Effect of Early Adjuvant Chemotherapy on Survival of Advanced Gastric Cancer Patients: a Propensity Score-matched Analysis

Time interval between surgery and adjuvant chemotherapy in patients with gastric cancer after gastrectomy: a population-based cohort study using a nationwide claim database

Background

Adjuvant chemotherapy can reduce recurrence rates by eradicating microscopic metastases which may persist after curative resection. However, the optimal time interval (TI) between the surgery and chemotherapy remains controversial.

Objectives

This study investigated the optimal TI between surgery and chemotherapy.

Design

A population-based cohort study using a nationwide claims database.

Methods

The data were obtained from the Korean National Health Insurance Service (NHIS) of Korea. We included patients who underwent gastrectomy between 2013 and 2018. To determine the optimal cutoff point of TI, a restricted cubic spline Cox regression model was established, and categorized the population into three groups based on TI: the early (⩽20 days), the late (⩾35 days), and the reference group (21-34 days), and with the reference group having the lowest mortality and recurrence. Propensity score matching was performed for each group. The primary outcomes were disease-free survival (DFS) and overall survival (OS).

Results

After excluding ineligible participants, 6602 patients were included. The median DFS and OS did not differ significantly between the early and reference groups (p = 0.7258 and p = 0.6056, respectively). In comparison between the late and reference groups, it was significantly lower in the late group (p = 0.0079). Five-year DFS rates were 77.6% and 81.3% in the late and reference groups, respectively. The late group showed worse OS than the reference group (p = 0.0336). Five-year OS rates were 82.1% and 85.0% in the late and reference groups, respectively. In the multivariable analysis, DFS in the late group retained inferiority [adjusted hazard ratio (aHR): 1.138, 95% confidence interval (CI): 1.003-1.292, p = 0.045]. OS showed a worse trend without significance compared to the reference group (aHR: 1.138, 95% CI: 0.984-1.317, p = 0.0805).

Conclusion

Adjuvant chemotherapy after gastrectomy in patients with gastric cancer should be initiated within 5 weeks of surgery. A delay of more than 5 weeks may have a detrimental effect on the subsequent disease course.

Impact of Laparoscopic Gastrectomy on the Completion Rate of the Perioperative Chemotherapy Regimen in Gastric Cancer: A Swedish Nationwide Study

BACKGROUND

Omission of prescheduled chemotherapy following surgery for gastric cancer is a frequent clinical problem. This study examined whether laparoscopic gastrectomy (LG) had a positive impact on compliance with adjuvant chemotherapy compared with open (OG).

METHODS

Patients with cT2-4aN0-3M0 adenocarcinoma treated with gastrectomy and perioperative chemotherapy between 2015 and 2020 were identified in the Swedish national register. Additional information regarding chemotherapy was retrieved from medical records. Regression models were used to investigate the association between surgical approach and the following outcomes: initiation of adjuvant chemotherapy, modification, and time interval from surgery to start of treatment.

RESULTS

A total of 247 patients were included (121 OG and 126 LG, conversion rate 11%), of which 71.3% had performance status ECOG 0 and 77.7% clinical stage II/III. In total, 86.2% of patients started adjuvant chemotherapy, with no significant difference between the groups (LG 88.1% vs OG 84.3%, p = 0.5). Reduction of chemotherapy occurred in 37.4% of patients and was similar between groups (LG 39.4% vs OG 35.1%, p = 0.6), as was the time interval from surgery. In multivariable analysis, LG was not associated with the probability of starting adjuvant chemotherapy (OR 1.36, p = 0.4) or the need for reduction (OR 1.29, p = 0.4). Conversely, major complications had a significant, negative impact on both outcomes.

CONCLUSIONS

This nationwide study demonstrated a high rate of adjuvant chemotherapy initiation after curative intended surgery for gastric cancer. A beneficial effect of LG compared with OG on the completion rate was not evident.

Meta-analysis of Genetic polymorphism of Enhancer of Zeste Homolog2 gene in cancer susceptibility

The alteration in the expression of enhancer of zeste homolog-2 (EZH2) gene is very well known in the progression, severity, and aggressiveness of cancer. Hence, it is important to study the genomic variation of the EZH2 gene. Previously, many association-based studies investigated the association between rs2302427C>G and cancer susceptibility. However, the result had been inconsistent. Therefore, our meta-analysis aimed to identify the association between EZH2 rs2302427 and cancer risk. A systematic literature search was done for databases PubMed, Google Scholar, Science Direct, and Cochrane library up to September 2020 and statistical analysis was performed by RevMan v 5.3. A total of six studies comprised 1876 cases and 2555 controls were included in the current meta-analysis. The pooled analysis showed that overall, there is significant association of rs2302427 C>G change with reduced cancer risk (odds ratio = 0.60, 95% confidence interval [0.35-1.03], P = 0.07) but non-significantly. Further, the subgroup analysis also revealed that there is no significant difference between the Asian and European population, and both exhibit the protective nature of rs2302427 with cancer. The present meta-analysis indicated that EZH2 rs2302427 has an association with cancer in reducing the risk but for the Indian population studies are required as the Indian population comprises various sub-population genetically isolated for long.

Early Return to Intended Oncologic Therapy after implementation of an Enhanced Recovery After Surgery pathway for gastric cancer surgery

PURPOSE

Time to initiation and completion of adjuvant therapy are critical to improve postoperative oncologic outcomes. This study aims to determine whether an Enhanced Recovery After Surgery (ERAS) pathway for gastric cancer surgery promotes early Return to Intended Oncologic Therapy (RIOT).

METHODS

This is a before-after intervention study including patients with gastric adenocarcinoma who underwent surgery from January 2016 to January 2021. Two periods were denoted based upon the implementation date of our institutional ERAS pathway (June 2018). Our primary outcome was time to RIOT after surgery. Hodges-Lehmann analysis was used to estimate median differences of non-parametric outcomes.

RESULTS

Seventy patients with gastric adenocarcinoma were included (35 in pre-ERAS period and 35 in post-ERAS period). Fourteen of the pre-ERAS and twenty-two patients of the post-ERAS period received adjuvant therapy. Time to RIOT was reduced in the post-ERAS period (median 39 days, IQR 31-49) by 12 days (95% CI 3-14 days, p = 0.01) compared to the pre-ERAS period (median 51 days, IQR 42-62). Length of hospital stay (LOS) was lower in the ERAS group (6 days, IQR 5-11 vs 10 days, IQR 8-13, p < 0.01).

CONCLUSION

Our institutional ERAS pathway for gastric cancer surgery was associated with earlier RIOT and shorter LOS.

Optimal time interval from surgery to adjuvant chemotherapy in gastric cancer

The effect of adjuvant chemotherapy (AC) for resected gastric cancer is well established; however, delays in treatment and its impact on clinical outcomes have not yet been determined. The current study analyzed the survival rates based on time interval (TI) between surgery and AC administration to evaluate a potential association between the two variables. Patients diagnosed with stage II–III gastric adenocarcinoma between 2009 and 2016 at the Kyung Hee University Hospital were included. Patients' data including demographics, TNM stage, types of AC, and TI retrospectively collected from surgery to the start of AC. Patients were dichotomized based on the TI, which was predetermined at 3, 4, 5, 6, 7 or 8 weeks. Median disease-free survival (DFS) and overall survival (OS) were analyzed according to TI. In total, 172 patients were identified. The median follow-up duration was 40.8 (3–109) months. The median TI was 4.1 (2.1-9.8) weeks. DFS in patients with TI ≥4 weeks (n=106, 61.6%) was significantly lower compared with patients with TI <4 weeks (n=66, 38.4%), with a median DFS of TI < vs. ≥4 weeks of 8.1 vs. 6.0 years [hazard ratio (HR)=1.80, 95% confidence interval (CI): 1.067-3.045, P=0.0277]. OS was also significantly reduced in patients with TI ≥4 weeks, favoring TI <4 weeks [median OS of TI < vs. ≥4 weeks: Not reached (NR) vs. 7.0 years, HR=2.15, 95% CI: 1.173-3.939, P=0.0133]. Other predetermined TIs were not associated with survival outcomes. The current study demonstrated that AC within 4 weeks of surgery should be recommended for gastric cancer, and delays of >4 weeks may be detrimental to patients' survival.

Impact of postoperative complications on long-term outcomes of patients following surgery for gastric cancer: A systematic review and meta-analysis of 64 follow-up studies

Gastrectomy for cancer is a technically demanding procedure, with postoperative complications (POCs) reported to be in the range of 20%-46%. However, the effect of POCs on long-term survival of gastric cancer patients following surgery is far from conclusive. This systemic review aimed to determine the impact of postoperative complications (POCs) on the long-term survival of patients following surgery for gastric cancer. A systematic electronic search of PubMed and Scopus was performed from inception to June 26, 2018 to identify studies that described the relationship between POCs and long-term survival. Hazard ratios (HRs) for overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival (RFS) from each study were combined using a random-effects model. Sixty-four eligible studies with reported results for 46198 gastric cancer patients were included. A meta-analysis found a statistically significant difference in OS, CSS and RFS between gastric patients with unspecific POCs and no POCs, POCs ≥ Clavien-Dindo grade (CD) 2 and < CD2, major POCs and minor POCs, infectious and non-infectious complications, anastomotic and non-anastomotic complications, and cardiopulmonary and non-cardiopulmonary complications. Subgroup and sensitivity analyses did not significantly change the summary of OS risk estimates between patients with POCs and without POCs. No significant publication bias was observed for the same outcome. The meta-analysis revealed that POCs were associated with worse survival among patients with resected gastric cancer, suggesting that treatment strategies aimed at minimizing POCs may improve oncological outcomes.

Delaying adjuvant chemotherapy in advanced gastric cancer patients: Risk factors and its impact on survival outcome

Adjuvant chemotherapy following the curative resection could improve the survival outcome of advanced gastric cancer (GC) patients. However, it is unclear whether delayed initiation of adjuvant chemotherapy had a negative impact on survival outcome in GC patients. The purpose of this study was to review current published literature about the impact of delaying adjuvant chemotherapy on survival outcome and summarize risk factors for delaying adjuvant chemotherapy. Delayed initiation of adjuvant chemotherapy was quite frequent in GC patients who underwent gastrectomy due to postoperative complications, poor nutritional status, comorbid diseases and socioeconomic status. Therefore, it is important for these patients to have a sufficient and smooth transition from surgery to initiation of adjuvant chemotherapy. Based on current available evidence, there is no specific timing interval for the initiation of adjuvant chemotherapy in GC patients. Earlier initiation of adjuvant chemotherapy (<4 weeks) may not be mandatory for GC patients who underwent curative resection. However, the patients should be recommended to receive adjuvant chemotherapy within 6-8 weeks if their performance status and nutritional status were deemed to be appropriate. Minimizing postoperative complications and providing requisite nutritional advice may be helpful for timely initiation of adjuvant chemotherapy.

Does delayed initiation of adjuvant chemotherapy following the curative resection affect the survival outcome of gastric cancer patients: A systematic review and meta-analysis

BACKGROUND

Adjuvant chemotherapy(AC) following the curative resection could improve the survival outcome of advanced gastric cancer(GC) patients. However, there is no specific timing interval from radical surgery to initiation of AC. Whether delayed initiation of AC could affect the survival outcome of these patients remains unclear. In this study, we performed a systematic review and meta-analysis to evaluate the relationship between delaying AC and the survival outcome of GC patients.

METHODS

PubMed, Embase and Cochrane Library databases were systematically searched for eligible studies that evaluated the relationship between time to AC and survival outcome. Survival data for HR and 95% CI were extracted and converted to a regression coefficient(β) corresponding to a continuous representation per 4-week delay of AC. Individual adjusted β were combined using a fixed-effects or random-effects model. Heterogeneity was assessed by I² statistic and publication bias was detected using standard error-based funnel plots.

RESULTS

A total of 11 eligible studies involving 6,017 patients were included in this meta-analysis. Eight studies evaluated the impact of delaying AC on overall survival(OS) and five evaluated the impact of delaying AC on disease-free survival(DFS). The pooled results demonstrated that the initiation of AC per 4-week delay was associated with a significant decrease in OS(HR:1.05, 95% CI: 1.03-1.08, P < 0.001; I² = 18.5%) and DFS (HR:1.06, 95% CI: 1.02-1.10, P = 0.001; I² = 40.6%).

CONCLUSION

The initiation of AC per 4-week delay was associated with worse survival outcomes in GC patients. If physical status and postoperative recovery were appropriated, GC patients should be recommended to receive adjuvant chemotherapy timely.

Delay in initiation of postoperative adjuvant chemotherapy with S-1 monotherapy and prognosis for gastric cancer patients: analysis of a multi-institutional dataset

BACKGROUND

This study aimed to evaluate whether the timing of initiating postoperative chemotherapy with S-1 monotherapy affects gastric cancer patients' prognosis.

METHODS

A multi-institution dataset identified patients with pStage II or III gastric cancer who received S-1 monotherapy for over 6 months after curative resection between 2010 and 2014. Patients were divided into three groups based on the timing of S-1 monotherapy initiation. Prognostic factors for relapse-free survival (RFS) were investigated.

RESULTS

We classified 401 patients into groups as follows: S-1 administered within 6 weeks (n = 247), between 6 and 8 weeks (n = 95), and after 8 weeks (n = 59). The RFS times were not significantly different in the within 6 weeks group and the between 6 and 8 weeks group, but the after 8 weeks group had a shorter RFS time compared with the other two groups (within 6 weeks group vs. after 8 weeks group; P = 0.0044). By disease stage, this trend was the same. The multivariable analysis showed that a larger tumor size (≥ 50 mm), pStage III, and the after 8 weeks group were independent prognostic factors for RFS (after 8 weeks group: hazard ratio, 2.05; P = 0.0069). The prevalence of hematogenous metastasis as the initial recurrence site increased by delayed initiation of S-1. A forest plot revealed that delayed administration after 8 weeks was associated with a greater risk of recurrence in most subgroups.

CONCLUSIONS

Postoperative chemotherapy with S-1 monotherapy for gastric cancer is recommended to begin within 8 weeks after surgery.

Role of circular RNAs in gastric cancer: Recent advances and prospects

Circular RNA (circRNA) is a newly discovered non-coding RNA with special structure, which is widely expressed in eukaryotic organisms and mainly located in the cytoplasm. circRNAs participate in gene regulation by working as miRNA sponges that block the inhibitory effect of miRNA on its target genes. In addition, circRNAs can bind to RNA binding proteins to regulate gene expression. Based on characteristics of stability, expression specificity and participation in gene regulation, circRNAs are expected to be biomarkers for early diagnosis of cancer or potential targets for cancer therapy. With the help of bioinformatics analysis, circRNA microarray analysis and high-throughput sequencing technology, more circRNAs were discovered to participate in the progression of gastric cancer (GC) over the past three years. This article gives an overview of these recent research focusing on the roles of circRNAs in GC and highlights the advances.