Effects of adjuvant radiotherapy on completely resected gastric cancer: A radiation oncologist's view of the ARTIST randomized phase III trial

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.

Clinical Significance of Preoperative Hematological Parameters in Patients with D2-Resected, Node-Positive Stomach Cancer

The purpose of the present study was to investigate the clinical significance of preoperative hematological parameters in patients with advanced stomach cancer, and to explore who might benefit from adjuvant concurrent chemoradiotherapy (CCRT) compared to chemotherapy alone. Among 1032 patients with node-positive stomach cancer who had a confirmed diagnosis after complete D2 resection, and who received adjuvant chemotherapy alone or CCRT, a total of 692 patients was selected using propensity score matching. Among absolute neutrophil count, absolute lymphocyte count (ALC), absolute monocyte count (AMC), platelet count, neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and platelet-to-lymphocyte ratio, AMC was the most relevant prognostic factor for overall survival and recurrence-free survival (hazard ratio (HR) 1.674, 95% confidence interval (CI) 1.180–2.376; HR 1.908, 95% CI 1.650–2.695, respectively). In a subgroup with a high ALC, patients treated with adjuvant CCRT had a favorable recurrence-free survival (HR 0.620, 95% CI 0.393–0.980) compared to those treated with chemotherapy alone. Further study is needed to confirm our findings and to develop tailored adjuvant treatment.

Efficacy and toxicity of capecitabine combined with intensity-modulated radiotherapy after D1/D2 lymph node dissection in patients with gastric cancer

BACKGROUND

Adjuvant chemoradiotherapy (ACRT) with oral capecitabine and intensity-modulated radiotherapy (IMRT) were well tolerated in a phase I study in patients who had undergone partial or total gastrectomy for locally advanced gastric cancer (GC). This phase II study aimed to further determine the efficacy and toxicity of this combination after radical resection and D1/D2 lymph node dissection (LND) for patients with locally advanced GC.

AIM

To further determine the efficacy and toxicity of this combination after radical resection and D1/D2 LND for patients with locally advanced GC.

METHODS

Forty patients (median age, 53 years; range, 24-71 years) with pathologically confirmed adenocarcinoma who underwent D1/D2 LND were included in this study. The patients received ACRT comprising IMRT (total irradiation dose: 45 Gy delivered in daily 1.8-Gy fractions on 5 d a week over 5 wk) and capecitabine chemotherapy (dose: 800 mg/m² twice daily throughout the duration of radiotherapy). The primary study endpoint was disease-free survival (DFS), and the secondary endpoints were overall survival (OS), toxic effects, and treatment compliance.

RESULTS

The 3-year DFS and OS were 66.2% and 75%, respectively. The median time to recurrence was 19.5 mo (range, 6.1-68 mo). Peritoneal implantation (n = 10) was the most common recurrence pattern, and the lung was the most common site of extra-abdominal metastases (n = 5). Nine patients developed grade 3 or 4 toxicities during ACRT. Two patients discontinued ACRT, while eleven underwent ACRT without receiving the entire course of capecitabine. There were no treatment-related deaths.

CONCLUSION

The ACRT protocol described herein showed acceptable safety and efficacy for patients with locally advanced GC who received radical gastrectomy and D1/2 LND.

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.

Evaluating the benefit of adjuvant radiotherapy after extensive lymph node dissection for gastric cancer: a single-institute retrospective study

Objective:

This study aimed to evaluate whether adjuvant radiotherapy (RT) can improve the treatment outcome of patients with locally advanced gastric cancer who underwent extensive lymph node dissection (ELND).

Materials and Methods:

This retrospective study included patients with gastric cancer pathological stages IIA–IIIC at Taipei Tzu Chi Hospital between 2008 and 2015. Patients (a) aged >80 years, (b) with distant metastasis at diagnosis, (c) with coexisting malignancies, (d) who did not complete the prescribed RT course, and (e) who died 1 month after surgery were excluded. Among 420 patients diagnosed with gastric cancer, 98 were included.

Results:

The median follow-up was 24.5 months. Of 39 patients who underwent adjuvant RT, 38 also received adjuvant chemotherapy (CT). Of 59 patients who did not receive adjuvant RT, only 34 received adjuvant CT. ELND was performed in 67.3% of the patients. The 5-year overall survival (OS) rate was 40%. In the univariate analyses, adjuvant CT regimen, 5-fluorouracil + leucovorin, was associated with worst outcome, while TS-1 was associated with better survival outcome (P = 0.018). The number of involved lymph nodes was strongly related to the OS and disease-free survival (DFS) (P < 0.001). We tried using different numbers of involved lymph nodes as a cutoff point and found that adjuvant RT significantly improved both OS and DFS in patients whose involved lymph nodes were ≥4 (OS, P = 0.017; DFS, P = 0.015). In multivariate analyses, better DFS was associated with negative surgical margin (P = 0.04), earlier disease stage (P = 0.001), adjuvant radiotherapy (P = 0.045), and adjuvant CT regimen TS-1 (P = 0.001).

Conclusion:

Adjuvant RT could improve DFS of patients with locally advanced gastric cancer with or without ELND. When the number of involved lymph nodes is ≥4, adjuvant RT is strongly suggested.

The prognostic value of the lymph node ratio for local advanced gastric cancer patients with intensity-modulated radiation therapy and concurrent chemotherapy after radical gastrectomy in China

BACKGROUND

Nearly 50% of new gastric cancer cases and gastric cancer-related deaths worldwide occur in China. No global consensus has been reached about the optimal management of locally advanced gastric cancer. Although the Guidelines for the Diagnosis and Treatment of Gastric Cancer from the National Health Commission of China, which has been updated three times since 2010, explicitly emphasize the necessity of adjuvant chemoradiation, few clinical institutions in China routinely adhere to the recommended radiotherapy guidelines. This study aimed to examine the efficacy, in terms of locoregional control and long-term survival, and the safety of adjuvant radiotherapy using intensity-modulated radiation therapy (IMRT) with concurrent and adjuvant fluoropyrimidine-based chemotherapy for gastric cancer.

METHODS

This was a retrospective evaluation of 156 patients with high-risk gastric cancer who underwent adjuvant chemoradiotherapy between September 2008 and May 2019. The prescribed planning target volume median dose was 45 Gy in 1.8 Gy daily fractions, and all patients received concurrent and adjuvant fluoropyrimidine-based chemotherapy. Locoregional control, distant metastasis, and overall survival rates were estimated. Clinicopathological characteristics and patterns of failure were retrospectively reviewed to identify factors associated with survival and recurrence.

RESULTS

The median follow-up duration was 56 months (range 3-130 months) for all patients. Of the patients, 11 (7.1%) were lost to follow-up, and 49 (31.4%) and 104 (66.7%) had stage II or III disease according to the eighth edition of the American Joint Committee on Cancer tumor-node-metastasis staging criteria. The frequencies of acute grade 3 or 4 gastrointestinal and hematological toxicity were 9.6% and 10.9%, respectively. In total, 152 patients (97.4%) completed the entire chemoradiation regimen. No toxicity-related deaths occurred. Nineteen patients (12.2%) had locoregional recurrence, 26 (16.7%) had distant metastases, and 12 (7.7%) had peritoneal metastasis. The overall survival (OS) rates were 83.5%, 65.0%, and 59.5%, while the disease-free survival rates were 75.1%, 61.0%, and 55.6% at 1, 3, and 5 years, respectively. In the multivariate analysis, age, pathological T stage and lymph node ratio (LNR) were found to be independent predictors of OS.

CONCLUSION

Postoperative concomitant IMRT and chemotherapy were well tolerated, with acceptable toxicities and encouraging locoregional tumor control and long-term survival. The LNR can be used as an important prognostic indicator for OS. Adjuvant chemoradiotherapy should be considered for all patients with a high risk of locoregional recurrence, especially in China.

Improving survival of stage II-III primary gastric signet ring cell carcinoma by adjuvant chemoradiotherapy

Background

There is no consistent evidence about the appropriate treatment strategies for gastric signet ring cell carcinoma (GSRC) to improve prognosis. We conducted a population‐based study to examine the effects of combined modality therapies on survival outcomes using the Surveillance, Epidemiology, and End Results (SEER) data.

Methods

Analyses included stage II‐III primary GSRC patients who were diagnosed between 2006 and 2016. Therapies were categorized as gastrectomy group, adjuvant chemotherapy (CT) group, neoadjuvant radiotherapy (RT) group, and adjuvant chemoradiotherapy (CRT) group. Survival analyses were conducted by Kaplan‐Meier method and Cox proportional hazards models and subgrouped by gender, tumor site, stage at diagnosis, and number of lymph nodes removed.

Results

Of the 1717 cases of stage II‐III primary GSRC, the mean (SD) age was 59.6 (13.3) years, and over a half were male (52.8%). A total of 39.9% patients received adjuvant CRT and the 5‐year overall survival (OS) rate was 34.6%. The median OS of patients treated with adjuvant CRT was significantly longer than that of the gastrectomy group (33 months vs 24 months, aHR = 0.71, 95% CI: 0.59, 0.84). Although the crude model showed a significant association between adjuvant CT and total survival (cHR = 0.81, 95% CI: 0.68, 0.96), the effect measure turned null in the multivariable and sub‐group analysis. We did not find the significant effect of neoadjuvant RT.

Conclusions

In this study, GSRC patients with stage II‐III experienced improved overall survival after receiving adjuvant CRT, which provides several treatment implications. More clinical trials will be needed to verify the conclusion derived from this study.

Effect of baseline sarcopenia on adjuvant treatment for D2 dissected gastric cancer: Analysis of the ARTIST phase III trial

BACKGROUND AND PURPOSE

This study evaluated the clinical significance of preoperative sarcopenia according to adjuvant concurrent chemo-radiotherapy (XP-RT) or chemotherapy alone (XP) in the D2 dissected gastric cancer patient cohort of the ARTIST trial.

MATERIALS AND METHODS

Skeletal muscles at the L3 vertebra level from preoperative computed tomography images among the ARTIST trial participants were measured using validated in-house software. Skeletal muscle index (SMI) was defined as the measured skeletal muscle area divided by the square of the height, and sarcopenia was defined according to the Korean-specific cutoff, i.e. L3 SMI ≤ 49 cm²/m² for men and ≤31 cm²/m² for women.

RESULTS

Among the 440 patients in whom we were able to evaluate L3 SMI, 75 (17.0%) met the definition for preoperative sarcopenia. No differences in treatment-related toxicities or treatment compliance were observed according to the presence of preoperative sarcopenia in either treatment arm. In the subgroup of patients without preoperative sarcopenia, recurrence was significantly lower in the XP-RT arm than that in the XP arm (p = 0.02). Recurrence-free survival (RFS) was also significantly higher in the XP-RT arm (p = 0.02, hazard ratio 0.633, 95% confidence interval 0.433-0.926) in this subgroup. In the multivariate analysis, and after adjusting for significant prognostic factors, the superior outcome of XP-RT arm regarding RFS was maintained in the subgroup of the patients without preoperative sarcopenia.

CONCLUSIONS

Superior clinical outcomes of adjuvant XP-RT over XP were only observed in patients without preoperative sarcopenia.

Patterns of recurrence after curative D2 resection for gastric cancer: Implications for postoperative radiotherapy

BACKGROUND

High-quality randomized controlled trials have demonstrated the benefit of radiotherapy (RT) in patients with radical resected gastric cancer (GC), however, utilization rates of postoperative RT remain remarkably low. Patterns, incidences, and time of recurrence provide biological bases for clinical monitoring of GC patients and guiding potential complementary therapies. Thus, the aim of this study is to understand the location of locoregional recurrence which may allow individualized RT strategies and minimize radiation-related toxic effects.

METHODS

A relatively large sample of GC patients in a single institution who had undergone curative D2 resection was retrospectively reviewed and the relevant recurrence patterns were illustrated. Independent recurrence-related risk factors were analyzed by logistic regression analysis. New logistic regression models were further developed to predict the probability of recurrence.

RESULTS

Overall, among 776 GC patients who had continuous and complete follow-up data, 300 cases relapsed after curative resection. Lymphovascular invasion, lymph node metastases, and tumor stage were indicators for early recurrence. Peritoneal, regional, local, and distant recurrence initially occurred in 51 (6.6%), 151 (19.4%), 56 (7.2%), and 164 (21.1%) patients, respectively. Among patients with regional recurrence, the most common sites were lymph node stations 16a2, 8, 12, 16b1, and 9. Remnant stomach recurrence was not so prominent that it seemed reasonable to be excluded from an irradiation field for patients with negative surgical/pathologic margins.

CONCLUSIONS

For GC patients who underwent radical D2 resection, distant and regional recurrences were still common. Besides, optimizing regional control of lymph nodes outside the D2 dissected area was crucial for rational design of the RT field. Furthermore, the new logistic regression models might act as useful tools to evaluate recurrence risk and determine which patients should receive postoperative chemoradiotherapy.

Outcomes of Radiotherapy for Mesenchymal and Non-Mesenchymal Subtypes of Gastric Cancer

Background: The purpose of this study was to evaluate the clinical outcomes following postoperative chemotherapy (XP) versus chemoradiotherapy (XP-RT) according to mesenchymal subtype based on RNA sequencing in gastric cancer (GC) in a cohort of the Adjuvant chemoRadioTherapy In Stomach Tumor (ARTIST) trial. Methods: Of the 458 patients enrolled in the ARTIST trial, formalin-fixed, paraffin-embedded (FFPE) specimens were available from 106 (23.1%) patients for RNA analysis. The mesenchymal subtype was classified according to a previously reported 71-gene MSS/EMT signature using the NanoString assay. Results: Of the 106 patients analyzed (50 in XP arm, 56 in XP-RT arm), 36 (34.0%) patients were categorized as mesenchymal subtype by NanoString assay. Recurrence-free survival (RFS, p = 0.009, hazard ratio (HR) = 2.11, 95% confidence interval (CI): 1.21-3.70) and overall survival (OS, p = 0.003, HR = 2.28, 95% CI: 1.31-3.96) were significantly lower in the mesenchymal subtype than in the non-mesenchymal subtype. In terms of post-operative radiotherapy (RT), mesenchymal subtype was not an independent variable to predict RFS or OS regardless to the assigned arm (XP with or without RT) in this patient cohort. However, there was a trend in the adjuvant XP arm, which showed higher OS than the XP-RT arm for the mesenchymal subtype and lower OS than the XP-RT arm for the non-mesenchymal subtype. Conclusions: We could not determine any significant differences between the mesenchymal and non-mesenchymal subtypes with respect to the effects of adjuvant XP with or without RT in gastric cancer following curative surgery.

Low Expression of GLIS2 Gene Might Associate with Radiosensitivity of Gastric Cancer

Human gene GLIS family zinc finger 2 (GLIS2) is a member of GLI-similar zinc finger protein family. Previous studies indicated GLIS2 gene involved in tumorigenesis mechanisms. However, the association between GLIS2 expression and radiosensitivity of gastric cancer has not been well understood. In this study, we used the gastric cancer database in TCGA, and significant association was observed between the low expression of GLIS2 and radiosensitivity of patients with gastric cancer. The adjusted HR values for radiotherapy were 0.162(0.035-0.756) and 0.089(0.014-0.564), with p values 0.021 and 0.010, respectively, in training and testing data, for these patients with low expression of GLIS2, while for patients with high expression of GLIS2, there was no significant survival difference between radiotherapy and nonradiotherapy groups. The adjusted HR were 0.676(0.288-1.586) and 0.508(0.178-1.450), with p values 0.368 and 0.206 in training and testing data, respectively. Further study showed that, for low expression patients, radiotherapy did not significantly increase new tumor event rate and disease progression rate, which partially supported our assumption. These results suggested that low expression of GLIS2 might significantly associate with the radiosensitivity of patients with gastric cancer. The GLIS2 gene might be a potential effective molecular marker of gastric cancer for precise radiotherapy.

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.

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.

Comparison of the 7th and the 8th AJCC Staging System for Non-metastatic D2-Resected Lymph Node-Positive Gastric Cancer Treated with Different Adjuvant Protocols

PURPOSE

The purpose of this study was to compare prognostic differentiation performances of the 7th and the 8th edition of American Joint Commission on Cancer (AJCC) staging system for gastric cancer (GC) patients.

Materials and Methods

A total of 1,633 GC patients who underwent curative D2 resection followed by adjuvant chemotherapy alone (CA) or concurrent chemo-radiotherapy (CCRT) from 2004 to 2013 were included. Concordance index (c-index) was applied to compare the discriminatory ability.

RESULTS

In the 8th edition, migration of stage was detected in 248 patients (15.2%). Among them, 121 patients were up-staged while 127 patients were down-staged. Overall, there was no statistically significant difference in the discriminatory ability between the 7th and 8th editions. The new edition of staging system, however, showed a trend of better prognostic performance not only in recurrence-free survival (c-index=0.734; 95% confidence interval [CI], 0.706 to 0.762 in the 7th edition vs. c-index=0.740; 95% CI, 0.712 to 0.768 in the 8th edition; p=0.14), but also in overall survival (c-index=0.717; 95% CI, 0.688 to 0.745 in the 7th edition vs. c-index=0.722; 95% CI, 0.694 to 0.751 in the 8th edition; p=0.19), especially in stage III. This finding was repeated in the subgroup analysis regardless of adjuvant CA or CCRT.

CONCLUSION

Generally, the 8th edition of AJCC staging system had failed to show a superior discriminatory ability for curatively D2 resected GC patients than the 7th edition, although there was a trend of better prognostic performance of the new edition, regardless of adjuvant treatment method.

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.

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

BACKGROUND AND PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Current status and future prospects of clinical trials on CRS + HIPEC for gastric cancer peritoneal metastases

PURPOSE

There is no standard treatment for peritoneal metastases (PM) from gastric cancer (GC). The aim of this review is to evaluate the clinical trials on cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) for GC PM.

MATERIALS AND METHODS

The published clinical trials on CRS + HIPEC for GC PM are critically evaluated, and survival and safety are the primary endpoints. In addition, the registered ongoing clinical trials are summarised.

RESULTS

The natural course of GC PM is <5 months. CRS + HIPEC could improve the overall survival (OS). In prospective studies, the median OS was 11.0 months in the CRS + HIPEC group vs. 5.4 months in the CRS alone group. In case-control studies, the median OS was 13.3 months in the CRS + HIPEC group vs. 7.9 months in the CRS alone group. In cohort studies, the median OS after CRS + HIPEC was 13.3. The median 1-, 2- and 5-year survival rates after CRS + HIPEC were 50.0%, 35.8% and 13.0%, respectively. There is no statistically significant increase in serious adverse events that are directly attributed to CRS + HIPEC.

CONCLUSIONS

The combination of CRS and HIPEC is a promising integrated treatment strategy for GC PM that has encouraging initial results, calling for urgent further evaluation of this strategy in randomised control trials (RCTs).

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.

Outcomes of radiation therapy for resectable M0 gastric cancer

Background

The role of radiaotion therapy in resectable gastric cancer patients without distant metastases remains controversial. This retrospective analysis was performed to identify whether resectable gastric cancer patients without distant metastases might benefit from radiation.

Results

The results of the Kaplan-Meier analysis and log-rank test showed that a total of 3309 patients had a MST of 29.0 months, a 1-year survival rate of 74.7%, and a 3-year survival rate of 45.5%. Among them, the MST of the "RPS" group and the "RAS" group were significantly longer compared with that of the "No Radiation" group (32.7vs 32.9 vs 25.3 months, P < 0.05). The 1-year survival rates were 83.7%, 83.5% and 65.6% for the "RPS", "RAS" and "No radiation" groups, respectively (P < 0.05) and the 3-year survival rates were 52.6%, 63.6% and 44.9%, respectively (P < 0.05). The multivariate Cox proportional hazard regression analysis showed that radiation was an independent prognostic factor.

Materials and Methods

A total of 5744 patients from the SEER database who were initially diagnosed with histologically confirmed gastric cancer without distant metastases from 2010 to 2013 were included. Patients were divided into three groups as follows: patients who underwent radiation after surgery ("RAS" group), patients who underwent radiation prior to surgery ("RPS" group) and patients who did not undergo radiation ,only surgery performed ("No radiation'"group).

Conclusions

This retrospective analysis demonstrated that "RPS" or "RAS"alone were independent prognostic factors for survival improvement in selected gastric cancer patients without distant metastases.

Patterns of Care for Radiotherapy in the Neoadjuvant and Adjuvant Treatment of Gastric Cancer: A Twelve-Year Nationwide Cohort Study in Korea

Purpose

Although Korea has the highest incidence of gastric cancer worldwide and D2-lymphadenectomies are routinely performed, radiotherapy (RT) practice patterns have not been well studied. Therefore, we examined RT usage trends for neoadjuvant/adjuvant patients and identified factors associated with RT. We also examined survival benefits and net medical cost advantages of adding RT.

Materials and Methods

Patients diagnosed with gastric cancer who underwent gastrectomy from 2002-2013 were identified using National Health Insurance Service-National Sample Cohort.

Results

Annually, 30.9 cases per 100,000 population in crude rate underwent gastrectomy in 230 hospitals and 49.8% received neoadjuvant/adjuvant therapy in 182 hospitals. For neoadjuvant/adjuvant patients, postoperative chemo-RT was administered in 4% of cases in 26 hospitals. No significant trends regarding treatment type were observed over time. Having undergone RT was inversely associated with being ≥ 60 years old and having a low income. Having undergone RT was positively related to having a Charlson comorbidity index ≥ 4, hospital location and hospital volume (≥ 2,000 beds). Significant portions of patients treated with RT in this nation (52%) were concentrated in one large-volume hospital. Use of RT linked to increased cost of primary treatment, yet not to reduced overall medical expense. RT did not influence both on overall and disease-specific survivals after adjusting for potential confounders (p > 0.05).

Conclusion

RT was uncommonly utilized as adjuvant or neoadjuvant treatment by physicians in Korea. Despite intrinsic drawback in this data, we did not find either survival benefit or net medical cost advantage by adding RT in adjuvant treatment.

Locoregional relapse after gastrectomy with D2 lymphadenectomy for gastric cancer

BACKGROUND

Risk for and site of locoregional relapse have not been well studied in patients undergoing gastrectomy with D2 lymphadenectomy for gastric cancer.

METHODS

Patients who had undergone gastrectomy with D2 lymphadenectomy for gastric cancer between 2004 and 2007 were identified from an institutional database. The locoregional relapse rate was estimated by competing risk analysis, and risk groups were derived according to locoregional relapse risk using recursive partitioning analysis (RPA). The locations of nodal relapses were evaluated according to Japanese Classification of Gastric Carcinoma criteria.

RESULTS

Some 2618 patients were included. With a median follow-up of 78·0 (range 28·5-122·6) months, relapse was diagnosed in 471 of 2618 patients (18·0 per cent). The cumulative incidence of locoregional relapse at 5 years was 8·5 (95 per cent c.i. 7·4 to 9·6) per cent. The 5-year locoregional recurrence rates for high-risk (N3), intermediate-risk (N1-2) and low-risk (N0) groups were 32·4, 12·3 and 1·7 per cent respectively (P < 0·001). Among patients with regional relapse, 90·4 per cent had involvement outside the D2 dissected area, and the most commonly involved site was station 16b1. This pattern was maintained in the RPA risk groups (P = 0·329).

CONCLUSION

Locoregional relapse at 5 years after gastrectomy with D2 lymphadenectomy was 8·5 per cent, and was most often seen outside the D2 dissected area.

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.