S-1-based vs non-S-1-based chemotherapy in advanced gastric cancer: A meta-analysis

MicrobeRX: a tool for enzymatic-reaction-based metabolite prediction in the gut microbiome

BACKGROUND

The gut microbiome functions as a metabolic organ, producing numerous enzymes that influence host health; however, their substrates and metabolites remain largely unknown.

RESULTS

We present MicrobeRX, an enzyme-based metabolite prediction tool that employs 5487 human reactions and 4030 unique microbial reactions from 6286 genome-scale models, as well as 3650 drug metabolic reactions from the DrugBank database (v.5.1.12). MicrobeRX includes additional analysis modules for metabolite visualization and enzymatic and taxonomic analyses. When we applied MicrobeRX to 1083 orally administered drugs that have been approved in at least one jurisdiction at some point in time (DrugBank), it predicted metabolites with physicochemical properties and structures similar to metabolites found in biosamples (from MiMeDB). It also outperformed another existing metabolite prediction tool (BioTransformer 3.0) in terms of predictive potential, molecular diversity, reduction of redundant predictions, and enzyme annotation.

CONCLUSIONS

Our analysis revealed both unique and overlapping metabolic capabilities in human and microbial metabolism and chemo- and taxa-specific microbial biotransformations. MicrobeRX bridges the genomic and chemical spaces of the gut microbiome, making it a valuable tool for unlocking the chemical potential of the gut microbiome in human health, the food and pharmaceutical industries, and environmental safety. Video Abstract.

The efficacy and safety of apatinib combined with S-1 for advanced gastric cancer: A systematic review and meta-analysis

BACKGROUND

Advanced gastric cancer (AGC) that does not respond to first-line therapy poses a challenge to clinical management. The objective of this study was to compare the efficacy and safety of apatinib combined with S-1 in second-line and above treatment of AGC.

METHODS

Cochrane Library, Science Direct, EMBASE, PubMed, and CNKI were searched for randomized controlled trial until August 2023. Only patients who met "Standardized Diagnosis and Treatment Guide for Gastric Cancer" were included in the study. The accurate data and distinguishing between follow-up time and drug dose were extracted to reduce heterogeneity and the risk of bias of the included trials was evaluated according to the Cochrane Handbook. Finally, the survival benefit of the treatment was evaluated based on clinical response rate, survival period, biochemical index, and adverse event occurrence in the trial.

RESULTS

The meta-analysis included 29 randomized controlled trials involving 2149 participants. Statistically significant increases in clinical effective rate (odds ratios = 2.61, 95% confidence interval [2.13-3.20], P < .00001) and disease control rate (odds ratios = 3.16, 95% confidence interval [2.54-3.94], P < .00001) were found when apatinib combined with S-1, and also had obvious advantages in reducing tumor markers and regulating immune factors. In addition, apatinib combined with S-1 significantly increased the risk of hypertension but reduced damage to liver function, while the improvement of other adverse events was not pronounced.

DISCUSSION

Apatinib combined with S-1 is more effective and safe for second-line and above treatment of AGC. This study minimized the conclusion bias caused by the basic data sources, but more high-quality studies are still needed to validate these conclusions.

Practical Consensus Guidelines for the Use of S-1 in GI Malignancies

Purvish M ParikhS-1 (5-fluorouracil prodrug [tegafur] in combination with 5-chloro-2,4-dihydroxypyridine [CDHP] and potassium oxonate [OXO]) was first approved in 1999. In order to make it easy for community oncologists, we decided to put together this expert consensus guideline for its use in gastrointestinal (GI) malignancies. A total of 15 subject matter experts used modified Delphi method to discuss, analyze, and vote on key aspects regarding practical approach to use of S-1 in GI cancers, a process involving 6 months of work. The consensus guidelines specify how S-1 use can be optimized in patients with colorectal, gastric, and pancreatic tumors. The voting for the 17 key points resulted in a majority consensus for all the statements (approval ranging from 13/15 [87%] to 15/15 [100%]). S-1 is a combination of three drugs (tegafur, CDHP, and OXO) specifically designed to reduce toxicity and enhance efficacy; clinical data and meta-analysis confirm both factors; and it is recommended as standard of care for GI cancers. S-1 is approved and one of the standards of care for all lines of therapy in colorectal cancer and pancreatic cancers. S-1 with oxaliplatin is the standard of care for gastric cancers.

S-1 maintenance therapy in advanced gastric cancer without disease progression after first-line chemotherapy: A retrospective analysis

For patients with advanced gastric cancer after chemotherapy, the optimal mode of maintenance therapy is not yet clear. This research aimed to compare the efficacy and adverse effects of S-1 maintenance therapy and follow-up observation in patients with advanced gastric cancer without disease progression after first-line combined chemotherapy. This study retrospectively analyzed 106 patients from January 2018 to December 2021. The primary endpoints were overall survival and progression-free survival, the secondary endpoint was chemotherapy-related toxicity, and the curative effects and baseline characteristics of the patients were analyzed. Longer progression-free survival and overall survival were observed in the S-1 maintenance treatment group than in the follow-up observation group (p < 0.001). No obvious differences existed in the subgroup results regarding progression-free survival or overall survival (p > 0.05). In the maintenance treatment group, the occurrence of thrombocytopenia and hand-foot syndrome was significantly increased (p < 0.001). No toxicity-related deaths occurred. The included patients without disease progression after first-line combined chemotherapy can achieve significant survival benefits by receiving S-1 maintenance therapy. The patient's tolerance to S-1 maintenance therapy was good.

S-1 and 5-Fluorouracil-related adverse events in patients with advanced gastric cancer: A meta-analysis

OBJECTIVE

To assess S-1 and 5-fluorouracil (5-FU)-related adverse events in patients with advanced gastric cancer and provide focused health care approaches to improve patient compliance and quality of survival.

METHODS

The PubMed, Web of Science, Medline, Cochrane Library, EMbase, SinoMed, Wan Fang Data, CNKI, and VIP databases were searched, and relevant literature was screened from the database construction date through March 31, 2023. Review Manager 5.4.1 and Stata 12.0 were used to analyze the data and GRADEpro was used to assess the quality of the literature. Relative risk ratio (RR) and a 95% confidence interval (CI) were employed as markers to compare adverse events due to S-1 vs 5-FU.

RESULTS

Eight randomized controlled trials (RCT) were included, which contained 3,455 patients. The S-1 group had 1,804 patients, and the 5-FU group had 1,651 patients. There were 17 recorded adverse events in total. Stomatitis, hypokalemia, mucosal inflammation, and hypophosphatemia were more common in the 5-FU group than in the S-1 group (P < 0.001). No significant difference was observed between S-1 and 5-FU for other adverse events.

CONCLUSIONS

Although both S-1 and 5-FU cause a variety of side effects, 5-FU resulted in a higher incidence of stomatitis, hypokalemia, mucosal inflammation, and hypophosphatemia than S-1. Medical professionals should closely monitor the occurrence of adverse drug events and provide timely, rational guidance and nursing care to improve patient compliance and quality of life.

The Use of (Network) Meta-Analysis in Clinical Oncology

Meta-analysis is important in oncological research to provide a more reliable answer to a clinical research question that was assessed in multiple studies but with inconsistent results. Pair-wise meta-analysis can be applied when comparing two treatments at once, whereas it is possible to compare multiple treatments at once with network meta-analysis (NMA). After careful systematic review of the literature and quality assessment of the identified studies, there are several assumptions in the use of meta-analysis. First, the added value of meta-analysis should be evaluated by examining the comparability of study populations. Second, the appropriate comparator in meta-analysis should be chosen according to the types of comparisons made in individual studies: (1) Experimental and comparator arms are different treatments (A vs. B); (2) Substitution of a conventional treatment by an experimental treatment (A+B vs. A+C); or (3) Addition of an experimental treatment (A+B vs. B). Ideally there is one common comparator treatment, but when there are multiple common comparators, the most efficacious comparator is preferable. Third, treatments can only be adequately pooled in meta-analysis or merged into one treatment node in NMA when considering likewise mechanism of action and similar setting in which treatment is indicated. Fourth, for both pair-wise meta-analysis and NMA, adequate assessment of heterogeneity should be performed and sub-analysis and sensitivity analysis can be applied to objectify a possible confounding factor. Network inconsistency, as statistical manifestation of violating the transitivity assumption, can best be evaluated by node-split modeling. NMA has advantages over pair-wise meta-analysis, such as clarification of inconsistent outcomes from multiple studies including multiple common comparators and indirect effect calculation of missing direct comparisons between important treatments. Also, NMA can provide increased statistical power and cross-validation of the observed treatment effect of weak connections with reasonable network connectivity and sufficient sample-sizes. However, inappropriate use of NMA can cause misleading results, and may emerge when there is low network connectivity, and therefore low statistical power. Furthermore, indirect evidence is still observational and should be interpreted with caution. NMA should therefore preferably be conducted and interpreted by both expert clinicians in the field and an experienced statistician. Finally, the use of meta-analysis can be extended to other areas, for example the identification of prognostic and predictive factors. Also, the integration of evidence from both meta-analysis and expert opinion can improve the construction of prognostic models in real-world databases.

Proposal of a Scoring Scale to Estimate Risk of the Discontinuation of S-1 Adjuvant Monotherapy in Patients with Stage II to III Gastric Cancer: A Multi-Institutional Dataset Analysis

BACKGROUND

Discontinuation of postoperative S-1 adjuvant monotherapy is a frequent problem in the management of patients with gastric cancer.

METHODS

A total of 355 stage II/III gastric cancer patients who underwent gastrectomy and adjuvant S-1 were retrospectively analyzed using a multicenter dataset. We randomly assigned patients into either discovery or validation cohort in a 2:1 ratio. In the discovery cohort, 29 parameters were assessed as candidate factors to predict discontinuation of S-1 adjuvant within 6 months. A scoring system was designed using independent risk factors identified by the multivariate analysis. Reproducibility was tested in the validation cohort.

RESULTS

Overall, 92 patients (25.9%) discontinued the treatment within 6 months because of adverse effects. Age, preoperative urea nitrogen (UN) and the preoperative albumin-to-bilirubin index (ALBI) showed the highest area under the curve (AUC) for the discontinuation of S-1 adjuvant within 6 months in each category: body status, blood tests and indices. In the multivariate analysis, age ≥ 64 years, preoperative UN ≥ 15.2 mg/dl and preoperative ALBI ≥ -0.265 were identified as independent risk factors. A scoring scale consisting of these three factors was developed for the prediction of drug discontinuation and demonstrated a greater AUC (0.728) than that of each of the three constituents. The time to treatment discontinuation decreased incrementally as the risk score increased. The reproducible findings were confirmed in the validation cohort.

CONCLUSIONS

We identified risk factors and developed a scoring scale to predict S-1 adjuvant monotherapy discontinuation in patients with stage II/III gastric cancer.

S-1 combined with paclitaxel may benefit advanced gastric cancer: Evidence from a systematic review and meta-analysis

BACKGROUND

Gastric cancer, as one of the increasingly common malignancies, has experienced high morbidity throughout many countries at present. Currently, chemotherapy regimen with more efficacy and safety for advanced gastric cancer (AGC) is needed. We aimed to assess the clinical efficacy and safety of S-1 combined with paclitaxel (PTX) for AGC by performing a systematic review and meta-analysis of the published studies.

METHOD

All published randomized controlled trials (RCTs) of S-1 combined with PTX for AGC were searched. Studies that included patients with locally advanced or metastases' gastric cancers were included. We searched the databases included Cochrane Library of Clinical Comparative Trials, MEDLINE, Embase, American Society of Clinical Oncology meeting abstracts and China National Knowledge Internet (CNKI) from 2000 to 2018. We searched the database up to January 2018. The first endpoint was overall survival (OS). Other endpoints were progression-free survival (PFS), objective response rate (ORR) and disease control rate (DCR). Safety analyses were also performed.

RESULTS

A total of 7 trials (including 1407 patients, 711 patients in intervention group and 696 patients in control group) were included in the present analysis. S-1 combined with PTX significantly improved the OS [HR = 0.78, 95% CI: 0.60-0.97, P = 0.000],PFS [HR = 0.70, 95% CI: 0.55-0.85, P = 0.000], ORR [RR = 1.30, 95%CI: 1.05-1.60, P = 0.017] and DCR [RR = 1.15, 95%CI: 1.04-1.27, P = 0.008] of patients with AGC. The grade 3 or 4 haematological and non-hematologic toxicities were anemia [RR = 1.71, 95% CI: 1.04-2.79, P = 0.03], neutropenia [RR = 1.65, 95% CI: 1.32-2.06, P < 0.0001] and anorexia [RR = 1.66, 95% CI: 1.05-2.64, P = 0.03] respectively.

CONCLUSION

S-1 combined with PTX may be a good choice for patients with AGC. S-1 plus PTX experienced more efficacy and safety when compared with S-1 alone or S-1 plus other drugs.

The clinical outcomes of S-1 plus cisplatin for patients with advanced gastric cancer: A meta-analysis and systematic review

BACKGROUND

To evaluate the clinical outcomes of S-1 plus cisplatin (SC) for the treatment of patients with advanced gastric cancer (AGC).

METHODS

A systematic literature search was conducted by searching PubMed, the Cochrane Library, Embase, China Biology Medicine disc (CBMdisc), China National Knowledge Infrastructure (CNKI), and WanFang Database, for all year up to January 2017. Pooled analyses of overall survival (OS), progress-free survival rates, and adverse events were performed.

RESULTS

A total of 8 random controlled trails (RCTs) consisting of 2699 patients with AGC were selected and included in this meta-analysis. The results of our meta-analysis showed that AGC patients who treated with SC regimen receive a similar OS (HR = 1.01, 95%CI: 0.86-1.18, P = .928), PFS (HR = 0.89, 95%CI: 0.72-1.09, P = .263), and overall response rate (HR = 0.88, 95%CI: 0.70-1.11, P = .283). However, SC regimen may increase the risk of 1 to 2 grade (OR = 1.128, 95%CI: 1.075-1.184, P = .000) and 3 to 4 grade (OR = 1.24, 95%CI: 1.01-1.52, P = .039) adverse events.

CONCLUSION

SC chemotherapy showed no difference in survival compared with 5-FU- and S-1-based other therapy, but has a higher rate of adverse events compared with other chemotherapy regimens.

The combination of apatinib and S-1 for the treatment of advanced gastric cancer in China: A meta-analysis of randomized controlled trials

BACKGROUND

Apatinib-targeted therapy is considered a promising treatment option for malignancies. This study systematically evaluated the efficacy and safety of the combination of apatinib and S-1 for the treatment of patients with advanced gastric cancer (GC).

METHODS

Clinical trials were searched from the PubMed, Cochrane Library, Embase, CNKI, and Wanfang databases. Outcome measures including therapeutic efficacy, quality of life (QoL), and adverse events were extracted and evaluated.

RESULTS

Data from 8 trials including 393 patients with advanced GC were included. The results indicated that, compared with S-1 alone, the combination of apatinib with S-1 significantly improved patient partial response rate (odds ratio [OR] = 1.91, 95% confidence interval [CI] = 1.21-3.02, P = .005), overall response rate (ORR, OR = 2.40, 95% CI = 1.51-3.82, P = .0002), and disease control rate (DCR, OR = 2.78, 95% CI = 1.51-5.10, P = .0010), whereas the rates of complete response (CR, OR = 2.38, 95% CI = 0.93-6.12, P = .07) and stable disease (SD, OR = 0.99, 95% CI = 0.64-1.54, P = .97) and QoL (OR = 1.22, 95% CI = 0.51-2.92, P = .66) did not differ significantly. Moreover, the group receiving the combined therapy had higher rates of hand-foot syndrome (OR = 2.23, 95% CI = 1.19-4.17, P = .01), hypertension (OR = 8.85, 95% CI = 4.07-19.26, P < .00001), albuminuria (OR = 11.25, 95% CI = 3.32-38.06, P = .0001), and hemoglobin reduction (OR = 3.19, 95% CI = 1.32-7.67, P = .010), whereas analysis of other adverse events did not show significant differences (P > .05).

CONCLUSION

The combination of apatinib and S-1 is more effective for GC treatment than S-1 alone. However, this combined treatment could lead to increased hand-foot syndrome, hypertension, albuminuria, and hemoglobin reduction. Therefore, the benefits and risks should be considered before treatment.

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.

Management of advanced gastric cancer: An overview of major findings from meta-analysis

This study aims to provide an overview of different treatment for advanced gastric cancer. In the present study, we systematically reviewed the major findings from relevant meta-analyses. A total of 54 relevant papers were searched via the PubMed, Web of Science, and Google scholar databases. They were classified according to the mainstay treatment modalities such as surgery, chemotherapy and others. Primary outcomes including overall survival, response rate, disease-free survival, recurrence-free survival, progression-free survival, time-to-progression, time-to failure, recurrence and safety were summarized. The recommendations and uncertainties regarding the treatment of advanced gastric cancer were also proposed. It was suggested that laparoscopic gastrectomy was a safe and technical alternative to open gastrectomy. Besides, neoadjuvant chemotherapy and adjuvant chemotherapy were thought to benefit the survival over surgery alone. And it was demonstrated in the study that targeted therapy like anti-angiogenic and anti-HER2 agents but anti-EGFR agent might have a significant survival benefit.

Comparing cytotoxic backbones for first-line trastuzumab-containing regimens in human epidermal growth factor receptor 2-positive advanced oesophagogastric cancer: A meta-analysis

According to the Trastuzumab for Gastric Cancer (ToGA) study, trastuzumab plus cisplatin and capecitabine/5-fluorouracil (5-FU) is standard first-line treatment for human epidermal growth factor receptor 2 (HER2)-positive advanced oesophagogastric cancer. We examined the relative efficacy and safety of alternative trastuzumab-based cytotoxic backbone regimens compared to the standard ToGA regimen using meta-analysis. We searched Medline, EMBASE, CENTRAL and ASCO and ESMO up to March 2017 for studies investigating alternative first-line trastuzumab-based regimens for HER2-positive oesophagogastric cancer, defined as high protein expression IHC3+ or IHC2+ and gene amplification by in situ hybridisation. We compared primary outcome overall survival (OS) of alternative trastuzumab-based regimens to the ToGA regimen. Hazard ratios (HRs) and 95% confidence intervals (95%CI) were calculated by extraction of the published Kaplan-Meier curves. Incidence counts and toxicity sample-sizes were extracted for adverse events and compared using single-arm proportion meta-analysis in R. Fifteen studies (N = 557 patients) were included. OS was significantly longer with regimen trastuzumab plus doublet oxaliplatin and capecitabine/5-FU (median OS = 20.7 months) versus ToGA (16.0 months, HR = 0.75, 95% CI = 0.59-0.99) and was less toxic. Trastuzumab plus doublet cisplatin and S-1 showed no OS difference versus ToGA, but showed a different toxicity profile, including less hand-foot syndrome. Trastuzumab plus cisplatin or capecitabine as singlet backbone showed significantly worse survival and more toxicity versus ToGA regimen. Trastuzumab with triplet cytotoxic backbones or with bevacizumab and doublet cytotoxic backbone showed no survival benefit and more toxicity. In conclusion, trastuzumab plus doublet cytotoxic backbone containing oxaliplatin is preferable over the ToGA regimen with cisplatin. S-1 can substitute capecitabine or 5-FU when specific toxicities are encountered.

Efficacy and safety comparison of chemotherapies for advanced gastric cancer: A network meta-analysis

OBJECTIVE

Chemotherapy is one of the commonly used therapies for advanced gastric cancer. In this study, we performed a network meta-analysis on the efficacy and safety of common treatments to give evidences of their relative benefits.

RESULTS

32 trials with 8550 patients and 20 regimens were included in this study. According to the results of primary outcomes, 5-FU plus OXA, 5-FU plus DOC, CAP plus CIS, CAP plus OXA, S-1 plus OXA and S-1 plus PAC performed well in improving OS and ORR. As for the adverse events, S-1 had a safer effect than other treatments, conversely, 5-FU plus CIS ranked the last. However, there was no regimen with outstanding performances in both efficacy and safety.

MATERIALS AND METHODS

Studies were searched from database and screened with criteria. The Bayesian framework based network meta-analysis was performed with software R and STATA. Overall survival (OS) and overall response rate (ORR) were considered as primary outcomes while adverse events as secondary outcomes. The outcomes were represented by hazard ratios or odd ratios with 95% corresponding credible intervals, respectively.

CONCLUSIONS

The network meta-analysis suggested that 5-FU plus OXA and 5-FU plus DOC were recommended when efficacy was stressed. S-1 was safest but poorly effective. A regimen, as an excellent combination of efficacy and safety, is still waiting to be discovered.

Phase I study of orally administered S-1 in combination with epirubicin and oxaliplatin in patients with advanced solid tumors and chemotherapy-naïve advanced or metastatic esophagogastric cancer

BACKGROUND

This phase I study investigated the safety and the maximum tolerated dose (MTD) of the oral fluoropyrimidine S-1 when combined with epirubicin and oxaliplatin (EOS).

METHODS

Patients aged ≥18 years with advanced or metastatic solid tumors were enrolled in a 3 + 3 design with S-1 dose escalation (two planned cohorts) performed according to the occurrence of dose-limiting toxicity (DLT). On day 1 of each 21-day cycle, patients received epirubicin 50 mg/m² followed by oxaliplatin 130 mg/m² (maximum 8 cycles) and then S-1 [20 mg/m² (cohort 1) or 25 mg/m² (cohort 2), twice daily]: first dose, evening of day 1; subsequent administration on days 2-14, twice daily; last dose, morning of day 15 (unlimited number of S-1 cycles). After protocol amendment, enrollment in a third cohort was restricted to patients with chemotherapy-naïve advanced or metastatic esophagogastric cancer.

RESULTS

DLT was reported for two of the five patients in cohort 2, defining 20 mg/m² twice daily as the MTD of S-1 combined with epirubicin and oxaliplatin in heavily pretreated patients. Thirteen patients with chemotherapy-naïve advanced or metastatic esophagogastric cancer were subsequently enrolled and treated at an S-1 dose level of 25 mg/m² twice daily; no DLTs were reported; median overall survival was 13.1 months. Of the 11 evaluable patients, three (27 %) had partial responses and seven (64 %) had stable disease. The safety profile was in line with expectations.

CONCLUSIONS

The promising activity of EOS (S-1 dose level, 25 mg/m² twice daily) and acceptable safety profile support further clinical development of this combination for the first-line treatment of patients with advanced or metastatic esophagogastric cancer.

Fluoropyrimidine-Based Chemotherapy as First-Line Treatment for Advanced Gastric Cancer: a Bayesian Network Meta-Analysis

Fluoropyrimidine-based regimens are the most common treatments in advanced gastric cancer. We used a Bayesian network meta-analysis to identify the optimal fluoropyrimidine-based chemotherapy by comparing their relative efficacy and safety. We systematically searched databases and extracted data from randomized controlled trials, which compared fluoropyrimidine-based regimens as first-line treatment in AGC. The main outcomes were overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and grade 3 or 4 adverse events (AEs). A total of 12 RCTs of 4026 patients were included in our network meta-analysis. Pooled analysis showed S-1 and capecitabine had a significant OS benefit over 5-Fu, with hazard ratios of 0.90 (95%CI = 0.81-0.99) and 0.88 (95%CI = 0.80-0.96), respectively. The result also exhibited a trend that S-1 and capecitabine prolonged PFS in contrast to 5-Fu, with hazard ratios of 0.84 (95%CI = 0.66-1.02) and 0.84 (95%CI = 0.65-1.03), respectively. Additionally, all the three fluoropyrimidine-based regimens were similar in terms of ORR and grade 3 or 4 AEs. Compared with regimens based on 5-Fu, regimens based on S-1 or capecitabine demonstrated a significant OS improvement without compromise of AEs as first-line treatment in AGC in Asian population. S-1 and capecitabine can be interchangeable according their different emphasis on AEs.

The efficacy and safety of S-1-based regimens in the first-line treatment of advanced gastric cancer: a systematic review and meta-analysis

BACKGROUND

S-1 is first-line therapy for advanced gastric cancer in Asia and is used with increased frequency in Western counties. We conducted a meta-analysis to investigate the efficacy and toxicity of S-1-based therapy compared with 5-fluorouracil (5-FU)/capecitabine-based therapy and S-1-based combination therapy compared with S-1 monotherapy.

METHODS

MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, American Society of Clinical Oncology meeting abstracts, European Society for Medical Oncology meeting abstracts and ClinicalTrials.gov were searched for randomized clinical trials until May 2015. Data were extracted for overall survival (OS), progression-free-survival (PFS), objective response rate (ORR) and grade 1-2 and grade 3-4 adverse events. Stratified OS data for subgroups were extracted.

RESULTS

S-1 was not different from 5-FU (eight studies, n = 2788) in terms of OS [hazard ratio (HR) 0.93, 95 % confidence interval (CI) 0.85-1.01] and PFS (HR 0.87, 95 % CI 0.73-1.04), whereas ORR was higher (risk ratio 1.43, 95 % CI 1.05-1.96). There was no subgroup difference in efficacy among Asian and Western patients, but in Western patients S-1 was associated with a lower rate of febrile neutropenia, toxicity-related deaths and grade 3-4 stomatitis and mucositis compared with 5-FU. S-1 showed no difference in efficacy compared with capecitabine (three studies, n = 329), but was associated with a lower rate of grade 3-4 neutropenia and grade 1-2 hand-foot syndrome. S-1-combination therapy was superior to S-1 monotherapy (eight studies, n = 1808) in terms of OS (HR 0.76, 95 % CI 0.65-0.90), PFS (HR 0.68, 95 % CI 0.56-0.82) and ORR (risk ratio 1.20, 95 % CI 1.04-1.38) but was more toxic. Survival benefit of S-1 combination therapy over S-1 monotherapy was most pronounced in patients with non-measurable disease, diffuse-type histological features and peritoneal metastasis.

CONCLUSIONS

S-1 is effective and tolerable as first-line therapy for advanced gastric cancer in both Asian and Western countries.

Clinical Benefit and Health-Related Quality of Life Assessment in Patients Treated with Cisplatin/S-1 Versus Cisplatin/5-FU: Secondary End Point Results From the First-Line Advanced Gastric Cancer Study (FLAGS)

PURPOSE

Patient-reported outcomes (PRO) of health-related quality of life (HRQoL) and time to worsening of clinical benefit parameters were evaluated as secondary end points in the phase 3 first-line advanced gastric cancer study (FLAGS) trial of cisplatin/S-1 versus cisplatin/5-fluorouracil (5-FU) in patients with previously untreated advanced gastric cancer.

METHODS

The primary PRO end point was the Trial Outcome Index of the Functional Assessment of Cancer Therapy-Gastric (FACT-Ga). FACT-Ga was completed at the beginning of the first 4 cycles, cycle 6, and then every 3 cycles thereafter. The Chemotherapy Convenience and Satisfaction Questionnaire (CCSQ) was administered before the first 4 cycles; clinical benefit parameters (performance status, weight loss, and anorexia) were assessed at baseline, prior to study drug administration on day 1 of each cycle after cycle 1, and at the end of study treatment.

RESULTS

Compliance to questionnaire fulfillment was more than 80 % through cycle 9. Significantly, fewer patients treated with cisplatin/S-1 reported worsened physical well-being (PWB) scores (45.1 versus 51.7 %, p = 0.044) and experienced significantly longer time to worsening in PWB scores, with a median of 4.5 months (95 % confidence interval (CI), 3.1-5.1) compared to 3.0 months (2.8-4.6) with cisplatin/5-FU (CF) (p = 0.01). Patients receiving cisplatin/S-1 also reported significantly higher best and worst score of PWB as well as CCSQ scores and a longer median time to worsening in clinical benefit parameters.

CONCLUSIONS

Differences in secondary end points of PWB, CCSQ scores, and clinical benefit parameters favoring the cisplatin/S-1 arm provide further evidence for considering this combination a standard therapeutic option for first-line treatment of advanced gastric cancer.

Emerging role of S-1 in gastric cancer

Gastric cancer remains one of the most important malignancies worldwide in terms of incidence and mortality. The treatment is based on the combination of local surgery and radiation therapy as well as systemic chemotherapy and targeted molecules. Fluoropyrimidines and particularly 5-fluorouracil (FU) represent still the backbone for gastric cancer chemotherapy and new molecular versions of this molecule have been brought to clinical practice in order to improve benefits and reduce adverse effects. S-1 is an oral prodrug of 5-FU, which has demonstrated high effectiveness for gastric cancer treatment and a favorable safety profile. Currently, there are geographic differences in the treatment of gastric cancer and in the use of S-1, which is a mainstay of gastric cancer management in Eastern countries, but is not part of the standard care in the rest of the world. In this review, we gathered data from phase I, II, and III trials of S-1 in gastric cancer, in order to define its real benefit-risk ratio and assess whether geographic differences in S-1 use are justified by unchangeable factors.

A Meta-analysis Reveals S-1-based Chemotherapy Improves the Survival of Patients With Advanced Gastric Cancer

The aim of this study was to compare the efficacy and safety of S-1-based therapy versus non-S-1-based therapy in advanced gastric cancer (AGC) patients.Eligible studies stratifying objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and adverse events (AEs) in AGC patients were identified from Embase, Pubmed, Cochrane Library, and China National Knowledge Infrastructure databases. The STATA package (version 11.0) was used to pool the data from the eligible studies.Fifteen studies with 2973 AGC cases, of which 1497 (50.4%) received S-1-based therapy and 1476 (49.6%) received non-S-1-based therapy, were identified in the meta-analysis. AGC patients who had received S-1-based therapy had a higher median OS, median PFS, and ORR than those who had received 5-fluorouracil (FU)-based therapy (OS: hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.80-0.98, P = 0.015; PFS: HR 0.88, 95% CI 0.80-0.98, P = 0.016; ORR: OR 1.25, 95% CI 1.08-1.45, P = 0.003, respectively). S-1-based therapy had similar efficacy to capecitabine-based therapy in terms of median OS (HR 1.14, 95% CI 0.91-1.41, P = 0.253), median PFS (HR 1.01, 95% CI 0.82-1.25, P = 0.927), and ORR (OR 0.84, 95% CI 0.63-1.12, P = 0.226). Subgroup analysis for grade 3 to 4 toxicity showed higher incidence of neutropenia (relative risk [RR] = 0.827, P = 0.006), nausea (RR = 0.808, P = 0.040), and lower diarrhea (RR = 1.716, P = 0.012) in 5-FU-based arm, and higher diarrhea (RR = 0.386, P = 0.007) in capecitabine-based arm.S-1-based chemotherapy is favorable to AGC patients with better clinical benefit than 5-FU-based chemotherapy and with equivalent antitumor compare with capecitabine-based therapy.

Chemoradiation therapy with S-1 for primary squamous cell carcinoma of the rectum: report of three cases

Purpose

Although successful treatment of squamous cell carcinoma (SCC) of the rectum using chemoradiation therapy (CRT) has been reported, a standard protocol has yet to be established. The aim is to ascertain the effectiveness of CRT with S-1 for three patients with SCC of the rectum.

Case presentation

We treated three female patients complaining of rectal bleeding. The patients were diagnosed as having primary SCC of the rectum by means of routine examinations; one of them was a very rare case because of the presence of two lesions in the lower rectum. We treated the patients using CRT with S1 at a radiation dose of 1.8 Gy/fraction given five times weekly (Monday to Friday) to a median dose of 59.4 (45 to 59.4) Gy; S-1 (80 mg/m²/day) was administered orally during radiation therapy. One of three patients had an adverse event involving massive hemorrhage from the tumor. All patients exhibited an excellent response to CRT with S-1; two patients had a complete response, and one patient had a partial response and underwent a posterior pelvic exenteration with advancement flap reconstruction as a salvage treatment. Pathological examination of the resected specimen and lymph nodes revealed no tumor cells indicating a pathological complete response. In this series, the response rate was 100%.

Conclusions

We suggest that CRT with S-1 be chosen as the first-line therapy for SCC of the rectum. However, a large study will be required to establish a safe and effective regimen.