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

Pathological N3 Stage (pN3/ypN3) Gastric Cancer: Outcomes, Prognostic Factors and Pattern of Recurrences After Curative Treatment

BACKGROUND

pN3 or ypN3 stage gastric cancers (GCs) are known to have aggressive clinical behaviour. This study aimed to investigate factors affecting survival and pattern of recurrences of N3 stage GCs, treated with curative intent.

METHODS

A total of 196 GC patients, operated on at the Tata Memorial Centre from 2003 to 2017 and reported as pN3 or ypN3 status on histopathology after D2 gastrectomy were included in this retrospective analysis.

RESULTS

On multivariate analysis, use of NACT (neoadjuvant chemotherapy) and LN ratio (≤ 0.5/> 0.5) emerged as significant predictors for long-term survival. Patients who received NACT but were still harbouring N3 nodes (ypN3; n = 102) had a worse prognosis than those operated on upfront (pN3; n = 94), with a median survival of 19 months versus 24 months respectively (p = 0.003). The 5-year overall survival of the entire cohort was 16.3% (95% CI 12.8-19.8%), while 5-year disease-free survival (DFS) was 14.6% (95% CI 12.6-20%). Adjuvant chemoradiotherapy, though offered in a small number of patients (n = 38) resulted in improvement in DFS. Median DFS of adjuvant CT versus adjuvant CRT was 13 months versus 23 months (p = 0.020). The commonest site of relapse was the peritoneum (49.18%) and incidence of isolated loco-regional failure was 10.7%.

CONCLUSION

In GCs with N3 stage determined after radical D2 gastrectomy, LN ratio of > 0.5 and ypN3 status are predictors of poor prognosis. Considering the high incidence of peritoneal and loco-regional relapse in these patients, the role of more radical surgery, adjuvant chemoradiotherapy after upfront resection and intraperitoneal chemotherapy should be evaluated in prospective randomized clinical trials.

The assessment of the optimal number of examined lymph nodes and prognostic models based on lymph nodes for predicting survival outcome in patients with stage N3b gastric cancer

BACKGROUND

The optimal number of examined lymph nodes (ELNs) and the prognostic value of different nodal staging systems remain unclear in the context of N3b gastric cancer.

AIM

To evaluate the optimal number of ELNs and compare the predictive ability of the ELN number, LN ratio (LNR), and log odds of metastatic LNs (LODDS) for overall survival (OS) in patients with resected stage N3b gastric adenocarcinoma in an international database.

METHODS

A total of 868 patients diagnosed between 2004 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database (training cohort) and 144 patients diagnosed between 2011 and 2016 at the Liaoning Cancer Hospital (validation cohort) were identified. Cutoff values were established with X-tile. The 5-year OS rates were compared using Kaplan-Meier curves. Multivariate analysis was conducted with a Cox regression model. The Harrell's concordance index and Akaike's information criterion were used to compare the predictive accuracy of different nodal staging systems.

RESULTS

The ELN number, LNR, and LODDS were independent prognostic factors for both the training and validation cohorts in the multivariate analysis. Patient with ≤26 ELNs, LNR of more than 0.9, and LODDS of more than 1.0 were associated with decrease OS. The LNR and LODDS had similar discriminatory ability for OS and performed better than the ELN number in the Eastern and Western populations.

CONCLUSION

The optimal number of ELN may be 27 or more because LNs retrieved ≤26 was an independent risk factor for the prognosis. The prognostic prediction efficacy of LNR and LODDS was similar and better than that of ELN. Thus, LNR and LODDS could both serve as valid tools to predict OS for stage N3b patients.

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.

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.

A prognostic model based on lymph node metastatic ratio for predicting survival outcome in gastric cancer patients with N3b subclassification

BACKGROUND

Determining the survival outcome for gastric cancer patients with metastases to more than 15 regional lymph nodes is difficult. This study aims to develop a lymph node metastatic ratio (LNR)-based prognostic model to predict the survival outcome after D2 surgery in such patient groups.

METHODS

Our study retrospectively enrolled 139 gastric cancer patients with metastases to more than 15 regional lymph nodes who underwent D2 surgery between 2007 and 2014. Clinicopathologic variables to predict overall survival (OS) using multivariate Cox regression were selected to create a prognostic model.

RESULTS

The prognostic model for predicting OS was developed based on five independent factors, namely, T-classification (T2 or T3 vs. T4), LNR (<0.80 vs. ≥0.80), carcinoembryonic antigen level (<5 vs. ≥5 ng/ml), Eastern Cooperative Oncology Group performance scale (scale 0-1 vs. ≥2), and adjuvant chemotherapy (yes vs. no). Using the prognostic score, patients were stratified into good, intermediate, and poor prognostic groups. The median OS in the good, intermediate, and poor prognostic risk groups was 32.0 months (95% confidence interval [CI]: 22.3-41.7), 12.4 months (95% CI: 8.5-16.3), and 5.4 months (95% CI: 2.1-8.7), respectively. The c-index of the prognostic model was 0.79 (95% CI: 0.71-0.87).

CONCLUSION

This study developed an accurate LNR-based prognostic model for predicting the survival outcome after D2 surgery in gastric cancer patients with metastasis to more than 15 regional lymph nodes. This model might assist clinicians in prognostic stratification of such patients and convince eligible patients to receive adjuvant chemotherapy.

Influence of perineural invasion in predicting overall survival and disease-free survival in patients With locally advanced gastric cancer

BACKGROUND

The aim of the present study was to evaluate the prognostic significance of perineural invasion (PNI) in locally advanced gastric cancer patients who underwent D2 gastrectomy and adjuvant chemotherapy.

METHODS

The records of a series of 103 patients undergoing D2 gastrectomy with curative intent combined with adjuvant chemotherapy from January 2004 to December 2014 were retrospectively reviewed.

RESULTS

PNI was positive in 47 (45.6%) specimens. The 1-, 3-, and 5-year overall survival rates were 81%, 55%, and 42%, respectively. The 1-, 3-, and 5-year disease-free survival (DFS) rates were 76%, 57%, and 49%, respectively. A multivariate analysis showed that age number of positive lymph nodes, T stage, and PNI were independently associated with overall survival. Regarding DFS, the multivariate analysis showed that only PNI was independently associated with DFS.

CONCLUSIONS

PNI and T stage and positive lymph nodes are independent markers of poor prognosis in patients with gastric cancer. PNI should be incorporated in the postoperative staging system for planning follow-up after surgery and in our opinion to propose more aggressive postoperative therapies in PNI-positive patients.

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 trial of concurrent 3D-CRT/IMRT and oxaliplatin, 5-fluorouracil and leucovorin (FOLFOX) in gastric cancer patients with R0 gastrectomy and D2 lymph node dissection

BACKGROUND

To evaluate the safety and efficacy of a concurrent three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) plus oxaliplatin, 5-fluorouracil and leucovorin (FOLFOX) regimen in completely resected gastric cancer patients with D2 lymph node dissection.

MATERIALS AND METHODS

Patients with stage IB-IIIC gastric cancer (per the AJCC, 7th edition) who had undergone R0 and D2 gastrectomy were recruited. Two cycles of FOLFOX with concurrent 3D-CRT or IMRT (50.4 Gy/28f) were administered. One and an additional five cycles of FOLFOX were delivered before and after concurrent chemoradiotherapy, respectively. Primary endpoints were relapse-free survival (RFS) and overall survival (OS), with adverse events as secondary endpoints.

RESULTS

From 2008 to 2011, 110 patients were evaluable. The 1-, 2- and 3-year RFS and OS were 86.2, 72.2, 67.8 and 94.7, 87.2, 77.6%, respectively. On multivariate analysis, stage (≤ IIIA vs. >IIIA) was a statistically significant factor affecting both RFS and OS. Additionally, the T-category (≤ T4a vs. = T4b) was a statistically significant factor affecting only the RFS. The most commonly observed grade 3 or 4 adverse events were nausea and vomiting, decreased appetite, leukopenia/neutropenia and fatigue, each of which occurred in 14.5, 11.8, 9.1 and 6.4% patients, respectively.

CONCLUSIONS

Adjuvant 3D-CRT/IMRT to a dose of 50.4 Gy/28f with concurrent FOLFOX is safe and effective in patients following radical gastrectomy with D2 lymph node dissection.

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

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