Postoperative chemoradiotherapy versus postoperative chemotherapy for completely resected gastric cancer with D2 Lymphadenectomy: a 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.

Postoperative Adjuvant Chemoradiotherapy on the Survival of Stage III Gastric Cancer

Objective

Although adjuvant therapy has been shown to be beneficial in gastric cancer, the use of adjuvant chemoradiotherapy remains controversial. This paper investigated the effects of postoperative adjuvant chemoradiotherapy on the survival of patients with stage III gastric cancer.

Methods

In total, the data of 72 stage III gastric cancer patients treated at our hospital from January 2014 to December 2019 were retrieved and assessed. They were categorized into a chemotherapy group (CT group) and a radiochemotherapy group (RCT group) according to their given treatment regimens. A 3-year follow-up was conducted to record their incidence of disease-free survival (DFS), overall survival (OS), and adverse events.

Results

For the CT and RCT groups, DFS was 86.4% and 92.6% in the first year, decreasing to 55.1% and 73.7% in the second year, and 41.3% and 69.1% in the third year. There was no significant difference in DFS between the two groups during the three-year follow-up. Additionally, for the CT and RCT groups, their respective 1-year, 2-year, and 3-year OS were 95.6% and 96.3%, 75.1% and 87.9%, and 50.3% and 74.2%, indicating that the OS of patients in the RCT group was significantly higher than that in the CT group during 3 years of follow-up. Further, no significant difference in the incidence of adverse events was found between the two treatment groups.

Conclusions

Collectively, adjuvant radiochemotherapy after radical gastrectomy for stage III gastric cancer was associated with better survival outcomes than chemotherapy, without increase in adverse events.

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

Background

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

Materials and methods

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

Results

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

Conclusion

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

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.

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.

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.

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.

Locally advanced gastro-oesophageal cancer: Recent therapeutic advances and research directions

Gastric (GC) and gastro-oesophageal (GOJC) adenocarcinomas are often considered as a single entity, even though differences exist in epidemiology, clinical presentation, molecular biology and treatment options. Locally advanced, resectable disease represents a particularly challenging scenario, as many critical issues need to be addressed. In both GC and GOJC among Western countries, systemic chemotherapy demonstrated the greatest benefit when administered before and after surgery and perioperative chemotherapy has been set as a standard in this setting. Nonetheless, multiple chemotherapy regimens have been tested and direct comparisons have been only recently presented. Adjuvant chemoradiotherapy is an option as well, but several trials have questioned its role when more effective combination regimens are used. With regards to GOJC, preoperative chemoradiotherapy is an alternative to perioperative chemotherapy, as it is associated with higher pathologic responses and a different toxicity profile: however, a definitive comparison with chemotherapy is ongoing. Herein, we review the current options for the treatment of resectable GC and GOJC and the main open questions in the management of these patients, trying to depict an update of the available algorithms for everyday practice. Moreover, we summarize the design and preliminary results of the randomized trials in progress that will hopefully give definitive answers to the most debated issues in the field.

Prognostic impact of nodal status and therapeutic implications

The prognostic impact of lymph node (LN) metastases in gastric cancer is generally accepted. In primarily resected patients the pN-category and LN ratio are independent prognostic factors. Number of involved LNs, number of resected LNs, lymphangiosis and micrometastases also influence the prognosis significantly. To guarantee a proper D2 lymphadenectomy (LAD) at least 25 LNs according to the German S3 guidelines for the treatment of gastric cancer should be removed. Also in neoadjuvantly treated patients the ypN-category and LN ratio play an important prognostic role, despite the fact that UICC staging system was development based only on primarily resected patients. The role of response of LNs in neoadjuvantly treated patients is still unclear and needs further investigation. It seems to be less important than the response of the primary tumor. Limited data exists, suggesting that preoperative treatment might reduce the number of LNs involved and improve ypN-category. Due to further development in gastric cancer like laparoscopic resection and effective perioperative treatment in locally advanced tumor the role and the prognostic impact of LAD is again in the focus of discussion.

[Role of postoperative chemoradiotherapy in the therapeutic management of adenocarcinomas of the stomach and oesogastric junction]

The available data in the literature show that for gastric adenocarcinoma or gastroesophageal junction adenocarcinoma, postoperative chemoradiotherapy improves disease-free survival after surgery with D0 or D1 lymph node dissection (and perhaps D2) as well as in case of positive node or R1 resection. With the publications of perioperative chemotherapy trials, the role of postoperative radiotherapy in the therapeutic arsenal of gastric adenocarcinoma or gastroesophageal junction adenocarcinoma becomes difficult to define. Postoperative radiotherapy is indicated in case of R1 resection.

Recent insights in the therapeutic management of patients with gastric cancer

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

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.

Current adjuvant treatment modalities for gastric cancer: From history to the future

The discrepancy between the surgical technique and the type of adjuvant chemotherapy used in clinical trials and patient outcomes in terms of overall survival rates has led to the generation of different adjuvant treatment protocols in distinct parts of the world. The adjuvant treatment recommendation is generally chemoradiotherapy in the United States, perioperative chemotherapy in the United Kingdom and parts of Europe, and chemotherapy in Asia. These options mainly rely on the United States Intergroup-0116, United Kingdom British Medical Research Council Adjuvant Gastric Infusional Chemotherapy, and the Asian Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer and Capecitabine and Oxaliplatin Adjuvant Study in Stomach Cancer trials. However, the benefits were evident for only certain patients, which were not very homogeneous regarding the type of surgery, chemotherapy regimens, and stage of disease. Whether the dissimilarities in survival are attributable to surgical technique or intrinsic biological differences is a subject of debate. Regardless of the extent of surgery, multimodal therapy may offer modest survival advantage at least for diseases with lymph node involvement. Moreover, in the era of individualized treatment for most of the other cancer types, identification of special subgroups comprising those who will derive more or no benefit from adjuvant therapy merits further investigation. The aim of this review is to reveal the historical evolution and future reflections of adjuvant treatment modalities for resected gastric cancer patients.

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.

Phase III Trial to Compare Adjuvant Chemotherapy With Capecitabine and Cisplatin Versus Concurrent Chemoradiotherapy in Gastric Cancer: Final Report of the Adjuvant Chemoradiotherapy in Stomach Tumors Trial, Including Survival and Subset Analyses

Purpose

The Adjuvant Chemoradiotherapy in Stomach Tumors (ARTIST) trial tested whether the addition of radiotherapy to adjuvant chemotherapy improved disease-free survival (DFS) in patients with D2-resected gastric cancer (GC).

Patients and Methods

Between November 2004 and April 2008, 458 patients with GC who received gastrectomy with D2 lymph node dissection were randomly assigned to either six cycles of adjuvant chemotherapy with capecitabine and cisplatin (XP) or to two cycles of XP followed by chemoradiotherapy and then two additional cycles of XP (XPRT). This final update contains the first publication of overall survival (OS), together with updated DFS and subset analyses.

Results

With 7 years of follow-up, DFS remained similar between treatment arms (hazard ratio [HR], 0.740; 95% CI, 0.520 to 1.050; P = .0922). OS also was similar (HR, 1.130; 95% CI, 0.775 to 1.647; P = .5272). The effect of the addition of radiotherapy on DFS and OS differed by Lauren classification (interaction P = .04 for DFS; interaction P = .03 for OS) and lymph node ratio (interaction P < .01 for DFS; interaction P < .01 for OS). Subgroup analyses also showed that chemoradiotherapy significantly improved DFS in patients with node-positive disease and with intestinal-type GC. There was a similar trend for DFS and OS by stage of disease.

Conclusion

In D2-resected GC, both adjuvant chemotherapy and chemoradiotherapy are tolerated and equally beneficial in preventing relapse. Because results suggest a significant DFS effect of chemoradiotherapy in subsets of patients, the ARTIST 2 trial evaluating adjuvant chemotherapy and chemoradiotherapy in patients with node-positive, D2-resected GC is under way.

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.

Controversies in the treatment of local and locally advanced gastric and esophageal cancers

Despite overall progress in the therapy of local and locally advanced esophageal, gastroesophageal junction, and gastric adenocarcinomas, death as a result of these tumors remains a common outcome. Most randomized phase III trials on which level-one evidence has been built have included the heterogeneous histologies and locations associated with these tumors. However, the different etiologies, molecular biology, and recurrence patterns associated with gastroesophageal malignancies suggest the need to split rather than lump. Biologic and response differences exist between squamous and adenocarcinomas, as well as diffuse and intestinal histologies. This may be a cause behind conflicting outcomes in similar trials. The accepted standard of chemoradiotherapy for locally advanced esophageal and gastroesophageal junction cancers is based on a few positive trials, with the best chemotherapy and total dose of radiation remaining controversial. In the West, the staging evaluations of locally advanced gastric cancer are not uniform. Yet, these evaluations will inform the results of preoperative and perioperative treatments. Although postoperative chemoradiotherapy for gastric cancer has been an accepted treatment option for the last decade, more recent studies have called into question the need for radiotherapy. In perioperative strategies, it has yet to be determined whether histologic or molecular changes in the operative specimen should inform postoperative treatment. An appropriate place for targeted therapy needs to be found in preoperative and postoperative treatment regimens. Finally, because so much is lost when trials are forced to close for lack of accrual, it is imperative to build multidisciplinary consensus before they are launched.

Adjuvant therapy for gastric cancer: What have we learned since INT0116?

Gastric cancer is one of the main cancer-related causes of death worldwide. The curative treatment of gastric cancer consists of tumor resection and lymphadenectomy. However, surgical treatment alone is associated with high recurrence rates. Adjuvant treatment strategies have been studied over the last decades, but there have been controversial results from the initial studies. The pivotal INT0116 study demonstrated that the use of adjuvant chemoradiotherapy with 5-fluorouracil increases relapse-free and overall survival, and it has been adopted across the Western world. The high toxicity of radiochemotherapy and suboptimal surgical treatment employed, with fewer than 10% of the patients submitted to D2 lymphadenectomy, were the main study limitations. Since its publication, other adjuvant treatment modalities have been studied, and radiochemotherapy is being refined to improve its efficacy and safety. A multimodal approach has been demonstrated to significantly increase relapse-free and overall survival, and it can be offered in the form of perioperative chemotherapy, adjuvant chemoradiotherapy or adjuvant chemotherapy, regardless of the extent of lymphadenectomy. The objective of the present review is to report the major advances obtained in the last decades in the adjuvant treatment of gastric cancer as well as the perspectives of treatment based on recent knowledge of the molecular biology of the disease.

Chemoradiation for gastric cancer: controversies, updates and novel techniques

The INT0116 trial established the role of adjuvant chemoradiation (CRT) in the multidisciplinary approach to the management of locally advanced gastric cancer. However, whether adjuvant CRT is indispensable for patients undergoing D2 dissection remains undefined. The adjuvant chemoradiation therapy in stomach cancer (ARTIST) trial, which was designed to compare adjuvant chemotherapy to CRT, failed to demonstrate differences in disease-free and overall survival in the whole study group; however, subgroup analysis indicated that patients with lymph node metastasis may benefit from additional radiation. A follow-up ARTIST II trial is currently under way. The efficacy of adjuvant CRT remains controversial because of variation among studies in the inclusion criteria and treatment delivery methods; however, the identification of patients who would benefit from CRT is critical. Advanced radiotherapy techniques such as intensity-modulated radiotherapy protect normal tissues via motion management and decreased radiation-induced toxicity and contribute to plan optimization. Further studies integrating clinical and molecular factors as well as neoadjuvant CRT are warranted.

Adjuvant chemoradiotherapy after D2 resection in gastric cancer: a single-center observational study

PURPOSE

Previous studies demonstrated survival benefits in association with the addition of chemoradiotherapy after surgery in gastric cancer. This study aimed to examine the efficacy in terms of loco-regional control and survival and safety of 5-FU-based adjuvant chemoradiotherapy after D2 curative surgery.

METHODS

This study included 228 patients (81 female, 147 male) treated for gastric cancer with curative surgery plus adjuvant chemoradiotherapy. Majority of the patients underwent at least D2 lymph node resection. Median three cycles of fluorouracil chemotherapy were administered, and 45-Gy radiotherapy was delivered at 1.8 Gy/fraction concomitantly during the second cycle of chemotherapy. Local control, regional control, distant metastasis and overall survival rates were estimated.

RESULTS

The median age of the patients was 54 years (range 25-74 years). The most common grade III toxicities were nausea (10%) and neutropenia (9%). During radiotherapy, grade IV local skin reaction occurred in one patient. Median duration of follow-up was 47 months. Local, regional and distant recurrence developed in 9 (4%), 41 (18%) and 45 (20%) patients, respectively. Overall 5-year survival rate was 57.2%, and disease-free 5-year survival rate was 53.8%. Multivariate analysis identified less than 15 lymph node involvement as an independent predictor of better survival (p < 0.001).

CONCLUSIONS

Concomitant 5-FU-based chemoradiotherapy seems to be an effective and tolerable adjuvant regimen on local control and survival in curatively resected node-positive stomach cancer, particularly when combined with D2 resection.

Postoperative adjuvant chemoradiotherapy in D2-dissected gastric cancer: Is radiotherapy necessary after D2-dissection?

Studies from the Far East have demonstrated that D2-dissection is superior to D0/1-dissection. The effect of postoperative chemoradiotherapy (CRT) after D2-dissection has not been accepted due to the lack of D2-dissection in Western countries, as well as the potential harmful effect of radiotherapy. In the current NCCN guideline, adjuvant chemotherapy alone is recommended in D2-dissected patients. However, three recent prospective randomized controlled trials in South Korea and China (ARTIST, NCC and Multicenter IMRT Trials) demonstrated that adjuvant CRT can be safely administered to D2-dissected patients with notable benefits. To identify the role of radiotherapy (RT) in the D2-dissected postoperative setting, clinical research attempts should include (1) identification of high-risk patients for loco-regional recurrence who might benefit from CRT; (2) modification of RT target volume based on the findings that failure patterns should be different after D1- and D2-dissection; and (3) integration of new RT techniques to decrease treatment-related toxicity. The present paper is a review of recent studies addressing these fields. Well-designed prospective randomized studies are needed to clearly define the role of adjuvant CRT in D2-dissected gastric cancer, however, future clinical studies should also focus on answering these questions.

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.

Adjuvant chemotherapy for gastric cancer: Current evidence and future challenges

Gastric cancer still represents one of the major causes of cancer mortality worldwide. Patients survival is mainly related to stage, with a high proportion of patients with metastatic disease at presentation. Thus, the cure rate largely depend upon surgical resection. Despite the additional, albeit small, benefit of adjuvant chemotherapy has been clearly demonstrated, no general consensus has been reached on the best treatment option. Moreover, the narrow therapeutic index of adjuvant chemotherapy (i.e., limited survival benefit with considerable toxicity) requires a careful assessment of expected risks and benefits for individual patients. Treatment choices vary widely based on the different geographic areas, with chemotherapy alone more often preferred in Europe or Asia and chemoradiotherapy in the United States. In the present review we discuss the current evidence and future challenges regarding adjuvant chemotherapy in curatively resected gastric cancer with particular emphasis on the recently completed landmark studies and meta-analyses. The most recent patient-level meta-analysis demonstrated the benefit of adjuvant chemotherapy over curative surgery; the same Authors also showed that disease-free survival may be used as a surrogate end-point for overall survival. We finally discuss future research issues such as the need of economic evaluations, development of prognostic or predictive biomarkers, and the unmet clinical need of trials comparing perioperative chemotherapy with adjuvant treatment.

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.

Indirect comparison showed survival benefit from adjuvant chemoradiotherapy in completely resected gastric cancer with d2 lymphadenectomy

Background. Little data on directly comparing chemoradiotherapy with observation has yet been published in the setting of adjuvant therapy for resected gastric cancer who underwent D2 lymphadenectomy. The present indirect comparison aims to provide more evidence on comparing the two approaches. Methods. We conducted a systematic review of randomized controlled trials, extracted time-to-event data using Tierney methods (when not reported), and performed indirect comparison to obtain the relative hazards of adjuvant chemoradiotherapy to observation on overall and disease-free survival. Results. seven randomized controlled trials were identified. Three trials compared adjuvant chemoradiotherapy with adjuvant chemotherapy, and 4 trials compared adjuvant chemotherapy with observation. Using indirect comparison, the relative hazards of adjuvant chemoradiotherapy to observation were 0.43 (95% CI: 0.33-0.55) in disease-free survival and 0.52 (95% CI: 0.38-0.71) in overall survival for completely resected gastric cancer with D2 lymphadenectomy. Conclusions. Postoperative chemoradiotherapy can prolong survival and decrease recurrence in patients with resected gastric cancer who underwent D2 gastrectomy. Molecular biomarker might be a promising direction in the prediction of clinical outcome to postoperative chemoradiotherapy, which warranted further study.