The optimal strategy of multimodality therapies for resectable gastric cancer: evidence from a network meta-analysis

Role of Preoperative Radiation Therapy for Resectable Gastric Cancer

PURPOSE

While surgery is the primary curative treatment for resectable gastric and gastroesophageal junction (GEJ) cancer, rates of locoregional and distant recurrence remain high with surgery alone, especially in more advanced disease. Multimodal approaches with perioperative therapy including chemotherapy and/or radiation therapy (RT) have thus evolved as ways to reduce the rates of disease recurrence and improve survival outcomes. This review article provides a comprehensive literature review on the role of preoperative RT for resectable gastric and GEJ cancer.

METHODS

A literature review on the role of preoperative RT for resectable gastric and GEJ cancer was conducted.

RESULTS

Preoperative RT has the potential to facilitate tumor downstaging and improved R0 resection, allowing for better locoregional control and thereby survival. For resectable locally advanced GEJ cancer, preoperative chemoradiotherapy (CRT) is currently a standard of care option along with perioperative chemotherapy, based on evidence from randomized trials. In resectable gastric cancer, however, the role of preoperative CRT is less defined with no randomized data to date, although phase II single-arm studies have shown promising results. Current standard of care for gastric cancer remains perioperative chemotherapy, with consideration for preoperative CRT in select cases.

CONCLUSION

Results from ongoing and future randomized controlled trials are expected to help define the role of preoperative CRT compared to perioperative chemotherapy alone as well as postoperative CRT for gastric and GEJ cancer.

Early Outcomes of Different Reconstruction Procedures in Radical Distal Gastrectomy: A Retrospective Propensity Score Matching Study

OBJECTIVE

To evaluate the short-term effects of Billroth I (B-I), Billroth Ⅱ (B-Ⅱ), Billroth Ⅱ+Braun (B-B), and Roux-en-Y (R-Y) reconstruction procedures in radical distal gastrectomy using propensity score matching (PSM).

MATERIALS AND METHODS

The clinical data of 1994 patients who underwent radical distal gastrectomy in the past 10 years were retrospectively analyzed. Subsequently, PSM analyses were performed 3 times on the 4 reconstruction procedures, and the matching capacity was set to 0.01. Data regarding control variables and outcome indicators obtained using PSM were compared and analyzed.

RESULTS

Compared with the other reconstruction procedures, patients in the B-I group had shorter operation time ( P =0.002), fewer abdominal drainage tubes ( P <0.001), and a lower risk of postoperative gastroparesis ( P =0.001) and gastrointestinal bleeding ( P =0.034), but tended to experience a longer postoperative indwelling time of bladder catheter ( P <0.001), gastrointestinal decompression ( P <0.001), fasting ( P =0.001), and hospital stays ( P =0.005). The B-B group tended to have fewer applications of the abdominal drainage tube ( P =0.014), a lower risk of postoperative gastrointestinal fistula ( P =0.040), shorter postoperative time of gastrointestinal decompression ( P =0.043), fasting ( P <0.001), and a shorter hospital stay ( P <0.001) than the R-Y group. Furthermore, the B-B group had a shorter postoperative time for gastrointestinal decompression ( P =0.014) and fasting ( P <0.001) than the B-Ⅱ group.

CONCLUSION

Billroth I reconstruction has the advantages of simple operation, short operative time, and few early complications, but tends to result in a long recovery time during postoperative hospitalization. The B-B operation is associated with faster postoperative recovery than the R-Y or B-Ⅱ operation.

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.

Progress in Metabolic Studies of Gastric Cancer and Therapeutic Implications

Background:

Worldwide, gastric cancer is ranked the fifth malignancy in incidence and the third malignancy in mortality. Gastric cancer causes an altered metabolism that can be therapeutically exploited.

Objective:

To provide an overview of the significant metabolic alterations caused by gastric cancer and propose a blockade.

Methods:

A comprehensive and up-to-date review of descriptive and experimental publications on the metabolic alterations caused by gastric cancer and their blockade. This is not a systematic review.

Results:

Gastric cancer causes high rates of glycolysis and glutaminolysis. There are increased rates of de novo fatty acid synthesis and cholesterol synthesis. Moreover, gastric cancer causes high rates of lipid turnover via fatty acid -oxidation. Preclinical data indicate that the individual blockade of these pathways via enzyme targeting leads to antitumor effects in vitro and in vivo. Nevertheless, there is no data on the simultaneous blockade of these five pathways, which is critical, as tumors show metabolic flexibility in response to the availability of nutrients. This means tumors may activate alternate routes when one or more are inhibited. We hypothesize there is a need to simultaneously blockade them to avoid or decrease the metabolic flexibility that may lead to treatment resistance.

Conclusions:

There is a need to explore the preclinical efficacy and feasibility of combined metabolic therapy targeting the pathways of glucose, glutamine, fatty acid synthesis, cholesterol synthesis, and fatty acid oxidation. This may have therapeutical implications because we have clinically available drugs that target these pathways in gastric cancer.

Tumor mutation burden is correlated with response and prognosis in microsatellite-stable (MSS) gastric cancer patients undergoing neoadjuvant chemotherapy

BACKGROUND

Neoadjuvant chemotherapy (NACT) before radical gastrectomy is preferred for locally advanced gastric cancer (GC). However, clinical practices demonstrate that a considerable proportion of GC patients do not benefit from NACT, largely due to the lack of biomarkers for patient selection and prognosis prediction. A recent study revealed that patients with microsatellite instability-high (MSI-H) may be resistant to NACT, however, most tumors in Chinese GC patients (~ 95%) are characterized by microsatellite stability (MSS). Here, we aimed to discover new molecular biomarkers for this larger population.

METHODS

We performed whole-exome sequencing on 46 clinical samples (pre- and post-treatment) from 30 stage II/III MSS GC patients whose response to NACT was rigorously defined. Serum tumor markers (TMs), including AFP, CEA, CA199, CA724 and CA242 were measured during the course.

RESULTS

High tumor mutation burden (TMB-H) and 19q12 amplification (19q12 +) were positively associated with the NACT response. When TMB and 19q12 amplification were jointly analyzed, those with TMB-H or 19q12 + showed favorable response to NACT (p = 0.035). Further, TMB-H was negatively correlated with ypN stage, lymph node metastasis, and macrophage infiltration. Patients with TMB-H showed better disease-free survival (DFS) than those with TMB-L (P = 0.025, HR = 0.1331), and this was further validated using two larger GC datasets: TCGA-STAD (p = 0.004) and ICGC-CN (p = 0.045).

CONCLUSION

The combination of TMB-H and 19q12 + can serve as an early indicator of response to NACT. Superior to traditional clinical indicators, TMB-H is a robust and easily accessible candidate biomarker associated with better DFS, and can be evaluated at the time of diagnosis.

Neoadjuvant versus Postoperative Chemoradiotherapy is Associated with Improved Survival for Patients with Resectable Gastric and Gastroesophageal Cancer

BACKGROUND

The optimal timing of chemoradiotherapy (CRT) for patients with localized gastric cancer remains unclear. This study aimed to compare the survival outcomes between neoadjuvant and postoperative CRT for patients with gastric and gastroesophageal junction (GEJ) cancer.

METHODS

This retrospective study analyzed 152 patients with gastric (42%) or GEJ (58%) adenocarcinoma who underwent definitive surgical resection and received either neoadjuvant or postoperative CRT between 2005 and 2017 at the authors' institution. The primary end point of the study was overall survival (OS).

RESULTS

The median follow-up period was 37.5 months. Neoadjuvant CRT was performed for 102 patients (67%) and postoperative CRT for 50 patients (33%). The patients who received neoadjuvant CRT were more likely to be male and to have a GEJ tumor, positive lymph nodes, and a higher clinical stage. The median radiotherapy (RT) dose was 50.4 Gy for neoadjuvant RT and 45.0 Gy for postoperative RT (p < 0.001). The neoadjuvant CRT group had a pathologic complete response (pCR) rate of 26% and a greater rate of R0 resection than the postoperative CRT group (95% vs. 76%; p = 0.002). Neoadjuvant versus postoperative CRT was associated with a lower rate of any grade 3+ toxicity (10% vs. 54%; p < 0.001). The multivariable analysis of OS showed lower hazards of death to be independently associated neoadjuvant versus postoperative CRT (hazard ratio [HR] 0.57; 95% confidence interval [CI] 0.36-0.91; p = 0.020) and R0 resection (HR 0.50; 95% CI 0.27-0.90; p = 0.021).

CONCLUSIONS

Neoadjuvant CRT was associated with a longer OS, a higher rate of R0 resection, and a lower treatment-related toxicity than postoperative CRT. The findings suggest that neoadjuvant CRT is superior to postoperative CRT in the treatment of gastric and GEJ cancer.

Interpretation of the development of neoadjuvant therapy for gastric cancer based on the vicissitudes of the NCCN guidelines

Gastric cancer is one of the most common digestive system tumors in China, and locally advanced gastric cancer (LAGC) accounts for a high proportion of newly diagnosed cases. Although surgery is the main treatment for gastric cancer, surgical excision alone cannot achieve satisfactory outcomes in LAGC patients. Neoadjuvant therapy (NAT) has gradually become the standard treatment for patients with LAGC, and this treatment can not only achieve tumor downstaging and improve surgical rate and the R0 resection rate, but it also significantly improves the long-term prognosis of patients. Peri/preoperative neoadjuvant chemotherapy and preoperative chemoradiotherapy are both recommended according to a large number of studies, and the regimens have also been evolved in the past decades. Since the NCCN guidelines for gastric cancer are one of the most authoritative evidence-based guidelines worldwide, here, we demonstrate the development course and major breakthroughs of NAT for gastric cancer based on the vicissitudes of the NCCN guidelines from 2007 to 2019, and also discuss the future of NAT.