Effect of gastrectomy on the pharmacokinetics of S-1, an oral fluoropyrimidine, in resectable gastric cancer patients

Addition of sintilimab to nanoparticle albumin-bound paclitaxel and S-1 as adjuvant therapy in stage IIIC gastric cancer

The prognosis of stage III gastric cancer (GC) is not satisfying and the specific chemotherapy regimens for GC of stage IIIC based on the 8th edition of the UICC/AJCC TNM staging system are still inconclusive. Peritoneal recurrence is the common and severe relapse pattern. Nanoparticle albumin-bound paclitaxel (Nab-PTX) is safer and more effective than PTX in the peritoneal metastasis. Clinical trial has demonstrated the safety and efficacy of sintilimab in GC. A combination of Nab-PTX, S-1 and sintilimab could be a promising triplet regimen as adjuvant therapy for GC. The aim of this article is to describe the design of this prospective Dragon-VII trial, conducted to evaluate the safety and efficacy of the combination of Nab-PTX, S-1 and sintilimab. Clinical trial registration: NCT04781413.

A Phase II Study Demonstrates No Feasibility of Adjuvant Treatment with Six Cycles of S-1 and Oxaliplatin in Resectable Esophageal Adenocarcinoma, with ERCC1 as Biomarker for Response to SOX

Simple Summary

Neoadjuvant chemoradiotherapy followed by surgery is currently standard of care in esophageal adenocarcinoma. However, prognosis remains dismal. The aim of our study was to assess the feasibility of administering six cycles of adjuvant S-1 and oxaliplatin following neoadjuvant chemoradiotherapy and esophagectomy. Although six cycles of adjuvant S-1 and oxaliplatin were not feasible in pretreated patients, mainly due to toxicity, efficacy results were promising compared to a propensity-score matched cohort. Exploratory biomarker analyses demonstrated potential benefit for patients with Excision repair cross-complementation group 1 (ERCC1) negative tumor expression. A proteomics biomarker model provided valuable information for prediction of survival and pharmacokinetics of 5-FU showed a correlation with treatment-related toxicity. Although it remains unclear if additional chemotherapy should be provided in the adjuvant setting, subgroups such as patients with ERCC1 negativity, could potentially benefit from this treatment option based on our exploratory biomarker research.

Abstract

We assessed the feasibility of adjuvant S-1 and oxaliplatin following neoadjuvant chemoradiotherapy (nCRT) and esophagectomy. Patients treated with nCRT (paclitaxel, carboplatin) and esophagectomy received six 21-day cycles with oxaliplatin (130 mg/m²) on day 1 and S-1 (25 mg/m² twice daily) on days 1–14. The primary endpoint was feasibility, defined as ≥50% completing treatment. We performed exploratory propensity-score matching to compare survival, ERCC1 and Thymidylate Synthase (TS) immunohistochemistry analyses, proteomics biomarker discovery and 5-FU pharmacokinetic analyses. Forty patients were enrolled and 48% completed all adjuvant cycles. Median dose intensity was 98% for S-1 and 62% for oxaliplatin. The main reason for early discontinuation was toxicity (67%). The median recurrence-free and overall survival were 28.3 months and 40.8 months, respectively (median follow-up 29.1 months). Survival was not significantly prolonged compared to a matched cohort (p = 0.09). Patients with ERCC1 negative tumor expression had significantly better survival compared to ERCC1 positivity (p = 0.01). Our protein signature model was predictive of survival [p = 0.04; Area under the curve (AUC) 0.80]. Moreover, 5-FU pharmacokinetics significantly correlated with treatment-related toxicity. To conclude, six cycles adjuvant S-1 and oxaliplatin were not feasible in pretreated esophageal adenocarcinoma. Although the question remains whether additional treatment with chemotherapy should be provided in the adjuvant setting, subgroups such as patients with ERCC1 negativity could potentially benefit from adjuvant SOX based on our exploratory biomarker research.

Comparison of S-1 plus oxaliplatin (SOX) and capecitabine plus oxaliplatin (XELOX) as adjuvant chemotherapies for stage II and III gastric cancer after D2 resection: A single-center retrospective study

Background

Capecitabine plus oxaliplatin (XELOX) as adjuvant therapy for gastric cancer (GC) reduces cancer recurrence and improves survival. S‐1 plus oxaliplatin (SOX) is well‐tolerated and effective against advanced GC, and also be used widely in adjuvant treatment. However, data comparing SOX and XELOX as adjuvant treatments are lacking.

Method

Data on treatment modalities, adverse events, recurrence and metastasis were collected from 180 patients with stage II and III GC, who received SOX or XELOX after D2 gastrectomy between January 2012 and December 2015, and analyzed retrospectively. The primary endpoint was 3‐year disease‐free survival (DFS) rate.

Results

Median follow was 52.9 months; 3‐year DFS rate and overall survival (OS) rate were 75.2% and 67.6% (P = 0.359) and 81.2% and 83.3% (P = 0.77) in the SOX and XELOX groups, respectively. There was no significant difference in peritoneal metastasis rates in the SOX and XELOX groups (8.6% vs 15%, respectively; P = 0.232). Compound recurrent disease was associated with significantly shorter OS. Multivariate analysis identified metastatic lymph node ratio (LNR) as an independent prognostic factor for OS (P = 0.036; hazard ratio = 2.875; 95% confidence interval, 1.069–7.729); the LNR ≥17% group had inferior 3‐year OS rate to the LNR <17% group (P = 0.001). The incidence of grades 3 and 4 adverse events was similar in both groups; however, grade ≥2 hand–foot syndrome was significantly less frequent in the SOX group (P = 0.01).

Conclusion

SOX has similar survival benefits to XELOX and is well‐tolerated in Chinese patients with GC following D2 gastrectomy.

Efficacy and Safety of Trifluridine/Tipiracil Treatment in Patients With Metastatic Gastric Cancer Who Had Undergone Gastrectomy: Subgroup Analyses of a Randomized Clinical Trial

Question

Is trifluridine/tipiracil treatment safe and effective for the subpopulation of patients with previously treated metastatic gastric or gastroesophageal junction cancer who have undergone gastrectomy?

Findings

In this subgroup analysis of a randomized clinical trial, trifluridine/tipiracil treatment improved overall survival and progression-free survival compared with placebo among patients with previously treated metastatic gastric or gastroesophageal junction cancer and who had or had not undergone gastrectomy. No new safety concerns were reported, and hematologic toxic effects were more frequent among the subgroup who had undergone gastrectomy but were treated using dosing modifications.

Meaning

Trifluridine/tipiracil is a safe and effective treatment option for patients with pretreated metastatic gastric or gastroesophageal junction cancer regardless of previous gastrectomy.

Importance

Trifluridine/tipiracil (FTD/TPI) treatment has shown clinical benefit in patients with pretreated metastatic gastric cancer or gastroesophageal junction cancer (mGC/GEJC). Patients who have undergone gastrectomy constitute a significant proportion of patients with mGC/GEJC.

Objective

To assess the efficacy and safety of FTD/TPI among patients with previously treated mGC/GEJC who had or had not undergone gastrectomy.

Design, Setting, and Participants

This preplanned subgroup analysis of TAGS (TAS-102 Gastric Study), a phase 3, randomized, placebo-controlled, clinical trial included patients with mGC/GEJC who had received at least 2 previous chemotherapy regimens, and was conducted at 110 academic hospitals in 17 countries in Europe, Asia, and North America, with enrollment between February 24, 2016, and January 5, 2018; the data cutoff was March 31, 2018.

Interventions

Patients were randomized 2:1 to receive oral FTD/TPI 35 mg/m² twice daily or placebo twice daily with best supportive care on days 1 through 5 and days 8 through 12 of each 28-day treatment cycle.

Main Outcomes and Measures

The primary end point was overall survival. This subgroup analysis was conducted to examine potential trends and was not powered for statistical significance. Efficacy and safety end points were evaluated in the subgroups.

Results

Of 507 randomized patients (369 [72.8%] male; mean [SD] age, 62.5 [10.5] years), 221 (43.6%) had undergone gastrectomy (147 randomized to FTD/TPI and 74 to placebo) and 286 (56.4%) had not undergone gastrectomy (190 randomized to FTD/TPI and 96 to placebo). In the gastrectomy subgroup, the overall survival hazard ratio (HR) in the FTD/TPI group vs placebo group was 0.57 (95% CI, 0.41-0.79), and the progression-free survival HR was 0.48 (95% CI, 0.35-0.65). In the no gastrectomy subgroup, the overall survival HR in the FTD/TPI group vs placebo group was 0.80 (95% CI, 0.60-1.06), and the progression-free survival HR was 0.65 (95% CI, 0.49-0.85). Among FTD/TPI-treated patients, grade 3 or higher adverse events of any cause occurred in 122 of 145 patients (84.1%) in the gastrectomy subgroup and 145 of 190 (76.3%) in the no gastrectomy subgroup: 64 (44.1%) in the gastrectomy subgroup and 50 (26.3%) in the no gastrectomy subgroup had grade 3 or higher neutropenia, 31 (21.4%) in the gastrectomy subgroup and 33 (17.4%) in the no gastrectomy subgroup had grade 3 or higher anemia, and 21 (14.5%) in the gastrectomy subgroup and 10 (5.3%) in the no gastrectomy subgroup hD grade 3 or higher leukopenia. In the gastrectomy subgroup, 94 (64.8%) had dosing modifications because of adverse events vs 101 (53.2%) in the no gastrectomy subgroup; 15 (10.3%) in the gastrectomy group and 28 (14.7%) in the no gastrectomy group discontinued treatment because of adverse events. Treatment exposure was similar between groups.

Conclusions and Relevance

The FTD/TPI treatment was tolerable and provided efficacy benefits among patients with pretreated mGC/GEJC regardless of previous gastrectomy.

Trial Registration

ClinicalTrials.gov identifier: NCT02500043

Development of an S-1 dosage formula based on renal function by a prospective pharmacokinetic study

BACKGROUND

S-1 is an oral anticancer drug, containing tegafur (a prodrug of 5-fluorouracil, 5-FU), 5-chloro-2,4-dihydroxypyridine, and potassium oxonate. As renal dysfunction is known to increase exposure of 5-FU following S-1 administration, the incidence of severe adverse reactions is increased in patients with impaired renal function. However, no reliable information on its dose modification for patients with renal dysfunction has been provided.

METHODS

We conducted a prospective pharmacokinetic study to develop an S-1 dosage formula based on renal function. Sixteen cancer patients with various degrees of renal function received a single dose of S-1 at 40 mg/m(2). A series of blood samples were collected at predefined times within 24 h to assess the plasma concentration profiles of 5-FU, 5-chloro-2,4-dihydroxypyridine, and tegafur. A mathematical model for the relationship between renal function and exposure of 5-FU was constructed by a population pharmacokinetic analysis.

RESULTS

The clearance of 5-FU following S-1 administration was related to body surface area and creatinine clearance in the range 15.9-108.8 mL/min as estimated by the Cockcroft-Gault equation. The S-1 dosage formula was derived as follows:[Formula: see text]where AUC is the area under the concentration-time curve, CLcr is creatinine clearance, and BSA is body surface area. The recommended daily doses of S-1 in Asia and Europe were also proposed as nomograms according to exposure matching to the previously reported area under the concentration-time curve of 5-FU, which confirmed the efficacy and toxicity in pivotal registration studies.

CONCLUSIONS

We have developed a novel formula for determining the S-1 dosage on the basis of renal function. Further validation is needed to confirm the formula for practical application.

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.

Does surgery have a role in managing incurable gastric cancer?

Although the incidence of gastric cancer is decreasing, the outcomes of this disease are among the poorest of all solid-organ tumours, predominantly due to the frequent presence of stage IV metastatic disease at primary presentation. Stage IV gastric cancer is incurable and carries a very poor prognosis (5-year survival rate of ∼4%); palliative chemotherapy remains the standard of care, but increasing evidence indicates that palliative surgery can provide a prognostic and symptomatic benefit, particularly in combination with chemotherapy and/or radiotherapy. Ongoing prospective trials should further clarify the efficacy of palliative surgery in comparison with other treatment modalities. Until such data are available, surgery should not be offered as a standard first-line treatment, but can be considered in selected cases after thorough multidisciplinary discussions involving the patient. Patient selection for both gastrectomy and nonresectional surgery must include consideration of various factors that predict quality of life after surgery. This Perspectives summarizes the available evidence and discusses the utility of palliative surgery in relation to other therapeutic modalities in the management of incurable gastric cancer.

Effects of Continuing Adjuvant S-1 for 1 Year on the Prognosis of Gastric Cancer Patients: Results from a Prospective Single Center Study

Purpose

Although several clinical trials have proven the efficacy of adjuvant S-1 treatment in gastric cancers, it is still unclear which patients receive the most benefit. In this study, we prospectively recruited patients with locally advanced gastric cancer who had undergone curative resection followed by adjuvant S-1 administration to investigate which factors affect the outcomes.

Materials and Methods

Between July 2010 and October 2011, we enrolled 49 patients who underwent curative resection for stage II or III gastric cancer and who subsequently received adjuvant S-1 treatment for 1 year.

Results

Twenty-nine patients (59.2%) continued S-1 treatment for 1 year, and 12 patients (24.5%) experienced recurrent disease during the follow-up period. Patients with continuation of S-1 for 1 year had significantly increased rates of disease-free survival (P<0.001) and overall survival (P=0.001) relative to the patients who discontinued S-1 during year 1. Multivariate analysis indicated poor outcomes for patients with stage III disease and those who discontinued S-1 treatment. Excluding patients who discontinued S-1 due to cancer progression (n=7), adjuvant treatment with S-1 still demonstrated a significant difference in the disease-free survival rate between the patients who continued treatment and those who discontinued it (P=0.020).

Conclusions

S-1 is tolerated as adjuvant treatment in gastric cancer patients. However, discontinuing S-1 treatment may be an unfavorable factor in the prevention of recurrence. S-1 adjuvant treatment should be continued for 1 year if possible through the proper management of toxicities.

Postgastrectomy pharmacokinetic changes of S-1 in patients with localized advanced gastric cancer

S-1 is an oral 5-fluorouracil agent containing tegafur, 5-chloro-2, 4-dihydroxypyridine (CDHP), and potassium oxonate. This study explored the pharmacokinetics of S-1 and pharmacokinetic changes after gastric surgery in patients with resectable gastric cancer who received pre- and postoperative S-1 plus docetaxel. Serial blood was drawn before and after gastrectomy from 37 patients for pharmacokinetic analysis. The pharmacokinetics of tegafur, 5-fluorouracil, and CDHP were analyzed by noncompartmental analysis (NCA) methods and by modeling. In modeling analysis, CHDP concentrations were incorporated in the model as a time-varying covariate that inhibits the clearance of 5-fluorouracil following an inhibitory Emax model. In NCA, the pharmacokinetics of tegafur and 5-FU before and after gastric surgery were similar, although average maximum concentrations of 5-FU were decreased with statistical significance after gastrectomy. Median Tmax of tegafur was shorter after surgery without statistical significance. In modeling analysis, tegafur was best fitted by mixed zero and first-order absorption. The only difference in the final pharmacokinetic model around gastrectomy was the presence of an absorption lag of 0.23 hours before surgery. Incorporation of CDHP concentrations significantly improved the model. Although some pharmacokinetic results showed statistically significant changes after gastrectomy, these differences seem to be too small to have any clinical implication.

Dose-finding study on adjuvant chemotherapy with S-1 plus oxaliplatin for gastric cancer

Gastric cancer (GC) is the fourth most common type of cancer, accounting for an estimated one million new cases annually worldwide. Locally advanced GC often recurs, even following curative surgical resection. Therefore, there is a need for an effective adjuvant chemotherapy regimen. The aim of this trial was to investigate the maximum tolerated dose (MTD) of S-1 when administered in combination with oxaliplatin in postoperative GC patients. Oxaliplatin was administered at a fixed dose of 130 mg/m² on day 1. S-1 was administered from day 1 to 14 of a 3-week cycle and escalated by 10 mg/m²/day from 60 to 80 mg/m²/day. A total of 15 patients were enrolled in this study. No dose-limiting toxicities (DLTs) occurred at level 1 (S-1, 60 mg/m²; n=3). One case of DLT (grade 3 vomiting) occurred at level 2 (S-1, 70 mg/m²; n= 6), whereas 2 cases of grade 3 vomiting were observed at level 3 (S-1, 80 mg/m²; n=6). Based on these results, the MTD of S-1 was initially determined to be 70 mg/m². Furthermore, we observed that cytochrome P450 2A6 (CYP2A6) 41349640C>G was associated with severe neutropenia (C/C vs. C/G vs. G/G = 0 vs. 33.33 vs. 100%; P=0.03297, Fisher's exact test) during the entire course of the treatment.

Feasibility of adjuvant chemotherapy with S-1 consisting of a 4-week administration and a two-week rest period in patients with completely resected non-small cell lung cancer

The efficacy of adjuvant chemotherapy with S-1 in patients with completely resected non-small cell lung cancer (NSCLC) has yet to be clarified, and the appropriate schedule for the adjuvant chemotherapy with S-1 remains unknown. A phase II study was conducted to evaluate the feasibility and efficacy of adjuvant chemotherapy with S-1. Patients enrolled in this study were 20-75 years old, had pathological stage IB-IIIA NSCLC, and had received complete resection of NSCLC. S-1 (80 mg/m²) was administered orally to the patients for four weeks followed by a two-week rest period (conventional schedule), for a maximum of eight cycles. The primary endpoint was relative dose intensity (RDI), while the secondary endpoints were safety and 1 year of disease-free survival (1y-DFS). Between May 2007 and October 2009, 28 patients were enrolled. The RDI was 63.1% (95% CI, 48.6-77.7). No grade 3 or worse hematological toxicity was observed. Grade 3 non-hematological toxicities were observed in four patients. No grade 4 or worse hematological toxicity was detected. The probability of 1y-DFS was 85.7% (95% CI, 72.8-98.6). In the subgroup analysis, the median RDI of patients over 65 years old was lower compared to the other patients (44.8 vs. 100%; P=0.013; Mann-Whitney U test). Creatinine clearance (CCr) was lower in the older group, with more grade 2 or 3 non-hematological toxicities in the elderly patients. These results suggest that the conventional schedule of adjuvant chemotherapy with S-1 is not likely to be feasible in older patients with completely resected NSCLC.

Lacrimal drainage obstruction in gastric cancer patients receiving S-1 chemotherapy

BACKGROUND

This study was conducted to determine the incidence and clinical characteristics of lacrimal drainage obstruction (LDO) in patients receiving S-1 chemotherapy.

PATIENTS AND METHODS

Consecutive 170 patients with gastric cancer who underwent curative surgery and received adjuvant S-1 chemotherapy were enrolled. S-1 was administered orally (40 mg/m2 b.i.d. on days 1-28 every 6 weeks) for 1 year. Ophthalmologic examinations were carried out on patients complaining of epiphora.

RESULTS

Thirty-one patients (18%) developed epiphora. Among 31 patients, 25 underwent ophthalmologic examinations and 22 (88%) were diagnosed with LDO. The median time to the onset of LDO was 2.9 months. The most common site of obstruction was the nasolacrimal duct [86% (19/22)]; punctal [23% (5/22)] and canalicular obstruction [14% (3/22)] were also noted. In multivariate analysis, total gastrectomy [versus partial gastrectomy: hazard ratio (HR), 2.9; P=0.014] and creatinine clearance<50 ml/min (versus ≥50 ml/min: HR, 2.9; P=0.038) were independent risk factors for the development of LDO.

CONCLUSION

Considering the high incidence of LDO in patients receiving S-1 chemotherapy, oncologists should be alert to epiphora and cooperate with ophthalmologists in the early stages to improve the quality of life of patients and avoid more complicated ophthalmologic procedures.

Management of advanced gastric cancer

The management of advanced gastric cancer has only evolved a little over the last 15 years: platinum and fluoropyrimidine chemotherapy remains the backbone of therapy with ongoing debate as to the benefit of triplet therapy with either an anthracycline or taxane. Recently published trials of biological agents, in particular those targeting the Her2 receptor, have provided some signs of improvement. This article summarizes the relevant literature, discusses the role of these agents, as well as geographical variations in use, and provides recommendations regarding both 'standard chemotherapy' and the role of biological agents in advanced gastric cancer. Given the relative lack of progress for gastric cancer over the last 15 years, the focus for the next 5 years should be on an improved understanding of the molecular basis of gastric cancer, thus allowing rational integration of new molecular agents.

Management of adjuvant S-1 therapy after curative resection of gastric cancer: dose reduction and treatment schedule modification

BACKGROUND

The aim of this study was to determine the optimal management of adjuvant S-1 therapy for stage II or III gastric cancer, encompassing the details of dose reduction and treatment schedule modification.

METHODS

We retrospectively examined 97 patients with stage II or III gastric cancer who received S-1 chemotherapy following gastrectomy between January 2003 and December 2007. S-1 (80 mg/m² per day) was orally administered twice daily for 4 weeks, followed by a 2-week rest. As a rule, treatment was continued for 1 year after gastrectomy. Dose reduction or treatment schedule modification was performed according to toxicity profiles.

RESULTS

Among the 97 patients, 57 (59%) underwent dose reduction at least once and 39 (40%) received treatment schedule modification. Of the 57 patients who required dose reduction, 45 (79%) underwent reduction within 3 months of the beginning of treatment. The most common reasons for dose reduction were anorexia (47%), followed by diarrhea (32%), leukopenia (24%), and rash (16%), with the reasons overlapping. Although the difference in the requirement for dose reduction was not significant, patients with a low creatinine clearance level or those who underwent total gastrectomy had a greater tendency to require dose reduction. The duration of the S-1 treatment period was at least 3 months in 88% of the patients, at least 6 months in 82%, and the planned 1-year period in 73% of the patients.

CONCLUSIONS

In most patients, the planned 1-year adjuvant S-1 therapy for stage II or III gastric cancer could be completed by modifying the dose reduction and treatment schedule.

Feasibility study of adjuvant chemotherapy with S-1 plus cisplatin for gastric cancer

PURPOSE

To evaluate the feasibility of S-1 plus cisplatin as adjuvant chemotherapy for stage III gastric cancer after curative resection.

METHODS

Japanese patients with stage III gastric cancer who underwent gastrectomy with D2 lymph node resection were enrolled. Treatment consisted of 3 cycles of S-1 (80 mg/m(2)/day, b.i.d.) for 21 days followed by a 14-day rest, and cisplatin (60 mg/m(2) iv) on day 8. After that, S-1 monotherapy was given on days 1-28 every 6 weeks until 1-year postsurgery. After protocol amendment, the first chemotherapy cycle consisted of S-1 monotherapy; cisplatin was added to cycles 2, 3, and 4, followed by S-1 monotherapy up to 1-year postsurgery. The primary endpoint was the completion rate of three cycles of S-1 plus cisplatin.

RESULTS

A total of 63 enrolled patients have been evaluated. Grade 3/4 toxicities included neutropenia (40%), anorexia (28%), and febrile neutropenia (4%) before protocol amendment (n = 25), and neutropenia (37%), anorexia (8%), and febrile neutropenia (3%) after amendment implementation (n = 38). Excluding ineligible cases, treatment completion rates were 57% (12/21) before and 81% (30/37) after the protocol amendment.

CONCLUSIONS

The amended S-1 plus cisplatin is more feasible than the original protocol because of early dose reduction of S-1 prior to cisplatin addition and greater recovery time from surgery prior to cisplatin. This treatment should be considered as a feasible experimental arm for the next postoperative adjuvant phase III trial.

A phase II and pharmacokinetic study of first line S-1 for advanced gastric cancer in Taiwan

PURPOSE

To evaluate the efficacy, safety and pharmacokinetic profiles of S-1, which composed of tegafur (FT, a prodrug of 5-FU), 5-chloro-2,4-dihydroxypyridine and potassium oxonate (Oxo), in Taiwanese advanced gastric cancer (AGC) patients.

METHODS

Patients with chemo-naïve, histologically confirmed AGC were eligible. S-1 was given orally at dose of 40, 50 or 60 mg, twice daily for patients with body surface <1.25, 1.25-1.5 and >1.5 m(2), respectively, on day 1-28 every 42 days/cycle.

RESULTS

Thirty-four patients were included. On intent-to-treat analysis, the overall response rate, median progression-free and overall survival were 35.3% [95% confidence interval (CI): 19.2-51.3%], 2.9 (95% CI: 2.4-5.8) months and 9.8 (95% CI: 6.1-NA) months, respectively. The most common grade 3-4 toxicities were anemia 23.5% and neutropenia 11.8%. There were two treatment-related mortality, which occurred in patients with suboptimal renal function underestimated by serum creatinine level at study entry. Single-dose pharmacokinetic study showed trend toward lower AUC(5-FU), and higher AUC(FT) and AUC(Oxo) comparing to most Western reports.

CONCLUSIONS

The efficacy, toxicity and pharmacokinetic profiles of S-1 in current study are compatible with those from other Asian populations. Accurate renal function assessment and more closely monitoring is mandatory for S-1 therapy in patients with low body mass. Literature review suggests that, besides AUC(5-FU), AUC(Oxo) may also attribute to the difference in the compliance to S-1 between Asian and Caucasian populations.

S-1: a promising new oral fluoropyrimidine derivative

S-1 is an oral fluoropyrimidine that is designed to improve the antitumor activity of 5-fluorouracil (5-FU) concomitantly with an intent to reduce its toxicity. S-1 consists of tegafur, a prodrug of 5-FU combined with two 5-FU biochemical modulators:5-chloro-2,4-dihydroxypyridine (gimeracil or CDHP), a competitive inhibitor of dihydropyrimidine dehydrogenase and oteracil potassium which inhibits phosphorylation of 5-FU in the gastrointestinal tract decreasing serious gastrointestinal toxicities,including nausea, vomiting, stomatitis and diarrhea. Being an oral agent, S-1 offers convenience of administration and prevents complications of central venous access such as infection, thrombosis and bleeding. S-1 has shown efficacy in both gastrointestinal as well non-gastrointestinal malignancies. The authors review the current literature and provide their expert opinion on the incorporation of S-1 in the treatment of solid malignancies [corrected].

Contribution of capecitabine for therapy of patients with gastroesophageal cancer: an update of recent phase III results

Background

Capecitabine, an orally administered fluoropyrimidines, is widely used in the treatment of multiple malignancies. It has been extensively evaluated in patients with gastroesophageal carcinoma. Since recent reviews have discussed phase I/II trials (Cancer 107:221–231, 2006; Drugs 67:601–610, 2007), we focus on the impact of the results of the most current phase III trials using capectiabine in the treatment of advanced gastroesophageal cancers, primarily in the first-line setting.

Methods

To find published phase III trials, Medline was searched for English-language clinical trials published from 1996 through June 2007 along with relevant abstracts presented at the American Society of Clinical Oncology, and meetings of the European Cancer Conference and European Society of Medical Oncology. Only representative trials were chosen for this manuscript.

Results

The most frequently investigated combinations are capecitabine with taxanes, platinols, and camptothecins. Recent results of a large phase III trial (REAL-2) in untreated patients with gastroesophageal cancer suggest that capecitabine is a non-inferior substitute for intravenous 5-fluorouracil. These results of REAL-2 trial are substantiated by a smaller phase III trial. Previous analysis of multiple trials had suggested that capecitabine, when combined in doses lower than 1250 mg/m² twice daily, consistently resulted in lower frequency of Grade 3 or 4 toxic effects.

Conclusions

Capecitabine provides much needed convenience to patients with gastroesophageal cancer. The recent data derived from two phase III trials confirm that capecitabine is a suitable substitute for intravenous 5-fluorouracil in patients whose swallowing is not greatly affected. Capecitabine remains a subject of further investigations in this group of patients with interest.

Adjuvant chemotherapy for gastric cancer with S-1, an oral fluoropyrimidine

BACKGROUND

Advanced gastric cancer can respond to S-1, an oral fluoropyrimidine. We tested S-1 as adjuvant chemotherapy in patients with curatively resected gastric cancer.

METHODS

Patients in Japan with stage II or III gastric cancer who underwent gastrectomy with extended (D2) lymph-node dissection were randomly assigned to undergo surgery followed by adjuvant therapy with S-1 or to undergo surgery only. In the S-1 group, administration of S-1 was started within 6 weeks after surgery and continued for 1 year. The treatment regimen consisted of 6-week cycles in which, in principle, 80 mg of oral S-1 per square meter of body-surface area per day was given for 4 weeks and no chemotherapy was given for the following 2 weeks. The primary end point was overall survival.

RESULTS

We randomly assigned 529 patients to the S-1 group and 530 patients to the surgery-only group between October 2001 and December 2004. The trial was stopped on the recommendation of the independent data and safety monitoring committee, because the first interim analysis, performed 1 year after enrollment was completed, showed that the S-1 group had a higher rate of overall survival than the surgery-only group (P=0.002). Analysis of follow-up data showed that the 3-year overall survival rate was 80.1% in the S-1 group and 70.1% in the surgery-only group. The hazard ratio for death in the S-1 group, as compared with the surgery-only group, was 0.68 (95% confidence interval, 0.52 to 0.87; P=0.003). Adverse events of grade 3 or grade 4 (defined according to the Common Toxicity Criteria of the National Cancer Institute) that were relatively common in the S-1 group were anorexia (6.0%), nausea (3.7%), and diarrhea (3.1%).

CONCLUSIONS

S-1 is an effective adjuvant treatment for East Asian patients who have undergone a D2 dissection for locally advanced gastric cancer. (ClinicalTrials.gov number, NCT00152217 [ClinicalTrials.gov].).