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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

MAGIC versus MacDonald treatment regimens for gastric cancer: Trends and predictors of multimodal therapy for gastric cancer using the National Cancer Database

BACKGROUND

Multimodal therapy is beneficial in gastric cancer, however this practice is not universal. This study examines trends, identifies associative factors, and examines overall survival (OS) benefit from multimodal therapy in gastric cancer.

METHODS

Gastric cancer patients staged IB-III from 2005 to 2014, identified using the National Cancer Database, were categorized by treatment: surgery alone, perioperative chemotherapy, and adjuvant chemoradiation. Groups were analyzed to identify associative factors of perioperative therapy.

RESULTS

We examined 9243 patients, with the majority receiving multimodal therapy (57%). The proportion of those receiving perioperative chemotherapy rose dramatically from 7.5% in 2006 to 46% in 2013. Academic center treatment was strongly associated with perioperative over adjuvant therapy (p < 0.0001). An OS advantage was clearly seen in those receiving multimodal therapy versus surgery alone (p < 0.0001), with no difference between perioperative and adjuvant therapies.

CONCLUSIONS

Treatment of gastric cancer with multimodal therapy has risen significantly since 2005, largely due to increasing use of perioperative chemotherapy. As perioperative therapy becomes more prevalent, more patients will have the opportunity for the improved survival benefit of multimodal therapy.

Novel immune-risk score of gastric cancer: A molecular prediction model combining the value of immune-risk status and chemosensitivity

Gastric cancer is still one of the most common and deadly malignancies in the world. Not all patients could benefit from chemotherapy or chemoradiotherapy due to tumor heterogeneity. Therefore, identifying different subgroups of patients is an important trend for obtaining more effective responses. However, few molecular classifications associated with chemosensitivity are based on immune–risk status. In this study, we obtained six key immune–related genes. Using these genes, we constructed a molecular model related to immune–risk status and calculated an individual immune–risk score. The score showed great efficiency and stability in predicting prognosis and identifying different subgroups where persons could benefit from postoperative adjuvant therapy. The patients could be divided into different risk groups based on the immune–related score. For patients in the low–risk group, both postoperative chemoradiotherapy and chemotherapy could significantly improve prognosis on overall survival (OS) and disease–free survival (DFS) (DFS, P < 0.001 and P = 0.041, respectively; OS, P < 0.001, P = 0.006, respectively) and chemoradiotherapy was significantly superior than simple chemotherapy (DFS, P = 0.031; OS, P = 0.027). For patients with an intermediate–risk score, postoperative chemoradiotherapy showed a statistically significant survival advantage over no anticancer treatment (P = 0.004 and P = 0.002, respectively), while chemotherapy did not. Compared with no adjuvant treatment, neither postoperative chemoradiotherapy nor chemotherapy made significant difference for patients in the high–risk group. Combining the value of immune–risk status and chemosensitivity, the immune–risk score could not only offer us prognostic evaluation and adjuvant treatment guidance, but also improve our understanding about the binding point between chemotherapy or chemoradiotherapy and the immune system, which may be helpful for further expanding the application of immunotherapy.