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

The order of surgery and chemotherapy matters: Multimodality therapy and stage-specific differences in survival in gastric cancer

BACKGROUND AND OBJECTIVES

Multimodality treatment improves survival for gastric cancer (GC). However, the effect of treatment sequence by stage remains unclear. We aim to compare outcomes between patients receiving neoadjuvant(neoadj) and adjuvant chemotherapy (adj).

METHODS

Nonmetastatic GC patients with clinical stage ≥ T2N0 who underwent both resection and neoadj or adj were identified using the National Cancer Database (2005-2014). Multivariable Cox regression analyses were performed on propensity score-matched (PSM) cohorts stratified by stage to compare overall survival (OS).

RESULTS

We identified 11 984 patients; 55% stage I (SI), 76% stage II (SII) and 57% stage III (SIII) received neoadj. Unadjusted analysis showed worse survival among SI neoadj patients (hazard ratio [HR] 1.195, confidence interval [CI] 1.04-1.38) and improved survival for SII (HR 0.93 CI 0.87-0.998) and SIII (HR 0.75, CI 0.68-0.84). After PSM, SI patients with neoadj had worse OS with increased risk of death compared to Adj (HR 1.186, CI 1.004-1.402). SII patients had no difference in OS (HR 0.98, CI 0.91-1.07) and SIII patients had improved OS (HR 0.78, CI 0.69-0.90).

CONCLUSIONS

In patients who received surgery and chemotherapy, the benefit of neoadj was limited to SIII with worse survival for SI. A clinical trial to examine the optimal sequence of chemotherapy is warranted.

Prognostic significance of metastatic lymph node ratio in patients with gastric cancer after curative gastrectomy: a single-center retrospective study

BACKGROUND

The objective of this study was to evaluate the prognostic value of Metastatic lymph node ratio (MLNR) after curative gastrectomy in patients with gastric cancer (GC) and the potential for new indicators to strengthen the current guidelines.

METHODS

We retrospectively researched 3864 GC patients with curative gastrectomy between February 2011 and February 2016. The following clinical data were collected from the included patients: gender, type of gastrectomy, tumor location, T stage, N stage, ELN, tumor size, age at surgery, perineural invasion, vascular invasion, TNM stage, survival time and survival status. Patients were divided into low-MLNR (L-MLNR), and high-MLNR (H-MLNR) groups based on adjusted the X-tile cutoff-value of 0.25 for MLNR, the survival rates and clinicopathological characteristics of each group were compared. For the assessment of significant associations between clinicopathological characteristics and patients' survival, univariate and multivariate analyses were performed using the Kaplan-Meier method and Cox proportional hazards analysis. The log-rank test was used to examine the statistical significance of differences among different survival curves. Clinicopathological features significantly associated with MLNR were assessed by the Chi-square test and multinomial logistic regression. The discriminative ability was measured by calculating the Bayesian Information Criterion (BIC) values for each category. Assessment of the effect of clinicopathological features on MLNR for predicting prognosis of GC patients used stratum analysis through Kaplan-Meier analysis and Cox proportional risk Analysis.

RESULTS

Survival analysis indicated that MLNR was negatively associated with overall survival (OS) (p < .001) and was an independent prognostic predictor in 3864 GC patients (p < .001). MLNR had significant prognostic significance in various subgroups with clinicopathological characteristics (gender, type of gastrectomy, tumor location, T stage, N stage, ELN, tumor size, age at surgery, perineural invasion, vascular invasion, and TNM stage) (p < .001).

CONCLUSIONS

The MLNR may become a new indicator to assess the prognosis of GC patients who underwent curative gastrectomy. The results may have potential clinical implications that should be considered when developing clinical practice guidelines or the design of the future investigation.

Stepwise-Hierarchical Pooled Analysis for Synergistic Interpretation of Meta-analyses Involving Randomized and Observational Studies: Methodology Development

Background

The necessity of including observational studies in meta-analyses has been discussed in the literature, but a synergistic analysis method for combining randomized and observational studies has not been reported. Observational studies differ in validity depending on the degree of the confounders’ influence. Combining interpretations may be challenging, especially if the statistical directions are similar but the magnitude of the pooled results are different between randomized and observational studies (the ”gray zone”).

Objective

To overcome these hindrances, in this study, we aim to introduce a logical method for clinical interpretation of randomized and observational studies.

Methods

We designed a stepwise-hierarchical pooled analysis method to analyze both distribution trends and individual pooled results by dividing the included studies into at least three stages (eg, all studies, balanced studies, and randomized studies).

Results

According to the model, the validity of a hypothesis is mostly based on the pooled results of randomized studies (the highest stage). Ascending patterns in which effect size and statistical significance increase gradually with stage strengthen the validity of the hypothesis; in this case, the effect size of the observational studies is lower than that of the true effect (eg, because of the uncontrolled effect of negative confounders). Descending patterns in which decreasing effect size and statistical significance gradually weaken the validity of the hypothesis suggest that the effect size and statistical significance of the observational studies is larger than the true effect (eg, because of researchers’ bias).

Conclusions

We recommend using the stepwise-hierarchical pooled analysis approach for meta-analyses involving randomized and observational studies.

Assessment of the value of adjuvant radiotherapy for treatment of gastric adenocarcinoma based on pattern of post-surgical progression

PURPOSE

To assess the value of adjuvant radiotherapy for treatment of gastric adenocarcinoma and to investigate subgroups of patients suitable for adjuvant radiotherapy.

METHODS AND MATERIALS

Data from 785 patients with gastric adenocarcinoma who had undergone D1/D2 radical resection and adjuvant chemotherapy were collected, the site of first progression was determined, and the relationship between the rate of local recurrence and clinicopathologic features was analyzed.

RESULTS

By the end of the follow-up period, progression was observed in 405 patients. Local recurrence was observed as the first progression in 161 cases. The local recurrence rate was significantly lower than the non-local progression rate (20.5% vs 31.5%, p=0.007). Multivariate Cox regression analysis showed a significant relationship among degree of differentiation, T stage, N stage, and rate of local recurrence.

CONCLUSIONS

Not all patients with gastric carcinoma required adjuvant radiotherapy. However, patients with poorly differentiated cancer cells, advanced T stage (T3/T4), and positive lymph nodes, which included patients in the T4N1-2M0 subgroup, were recommended for adjuvant radiotherapy.

Vitamin D modulation and microRNAs in gastric cancer: prognostic and therapeutic role

Gastric adenocarcinoma arises after a complex interaction between the host and environmental factors. Tumor location and TNM are the tools that currently guide treatment decisions. Surgery is the only curative treatment, but relapse is common. After relapse or advanced staged disease survival is poor and systemic treatment has modestly improved survival. An association between sun exposure, vitamin D status and gastric cancer (GC) incidence and mortality has been reported. The molecular differences of the histological subtypes and the new molecular classifications account for the great heterogeneity of this disease and are the basis for the discovery of new therapeutic targets. New prognostic and predictive factors are essential and microRNAs (miRNAs) are endogenous small non-coding RNA molecules with a great potential for diagnosis, prognosis and treatment of cancer. There are hundreds of miRNAs with altered expression in tumor gastric tissue when compared to normal gastric tissue. Many of these miRNAs are associated with clinicopathological variables and survival in patients with GC. Furthermore, the expression of some of these miRNAs with prognostic importance in CG is influenced by vitamin D and others are mediators of some of the actions of this vitamin. This review aims to update the evidence on several miRNAs with prognostic value and therapeutic potential in GC, whose expression may be influenced by vitamin D or may regulate vitamin D signaling.

Is there still a place for conventional histopathology in the age of molecular medicine? Laurén classification, inflammatory infiltration and other current topics in gastric cancer diagnosis and prognosis

Gastric cancer (GC) is the fifth most common cancer and the third cause of cancer-related deaths worldwide. In western countries, more than half of GC patients are diagnosed at advanced stages and 5-year survival rates range between 20-30%. The only curative treatment is surgery, and despite recent advances in oncological therapies, GC prognosis is still poor. The main prognostic tool for patient categorization and treatment selection is the TNM classification, but its limitations are being increasingly recognized. Early recurrences may occur in early-stage disease, and patients at the same stage show heterogeneous outcomes. Thus, there is a need to improve GC stratification and to identify new prognostic factors, which may allow us to select drug-susceptible populations, refine patient grouping for clinical trials and discover new therapeutic targets. Molecular classifications have been developed, but they have not been translated to the clinical practice. On the other hand, histological assessment is cheap and widely available, and it is still a mainstay in the era of molecular medicine. Furthermore, histological features are acquiring new roles as reflectors of the genotype-phenotype correlation, and their potential impact on patient management is currently being analyzed. The aim of this literature review is to provide a modern overview of the histological assessment of GC. In this study, we discuss recent topics on the histological diagnosis of GC, focusing on the current role of Laurén classification and the potential value of new histological features in GC, such as inflammatory infiltration and tumor budding.

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.

Comparison of Treatment Modalities for Locally Advanced Gastric Cancer: A Propensity Score Matching Analysis

Background: A consensus regarding optimum treatment strategies for locally advanced gastric cancer (LAGC) has not yet been reached. We aimed to evaluate the efficacy of various treatment modalities for LAGC and provided clinicians salvage options under real-world situation. Methods: Medical charts of patients with LAGC who underwent radical resection plus adjuvant chemotherapy or chemoradiotherapy from July 2003 to December 2014 were included. Validation cohort were selected from SEER database between 2004 and 2014. Kaplan-Meier and Cox proportional hazardous models were used to evaluate the overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). Propensity score matching (PSM) was used to adjust for potential baseline confounding. Results: A total of 350 patients were included and divided into D1 dissection plus chemotherapy group (D1CT, n = 74), D1 dissection plus adjuvant chemoradiotherapy group (D1CRT, n = 69), D2 dissection plus adjuvant chemotherapy group (D2CT, n = 134), and D2 dissection plus adjuvant chemoradiotherapy group (D2CRT, n = 73). PSM identified 50 patients in each group. After PSM, better DFS (P for D2CRT vs. D1CT, D1CRT, and D2CT was 0.001, 0.006, and 0.001, respectively) and OS (P for D2CRT vs. D1CT, D1CRT, and D2CT was 0.001, 0.011, and 0.022, respectively) were found for the D2CRT group (mean, OS = 110.7months, DFS = 95.2 months) than the other groups. Similar findings were further validated in the Surveillance, Epidemiology, and End Results database (SEER) cohort. In addition, patients in the D1CRT group achieved similar survival outcomes to those in the D2CT group (mean OS, 72.8 vs. 59.1 months, P = 0.86; mean DFS, 54.4 vs. 34.1 months, P = 0.460). Conclusions: The results of the study indicated the better role for D2CRT in treating the LAGC, meanwhile, the patients treated with D1CRT might achieve similar survival as that of D2CT patients.

Consensus statement of the Hellenic and Cypriot Gastric Cancer Study Group on the diagnosis, staging and management of gastric cancer

Gastric Cancer epidemics have changed over recent decades, declining in incidence, shifting from distal to proximal location, transforming from intestinal to diffuse histology. Novel chemotherapeutic agents combined with modern surgical operations hardly changed overall disease related survival. This may be attributed to a substantial inherent geographical variation of disease genetics, but also to a failure to standardize and implement treatment protocols in clinical practice. To overcome these drawbacks in Greece and Cyprus, a Gastric Cancer Study Group under the auspices of the Hellenic Society of Medical Oncology (HeSMO) and Gastrointestinal Cancer Study Group (GIC-SG) merged their efforts to produce a consensus considering ethnic parameters of healthcare system and the international proposals as well. Utilizing structured meetings of experts, a consensus was reached. To achieve further consensus, statements were subjected to the Delphi methodology by invited multidisciplinary national and international experts. Sentences were considered of high or low consensus if they were voted by ≥ 80%, or < 80%, respectively; those obtaining a low consensus level after both voting rounds were rejected. Forty-five statements were developed and voted by 71 experts. The median rate of abstention per statement was 9.9% (range: 0-53.5%). At the end of the process, one statement was rejected, another revised, and all the remaining achieved a high consensus. Forty-four recommendations covering all aspects of the management of gastric cancer and concise treatment algorithms are proposed by the Hellenic and Cypriot Gastric Cancer Study Group. The importance of centralization, care by a multidisciplinary team, adherence to guidelines, and individualization are emphasized.

Adjuvant Chemoradiotherapy for Gastric Cancer: Efficacy and Cost-Effectiveness Analysis

Purpose: The benefit of adjuvant chemotherapy (CT) for localized gastric cancer (GC) after D2-gastrectomy has been clearly demonstrated. However, adjuvant chemoradiotherapy (CRT) remains controversial. This study aimed to assess the efficacy and cost-effectiveness of treatment for GC after D2-gastrectomy. Materials and methods: Stage IB-IIICGC patients who had received adjuvant CRT or CT, or who had just been observed after D2-gastrectomy were retrospectively selected. Therapeutic strategy after surgery, disease-free survival (DFS), overall survival (OS), adverse events and costs were recorded retrospectively. A Markov model was developed to simulate the process of GC after D2-gastrectomy. Health outcomes were measured using quality-adjusted life-years (QALYs). Incremental cost-effectiveness ratio (ICER) was regarded as the primary outcome. Results: A total of 254 patients were selected. Three year OS and DFS were 83.02 and 64.15% in the adjuvant CRT group, 74.19 and 63.54% in the adjuvant CT group, and 45.45 and 43.35% in the observation group. Total grade 3 or 4 toxicity was higher in the CRT group than in the CT group (54.72% vs. 37.10%, p < 0.05). The ICER of the CT and CRT groups vs. the observation group were $10,571.55 and $11,467.41/QALY, respectively. The probability of CT, CRT and observation being cost-effective were 28.9, 37.9, and 33.2%, respectively, when a willingness-to-pay threshold (WTP) of $25,648.45/QALY was used. Conclusions: Adjuvant CRT was associated with improved OS and DFS compared with adjuvant CT and postoperative observation. Both adjuvant CRT and CT are likely to be cost effective compared with postoperative observation. However, adjuvant CRT was the optimal choice for a WTP threshold of $25,648.45/QALY.

Adjuvant chemoradiotherapy versus adjuvant chemotherapy for patients with N3 gastric cancer after D2/R0 resection: a retrospective study based on propensity score analyses

Purpose: N3 gastric cancer (GC) is characterized by a heavy burden of lymph node metastasis and a high postoperative recurrence rate. The role of radiotherapy in this group of patients remains undetermined. The purpose of this study was to compare the effectiveness of adjuvant chemoradiotherapy (CRT) and adjuvant chemotherapy (ChT) for N3 GC after D2/R0 resection.

Patients and methods: From January 2004 to December 2015, patients with N3 GC in the database of Fudan University Shanghai Cancer Center were retrospectively reviewed. The eligible patients were enrolled in an adjuvant CRT group and an adjuvant ChT group. Four different methods based on a propensity score model were used to balance the baseline characteristics. Then, survival analyses between the two groups were performed in addition to patterns of recurrence and subgroup analyses.

Results: In total, 175 and 365 eligible patients were enrolled into the CRT and ChT groups, respectively. After balancing, the disease-free survival (DFS) of patients in the CRT group was significantly better than that of patients in the ChT group (p=0.021). Subgroup analyses showed that patients with N3a GC benefitted from adjuvant CRT.

Conclusion: Compared with adjuvant ChT, adjuvant CRT can further improve the DFS of patients with N3 GC after D2/R0 resection. Patients with lymph node metastases should be further stratified when selecting patients for adjuvant CRT.

Efficacy and safety of intensity-modulated radiation therapy versus three-dimensional conformal radiation treatment for patients with gastric cancer: a systematic review and meta-analysis

BACKGROUND

Radiation or radiochemotherapy is a common adjuvant therapy for gastric cancer. Intensity-modulated radiation therapy (IMRT) has been demonstrated to provide better dose conformity, allowing dose escalation and/or reduction of normal tissue exposure compared with three-dimensional conformal radiation treatment (3D-CRT). However, the efficacy of IMRT and 3D-CRT in gastric cancer remains controversial. This study aimed to compare the efficacy and safety of IMRT with those of 3D-CRT in treating patients with gastric cancer through conducting a meta-analysis of 3-year survival rates [overall survival (OS) and disease-free survival (DFS)], local control rates, and toxic event rates.

METHODS

Embase, PubMed, the Cochrane Library, and clinical trial databases were searched to identify the clinical trials of IMRT versus 3D-CRT for treating patients with gastric cancer. The obtained data of survival and safety were analyzed using the Stata 14.0 software.

RESULTS

A total of 9 controlled clinical studies, including 516 patients with gastric cancer, met the inclusion criteria and were included in this meta-analysis. The results of the meta-analysis showed that the 3-year OS rate was slightly higher in the IMRT group than in the 3D-CRT group, without any statistical significance. The 3-year local control rate was significantly higher in the IMRT group than in the 3D-CRT group. No significant difference in the 3-year DFS rate was found between the IMRT and 3D-CRT groups. Grade 2-4 toxicities were similar between the IMRT and 3D-CRT groups.

CONCLUSION

The findings suggested that IMRT might be superior to 3D-CRT in treating patients with gastric cancer in terms of local control rates without increasing toxicity.

Treatment in resectable non-metastatic adenocarcinoma of stomach: Changing paradigms

Adjuvant treatment in gastric adenocarcinoma has been a challenge for the treating specialists, and despite several trials, a clear consensus is yet to be defined. The higher propensity for lymph nodal involvement and locoregional recurrences led to the hypothesis that locoregional and systemic treatments need to be equally aggressive to achieve better outcomes in the management of gastric adenocarcinoma. Regional, ethnic, and biological differences between the Eastern and Western population are also found to reflect in the tumor behavior and its response to treatment. The MAGIC (Medical Research Council Adjuvant Gastric Infusional Chemotherapy), Intergroup 0116, ACTS-GC (Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer), CLASSIC (Capecitabine and Oxaliplatin Adjuvant Study in Stomach Cancer), ARTIST (Adjuvant Chemoradiation Therapy in Stomach Cancer), and the recently published CRITICS (Chemoradiotherapy after Induction Chemotherapy in Cancer of the Stomach) trials were a few of the randomized controlled trials that tried to give a clearer perspective of this tumor, though it still remains a dilemma. A study incorporating the tumor and demographic factors along with the availability of skilled talent and resources might generate an answer.

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.

Optimal Timing for Postsurgical Adjuvant Therapy in Patients with Gastric Cancer: A Propensity Score Matching Study

Background:In clinical trials, adjuvant therapy (AT) has been shown to improve the prognosis in patients with gastric adenocarcinoma who undergo curative gastrectomy and adequate lymph node dissection. However, the optimal timing for initiating AT is still unclear.

Method:We collected data from 538 patients with stage II-III gastric cancer who underwent curative gastrectomy and AT in two tertiary hospitals from 2006 to 2013. Patients were divided into the early group (≤8 weeks, n=393) and the late group (>8 weeks, n=145), based on the interval between gastrectomy and initiation of AT. Propensity score matching was applied according to baseline characteristics.

Results:After 1:1 propensity score matching, an even distribution of characteristics in both groups (143:143) was achieved. The 5-year overall survival (OS) rates were 56.6% and 40.2% in the matched early and late groups, respectively (p=0.062), while the corresponding 5-year recurrence-free survival (RFS) rates were 57.6% and 46.4%, respectively (p=0.028). The time to AT initiation was correlated with RFS and had a positive association with OS. The 5-year distant metastasis-free survival was also significantly better (HR 0.682, 95% CI 0.472-0.985, p=0.040), suggesting an early AT results in a better outcome in patients.

Conclusion:We observed that initiation of AT within 8 weeks of curative gastrectomy produces better disease control and may contribute to better overall survival.

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.

Between evidence and new perspectives on the current state of the multimodal approach to gastric cancer: Is there still a role for radiation therapy?

In patients affected by gastric cancer (GC), especially those in advanced stage, the multidisciplinary approach of treatment is fundamental to obtain a good disease control and quality of life. Although many chemotherapeutics in combination to radiotherapy are adopted in the peri- or postoperative setting, the most optimal timing, regimens and doses remains controversial. In the era of radical surgery performed with D2-lymphadenectomy, the role of radiation therapy remains to be better defined. Categories of patients, who could benefit more from an intensified local treatment rather than more toxic systemic therapy, are still under investigation. Evidence and recent updates of the randomized trials, meta-analysis and prospective trials show that the postoperative radiotherapy plays a fundamental role in reducing the loco-regional recurrence and in turn the disease-free survival in operable advanced GC patients, also after a well performed D2 surgery. Therapeutic decisions should be taken considering the individual patients, but the multimodal approach is necessary to guarantee a longer survival and a good quality of life. Ongoing randomized trials could better define the timing and the combination of radiotherapy and systemic therapy.

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 chemoradiotherapy versus adjuvant chemotherapy for R1 resected gastric cancer: a retrospective cohort study

OBJECTIVE

The aim of this study was to compare the effects of adjuvant chemoradiotherapy (CRT) and adjuvant chemotherapy (ChT) on the survival of locally advanced gastric cancer (LAGC) patients treated with R1 resection.

METHODS

The patients with LAGC and microscopically positive margins after a potentially curative gastrectomy in Fudan University Shanghai Cancer Centre were retrospectively identified. The patients who were referred to our hospital for adjuvant CRT after an R1 resection elsewhere were also included. The patients were divided into either the CRT group or ChT group according to the treatment strategy. We, then, examined the patient survival results and patterns of recurrence for each group.

RESULTS

There were 114 LAGC patients treated with an R1 resection identified (CRT, n = 33; ChT, n = 81). The baseline characteristics between the two groups were not different. The estimated 3 year recurrence-free survival and overall survival in the CRT and ChT groups were 45.1% vs 31.8% (p = 0.09) and 49.6% vs 39.4% (p = 0.20), respectively. The results indicated that only nodal status was an independent prognostic factor (hazard ratio 4.04, 95% confidence interval 2.06-7.93). The risk of locoregional recurrence was increased in the ChT group. The subgroup analysis revealed that patients with pN0-2 GC showed a better recurrence-free survival due to adjuvant CRT (hazard ratio 0.19, 95% confidence interval 0.04-0.90; p = 0.022).

CONCLUSION

Adjuvant CRT improves locoregional control and may benefit patients with pN0-2 GC after R1 resection. The nodal status may be the most important predictor for patient selection. Advances in knowledge: Nodal status may be the most important predictor for patient selection. Compared with adjuvant ChT, LAGC patients with pN0-2 disease may further benefit from additional radiotherapy after R1 resection.

Optimal management of resected gastric cancer

Although advances in medical treatment for gastric cancer (GC) have been made, surgery remains the mainstay of cure for patients with localized disease. Improvement in surgical modalities leads to increased chance of cure for resected patients, but a non-negligible number of patients eventually relapse. On this basis, it has been hypothesized that the addition of complementary systemic or local treatments (such as chemotherapy and radiotherapy) could help in improving patients' survival by reducing the risk of recurrence. Several studies have tried to identify the best approach in localized GC: some of them have assessed the role of perioperative chemotherapy [CT] with different drug combinations, while others have focused on the benefit obtained by addition of radiotherapy, whose role is still under investigation. In particular, the role of chemoradiotherapy, both in adjuvant and neoadjuvant settings, is still uncertain. In the last few years, several clinicopathological and molecular factors have been investigated and identified as potential prognostic markers in GC. Many of these factors could have influenced the outcome of patients receiving combined treatments in the abovementioned studies. Patients have not been generally distinguished by the site of disease (esophageal, gastric and junctional cancers) and surgical approach, making data difficult to be interpreted. The purpose of this review was to shed light on these highly controversial topics.

A Case Report of Salvage Radiotherapy for a Patient with Recurrent Gastric Cancer and Multiple Comorbidities Using Real-time MRI-guided Adaptive Treatment System

The stomach is one of the most deforming organs caused by respiratory motions and daily variation by food intake. Applying radiotherapy has been quite a challenge due to the high risk of missing the target as well as radiation exposure to large volumes of normal tissue. However, real-time magnetic resonance (MR)-guided radiotherapy with adaptive planning could focus the high dose radiation to the target area while minimizing neighboring normal tissue exposure and compensate for not only daily but real-time variation. Here is a case report of a patient with recurrent gastric cancer and multiple co-morbidities, unsuitable for both resection and chemotherapy, who underwent MR guided adaptive radiotherapy.

Chemoradiotherapy versus chemotherapy as adjuvant treatment for localized gastric cancer: a propensity score-matched analysis

BACKGROUND

Treatment of localized gastric cancer (LGC) consists of surgical resection followed by adjuvant treatment. Both chemoradiation (CRT) and chemotherapy (CT) regimens have shown benefit in survival outcomes versus observation. However, there are few data comparing these approaches.

METHODS

This study included consecutive patients with LGC treated at Instituto do Cancer do Estado de Sao Paulo (ICESP) from 2012 to 2015. CRT was based on the INT-0116 regimen and CT consisted of a platinum and fluoropyrimidine doublet. Treatment choice was based on physician preference. Toxicity was evaluated for every cycle. Overall survival (OS) analysis was performed by Kaplan-Meier. A propensity score-matched analysis was performed to minimize selection bias.

RESULTS

A total of 309 patients were evaluated, 227 in CRT group and 82 in CT group. The most prevalent grade 3/4 toxicities in CRT and CT groups were: nausea/vomiting (9.25 vs 4.9%), fatigue (9.3% vs 2.4%), mucositis (4.4% vs 1.2%), neutropenia (37.8% vs 20.9%), febrile neutropenia (3.9% vs 0%), anemia (4.3% vs 6.1%), thrombocytopenia (2.6% vs 4.9%), neuropathy (0 vs 2.4%) and hand-foot syndrome (0.4% vs 2.4%). Two grade 5 toxicities (febrile neutropenia and anemia) occurred in CRT group. There was no difference in the pattern of recurrence. After a median follow-up of 23.5 months (CRT) and 20.6 months (CT), there was no difference in OS between groups.

CONCLUSIONS

CT and CRT present similar efficacy and tolerability as adjuvant treatment for LGC.

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.