve, and calibration plots; and clinical usefulness was assessed using decision curve analysis. Cross-validation was also conducted to evaluate the accuracy and stability of the models. Prognostic factors identified by Cox regression were analyzed using Kaplan-Meier survival analysis.

Results

A total of 2,646 patients were included in our OS study. Age, primary site, differentiation grade, AJCC 6th_TNM stage, chemotherapy, radiotherapy, and number of regional nodes examined were identified as prognostic factors for OS in advanced GAC patients with surgery (P < 0.05). A total of 2,369 patients were included in our CSS study. Age, primary site, differentiation grade, AJCC 6th_TNM stage, chemotherapy, radiotherapy, and number of regional nodes examined were identified as risk factors for CSS in these patients (P < 0.05). These factors were used to construct the nomogram to predict the 1-, 3-, and 5-year OS and CSS of advanced GAC patients with surgery. The consistency index and area under the receiver operating characteristic curve demonstrated that the models effectively differentiated between events and nonevents. The calibration plots for 1-, 3-, and 5-year OS and CSS probability showed good consistence between the predicted and the actual events. The decision curve analysis indicated that the nomogram had higher clinical predictive value and more significant net gain than AJCC 6th_TNM stage in predicting OS and CSS of advanced GAC patients with surgery. Cross-validation also revealed good accuracy and stability of the models.

Conclusion

The developed predictive models provided available prognostic estimates for advanced GAC patients with surgery. Our findings suggested that both OS and CSS can benefit from chemotherapy or radiotherapy in these patients.

Multidisciplinary treatment for locally advanced gastric cancer: A systematic review and network meta-analysis

Introduction

This study aimed to evaluate the efficacy of multidisciplinary treatment for patients with locally advanced gastric cancer (LAGC) who underwent radical gastrectomy.

Patients and Methods

Randomised controlled trials (RCTs) comparing the effectiveness of surgery alone, adjuvant chemotherapy (CT), adjuvant radiotherapy (RT), adjuvant chemoradiotherapy (CRT), neoadjuvant CT, neoadjuvant RT, neoadjuvant CRT, perioperative CT and hyperthermic intraperitoneal chemotherapy (HIPEC) for LAGC were searched. Overall survival (OS), disease-free survival (DFS), recurrence and metastasis, long-term mortality, adverse events (grade ≥3), operative complications and R0 resection rate were used as outcome indicators for meta-analysis.

Results

Forty-five RCTs with 10077 participants were finally analysed. Adjuvant CT had higher OS (hazard ratio [HR] = 0.74, 95% credible interval [CI] = 0.66-0.82) and DFS (HR = 0.67, 95% CI = 0.60-0.74) than surgery-alone group. Perioperative CT (odds ratio [OR] = 2.56, 95% CI = 1.19-5.50) and adjuvant CT (OR = 0.48, 95% CI = 0.27-0.86) both had more recurrence and metastasis than HIPEC + adjuvant CT, while adjuvant CRT tended to have less recurrence and metastasis than adjuvant CT (OR = 1.76, 95% CI = 1.29-2.42) and even adjuvant RT (OR = 1.83, 95% CI = 0.98-3.40). Moreover, the incidence of mortality in HIPEC + adjuvant CT was lower than that in adjuvant RT (OR = 0.28, 95% CI = 0.11-0.72), adjuvant CT (OR = 0.45, 95% CI = 0.23-0.86) and perioperative CT (OR = 2.39, 95% CI = 1.05-5.41). Analysis of adverse events (grade ≥3) showed no statistically significant difference between any two adjuvant therapy groups.

Conclusion

A combination of HIPEC with adjuvant CT seems to be the most effective adjuvant therapy, which contributes to reducing tumour recurrence, metastasis and mortality - without increasing surgical complications and adverse events related to toxicity. Compared with CT or RT alone, CRT can reduce recurrence, metastasis and mortality but increase adverse events. Moreover, neoadjuvant therapy can effectively improve the radical resection rate, but neoadjuvant CT tends to increase surgical complications.

Role of Adjuvant Radiotherapy in Gastric Cancer

Although continuous improvement in the treatment outcome of localized gastric cancer has been achieved through early screening, diagnosis, and treatment and the active application of surgery and adjuvant chemotherapy, the necessity of adjuvant radiotherapy (RT) remains controversial. In this review, based on the results of two recently published randomized phase III studies (Adjuvant Chemoradiation Therapy In Stomach Cancer 2 and ChemoRadiotherapy after Induction chemoTherapy of Cancer in the Stomach) and a meta-analysis of six randomized trials including these two studies, the role of adjuvant RT in gastric cancer was evaluated and discussed, especially in patients who underwent curative gastrectomy with D2 lymphadenectomy. This article also reported the possible indications for adjuvant RT in the current clinical situation and in future research to enable patient-specific treatments according to the risk of recurrence.

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Effect of Chemoradiotherapy on the Survival of Resectable Gastric Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Adjuvant chemotherapy (CT) and chemoradiotherapy (CRT) after surgery are necessary to reduce the risk of metastasis and recurrence for resectable gastric cancer (GC) patients. Adjuvant CT and CRT have been proven to significantly improve the prognosis for GC patients, when compared with surgery only. However, it is still unclear whether radiotherapy offers additional survival benefits to advanced gastric cancer (AGC) patients.

METHODS

PubMed, Cochrane Library, and Embase databases were systematically searched for eligible studies that compared survival benefits between CRT and CT. The endpoints of this meta-analysis were measured as HR for OS or DFS and 95% CI using fixed- or random-effect models. Additionally, side effects, completed rate, and metastatic risk, were calculated as OR. Subgroup analyses according to clinicopathological factors were presented.

RESULTS

A total of 28 eligible studies involving 20,220 patients were included in our study. Of these, 17 studies evaluated the survival benefits of additional radiotherapy on overall survival (OS) of gastric cancer patients, ten reported the impact of CRT on disease-free survival (DFS), and 26 studies showed long-term survival rate. The pooled results were significant (HR for OS 0.84, 95% CI 0.71-0.99; HR for DFS 0.76, 95% CI 0.66-0.89). The subgroup analysis showed that adjuvant CRT increased OS for patients without preoperative treatment; showed similar nausea/vomiting, but an increased risk of neutropenia; reduced the risk of locoregional recurrence; failed to improve OS for lymph node (LN)-positive GC patients; and significantly improved prognosis for R1-treated patients. Of note, DFS was improved in all the subgroups via decreasing the locoregional recurrence.

CONCLUSION

Compared with CT, adjuvant CRT can improve survival for advanced gastric cancer patients, with similar nausea/vomiting, but increased risk of neutropenia. Patients without preoperative treatment or with positive surgical margins should be strongly recommended to undergo CRT. Treatment regimens should be carefully decided by doctors based on patients' tolerance, physical status, and reaction to treatment. Moreover, CRT improves the DFS for patients regardless of subgroups, because it significantly reduced the risk of locoregional recurrence.

Current and future strategies for radiation therapy in gastric cancer

Gastric cancers are heterogeneous. There are important differences between gastric and junctional tumors and a focus on evidence based on true gastric cancers is important to guide treatment decision and the design of innovative strategies. We present key evidence shaping the current use of radiotherapy, discuss technical radiotherapy considerations that are important to consider in multidisciplinary decision-making, and highlight selected research strategies including radiotherapeutic advances, theranostic approaches and key ongoing clinical trials to watch that will shape the role of radiotherapy in gastric cancers for the future.

Multidisciplinary treatment strategy for locally advanced gastric cancer: A systematic review

BACKGROUND

Multidisciplinary management of patients with locally advanced gastric cancer (LAGC) remains unstandardized worldwide. We performed a systemic review to summarize the advancements, regional differences, and current recommended multidisciplinary treatment strategies for LAGC.

METHODS

Eligible studies were identified through a comprehensive search of PubMed, Web of Science, Cochrane Library databases and Embase. Phase 3 randomized controlled trials which investigated survival of patients with LAGC who underwent gastrectomy with pre-/perioperative, postoperative chemotherapy, or chemoradiotherapy were included.

RESULTS

In total, we identified 11 studies of pre-/perioperative chemotherapy, 38 of postoperative chemotherapy, and 14 of chemoradiotherapy. In Europe and the USA, the current standard of care is perioperative chemotherapy for patients with LAGC using the regimen of 5-FU, folinic acid, oxaliplatin and docetaxel (FLOT). In Eastern Asia, upfront gastrectomy and postoperative chemotherapy is commonly used. The S-1 monotherapy or a regimen of capecitabine and oxaliplatin (CapOx) are used for patients with stage II disease, and the CapOx regimen or the S-1 plus docetaxel regimen are recommended for those with stage III Gastric cancer (GC). The addition of postoperative radiotherapy to peri- or postoperative chemotherapy is currently not recommended. Additionally, clinical trials testing targeted therapy and immunotherapy are increasingly performed worldwide.

CONCLUSIONS

Recent clinical trials showed a survival benefit of peri-over postoperative chemotherapy and chemoradiotherapy. As such, this strategy may have a potential as a global standard for patients with LAGC. Outcome of the ongoing clinical trials is expected to establish the global standard of multidisciplinary treatment strategy in patients with LAGC.

Oncologic Benefit of Adjuvant Chemoradiation after D2 Gastrectomy: A Stepwise Hierarchical Pooled Analysis and Systematic Review

Our study aimed to evaluate the benefits of chemoradiotherapy (CRT) after D2 gastrectomy, as compared to adjuvant chemotherapy, alone. PubMed, MEDLINE, Embase, and the Cochrane Library were systematically searched. We applied stepwise analyses that enabled the evaluation of data from randomized controlled trials (RCTs), balanced studies, and all studies separately and in a hierarchical manner. Thirteen controlled studies, including six RCTs involving 2603 patients, were included. Overall pooled analysis revealed a disease-free survival benefit of CRT (odds ratio (OR): 1.264, p = 0.053), which was more evident in the subgroup analysis of RCTs (OR: 1.440, p = 0.006) and balanced studies (OR: 1.417, p < 0.001). Overall survival was insignificantly different in the overall pooled analysis (OR: 1.124, p = 0.347). However, the difference was marginally significant in the subgroup analysis of balanced studies (OR: 1.279, p = 0.055) and significant in the subgroup analysis of studies involving stage ≥III patients only (OR: 1.663, p = 0.005). Locoregional recurrence (LRR) reduction was noted in the overall pooled analysis (OR: 0.559, p = 0.012; pooled rate: 11.3% vs. 18.1%) and was more robust in the subgroup analyses. Grade ≥3 leukopenia was higher in the CRT arm (OR: 1.387, p = 0.004; pooled rate: 26.4% vs. 15.7%). CRT after D2 gastrectomy should be applied for patients with high risk of LRR (e.g., stage ≥ III), along with efforts to reduce leukopenia.

COMplot, A Graphical Presentation of Complication Profiles and Adverse Effects for the Curative Treatment of Gastric Cancer: A Systematic Review and Meta-Analysis

Background: For the curative treatment of gastric cancer, several neoadjuvant, and adjuvant treatment-regimens are available which have shown to improve overall survival. No overview is available regarding toxicity and surgery related outcomes. Our aim was to construct a novel graphical method concerning adverse events (AEs) associated with multimodality treatment and perform a meta-analysis to compare different clinically relevant cytotoxic regimens with each other.

Methods: The PubMed, EMBASE, CENTRAL, and ASCO/ESMO databases were searched up to May 2019 for randomized controlled trials investigating curative treatment regimens for gastric cancer. To construct single and bidirectional bar-charts (COMplots), grade 1–2 and grade 3–5 AEs were extracted per cytotoxic regimen. For surgery-related outcomes a pre-specified set of complications was used. Thereafter, treatment-arms comparing the same regimens were combined in a single-arm random-effects meta-analysis and pooled-proportions were calculated with 95% confidence-intervals. Comparative meta-analyses were performed based on clinical relevance and compound similarity.

Results: In total 16 RCTs (n = 4,526 patients) were included investigating pre-operative-therapy and 39 RCTs investigating adjuvant-therapy (n = 13,732 patients). Pre-operative COMplots were created for among others; 5-fluorouracil/leucovorin-oxaliplatin-docetaxel (FLOT), epirubicin-cisplatin-fluoropyrimidine (ECF), cisplatin-fluoropyrimidine (CF), and oxaliplatin-fluoropyrimidine (FOx). Pre-operative FLOT showed a minor increase in grade 1–2 and grade 3–4 AEs compared to pre-operative ECF, CF, and FOx. A pooled analysis of patients who had received pre-operative therapy compared to patients who underwent direct surgery did not reveal any significant difference in surgery related morbidity/mortality. When we compared three commonly used adjuvant regimens; S-1 had the lowest amount of grade 3–4 AEs compared to capecitabine with oxaliplatin (CAPOX) and 5-FU with radiotherapy (5-FU+RT).

Conclusion: COMplot provides a novel tool to visualize and compare treatment related AEs for gastric cancer. Based on our comparisons, pre-operative FLOT had a manageable toxicity profile compared to other pre-operative doublet or triplet regimens. We found no evidence indicating surgical outcomes might be hampered by pre-operative therapy. Adjuvant S-1 had a more favorable toxicity profile compared to CAPOX and 5-FU+RT.

Chemoresistance in gastric cancer is attributed to the overexpression of excision repair cross-complementing 1 (ERCC1) caused by microRNA-122 dysregulation

MicroRNAs are deemed as key regulators of gene expression. In particular, the elevated expression of excision repair cross-complementing 1 (ERCC1) significantly reduced the effectiveness of gastric cancer treatment by cisplatin (CDDP)-based therapies. In this paper, qRT-PCR and western blot were adopted to measure miR-122 and ERCC1 messenger RNA (mRNA) expression in all samples. Luciferase assay was carried out to verify the role of ERCC1 as a target of miR-122. The CCK-8 assay was carried out to study the effect of ERCC1 and miR-122 on cell survival and apoptosis. The results demonstrated that miR-122 expression was reduced in cisplatin-resistant gastric cancer. Using bioinformatic analysis, miR-122 was shown to target the 3'-UTR of human ERCC1. A dual-luciferase assay demonstrated that miR-122 downregulated ERCC1 expression, while the mutations in ERCC1 3'-UTR abolished its interaction with miR-122. Transfection of miR-122 mimics decreased the levels of ERCC1 mRNA and protein expression, while the transfection of miR-122 inhibitors increased the levels of both ERCC1 mRNA and protein expression. Furthermore, we found that overexpressed miR-122 promoted the proliferation of MKN74 cells and reduced their apoptotic by targeting ERCC1. In addition, the levels of miR-122 and ERCC1 were negatively correlated in gastric cancer samples. In summary, the reduced miR-122 expression may play an essential role in the induction of cisplatin-resistance by increasing ERCC1 expression.

Adjuvant radiochemotherapy vs. chemotherapy alone in gastric cancer: a meta-analysis

BACKGROUND

As an adjuvant therapeutic strategy in advanced gastric cancer, both adjuvant chemotherapy (CTx) and postoperative radiochemotherapy (RCTx) can be considered. Both approaches have been shown to improve overall survival compared to resection alone. Several prospective randomized trials have compared the two postoperative concepts.

METHODS

We performed a literature search to identify prospective randomized trials which compared adjuvant chemotherapy to adjuvant radiochemotherapy in patients with advanced gastric cancer. As effect sizes, we extracted hazard ratios (HR) as well as event rates from the included trials for the endpoints overall survival, disease-free survival and locoregional control.

RESULTS

We identified seven studies that enrolled 1807 patients overall. Combined radiochemotherapy showed no significant improvement of overall survival in comparison to chemotherapy alone (HR = 0.93; 95%CI: 0.82-1.06; p = 0.28). For disease-free survival (HR = 0.86; 95%CI: 0.76-0.98; p = 0.023) and locoregional control (odds ratio [OR] = 0.56; 95%CI: 0.42-0.75; p = <0.001) we detected significant advantages from the addition of radiation to chemotherapy. A subgroup analysis demonstrated an improvement in survival when the radiochemotherapy protocol was not de-intensified.

CONCLUSIONS

Adjuvant chemotherapy or radiochemotherapy demonstrate similar oncologic efficacy and therapy-associated toxicity. Individual patient characteristics should therefore determine the therapeutic approach in a multidisciplinary discussion. Irradiation added to standard-dose chemotherapy possibly results in a survival benefit.

The Efficacy and Safety of (Neo)Adjuvant Therapy for Gastric Cancer: A Network Meta-analysis

Background: Alternatives in treatment-strategies exist for resectable gastric cancer. Our aims were: (1) to assess the benefit of perioperative, neoadjuvant and adjuvant treatment-strategies and (2) to determine the optimal adjuvant regimen for gastric cancer treated with curative intent. Methods: PubMed, EMBASE, CENTRAL, and ASCO/ESMO conferences were searched up to August 2017 for randomized-controlled-trials on the curative treatment of resectable gastric cancer. We performed two network-meta-analyses (NMA). NMA-1 compared perioperative, neoadjuvant and adjuvant strategies only if there was a direct comparison. NMA-2 compared different adjuvant chemo(radio)therapy regimens, after curative resection. Overall-survival (OS) and disease-free-survival (DFS) were analyzed using random-effects NMA on the hazard ratio (HR)-scale and calculated as combined HRs and 95% credible intervals (95% CrIs). Results: NMA-1 consisted of 9 direct comparisons between strategies for OS (14 studies, n = 4187 patients). NMA-2 consisted of 16 direct comparisons between adjuvant chemotherapy/chemoradiotherapy regimens for OS (37 studies, n = 10,761) and 14 for DFS (30 studies, n = 9714 patients). Compared to taxane-based-perioperative-chemotherapy, surgery-alone (HR = 0.58, 95% CrI = 0.38⁻0.91) and perioperative-chemotherapy regimens without a taxane (HR = 0.79, 95% CrI = 0.58⁻1.15) were inferior in OS. After curative-resection, the doublet oxaliplatin-fluoropyrimidine (for one-year) was the most efficacious adjuvant regimen in OS (HR = 0.47, 95% CrI = 0.28⁻0.80). Conclusions: For resectable gastric cancer, (1) taxane-based perioperative-chemotherapy was the most promising treatment strategy; and (2) adjuvant oxaliplatin-fluoropyrimidine was the most promising regimen after curative resection. More research is warranted to confirm or reproach these findings.

Adjuvant Radiochemotherapy versus Chemotherapy Alone for Gastric Cancer: Implications for Target Definition

The INT0116 trial was a milestone study and laid the foundation for the adjuvant radiotherapy (RT) associated to concurrent chemotherapy (CT) for the treatment of gastric cancer (GC) after gastrectomy. However, it is still controversial whether adding RT to CT could further benefit D2-dissected GC patients. The ARTIST trial indicated that the addition of RT to CT did not have a positive impact on disease-free survival (DFS). Nevertheless, in a subgroup of 396 patients with positive pathological lymph nodes, combined treatment with RT was superior to CT alone. A similar randomized Chinese trial confirmed the superiority of adding RT to CT in terms of DFS for patients with D2 lymphadenectomy. However, several previous randomized studies provided inconsistent results with the benefits of combined treatment of RT and CT. The inconsistent results of several studies may be due to the differences between tumor epidemiology, treatment policies, and treatment outcomes. During the past decade, major progress in accurate target delineation utilizing RT technology has been observed. However, even though the use of adjuvant RT doubled after the INT-0116 trial results became public, the fraction of patients receiving adjuvant RT was still low according to the SEER database. The low rate of adjuvant RT can partially be explained by concern over toxicity while undergoing RT. Several studies have also defined the specific location of locoregional recurrence for postoperative RT in GC, but these studies are still limited. A number of retrospective studies demonstrated that the most prevalent nodal recurrence was outside the D2 dissection field. In order to overcome the restricted nature of a retrospective study and provide more individual radiation field determination, additional large-scale prospective multicenter studies are required to evaluate the optimal RT target.

Comparative effectiveness of adjuvant treatments for resected gastric cancer: a network meta-analysis

BACKGROUND

Different adjuvant treatments are available for patients with gastric cancer, but conventional meta-analyses performing direct comparisons between two alternative treatments did not have enough power to compare all the adjuvant treatments. Thus, we did a network meta-analysis summarizing the direct and indirect comparisons to identify the optimum treatment.

METHODS

We systematically searched for RCTs of adjuvant treatments for gastric cancer comparing two or more of the following treatments: surgery alone, radiotherapy with fluoropyrimidine, S-1-based regimens, and XELOX. The treatments offering available indirect evidence to investigate the comparative effectiveness of adjuvant treatments mentioned above were also included. Then we performed a Bayesian network meta-analysis to summarize the direct and indirect comparisons. We estimated hazard ratios with 95% credible intervals (CrI) for OS and DFS.

RESULTS

11 eligible RCTs (5620 patients) were included in the network meta-analysis. Radiotherapy with fluorouracil (5-FU/RT), S-1-based regimens, and XELOX significantly improved OS as compared with surgery alone [(HR = 0.75 with 95% CrI: 0.63-0.89), (HR = 0.63 with 95% CrI: 0.52-0.76), and (HR = 0.66 with 95% CrI: 0.51-0.85), respectively]. No treatment was clearly superior to others; however, S-1-based regimes and XELOX showed a statistically non-significant trend to better survival as compared with 5-FU/RT.

CONCLUSIONS

S-1-based chemotherapy and XELOX are likely to be the most effective adjuvant treatments for patients with resected gastric cancer. 5-FU alone provided little survival benefits as compared with surgery alone. Further clinical trials may be required to investigate S-1-based and XELOX-based adjuvant treatment strategies.

Survival Benefit of Three Different Therapies in Postoperative Patients With Advanced Gastric Cancer: A Network Meta-Analysis

Purpose: Gastric cancer is mainly treated by gastrectomy, the results of which were unsatisfactory without any adjuvant treatments. This study aimed to examine the performance of radiotherapy, chemotherapy, and chemoradiotherapy after surgery in order to acquire the optimal adjuvant treatment. Method: Embase and PubMed were retrieved to conduct a systematic research. Hazard ratios (HR) of overall survival (OS) and progression-free survival (PFS) as outcomes were calculated by synthesizing direct and indirect evidence to evaluate the efficacy of three treatments against surgery alone. The P-score ranking was utilized to rank the therapies. Consistency was assessed by heat plot. Begg's test was performed to evaluate publication bias. Results: A total of 35 randomized controlled studies (RCTs) with 8973 patients were included in our network meta-analysis (NMA). As for efficacy outcomes, OS and PFS of 1, 2, 3, and 5 years, all revealed chemoradiotherapy (CRT) as the best of three adjuvant therapies. Meanwhile, P-score ranking results also displayed that CRT was the optimal regimen. Additionally, radiotherapy (RT) and chemotherapy (CT) were two alternative options following CRT since RT performed well in short-term survival while CT could improve the long-term survival. Conclusion: CRT was the most recommended therapy to accompany surgery according to our results. However, no analysis about the safety of these three treatments was mentioned in our study. Further studies including safety outcomes were required to draw a more comprehensive conclusion.

Adjuvant chemoradiation for gastric carcinoma: State of the art and perspectives

An estimated 990,000 new cases of gastric cancer are diagnosed worldwide each year. Surgical excision, the only chance for prolonged survival, is feasible in about 20% of cases. Even after surgery, the median survival is limited to 12 to 20 months due to the frequency of locoregional and/or metastatic recurrences. This led to clinical trials associating surgery with neoadjuvant or adjuvant treatments to improve tumor control and patient survival. The most studied modalities are perioperative chemotherapy and adjuvant chemoradiotherapy. To date, evidence has shown a survival benefit for postoperative chemoradiotherapy and for perioperative chemotherapy. Phase III trials are ongoing to compare these two modalities. The aim of this review is to synthesize current knowledge about adjuvant chemoradiotherapy in the management of gastric adenocarcinoma, and to consider its prospects by integrating modern radiotherapy techniques.

Can the addition of radiotherapy postoperatively increase clinical outcome of patients with gastric cancer? A systematic review of the literature and meta-analysis

BACKGROUND

Although several studies have been carried out to determine the best treatment for gastric carcinoma, the data on survival rate still remain inconclusive.

OBJECTIVE

To evaluate the effects of postoperative radio-chemotherapy on overall and disease-free survival.

DATA SOURCES

MEDLINE and CANCERLIT searches of reference lists (for the period 1970 to 2016) were supplemented with hand search of reference lists.

STUDY SELECTION

The present work includes randomized controlled trials comparing postoperative radio-chemotherapy to postoperative chemotherapy or to surgery alone in patients with resected gastric carcinoma without evidence of metastatic disease. Ten randomized controlled trials were analyzed in total: four compared postoperative radiochemotherapy to surgery alone (708 patients), and six compared postoperative radiochemotherapy to postoperative chemotherapy (1020 patients).

DATA EXTRACTION

According to "intention to treat" method, three independent observers have extracted from each trial, the data on patients, intervention, and outcomes. These data were subsequently combined using DerSimonian and Laird methods.

RESULTS

Postoperative radiochemotherapy significantly increases 3-year and 5-year overall survival and 3-year and 5-year disease free survival rate compared to postoperative chemotherapy (RR 0.89; 95%CI 0.81-0.97 and RR 0.82; 95%CI 0.71-0.95) or surgery alone (RR 0.83; 95% CI 0.77-0.91 and RR 0.80; 95% CI 0.65-0.98).

CONCLUSIONS

In patients with resected gastric cancer, postoperative radiochemotherapy obtains: 1) an increase in overall survival, 2) an increase in disease free survival, and 3) a gain in 5 year disease free survival independent of surgical procedure.

Prognostic effect of adjuvant chemoradiotherapy for patients with gastric cancer: an updated evidence of randomized controlled trials

The prognostic effect of chemoradiotherapy in gastric cancer has been evaluated for decades while the results are still in debate and heterogeneous. We thus comprehensively updated the evidence through systematic review and meta-analysis to evaluate chemoradiotherapy in gastric cancer to determine its effect. Pubmed, EMBASE, and Cochrane Library from the earliest possible year to April 2017 were searched. Randomised controlled trials (RCTs) that assessed the effects of combined chemoradiotherapy for patients with gastric cancer compared with that of single chemotherapy were included. The main outcome measure was 5-year overall survival (OS) and the second was disease-free survival (DFS) or recurrence-free survival (RFS). Fifteen RCTs involving 3347 patients were included into this meta-analysis. Compared with single chemotherapy, the relative risk (RR) for 5-year OS for chemoradiotherapy was 1.05 (95% CI 0.88 to 1.25), with moderate heterogeneity across eligible trials (I² = 55.7%, p = 0.016). Subgroup analyses and sensitivity analyses confirmed the consistent findings. We found that significant survival benefit for 5-year DFS/RFS for chemoradiotherapy over single chemotherapy (RR 0.89 95% CI 0.81 to 0.98) for patients with gastric cancer. This updated meta-analysis does not provide strong evidence for a 5-year survival benefit of chemoradiotherapy over chemotherapy alone in patients with gastric cancer. A clear advantage of chemoradiotherapy over chemotherapy has not been established. Further larger RCTs should be conducted to determine its true effect.

Role of Chemotherapy and Radiation Therapy in the Management of Gastric Adenocarcinoma

Gastric adenocarcinoma is the fifth most common cancer worldwide and is often diagnosed at a late stage with nearly 50% of patients having locally advanced, unresectable, or metastatic disease at the time of presentation. Efforts to improve outcomes in patients with resected and unresectable gastric cancer with various chemotherapy and radiation regimens are ongoing. Appropriate evaluation and management is often not straightforward and requires the input of a multidisciplinary team. There is no consensus as to the best approach for treatment of gastric cancer; however, the available data and our institutional approach to the management of gastric cancer are discussed.

Postoperative chemoradiotherapy versus chemotherapy for R0 resected gastric cancer with D2 lymph node dissection: an up-to-date meta-analysis

BACKGROUND

This meta-analysis aims to provide more evidence on the role of postoperative chemoradiotherapy (CRT) for gastric cancer (GC) patients in Asian countries where D2 lymphadenectomy is prevalent.

METHODS

We conducted a systematic review of randomized controlled trials (RCTs), extracted data of survival and toxicities, and pooled data to evaluate the efficacy and toxicities of CRT compared with chemotherapy (CT) after D2 lymphadenectomy.

RESULTS

A total of 960 patients from four RCTs were selected. The results showed that postoperative CRT significantly reduced loco-regional recurrence rate (LRRR: RR = 0.50, 95 % CI = 0.34-0.74, P = 0.0005) and improved disease-free survival (DFS: HR = 0.73, 95 % CI = 0.60-0.89, P = 0.002). However, CRT did not affect distant metastasis rate (DMR: RR = 0.81, 95 % CI = 0.60-1.08, P = 0.15) and overall survival (OS: HR = 0.91, 95 % CI = 0.74-1.11, P = 0.34). The main grade 3-4 toxicities manifested no significant differences between the two groups.

CONCLUSIONS

Overall, CRT after D2 lymphadenectomy may reduce LRRR and prolong DFS. The role of postoperative CRT should be further investigated in the population with high risk of loco-regional recurrence.

A phase II study of adjuvant S-1/cisplatin chemotherapy followed by S-1-based chemoradiotherapy for D2-resected gastric cancer

PURPOSE

Surgery is the only possible curative treatment for gastric cancer. However, the high recurrence rate makes gastric cancer difficult to cure by surgery alone. The present study was conducted to evaluate the clinical outcomes and toxicity of adjuvant treatment, including S-1/cisplatin chemotherapy followed by radiotherapy with concurrent S-1.

METHODS

Patients with radically D2-resected adenocarcinoma of the stomach of stage IB-IV (M0) were eligible. Patients were treated with S-1 (40-60 mg depending on the patient's body surface area) twice daily for 3 weeks and cisplatin (60 mg/m(2)) intravenously on day 1 every 5 weeks. Patients received CRT (45 Gy of radiation at 1.8 Gy/day, 5 days per week, for 5 weeks with the same dose of S-1 during radiation) followed by two additional cycles of S-1/cisplatin. The primary endpoint was the 3-year disease-free survival (DFS) rate; the secondary endpoints were the 3-year overall survival rate and toxicities.

RESULTS

Until May 2012, 46 patients were enrolled, and 34 (73.9%) completed the planned treatment. The median age was 53 years (range: 31-69 years), and the numbers of patients with stage IB, II, III and IV disease were 0, 17, 25 and 4, respectively. Main grade 3-4 toxicities were as follows: neutropenia (28.2%), nausea (17.4%), vomiting (8.7%) and anorexia (15.2%). At the time of analysis, after a median follow-up period of 56.5 months (3.03-74.0 months), 16 recurrence events and 15 deaths were reported. The estimated 3-year DFS and survival rates were 65.2 and 76.1%, respectively. The most common site of recurrence was the peritoneum (n = 12).

CONCLUSIONS

The results of this phase II study show that intensified adjuvant treatment with S-1/cisplatin chemotherapy and S-1-based chemoradiotherapy was tolerable and effective in reducing disease recurrence. The addition of radiotherapy to chemotherapy may be effective in D2-resected gastric cancer. Although the data here are promising, a randomized trial is needed between patients treated with the current regimen and an appropriate comparator arm.

Adjuvant and neoadjuvant options in resectable gastric cancer: is there an optimal treatment approach?

Gastric cancer is one of the most prevalent and deadliest forms of cancer worldwide. Even though neoadjuvant, perioperative, and adjuvant chemotherapy and/or radiation therapy may improve outcomes compared with surgery alone, the optimal combination of treatment modalities remains controversial. While European and North American trials established perioperative chemotherapy and adjuvant chemoradiation regimens for gastric cancer, Asian countries have focused on the use of adjuvant chemotherapy. This review summarizes results from contemporary randomized controlled trials and meta-analyses to elucidate the relative merits of each treatment approach.

Towards curative therapy in gastric cancer: Faraway, so close!

Although recent diagnostic and therapeutic advances have substantially improved the survival of patients with gastric cancer (GC), the overall prognosis is still poor. Surgery is the only curative treatment and should be performed in experienced centers. Due to high relapse following surgery, complementary and systemic treatment aimed at eradicating micrometastasis should be performed in most cases. Cytotoxic treatments are effective in downstaging locally advanced cancer, but different sensitivities and toxicities probably exist in different GC subtypes. Current treatment protocols are based primarily on clinical data and histological features, but molecular biomarkers that would allow for the prediction of treatment responses are urgently needed. Understanding how host factors are responsible for inter-individual variability of drug response or toxicity will also contribute to the development of more effective and less toxic treatments.

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.

Adjuvant Chemoradiation Therapy in Gastric Cancer: Critically Reviewing the Past and Visualizing the Next Step Forward

Gastric cancer remains one of the most common malignancies worldwide. Despite the significant advances in surgical treatment and multimodality strategies, prognosis has modestly improved over the last two decades. Locoregional relapse remains one of the main issues and the combined chemoradiation treatment seems to be one of the preferred approaches. However, more than ten years after the hallmark INT-0116 trial, minimal progress has been made both in terms of effectiveness and toxicity. Moreover, new regimens added to combined therapy failed to prove favourable results. Herein, we attempt a thorough literature review comparing pros and cons of all relative studies and potential bias, targeting well-designed future approaches.

Resected gastric cancer with D2 dissection: advances in adjuvant chemoradiotherapy and radiotherapy techniques

Surgery is the main treatment option for locally advanced gastric cancer. D2 dissection has been recommended worldwide as standard lymphadenectomy for resectable gastric cancer. Furthermore, the role of peri- or postoperative chemotherapy for D2-dissected gastric cancer has been established in both Western and European countries. It has been disputed whether adding radiotherapy to chemotherapy could further benefit those patients. Until recently, studies from Korea and China may have made it clear. In North America, however, the INT-0116 trial does not rule out that chemoradiotherapy is effective in patients with D2 dissection, but the ongoing CRITICS trial will, hopefully, clarify this. In addition, literature published in the past decade supports the theory that improved radiotherapy techniques are likely to accurately deliver radiation dose and significantly reduce radiation toxicity. Finally, the status of E2F-1 and HER-2 may be associated with efficacy of radiotherapy based on retrospective studies.

Postoperative chemoradiotherapy vs. preoperative chemoradiotherapy for locally advanced (operable) gastric cancer: clarifying the role and technique of radiotherapy

BACKGROUND

Worldwide, almost one million new cases of stomach cancer were diagnosed in 2012, making it the fifth most common cancer, and the third leading cause of cancer deaths. The current tumor node metastasis (TNM) staging system represents a consensus between the East and the West, and will serve as a strong foundation upon which to build future evidence. In this review article, we first discuss the definition and optimal surgery for locally advanced gastric cancer, followed by the general principles when considering a pre vs. postoperative radiotherapy (RT) strategy. We then provide a synthesis of the existing randomized trial evidence in an attempt clarify the role of pre and postoperative RT in the management of locally advanced gastric cancer.

METHODS

A Medline search 1966-Jun 2014 was undertaken. Randomized trials including patients with locally advanced gastric cancer (using established definitions), comparing RT [with or without chemotherapy (CT)], with surgery alone or other treatment modalities were included. Systematic reviews and evidence based practice guidelines that include this body of primary studies were preferentially discussed. Medline, Cochrane Library, Clinicaltrial.gov, Guidelines Clearinghouse were searched.

RESULTS

Sixteen randomized trials, three systematic reviews and one practice guideline were included as the evidence base. In this group of studies, two reports compared postoperative chemoradiotherapy (CRT) with surgery alone. Driven predominantly by INT0116, they established the role of postoperative CRT to provide a survival benefit in a patient group that underwent surgery with predominantly D0-1 dissections. Preoperative RT (four studies) showed promise for survival benefit but the risks of bias in these trials were high. Postoperative CRT compared with CT alone (eight trials) showed no survival benefit with the addition of radiation although some evidence of activity can be observed with improved local regional control.

CONCLUSIONS AND FUTURE DIRECTIONS

Technical expertise to enable the delivery of high quality RT to complex target volumes as is required in gastric cancer, and surgical standards to ensure the delivery of high quality surgery, have matured in recent years. Six trials with large sample sizes are currently ongoing to better define the role of preoperative CRT (two studies) and postoperative CRT (four studies), when used in conjunction with high quality surgery and RT, and contemporary CT regimens. The moderate likelihood of locoregional recurrences and the favorable therapeutic ratio with using RT preoperatively in other settings, provide optimism that preoperative CRT would have a pivotal role to play in locally advanced gastric cancer. Active accrual into ongoing trials is strongly encouraged.

Adjuvant therapy for gastric cancer: Current and future directions

The management of gastric cancer continues to evolve. Whilst surgery alone is effective when tumours present early, a large proportion of patients are diagnosed with loco-regionally advanced disease, resulting in high loco-regional and distant relapse rates, with subsequent poor survival. Early attempts at improving outcomes following resection were disappointing; however, randomized trials have now established either post-operative chemoradiotherapy (INT0116) or peri-operative chemotherapy as standard adjuvant therapies in the Western world. There remain, however, significant differences in the approach to management between the West and East. In Asia, where there is the highest incidence of gastric cancer, extended resection followed by adjuvant chemotherapy represents the standard of care. This review discusses current standard adjuvant therapy in gastric adenocarcinoma, as well as recent and ongoing trials investigating novel (neo)adjuvant approaches, which hope to build on the successes of previous studies.

Adjuvant chemoradiotherapy versus chemotherapy for gastric cancer: a meta-analysis of randomized controlled trials

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of adjuvant chemoradiotherapy (CRT) versus chemotherapy (CT) for patients with gastric cancer.

METHODS

Electronic databases including PUBMED, EMBASE, and Cochrane Library were retrieved for original studies from their inception to April 2014. Two reviewers independently evaluated the quality of the included studies and extracted the data. All Statistical analyses were performed using RevMan Version 5.2 software.

RESULTS

Six randomized controlled trials involving 1,171 patients were included. The meta-analysis showed that there were statistical significances between chemoradiotherapy group and chemotherapy group in 5-year disease free survival rate (OR = 1.56, 95% CI: 1.09-2.24), local-regional recurrence rate (OR = 0.46, 95% CI: 0.32-0.67) and neutropenia (OR = 1.47, 95% CI: 1.11-1.96). While treatment efficacy did not differ significantly by the 5-year overall survival rate (OR = 1.32, 95% CI: 0.92-1.88), 3-year disease free survival rate (OR = 1.28, 95% CI: 0.92-1.80), and new metastases (OR = 0.76, 95% CI: 0.57-1.03). Toxicities were not significantly different between two groups for nausea/vomiting, diarrhea, anemia, and thrombocytopenia.

CONCLUSIONS

For patients with gastric cancer, adjuvant chemoradiotherapy could significantly improve 5-year disease free survival rate and reduce local-regional recurrence rate compared with chemotherapy and, can be well accepted and tolerated.

Postoperative chemo-radiotherapy versus chemotherapy for resected gastric cancer: a systematic review and meta-analysis

INTRODUCTION

This study conducted a systematic review and meta-analysis (direct and indirect) of published randomised controlled trials (RCTs) to compare the effects of postoperative chemo-radiotherapy (ChRT) with chemotherapy (Ch) on overall and disease-free survival (DFS) for patients with resectable gastric cancer.

METHODS

We searched MEDLINE and CENTRAL from the date of inception and annual meeting proceedings of American Society of Clinical Oncology and American Society for Radiation Oncology from 1999 to November 2012 for RCTs comparing postoperative ChRT with Ch, postoperative ChRT with surgery alone and postoperative Ch with surgery alone. The primary outcome was overall survival (OS); secondary outcomes included DFS and toxicity. Hazard ratios (HRs), confidence intervals (CIs) and P values (P) were estimated with fixed effects models using Revman 5.1.

RESULTS

We found six trials comparing postoperative ChRT with Ch (n = 1171). Meta-analysis of direct comparison trials showed that postoperative ChRT significantly improved both OS (HR 0.80, 95% CI 0.65-0.98, P = 0.03) and DFS (HR 0.76, 95% CI 0.63-0.91, P = 0.003) when compared with Ch. There were no significant differences in toxicity between the two groups.

CONCLUSIONS

This study suggests a survival benefit of postoperative ChRT over Ch in patients with resected gastric cancer.

Role of (chemo)-radiotherapy in resectable gastric cancer

The prognosis of patients with locally advanced gastric cancer remains poor, despite radical surgical resection. Adjuvant therapy has been shown to improve survival and, in Western countries, is delivered either postoperatively (chemoradiotherapy) or perioperatively (chemotherapy). Debate continues as to which of these represents the optimal strategy. High-dose gastric irradiation comes at the expense of significant toxicity, and increasing efforts have focused on attempts to reduce toxicity and normal tissue doses. The development of advancing radiotherapy technologies now allows improved target delineation and coverage. However, gastric irradiation remains technically challenging and requires an understanding of postoperative surgical anatomy, patterns of failure and lymph node drainage, as well as an appreciation of the uncertainties around organ motion and filling. Ongoing trials are examining the optimal strategy in which to incorporate (chemo)-radiotherapy, as well as the addition of targeted therapies, in gastric cancer. This overview discusses the current role and evidence for (chemo)-radiotherapy, as well as the technical challenges encountered in the radiotherapeutic management of resectable gastric cancer.

Is postoperative adjuvant chemoradiotherapy efficacious and safe for gastric cancer patients with D2 lymphadenectomy? A meta-analysis of the literature

BACKGROUND

Adjuvant chemoradiotherapy (CRT) for patients with gastric cancer after D2 lymphadenectomy remains controversial. The objective of the present meta-analysis was to analyze efficacy and safety of postoperative CRT and establish a consensus on whether it is suitable for the patients.

METHODS

We searched PubMed, Ovid, Cochrane, and Web of Science. Statistical analysis was carried out by STATA version 12.0 software. The quality of evidence was assessed by Jadad and the Newcastle-Ottawa quality assessment scale.

RESULTS

Six studies involving 2135 patients were included for the meta-analysis. The results showed that, compared with non-CRT, postoperative adjuvant CRT was associated with a significant improvement in 5-year overall survival (OS) (HR = 0.79, 95% CI 0.68-0.92, P = 0.002) and 5-year relapse-free survival (RFS) (HR = 0.81, 95% CI 0.70-0.93, P = 0.004). However, there were no differences in distant metastasis (RR = 0.93, 95% CI 0.82-1.06, P = 0.304) and treatment-related toxicity between the two groups.

CONCLUSIONS

From the results of our study, postoperative adjuvant CRT may be associated with longer 5-year OS and 5-year RFS in patients with D2 lymphadenectomy, but might not improve 5-year disease-free survival compared to non-CRT. Methodologically high-quality comparative studies are needed for further evaluation.

Chemoradiation therapy versus chemotherapy alone for gastric cancer after R0 surgical resection: a meta-analysis of randomized trials

OBJECTIVE

Current national guidelines include category 1 recommendations for perioperative chemotherapy or adjuvant chemoradiation with surgical resection for patients with stage IB-IIIB gastric cancer. We conducted a meta-analysis of randomized trials in which chemotherapy was prospectively tested against chemoradiation with surgical resection.

METHODS

We electronically searched PubMed and EMBASE for randomized, controlled clinical trials involving patients with gastric adenocarcinoma, status post-R0 resection. The interventions compared were adjuvant chemotherapy versus chemoradiation, with any chemotherapy regimen. The primary outcomes of interest were disease-free survival and overall survival. The Mantel-Haenszel random-effects model was used to calculate effect sizes.

RESULTS

Six trials that included 1,171 patients were evaluated; 599 were randomized to adjuvant chemoradiation and 572 to chemotherapy alone. Chemoradiation was associated with a significant increase in disease-free survival (odds ratio 1.48, 95% confidence interval 1.08-2.03) when compared to chemotherapy alone. However, there was no significant difference in overall survival (odds ratio 1.27, 95% confidence interval 0.95-1.71). Five trials found no statistically significant differences in toxicities between the two groups.

CONCLUSION

In patients with gastric cancer status post-R0 resection, adjuvant chemoradiation was associated with higher disease-free survival when compared to chemotherapy alone. It remains appropriate to design trials testing new systemic agents with radiotherapy.

Radiotherapy for gastric cancer: a systematic review and meta-analysis

There have been many trials trying to prove the benefit of radiotherapy for gastric cancer; however, the results were either inclusive or controversial. The purpose of the study was to elucidate the effect of radiotherapy on gastric cancer delivered as perioperative or palliative treatment. We conducted systematic searches for trials exploring the effect of radiotherapy on gastric cancer. In the subgroup of patients receiving preoperative radiotherapy for gastric cancer, a significant benefit was found on 10-year overall survival with a hazard ratio (HR) of 0.75 (95% confidence interval (CI), 0.61 to 0.91); however, the benefit on 5-year overall survival was not proven (HR, 0.68; 95%CI, 0.45 to 1.01). There are also no significant differences in resection rate and radical resection rate between group of patients receiving radiotherapy and control group with a relative risk (RR) of 1.06 (95%CI, 0.99 to 1.13) and 1.12 (95%CI 0.93 to 1.36), respectively. In the subgroup of patients receiving postoperative radiotherapy for gastric cancer, survival benefits were found on 3- and 5-year progression-free survival with HR of 0.69 (95%CI, 0.53 to 0.90) and HR of 0.70 (95%CI, 0.61 to 0.80), respectively. Survival benefits of adjuvant radiotherapy on 3- and 5-year progression-free survival were also found; nonetheless, there was no evidence of significant difference in 3-year overall survival (HR, 0.70; 95%CI, 0.61 to 1.01). The effect of radiotherapy on 5-year overall survival was also quite controversial. In short, gastric cancer patients could benefit from radiotherapy both in the form of preoperative radiotherapy and postoperative radiotherapy.

Who benefits from adjuvant radiation therapy for gastric cancer? A meta-analysis

PURPOSE

Large randomized trials have demonstrated significant survival benefits with the use of adjuvant chemotherapy or chemoradiation therapy for gastric cancer. The importance of adjuvant radiation therapy (RT) remains unclear. We performed an up-to-date meta-analysis of randomized trials testing the use of RT for resectable gastric cancer.

METHODS AND MATERIALS

We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for randomized trials testing adjuvant (including neoadjuvant) RT for resectable gastric cancer. Hazard ratios describing the impact of adjuvant RT on overall survival (OS) and disease-free survival (DFS) were extracted directly from the original studies or calculated from survival curves. Pooled estimates were obtained using the inverse variance method. Subgroup analyses were performed to determine whether the efficacy of RT varies with chemotherapy use, RT timing, geographic region, type of nodal dissection performed, or lymph node status.

RESULTS

Thirteen studies met all inclusion criteria and were used for this analysis. Adjuvant RT was associated with a significant improvement in both OS (HR = 0.78, 95% CI: 0.70-0.86, P<.001) and DFS (HR = 0.71, 95% CI: 0.63-0.80, P<.001). In the 5 studies that tested adjuvant chemoradiation therapy against adjuvant chemotherapy, similar effects were seen for OS (HR = 0.83, 95% CI: 0.67-1.03, P=.087) and DFS (HR = 0.77, 95% CI: 0.91-0.65, P=.002). Available data did not reveal any subgroup of patients that does not benefit from adjuvant RT.

CONCLUSION

In randomized trials for resectable gastric cancer, adjuvant RT provides an approximately 20% improvement in both DFS and OS. Available data do not reveal a subgroup of patients that does not benefit from adjuvant RT. Further study is required to optimize the implementation of adjuvant RT for gastric cancer with regard to patient selection and integration with systemic therapy.

Comparison of two different adjuvant treatment modalities for pN3 gastric cancer patients after D2 lymph node dissection: can we avoid radiotherapy in a subgroup of patients?

Adjuvant chemoradiotherapy (CRT) is the standard of care for gastric cancer patients in the USA. However, in countries where D2 lymph node dissection is performed, the effect of radiotherapy on locoregional recurrence is controversial. The aim of this study is to compare the outcomes in pN3 gastric cancer patients following two adjuvant treatment modalities: chemotherapy (CT) and CRT after D2 lymph node dissection. Between 2005 and 2009, 71 gastric cancer patients who underwent D2 lymph node dissection and had pTanyN3M0 stage (according to AJCC 6th edition) were identified. Fifty-three patients were treated with CT and 18 patients received CRT. CRT consisted of bolus fluorouracil (FU) 425 mg/m(2) and leucovorin 20 mg/m(2) before, after, and during radiotherapy. For the CT arm, treatment protocols consisted of combination therapies involving FU and cisplatin as the backbone. Median overall survival (OS) and disease-free survival (DFS) rates for all patients were 26.3 months (15-37.7 months) and 12.5 months (8-17.1 months). Median OS in CT arm was 26.8 months and it was 34.2 months for CRT arm (p = 0.74). DFS rates did not differ statistically either (p = 0.56, 12.5 and 15.2 months for CT and CRT, respectively). Locoregional recurrence rates were also similar (p = 0.63). Only metastatic/dissected lymph node ratio (≥0.75) was identified as a prognostic factor in both univariate and multivariate analyses for DFS. Comparison of CT versus CRT for N3 stage gastric cancer patients with D2 lymph node dissection did not reveal any statistically significant difference in survival rates and locoregional recurrence.

Postoperative chemoradiotherapy in high risk locally advanced gastric cancer

Purpose

To evaluate treatment outcome of patients with high risk locally advanced gastric cancer after postoperative chemoradiotherapy.

Materials and Methods

Between May 2003 and May 2012, thirteen patients who underwent postoperative chemoradiotherapy for gastric cancer with resection margin involvement or adjacent structure invasion were retrospectively analyzed. Concurrent chemotherapy was administered in 10 patients. Median dose of radiation was 50.4 Gy (range, 45 to 55.8 Gy).

Results

The median follow-up duration for surviving patients was 48 months (range, 5 to 108 months). The 5-year overall survival rate was 42% and the 5-year disease-free survival rate was 28%. Major pattern of failure was peritoneal seeding with 46%. Locoregional recurrence was reported in only one patient. Grade 2 or higher gastrointestinal toxicity occurred in 54% of the patients. However, there was only one patient with higher than grade 3 toxicity.

Conclusion

Despite reported suggested role of adjuvant radiotherapy with combination chemotherapy in gastric cancer, only very small portion of the patients underwent the treatment. Results from this study show that postoperative chemoradiotherapy provided excellent locoregional control with acceptable and manageable treatment related toxicity in patients with high risk locally advanced gastric cancer. Thus, postoperative chemoradiotherapy may improve treatment result in terms of locoregional control in these high risk patients. However, as these findings are based on small series, validation with larger cohort is suggested.

The role of perioperative radiotherapy in gastric cancer

Gastric cancer is one of the most common neoplasms and a main cause of cancer-related mortality worldwide. Surgery remains the mainstay for cure and is considered for all patients with potentially curable disease. However, despite the fact that surgery alone usually leads to favorable outcomes in early stage disease, late diagnosis usually means a poor prognosis. In these settings, multimodal therapy has become the established treatment for locally advanced tumors, while the high risk of locoregional relapse has favored the inclusion of radiotherapy in the comprehensive therapeutic strategy. We provide a critical, non-systematic review of gastric cancer and discuss the role of perioperative radiation therapy in its treatment.

Quality of care indicators for the surgical treatment of gastric cancer: a systematic review

BACKGROUND

Quality assurance is increasingly acknowledged as a crucial factor for the (surgical) treatment of gastric cancer. The purpose of the current study was to define a minimum set of evidence-based quality of care indicators for the surgical treatment of locally advanced gastric cancer.

METHODS

A systematic review of the literature published between January 1990 and May 2011 was performed, using search terms on gastric cancer, treatment, and quality of care. Studies were selected based on predefined selection criteria. Potential quality of care indicators were assessed based on their level of evidence and were grouped into structure, process, and outcome indicators.

RESULTS

A total of 173 articles were included in the current study. For structural measures, evidence was found for the inverse relationship between hospital volume and postoperative mortality as well as overall survival. Regarding process measures, the most common indicators concerned surgical technique, perioperative care, and multimodality treatment. The only outcome indicator with supporting evidence was a microscopically radical resection.

CONCLUSIONS

Although specific literature on quality of care indicators for the surgical treatment of locally advanced gastric cancer is limited, several quality of care indicators could be identified. These indicators can be used in clinical audits and other quality assurance programs.

Gastrointestinal lymphomas: Morphology, immunophenotype and molecular features

Primary gastrointestinal lymphoma comprises 10-15% of all non-Hodgkin lymphomas and encompasses 30-40% of the total extranodal lymphomas. Approximately 60-75% of cases occur in the stomach, and then the small bowel, ileum, cecum, colon and rectum. Lymphoid neoplasms may consist of mature B, T and less commonly extranodal NK/T cells. Of these, the two most frequently encountered histologic subtypes are extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), where Helicobacter pylori infection is implicated in a number of cases, and diffuse large B cell lymphoma. Several B cell lymphomas are associated with chromosomal aberrations. Enteropathy-associated T cell lymphoma, type I in particular, usually arises in a background of celiac disease. T cell gene rearrangement confirms clonality. NK/T cell neoplasms are invariably associated with Epstein-Barr virus infection and are often aggressive; thus, differentiation from a benign NK-cell enteropathy is paramount. Although incidence of other hematopoietic malignancies in the gastrointestinal tract such as plasma cell myeloma associated with amyloidosis, plasmablastic lymphoma, Hodgkin disease, histiocytic sarcoma and mast cell sarcoma is extremely rare, these entities have been documented, with the latter two demonstrating aggressive clinical behavior. Endoscopic ultrasonography is an important adjunct in disease staging and follow-up. Conservative antibiotic treatment of stage I MALT lymphomas with associated Helicobacter pylori infection achieves good clinical outcome with high remission rate. Chemotherapy, radiation and rarely surgery are reserved for advanced diseases or cases resistant to conservative therapy and those not associated with Helicobacter pylori infection.

Lymph node dissection for gastric cancer: a critical review

Gastric cancer is one of the most common neoplasms and an important cause of cancer-related death worldwide. Efforts to reduce its high mortality rates are currently focused on multidisciplinary management. However, surgery remains a cornerstone in the management of patients with resectable disease. There is still some controversy as to the extent of lymph node dissection for potentially curable stomach cancer. Surgeons in eastern countries favor more extensive lymph node dissection, whereas those in the West favor less extensive dissection. Thus, extent of lymph node dissection remains one of the most hotly discussed aspects of gastric surgery, particularly because most stomach cancers are now often comprehensively treated by adding some perioperative chemotherapy or chemo-radiation. We provide a critical review of lymph nodes dissection for gastric cancer with a particular focus on its benefits in a multimodal approach.

Phase III trial comparing capecitabine plus cisplatin versus capecitabine plus cisplatin with concurrent capecitabine radiotherapy in completely resected gastric cancer with D2 lymph node dissection: the ARTIST trial

PURPOSE

The ARTIST (Adjuvant Chemoradiation Therapy in Stomach Cancer) trial was the first study to our knowledge to investigate the role of postoperative chemoradiotherapy therapy in patients with curatively resected gastric cancer with D2 lymph node dissection. This trial was designed to compare postoperative treatment with capecitabine plus cisplatin (XP) versus XP plus radiotherapy with capecitabine (XP/XRT/XP).

PATIENTS AND METHODS

The XP arm received six cycles of XP (capecitabine 2,000 mg/m2 per day on days 1 to 14 and cisplatin 60 mg/m2 on day 1, repeated every 3 weeks) chemotherapy. The XP/XRT/XP arm received two cycles of XP followed by 45-Gy XRT (capecitabine 1,650 mg/m2 per day for 5 weeks) and two cycles of XP.

RESULTS

Of 458 patients, 228 were randomly assigned to the XP arm and 230 to the XP/XRT/XP arm. Treatment was completed as planned by 75.4% of patients (172 of 228) in the XP arm and 81.7% (188 of 230) in the XP/XRT/XP arm. Overall, the addition of XRT to XP chemotherapy did not significantly prolong disease-free survival (DFS; P = .0862). However, in the subgroup of patients with pathologic lymph node metastasis at the time of surgery (n = 396), patients randomly assigned to the XP/XRT/XP arm experienced superior DFS when compared with those who received XP alone (P = .0365), and the statistical significance was retained at multivariate analysis (estimated hazard ratio, 0.6865; 95% CI, 0.4735 to 0.9952; P = .0471). CONCLUSION The addition of XRT to XP chemotherapy did not significantly reduce recurrence after curative resection and D2 lymph node dissection in gastric cancer. A subsequent trial (ARTIST-II) in patients with lymph node-positive gastric cancer is planned.