Phase I/II study of S-1 combined with irinotecan for metastatic advanced gastric cancer

REDOMA: Bayesian random-effects dose-optimization meta-analysis using spike-and-slab priors

The rise of cutting-edge precision cancer treatments has led to a growing significance of the optimal biological dose (OBD) in modern oncology trials. These trials now prioritize the consideration of both toxicity and efficacy simultaneously when determining the most desirable dosage for treatment. Traditional approaches in early-phase oncology trials have conventionally relied on the assumption of a monotone relationship between treatment efficacy and dosage. However, this assumption may not hold valid for novel oncology therapies. In reality, the dose-efficacy curve of such treatments may reach a plateau at a specific dose, posing challenges for conventional methods in accurately identifying the OBD. Furthermore, achieving reliable identification of the OBD is typically not possible based on a single small-sample trial. With data from multiple phase I and phase I/II trials, we propose a novel Bayesian random-effects dose-optimization meta-analysis (REDOMA) approach to identify the OBD by synthesizing toxicity and efficacy data from each trial. The REDOMA method can address trials with heterogeneous characteristics. We adopt a curve-free approach based on a Gamma process prior to model the average dose-toxicity relationship. In addition, we utilize a Bayesian model selection framework that uses the spike-and-slab prior as an automatic variable selection technique to eliminate monotonic constraints on the dose-efficacy curve. The good performance of the REDOMA method is confirmed by extensive simulation studies.

A straightforward meta-analysis approach for oncology phase I dose-finding studies

Phase I early-phase clinical studies aim at investigating the safety and the underlying dose-toxicity relationship of a drug or combination. While little may still be known about the compound's properties, it is crucial to consider quantitative information available from any studies that may have been conducted previously on the same drug. A meta-analytic approach has the advantages of being able to properly account for between-study heterogeneity, and it may be readily extended to prediction or shrinkage applications. Here we propose a simple and robust two-stage approach for the estimation of maximum tolerated dose(s) utilizing penalized logistic regression and Bayesian random-effects meta-analysis methodology. Implementation is facilitated using standard R packages. The properties of the proposed methods are investigated in Monte Carlo simulations. The investigations are motivated and illustrated by two examples from oncology.

Randomized phase II study of CPT-11 versus PTX versus each combination chemotherapy with S-1 for advanced gastric cancer that is refractory to S-1 or S-1 plus CDDP: OGSG0701

BACKGROUND

To compare irinotecan-alone, paclitaxel-alone, and each combination chemotherapy with S-1 in patients with advanced gastric cancer (AGC) that is refractory to S-1 or S-1 plus cisplatin (SP).

METHODS

Patients with AGC after first-line chemotherapy with S-1 or SP, or patients during adjuvant chemotherapy or within 26 weeks after adjuvant chemotherapy completion with S-1 with confirmed disease progression were eligible. Patients were randomly divided into four groups based on treatment: irinotecan-alone (irinotecan; 150 mg/m², day 1, q14 days), paclitaxel-alone (paclitaxel; 80 mg/m², days 1, 8, 15, q28 days), S-1 plus irinotecan (irinotecan; 80 mg/m², days 1, 15, S-1; 80 mg/m², days 1-21, q35 days), and S-1 plus paclitaxel (paclitaxel; 50 mg/m², day1, 8, S-1; 80 mg/m², days 1-14, q21 days). The primary endpoint was overall survival (OS) and secondary endpoints were progression-free survival (PFS), response rate, and safety.

RESULTS

From July 2008 to March 2012, 127 patients were enrolled. No difference in median OS was observed in the irinotecan vs. paclitaxel groups or in the monotherapy groups vs. the S-1 combination therapy groups. Median PFS was longer in the paclitaxel group compared with the irinotecan group (4.1 vs. 3.6 months, p = 0.035), although no difference was observed when comparing monotherapy vs. S-1 combination. The most common grade 3 to 4 hematological adverse events were neutropenia with no difference in incidence rate across the treatment groups.

CONCLUSIONS

There was no difference in OS between irinotecan and paclitaxel no in OS prolongation of S-1 combination therapy in second-line chemotherapy.

A phase II study of irinotecan combined with S-1 in patients with advanced or recurrent cervical cancer previously treated with platinum based chemotherapy

OBJECTIVES

We conducted a phase II study to investigate the efficacy and toxicities of irinotecan plus oral S-1 in patients with advanced or recurrent uterine cervical cancer.

METHODS

Patients with advanced or recurrent cervical cancer previously treated with platinum based chemotherapy were enrolled. Irinotecan (150 mg/m²) was administered intravenously over the course of 90 min on day 1, and S-1 (80 mg/m²) was given orally in two divided doses from days 1 to 14 of a 21 day cycle. The primary endpoint of this phase II study was response rate. Secondary endpoints included safety, progression free survival, and overall survival.

RESULTS

A total of 19 patients were enrolled and treated. The response rate was 29.4%. Grade 3-4 hematologic toxicities were observed in three patients (15.7%). The only grade 3-4 non-hematologic toxicity observed was grade 3 diarrhea. The median progression free survival and overall survival were 3 months and 9 months, respectively.

CONCLUSION

S-1 plus irinotecan in a 3 weekly setting is safe and active in women with advanced or recurrent cervical cancer previously treated with platinum based chemotherapy. Future corroborative clinical studies are warranted.

S-1 Based Doublet as an Adjuvant Chemotherapy for Curatively Resected Stage III Gastric Cancer: Results from the Randomized Phase III POST Trial

Purpose

We conducted a randomized, multicenter, phase III trial to compare S-1 plus docetaxel (DS) with S-1 plus cisplatin (SP) as adjuvant chemotherapy for stage III gastric cancer patients.

Materials and Methods

Stage III gastric cancer patients who had received curative gastrectomy with D2 lymphadenectomy were randomized into equal groups to receive adjuvant chemotherapy of eight cycles of DS (S-1 70 mg/m²/day on days 1-14 plus docetaxel 35 mg/m²on days 1 and 8) every 3 weeks or SP (S-1 70 mg/m²/day on days 1-14 plus cisplatin 60 mg/m²on day 1) every 3 weeks. The primary endpoint was 3-year disease-free survival (DFS) rate.

Results

Between November 2010 and July 2013, 153 patients (75 patients to DS and 78 patients to SP) were enrolled from 8 institutions in Korea. After the capecitabine plus oxaliplatin was approved based on the CLASSIC study, itwas decided to close the study early. With a median follow-up duration of 56.9 months, the 3-year DFS rate between two groups was not significantly different (49.14% in DS group vs. 52.5% in SP group). The most common grade 3-4 adverse event was neutropenia (42.7% in DS and 38.5% in SP, p=0.351). SP group had more grade 3-4 anemia (1.3% vs. 11.5%, p=0.037), whereas grade 3-4 hand-foot syndrome (4.1% vs. 0%, p=0.025) and mucositis (10.7% vs. 2.6%, p=0.001) were more common in DS group. Fifty-one patients (68%) in DS group and 52 (66.7%) in SP group finished planned treatment.

Conclusion

Our findings suggest that SP or DS is an effective and tolerable option for patients with curatively resected stage III gastric cancer.

Genomic predictors of chemotherapy efficacy in advanced or recurrent gastric cancer in the GC0301/TOP002 phase III clinical trial

Recent gastric cancer clinical trials have aimed to establish the efficacy of combination therapy over monotherapy, however, the role for genomic biomarkers in these trials has remained largely unexplored. Here, using the NanoString expression platform, we analyzed 105 gastric tumors from a randomized phase III Japanese clinical trial (GC0301/TOP002) testing the efficacy of irinotecan plus S-1(IRI-S) versus S-1 therapy. We found that previously established proliferative subtype signatures, were associated with older patients (>65 years) and liver metastasis while mesenchymal subtype signatures were associated with younger patients (≤65 years) and peritoneal metastasis. Genes associated with tumor microenvironment (CD4, CD14, ADAMTS1, CCL5, CXCL12, CCL19), therapeutic implications (DPYD) and oncogenic signaling (Wnt5A, PTRF) were significantly associated with patient age, histology, tumor status, measurable lesions and metastasis. We identified Wnt5A downregulation as a candidate predictor of improved progression free survival (>8 weeks) in S-1 but not in IRI-S treatment. Although statistical significance was not achieved, mesenchymal subtype showed a trend for treatment interaction with IRI-S for efficacy. These findings highlight promising genomic markers that could be useful predictors of chemotherapy efficacy for better prognosis and survival outcome in gastric cancer.

A case report of curative distal gastrectomy for stage IV gastric cancer after chemoradiotherapy in a patient with a gastrojejunal gastric bypass

Background

Advanced gastric cancer in the lower third of the stomach often results in stricture of the gastric cavity and digestive symptoms. Gastrojejunostomy has been suggested to improve such symptoms, and the advent of new anticancer agents for gastric cancer has improved the response rate of the disease, which makes it possible to perform R0 gastrectomy in part of patients with stage IV gastric cancer. We experienced a rare case in which a patient with stage IV gastric cancer and cancerous pyloric stenosis was treated with R0 surgery after undergoing a gastrojejunal bypass procedure and multidisciplinary treatment. There have not been any previous reports about cases in which a previous gastrojejunostomy was utilized as a reconstruction route during distal gastrectomy in a patient with gastric cancer that had been treated with chemotherapy and/or CRT.

Case presentation

An 80-year-old female with advanced gastric cancer and pyloric stenosis was admitted to Kagoshima University Hospital. As peritoneal washing cytology produced a positive result, laparoscopic gastrojejunostomy (modified Devine procedure) was performed to improve food passage, and S-1 (100 mg/body, days 1–14) plus paclitaxel (120 mg/body, days 1 and 15) was administered. Although the tumor was temporarily reduced in size, an abdominal computed tomography scan obtained after four courses of chemotherapy showed progressive disease. Thus, chemoradiotherapy (56 Gy, S-1: 60 mg/body, CDDP: 5 mg/body, days 1–5) was indicated. Marked tumor shrinkage and negative peritoneal washing cytological results were achieved. Curative gastrectomy with D2 lymphadenectomy was performed. We carried out distal gastrectomy and lymph node dissection, and the gastrojejunostomy produced as a gastric bypass in the previous operation was preserved. The patient has not suffered a tumor relapse in 4 years since the surgery.

Conclusions

We surgeons increase a chance to perform R0 gastrectomy for stage IV gastric cancer following intensive chemotherapy and/or CRT. We should choose proper position of gastrojejunostomy in producing alimentary bypass for stage IV gastric cancer patients to facilitate curative surgery.

Current Development of Anti-Cancer Drug S-1

S-1 is a novel oral fluoropyrimidine derivative, widely used for treating gastric, pancreatic, lung, head, neck and breast carcinomas. It is designed to enhance the clinical utility of an oral fluoropyrimidine and is associated with low gastrointestinal toxicity. S-1 consists of three pharmacological agents (at a molar ratio of 1:0.4:1)-Tegafur (FT), a prodrug of 5-Fluorouracil (5-FU), 5-Chloro-2-4-Dihydroxypyridine (CDHP), which inhibits the activity of Dihydropyrimidine Dehydrogenase (DPD) and Oxonic Acid (Oxo), which reduces Gastrointestinal (GI) toxicity of 5-FU. The present article reviews the current development of clinical study of S-1.

Phase I Clinical Study of Irinotecan Plus S-1 in Patients With Advanced or Recurrent Cervical Cancer Previously Treated With Platinum-Based Chemotherapy

OBJECTIVES

This study aimed to determine the maximum tolerated dose and acute dose-limiting toxicities (DLTs) of intravenous irinotecan plus oral S-1 in patients with advanced or recurrent uterine cervical cancer.

METHODS

Irinotecan was administered intravenously over the course of 90 minutes on day 1, and S-1 was given orally in 2 divided doses from days 1 to 14 of a 21-day cycle. The dose of S-1 was escalated in a stepwise fashion from 40 (level 1) to 60 mg/m (level 2) and then 80 mg/m (level 3), whereas the dosage of irinotecan remained the same (150 mg/m). The primary end point for the escalation study was acute DLT that occurred within 2 cycles of chemotherapy.

RESULTS

Twelve patients were enrolled and treated over 3 dose levels. Their median age was 47 years (range, 28-48 years). At level 1, one episode of grade 3 anemia and a grade 3 fatigue were observed, but no DLT developed. At level 2, the first patient experienced febrile neutropenia, which was considered to be a DLT. To evaluate the toxicity of this dose level, 5 more patients were evaluated. However, no DLT developed in these patients. At level 3, although grade 1 to 2 hematological and nonhematological toxicities developed, no DLT occurred.

CONCLUSIONS

In women with advanced or recurrent cervical cancer previously treated with platinum-based chemotherapy, S-1 plus irinotecan in a triweekly setting is a reasonable treatment regimen with an acceptable toxicity profile. The recommended doses of S-1 and irinotecan for this regimen are 80 and 150 mg/m, respectively.

Prognostic factors of intraperitoneal chemotherapy for peritoneal carcinomatosis of gastric cancer: A retrospective study from a single center

Peritoneal carcinomatosis (PC) of gastric origin is currently recognized as a terminal disease with a poor prognosis. Advancements in novel therapeutic approaches, including intraperitoneal chemotherapy (IPC), have recently been made and it is believed that this may have contributed to the improved survival observed in patients with PC. The present study aimed to investigate overall survival (OS) and the associated prognostic factors in patients with PC of gastric origin who underwent IPC. A total of 57 patients were studied, with a median age of 51 years. The median follow-up time was 12.4 months. PC was diagnosed in all patients with gastric cancer. The median survival time of all patients was 10.1 months, whilst the OS rate at 1, 2 and 3 years was observed to be 46, 19 and 12%, respectively. Symptomatic ascites and a signet ring cell (SRC) histopathological type were demonstrated to signify a poor prognosis. Complete resection of all gross disease (CCR-0) and an increased number of cycles of systemic chemotherapy were independent factors that were observed to correlate with increased OS. The most common morbidities of grade 3/4 adverse effects were bone marrow suppression, nausea or vomiting, and diarrhea. In conclusion, IPC is an important treatment option for patients with PC that has originated from gastric cancer. Symptomatic ascites and SRC adenocarcinoma serve as negative clinicopathological prognostic factors, whilst CCR-0 and increased systemic chemotherapy cycles (≥4 cycles) may prove to be an important therapeutic option for PC patients.

Comprehensive treatment for the peritoneal metastasis from gastric cancer

Recently, a novel comprehensive treatment consisting of cytoreductive surgery (CRS) and perioperative chemotherapy (POC) was developed for the treatment of peritoneal metastasis (PM) with a curative intent. In the treatment, the macroscopic disease is completely removed by the peritonectomy techniques in combination with POC. This article reviews the results of the comprehensive treatment for PM from gastric cancer, and verifies the effects of CRS and POC, including neoadjuvant chemotherapy (NAC) and hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC). Completeness of cytoreduction, peritoneal carcinomatosis index (PCI) less than the threshold levels after NAC, absence of ascites, cytologic status, pathologic response after NAC are the independent prognostic factors. Among these prognostic factors, PCI threshold level is the most valuable independent prognostic factor. After staging laparoscopy, patients with PM from gastric cancer are recommended to treat with NAC before CRS. After NAC, indication for CRS is determined by laparoscopy. The indications of the comprehensive treatment are patients with PCI less than the threshold levels, negative cytology, and responders after NAC. Patients satisfy these factors are the candidates for the CRS and HIPEC.

Phase II/III study of second-line chemotherapy comparing irinotecan-alone with S-1 plus irinotecan in advanced gastric cancer refractory to first-line treatment with S-1 (JACCRO GC-05)

BACKGROUND

In Japan, S-1 plus cisplatin has been used as first-line therapy for advanced gastric cancer (AGC). Patients with no response to first-line treatment with S-1 often receive a taxane-alone or irinotecan-alone as second-line treatment. However, second-line treatment with S-1 plus irinotecan is widely used in patients with AGC resistant to first-line S-1-based chemotherapy. The goal of this trial was to determine whether the consecutive use of S-1 plus irinotecan improves survival when compared with irinotecan-alone as second-line treatment for AGC.

PATIENTS AND METHODS

Patients who had disease progression during first-line S-1-based chemotherapy were randomly assigned to receive S-1 plus irinotecan or irinotecan-alone. The S-1 plus irinotecan group received oral S-1 (40-60 mg/m(2)) on days 1-14 and intravenous irinotecan (150 mg/m(2)) on day 1 of a 21-day cycle. The irinotecan-alone group received the same dose of irinotecan intravenously on day 1 of a 14-day cycle. The primary end point was overall survival (OS).

RESULTS

From February 2008 to May 2011, a total of 304 patients were enrolled. The median OS was 8.8 months in the S-1 plus irinotecan group and 9.5 months in the irinotecan-alone group. This difference was not significant (hazard ratio for death, 0.99; 95% confidence interval 0.78-1.25; P = 0.92). Grade 3 or higher toxicities were more common in the S-1 plus irinotecan group than in the irinotecan-alone group.

CONCLUSION

The consecutive use of S-1 plus irinotecan is not recommended as second-line treatment in patients who are refractory to S-1-based first-line chemotherapy. ClinicalTrials.gov ID: NCT00639327.

Peritoneal carcinomatosis

Several gastrointestinal and gynecological malignancies have the potential to disseminate and grow in the peritoneal cavity. The occurrence of peritoneal carcinomatosis (PC) has been shown to significantly decrease overall survival in patients with liver and/or extraperitoneal metastases from gastrointestinal cancer. During the last three decades, the understanding of the biology and pathways of dissemination of tumors with intraperitoneal spread, and the understanding of the protective function of the peritoneal barrier against tumoral seeding, has prompted the concept that PC is a loco-regional disease: in absence of other systemic metastases, multimodal approaches combining aggressive cytoreductive surgery, intraperitoneal hyperthermic chemotherapy and systemic chemotherapy have been proposed and are actually considered promising methods to improve loco-regional control of the disease, and ultimately to increase survival. The aim of this review article is to present the evidence on treatment of PC in different tumors, in order to provide patients with a proper surgical and multidisciplinary treatment focused on optimal control of their locoregional disease.

Phase II clinical trial of metronomic chemotherapy with combined irinotecan and tegafur-gimeracil-oteracil potassium in metastatic and recurrent breast cancer

BACKGROUND

We investigated the efficacy and safety of metronomic chemotherapy with combined irinotecan and tegafur-gimeracil-oteracil potassium (TS-1) in patients with metastatic and recurrent breast cancer (MRBC), and the association between irinotecan metabolizing enzyme UDP-glucuronosyltransferase 1A1 (UGT1A1) gene polymorphisms and adverse events.

METHODS

The study group comprised 40 patients aged 35-79 years. Irinotecan (60 mg/m(2) in 5 % dextrose) was administered by 120-min infusion on days 1, 8, and 15 every 4 weeks. TS-1 (prescribed in a standard quantity) was administered at 80 mg/m(2)/day orally on days 3-7, 10-14, and 17-21 every 4 weeks.

RESULTS

Tumor response data were available for 34 patients. Median follow-up was 12 months (range 1-45 months). Response rate was 47 % (one complete and 15 partial responses). Stable disease was observed in 17 patients (50 %). One patient had disease progression (3 %). Median progression-free survival was 14 months [95 % confidence interval (CI), 10-26]. Median overall survival was 26 months (95 % CI not calculable owing to sample size), and 79.3 % of patients survived for 1 year. The most common grade 3 or 4 adverse events were neutropenia (15 %), leukopenia (12.5 %), diarrhea (7.5 %), and anemia (2.5 %). All other adverse events were grade 1 or 2. Treatment-related toxicity was generally modest and manageable. No significant correlation was observed between UGT1A1 polymorphisms and hematological or non-hematological toxicities.

CONCLUSIONS

Metronomic chemotherapy with combined irinotecan and TS-1 was effective in MRBC patients. Adverse effects were mild and the regimen was safely administered without identifying UGT1A1 polymorphisms.

Phase I/II study of S-1 combined with biweekly irinotecan chemotherapy in previously treated advanced non-small cell lung cancer

PURPOSE

This phase I/II study was designed to evaluate a combination of irinotecan and S-1 a new regimen for salvage chemotherapy in patients with advanced or metastatic non-small cell lung cancer (NSCLC).

METHODS

The study group comprised patients with advanced or metastatic NSCLC who had previously received at least one platinum-containing chemotherapy. Patients received irinotecan on days 1, 15 and oral S-1 (40 mg/m(2) twice daily as a fixed dose) on day 1 to 14 of a 28-day cycle.

RESULTS

In the phase I part, irinotecan was given in escalating doses of 70 (Level 1), 80 (Level 2), and 90 mg/m(2) (Level 3). Three of the 5 patients given Level 3 had dose-limiting toxicity, and Level 2 (80 mg/m(2) of irinotecan) was designated as the recommended dose. In phase II, 38 patients received a median of 7.4 cycles of irinotecan at the recommended dose. The overall response rate was 15.8 % (90 % confidence interval (CI): 6.1-25.5 %), and the median progression-free and overall survival times were 4.5 months (95 % CI: 3.5-5.0) and 15.0 months (95 % CI: 9.5-20.6) months, respectively. Toxicity was generally mild. Grade 3 or higher toxicity included neutropenia in 17.9 % of the patients, thrombocytopenia in 5.1 % and nausea in 7.7 %.

CONCLUSION

Combination chemotherapy with S-1 and irinotecan was considered an effective salvage regimen in patients with advanced or metastatic NSCLC.

Effects of neoadjuvant intraperitoneal/systemic chemotherapy (bidirectional chemotherapy) for the treatment of patients with peritoneal metastasis from gastric cancer

Novel multidisciplinary treatment combined with neoadjuvant intraperitoneal-systemic chemotherapy protocol (NIPS) and peritonectomy was developed. Ninety-six patients were enrolled. Peritoneal wash cytology was performed before and after NIPS through a port system. Patients were treated with 60 mg/m(2) of oral S-1 for 21 days, followed by a 1-week rest. On days 1, 8, and 15, 30 mg/m(2) of Taxotere and 30 mg/m(2) of cisplatin with 500 mL of saline were introduced through the port. NIPS is done 2 cycles before surgery. Three weeks after NIPS, 82 patients were eligible to intend cytoreductive surgery (CRS) by gastrectomy + D2 dissection + periotnectomy to achieve complete cytoreduction. Sixty-eight patients showed positice cytology before NIPS, and the positive cytology results became negative in 47 (69%) patients after NIPS. Complete pathologic response on PC after NIPS was experienced in 30 (36.8%) patients. Stage migration was experienced in 12 patients (14.6%). Complete cytoreduction was achieved in 58 patients (70.7%). By the multivariate analysis, complete cytoreduction and pathologic response became a significantly good survival. However the high morbidity and mortality, stringent patient selection is important. The best indications of the therapy are patients with good pathologic response and PCI ≤ 6, which are supposed to be removed completely by peritonectomy.

Targeted therapies for gastric cancer: current status

Gastric cancer represents one of the most common cancers internationally. Unfortunately the majority of patients still present at an advanced stage, and despite advances in diagnostic and treatment strategies, outcomes still remain poor with high mortality rates despite a decline in incidence. Whilst the utility of classical chemotherapy agents has been explored thoroughly (and continues to be investigated, alone or in various combinations), advances have been slow and the efficacy of these agents has reached a plateau. As such, the focus of recent study has shifted toward developing a greater understanding of the molecular biology of carcinogenesis and the cancer cell phenotype, and, in turn, the development of rationally designed drugs that target molecular aberrancies in signal transduction pathways specific to gastric cancer. These targets include circulating growth and angiogenic factors, cell surface receptors, and other molecules that comprise downstream intracellular signalling pathways, including receptor tyrosine kinases. Therapeutic advances in this area significantly lag behind other solid organ malignancies such as breast and colorectal cancer. This article reviews the role of targeted therapies in gastric cancer, including rationale and mechanism of action, current and emerging data, as single-agent therapy or in combination regimens. A recently published randomized phaseIII trial supporting the use of trastuzumab, an anti-human epidermal growth factor receptor 2 (HER2)/neu monoclonal antibody, in a selected population of patients is discussed. Therapies that have been evaluated in phase II trials are also reviewed, as well as promising new therapies currently being investigated in preclinical or phase I studies. There is optimism that targeted therapies, whether as single-agent therapy or in combination with traditional therapies, including chemotherapy, radiotherapy and surgery, may yet have an impact on improvement of the overall prognosis of gastric cancer.

Randomized phase II trial of first-line treatment with tailored irinotecan and S-1 therapy versus S-1 monotherapy for advanced or recurrent gastric carcinoma (JFMC31-0301)

The pharmacokinetics of irinotecan vary markedly between individuals. This study sought to compare tailored irinotecan and S-1 therapy with S-1 monotherapy for the treatment of patients with advanced/recurrent gastric cancer. Patients with advanced/recurrent gastric cancer were randomized to receive tailored irinotecan and S-1 (arm A) therapy or S-1 therapy alone (arm B). Arm A received S-1 (80-120 mg/m(2)/day) for 14 days, with irinotecan on days 1 and 15. The initial irinotecan dose of 75 mg/m(2) (level 0) was adjusted for toxicity during an earlier course. In arm B, S-1 (80-120 mg/day) was administered alone for 28 days, followed by 14 days without therapy. Ninety-five patients were randomized (48 patients to arm A and 47 patients to arm B). The response rate of the primary tumor (Japanese criteria) was 25.0% in arm A (12 of 48 patients) and 14.9% in arm B (seven of 47 patients), whereas the response rates according to Response Evaluation Criteria In Solid Tumors were 27.8% (10 of 36) versus 21.9% (seven of 32). Hematological toxicity, anorexia, and diarrhea were significantly more common in arm A, but both arms had similar grades 3-4 toxicities. These findings suggest the usefulness of tailored irinotecan and S-1 therapy for gastric cancer.

Phase II feasibility study of adjuvant S-1 plus docetaxel for stage III gastric cancer patients after curative D2 gastrectomy

OBJECTIVE

The aim of this prospective study was to evaluate the feasibility and safety of adjuvant S-1 plus docetaxel in patients with stage III gastric cancer.

METHODS

We enrolled 53 patients with pathological stage III gastric cancer who underwent D2 gastrectomy. They received oral S-1 (80 mg/m(2)/day) administration for 2 consecutive weeks and intravenous docetaxel (40 mg/m(2)) on day 1, repeated every 3 weeks (1 cycle). The treatment was started within 45 days after surgery and repeated for 4 cycles, followed by S-1 monotherapy (4 weeks on, 2 weeks off) until 1 year after surgery. The feasibility of the 4 cycles of chemotherapy, followed by S-1 administration, was evaluated.

RESULTS

A total of 42 patients (79.2%, 95% CI 65.9-82.9) tolerated the planned 4 cycles of treatment with S-1 and docetaxel, and 34 patients (64.2%, 95% CI 49.8-76.9) completed subsequent S-1 monotherapy for 1 year. Grade 4 neutropenia was observed in 28% and grade 3 febrile neutropenia in 9% of the patients, while grade 3 nonhematological toxicities were relatively low.

CONCLUSIONS

Adjuvant S-1 plus docetaxel therapy is feasible and has only moderate toxicity in stage III gastric cancer patients. We believe that this regimen will be a candidate for future phase III trials seeking the optimal adjuvant chemotherapy for stage III gastric cancer patients.

A hierarchical Bayesian design for phase I trials of novel combinations of cancer therapeutic agents

We propose a hierarchical model for the probability of dose-limiting toxicity (DLT) for combinations of doses of two therapeutic agents. We apply this model to an adaptive Bayesian trial algorithm whose goal is to identify combinations with DLT rates close to a prespecified target rate. We describe methods for generating prior distributions for the parameters in our model from a basic set of information elicited from clinical investigators. We survey the performance of our algorithm in a series of simulations of a hypothetical trial that examines combinations of four doses of two agents. We also compare the performance of our approach to two existing methods and assess the sensitivity of our approach to the chosen prior distribution.

Randomized phase III study comparing the efficacy and safety of irinotecan plus S-1 with S-1 alone as first-line treatment for advanced gastric cancer (study GC0301/TOP-002)

BACKGROUND

Irinotecan hydrochloride and S-1, an oral fluoropyrimidine, have shown antitumor activity against advanced gastric cancer as single agents in phase I/II studies. The combination of irinotecan and S-1 (IRI-S) is also active against advanced gastric cancer. This study was conducted to compare the efficacy and safety of IRI-S versus S-1 monotherapy in patients with advanced or recurrent gastric cancer.

METHODS

Patients were randomly assigned to oral S-1 (80 mg/m² daily for 28 days every 6 weeks) or oral S-1 (80 mg/m² daily for 21 days every 5 weeks) plus irinotecan (80 mg/m² by intravenous infusion on days 1 and 15 every 5 weeks) (IRI-S). The primary endpoint was overall survival. Secondary endpoints included the time to treatment failure, 1- and 2-year survival rates, response rate, and safety.

RESULTS

The median survival time with IRI-S versus S-1 monotherapy was 12.8 versus 10.5 months (P = 0.233), time to treatment failure was 4.5 versus 3.6 months (P = 0.157), and the 1-year survival rate was 52.0 versus 44.9%, respectively. The response rate was significantly higher for IRI-S than for S-1 monotherapy (41.5 vs. 26.9%, P = 0.035). Neutropenia and diarrhea occurred more frequently with IRI-S, but were manageable. Patients treated with IRI-S received more courses of therapy at a relative dose intensity similar to that of S-1 monotherapy.

CONCLUSIONS

Although IRI-S achieved longer median survival than S-1 monotherapy and was well tolerated, it did not show significant superiority in this study.

A phase I study of S-1 and irinotecan combination therapy in previously treated advanced non-small cell lung cancer patients

BACKGROUND

This phase I study was conducted to evaluate the feasibility and to determine the recommended doses of the combination therapy of S-1 and irinotecan (CPT-11) in patients with advanced non-small cell lung cancer (NSCLC) as second-line treatment.

METHODS

Patients with NSCLC who were previously treated with one chemotherapy regimen and had a performance status of 0 or 1 were eligible. CPT-11 was administered at 60 mg/m² (level 1), 80 mg/m² (level 2) on days 1 and 8, and oral S-1 was administered at 80 mg/day for body surface area (BSA) less than 1.25 m², 100 mg/day for BSA 1.25-1.5 m², and 120 mg/day for BSA more than 1.5 m² on days 1-14 every 3 weeks. The dose-limiting toxicity (DLT) was defined as grade 4 leukocytopenia or neutropenia, grade ≥ 3 neutropenia with fever over 38°C, grade ≥ 3 thrombocytopenia, or grade ≥ 3 major nonhematological toxicities.

RESULTS

Nine patients were enrolled in the study. None of 3 patients enrolled in level 1 had any DLT. Of 6 patients in level 2, 2 patients had grade 3 diarrhea and one had grade 3 interstitial pneumonia. Level 1 was declared as the recommended dose.

CONCLUSION

The feasibility of the combination therapy of S-1 and CPT-11 was shown in the second-line setting for the treatment of advanced NSCLC. The recommended dose of CPT-11 was 60 mg/m² combined with standard dose of S-1 for phase II trials of pretreated advanced NSCLC patients.

Surgical treatment for peritoneal carcinomatosis from gastric cancer

This review describes the latest surgical treatments for peritoneal carcinomatosis (PC) arising from gastric cancer. Systemic chemotherapy is less effective against PC because of the existence of the blood-peritoneal barrier. Accordingly, perioperative intraperitoneal chemotherapy plus cytoreductive surgery (CRS) is a new trend of multidisciplinary therapy for PC. Intraperitoneally administered drugs penetrate directly into the peritoneal dissemination, resulting in the high loco-regional intensity of drugs. A new bidirectional chemotherapy called neoadjuvant intraperitoneal/systemic chemotherapy (NIPS) has been developed. After NIPS, the disappearance of PFCCs has been reported, and the incidence of complete cytoreduction has increased accordingly. Complete cytoreduction, a low peritoneal carcinomatosis index, and negative PFCCs are significant favorable prognostic factors. Hyperthermic intraperitoneal chemotherapy (HIPEC) after CRS is associated with improved survival with an acceptable postoperative mortality and morbidity. Early postoperative intraperitoneal chemotherapy (EPIC) has also contributed to improving survival after CRS.

Phase 1/2 clinical study of irinotecan and oral S-1 (IRIS) in patients with advanced gastric cancer

BACKGROUND

Irinotecan and S-1, an oral fluoropyrimidine composed of tegafur, gimeracil, and oteracil potassium, have demonstrated antitumor activity against advanced gastric cancer. We performed a phase 1/2 study to determine the recommended dose, antitumor activity, and safety of a combination of S-1 and irinotecan in patients with advanced gastric cancer.

METHODS

Patients with previously untreated advanced gastric cancer were enrolled. Patients received irinotecan intravenously on days 1 and 15 plus oral S-1 twice daily on days 1-14 of a 28-day cycle. In the phase 1 part, the dose of irinotecan was escalated from 100 mg/m(2) to 125 mg/m(2) and then to 150 mg/m(2).

RESULTS

A total of 24 patients were enrolled. Overall, the median number of treatment cycles per patient was 5.9, and 92% of the patients completed at least two cycles. The overall response rate was 54.2% (13 of 24). The response rates in differentiated and undifferentiated cancer were 56.3% (nine of 16) and 50.0% (four of eight), respectively. Median survival time was 581 days. The maximum tolerated dose of irinotecan was not reached at the highest level. However, grade 4 neutropenia occurred at 125 mg/m(2). We concluded that the recommended dose of irinotecan for the present regimen was 125 mg/m(2).

CONCLUSION

Treatment with S-1+irinotecan is considered effective in patients with advanced gastric cancer who have not previously received chemotherapy. A combination of irinotecan and S-1 was well tolerated in patients with advanced gastric cancer and could be given on an outpatient basis.

Pilot study of a combination of S-1 and paclitaxel for patients with peritoneal metastasis from gastric cancer

BACKGROUND

This pilot study was carried out to evaluate the efficacy of chemotherapy for patients with peritoneal dissemination from gastric cancer or positive lavage cytology diagnosed by staging laparoscopy.

METHODS

Sixteen patients were enrolled. Paclitaxel was administered at 120 mg/m(2) on day 1 and S-1 was administered orally at 80 mg/m(2) for 14 consecutive days, followed by a 1-week rest, as one course. After five courses of this therapy, the primary gastric tumors were evaluated and second-look laparoscopy was performed for patients showing partial response or stable disease with clinical benefit.

RESULTS

Partial response or stable disease with clinical benefit was confirmed in seven and five patients, respectively, and these patients underwent second-look laparoscopy. No viable cancer cells were detected on cytopathological investigation during second-look laparoscopy in 9 patients who underwent surgical treatment. The intent-to-treat response rate for gastric tumor was 44% and the rate of disappearance of peritoneal metastasis was 38% (6 cases) at surgery. The median survival time was 555 days. Leucopenia of grade 3 and neutropenia of grade 3 were recognized in two and three patients, respectively.

CONCLUSION

This chemotherapy regimen may be an acceptable option for patients with peritoneal dissemination. We plan to study this regimen further in gastric cancer patients with peritoneal dissemination.

Multidisciplinary therapy for treatment of patients with peritoneal carcinomatosis from gastric cancer

There is no standard treatment for peritoneal carcinomatosis (PC) from gastric cancer. A novel multidisciplinary treatment combining bidirectional chemotherapy [neoadjuvant intraperitoneal-systemic chemotherapy protocol (NIPS)], peritonectomy, hyperthermic intraperitoneal chemoperfusion (HIPEC) and early postoperative intraperitoneal chemotherapy has been developed. In this article, we assess the indications, safety and efficacy of this treatment, review the relevant studies and introduce our experiences. The aims of NIPS are stage reduction, the eradication of peritoneal free cancer cells, and an increased incidence of complete cytoreduction (CC-0) for PC. A complete response after NIPS was obtained in 15 (50%) out of 30 patients with PC. Thus, a significantly high incidence of CC-0 can be obtained in patients with a peritoneal cancer index (PCI) ≤ 6. Using a multivariate analysis to examine the survival benefit, CC-0 and NIPS are identified as significant indicators of a good outcome. However, the high morbidity and mortality rates associated with peritonectomy and perioperative chemotherapy make stringent patient selection important. The best indications for multidisciplinary therapy are localized PC (PCI ≤ 6) from resectable gastric cancer that can be completely removed during a peritonectomy. NIPS and complete cytoreduction are essential treatment modalities for improving the survival of patients with PC from gastric cancer.

Multidisciplinary therapy for treatment of patients with peritoneal carcinomatosis from gastric cancer

There is no standard treatment for peritoneal carcinomatosis (PC) from gastric cancer. A novel multidisciplinary treatment combining bidirectional chemotherapy [neoadjuvant intraperitoneal-systemic chemotherapy protocol (NIPS)], peritonectomy, hyperthermic intraperitoneal chemoperfusion (HIPEC) and early postoperative intraperitoneal chemotherapy has been developed. In this article, we assess the indications, safety and efficacy of this treatment, review the relevant studies and introduce our experiences. The aims of NIPS are stage reduction, the eradication of peritoneal free cancer cells, and an increased incidence of complete cytoreduction (CC-0) for PC. A complete response after NIPS was obtained in 15 (50%) out of 30 patients with PC. Thus, a significantly high incidence of CC-0 can be obtained in patients with a peritoneal cancer index (PCI) ≤ 6. Using a multivariate analysis to examine the survival benefit, CC-0 and NIPS are identified as significant indicators of a good outcome. However, the high morbidity and mortality rates associated with peritonectomy and perioperative chemotherapy make stringent patient selection important. The best indications for multidisciplinary therapy are localized PC (PCI ≤ 6) from resectable gastric cancer that can be completely removed during a peritonectomy. NIPS and complete cytoreduction are essential treatment modalities for improving the survival of patients with PC from gastric cancer.

Multidisciplinary therapy for treatment of patients with peritoneal carcinomatosis from gastric cancer

There is no standard treatment for peritoneal carcinomatosis (PC) from gastric cancer. A novel multidisciplinary treatment combining bidirectional chemotherapy [neoadjuvant intraperitoneal-systemic chemotherapy protocol (NIPS)], peritonectomy, hyperthermic intraperitoneal chemoperfusion (HIPEC) and early postoperative intraperitoneal chemotherapy has been developed. In this article, we assess the indications, safety and efficacy of this treatment, review the relevant studies and introduce our experiences. The aims of NIPS are stage reduction, the eradication of peritoneal free cancer cells, and an increased incidence of complete cytoreduction (CC-0) for PC. A complete response after NIPS was obtained in 15 (50%) out of 30 patients with PC. Thus, a significantly high incidence of CC-0 can be obtained in patients with a peritoneal cancer index (PCI) ≤ 6. Using a multivariate analysis to examine the survival benefit, CC-0 and NIPS are identified as significant indicators of a good outcome. However, the high morbidity and mortality rates associated with peritonectomy and perioperative chemotherapy make stringent patient selection important. The best indications for multidisciplinary therapy are localized PC (PCI ≤ 6) from resectable gastric cancer that can be completely removed during a peritonectomy. NIPS and complete cytoreduction are essential treatment modalities for improving the survival of patients with PC from gastric cancer.

Gastrojejunostomy as induction treatment for S-1-based chemotherapy in patients with incurable gastric cancer

PURPOSE

The development of new generation anticancer agents, including the oral drug, S-1, may alter the clinical importance of gastrojejunostomy in the treatment of incurable gastric cancer. We reviewed a series of patients who underwent gastrojejunostomy for this reason between 2002 and 2005.

METHODS

Fourteen patients underwent gastrojejunostomy followed by S-1-based chemotherapy for incurable gastric cancer with obstruction or stenosis of the gastric outlet at Niigata University Medical and Dental Hospital and two affiliated hospitals. The safety of gastrojejunostomy, outcome of palliation, and survival time were analyzed retrospectively. We compared the survival times with those of patients who underwent palliative gastrectomy or exploratory laparotomy between 1987 and 2001.

RESULTS

The median operative time and blood loss were 153 min and 66 ml, respectively. There were no major complications. The median starting time for chemotherapy after gastrojejunostomy was 15.5 days. All patients were discharged after gastrojejunostomy, and the median postoperative home stay ratio was 68%. The median survival time after gastrojejunostomy was 354 days, which was significantly longer than that of patients who underwent palliative gastrectomy or exploratory laparotomy.

CONCLUSION

Gastrojejunostomy for incurable gastric cancer contributes not only to improving quality of life (QOL), but to prolonging survival through the induction and maintenance of S-1-based chemotherapy.

Emerging drugs for ovarian cancer

BACKGROUND

Long-term survival of patients with ovarian cancer remains poor and therapy disappointing despite decades of experience with various chemotherapies, including the current gold standard, carboplatin/paclitaxel (TC).

OBJECTIVE

To review current and emerging therapies for ovarian cancer in search of ways to improve outcome, reduce toxicity, and maintain quality of life.

METHODS

This is a review of the current status of chemotherapy for ovarian cancer, the ongoing clinical studies, emerging therapies, and proposals for future research.

RESULTS/CONCLUSION

Novel chemotherapeutic agents are needed to reduce toxicity and improve efficacy. Effective biological agents must be found and tested, either in combination with TC or as maintenance therapy after TC. An appropriate regimen and number of repeat treatment cycles for intraperitoneal chemotherapy is urgently needed, and an effective regimen must be established for patients with clear cell/mucinous adenocarcinoma. The main strategy for recurrent ovarian cancer is to find the gene related to drug resistance, then treat the cancer based on its molecular biology.

Salvage gastrectomy following a combination of biweekly paclitaxel and S-1 for stage IV gastric cancer

BACKGROUND AND AIM

We investigated the clinical benefits of salvage gastrectomy for stage IV gastric cancer patients whose distant lesions showed complete response after chemotherapy.

METHODS

We enrolled 18 stage IV gastric cancer patients whose distant metastases had disappeared or were controlled by a combination of biweekly paclitaxel (PTX) and S-1. After chemotherapy, these patients received gastrectomy with lymph node dissection. The postoperative outcome was analyzed with respect to both the histological effects of chemotherapy and tumor behavior.

RESULTS

Of the 18 patients, 8 had distant lymph node metastases, 9 had peritoneal dissemination, and five had multiple liver metastases prior to chemotherapy. Fourteen patients received curative surgery (R0). No severe postoperative complications were encountered. Pathological evaluation revealed grade 3 and grade 2 tumor regression in the primary lesion in one and five patients, respectively, and grade 3 and grade 2 tumor regression in the lymph nodes in one and six patients, respectively. Univariate analysis of the patients' prognosis identified R number, gross tumor type, histological grade of tumor regression, and gender as significant factors. Multivariate analysis showed that only the R number was an independent prognostic factor.

CONCLUSION

R0 salvage gastrectomy following a combination of biweekly PTX and S-1 may have significant clinical efficacy for advanced gastric cancer patients.

A phase i study of bolus 5-fluorouracil and leucovorin combined with weekly paclitaxel (FLTAX) as first-line therapy for advanced gastric cancer

OBJECTIVE

To determine the dose-limiting toxicity (DLT) and the maximum-tolerated dose (MTD) of combination chemotherapy with leucovorin-modulated weekly bolus 5-fluorouracil (5-FU) and weekly paclitaxel in patients with advanced gastric cancer (GC).

METHODS

Chemotherapy-naive patients with histologically proven metastatic or recurrent GC were enrolled. Paclitaxel was administered as a 1-h intravenous (i.v.) infusion followed by 5-FU as a bolus i.v. infusion on Days 1, 8 and 15. A 2-h i.v. infusion of l-leucovorin was started at the same time as the paclitaxel infusion on Days 1, 8 and 15. Treatment cycles were repeated every 28 days until disease progression or unacceptable toxicity occurred. Patients were scheduled to receive 5-FU, l-leucovorin and paclitaxel at four dose levels (mg/m(2)/week): 500/250/60 (level 1), 500/250/80 (level 2), 600/250/80 (level 3) and 600/250/100 (level 4), respectively.

RESULTS

Eighteen patients were enrolled. During the first cycle of the highest dose level (level 4), two of the six patients had DLT involving Grade 3 diarrhea and Grade 3 skin rash. Furthermore, three of the four patients who received the second consecutive cycle of treatment at dose level 4 had Grade 4 neutropenia. Dose level 3 was thus determined to be the MTD. Eleven (61%) of the 18 patients had partial responses, and the median progression-free survival time was 6.8 months.

CONCLUSIONS

The MTD and the recommended dose for phase II studies of this regimen were determined to be 5-FU 600 mg/m(2)/week, l-leucovorin 250 mg/m(2)/week and paclitaxel 80 mg/m(2)/week.

Capecitabine in the treatment of advanced gastric cancer

Although the role of systemic chemotherapy has been established for the treatment of advanced gastric cancer, the prognosis of these patients remains poor, with a median overall survival of less than 1 year. Based on the results of several randomized Phase III trials, 5-fluorouracil continuous infusion plus cisplatin, with or without epirubicin, has become the global reference regimen for this patient population. However, treatment with fluorouracil infusion requires either frequent hospitalizations or the use of a central venous access device, harboring potential complications. Capecitabine, a tumor-activating oral prodrug of fluorouracil, may be more advantageous in terms of patient convenience, safety and efficacy. Two recent randomized Phase III trials have shown that capecitabine could replace infusional fluorouracil in cisplatin-based regimens. Furthermore, Phase II trials have shown that many other capecitabine-based doublet or triplet chemotherapy regimens incorporating newer cytotoxic agents are active and well tolerated. Many promising biological agents are now being tested in Phase III trials, incorporating capecitabine combinations as control arms, in patients with advanced gastric cancer.

Phase II study of a combination of irinotecan and S-1 in patients with advanced gastric cancer (OGSG0002)

BACKGROUND/AIMS

To investigate the efficacy and safety of the combination therapy of irinotecan (CPT-11) plus S-1 in patients with advanced gastric cancer at the dose recommended by a previous phase I study.

METHODS

A total of 23 patients received 80 mg/m(2) of CPT-11 on days 1 and 15, and S-1 at a dose level set on the basis of the body surface area (BSA): 40 (BSA <1.25 m(2)), 50 (BSA > or =1.25 to <1.5 m(2)) or 60 mg (BSA > or =1.5 m(2)) b.i.d. was given from days 1-21.

RESULTS

The overall response rate was 47.8% (11 of 23, 95% confidence interval, CI: 27.4-68.2%). The median time to progression (TTP) was 210 days (95% CI: 145-322 days) and the median survival time was 394 days (95% CI: 241-484 days). The incidence of grade 3 or 4 hematological and non-hematological toxicity was 17.4 and 8.7%. The most common hematological toxicity was anemia and the most common non-hematological toxicity was diarrhea.

CONCLUSION

The combination therapy of CPT-11 and S-1 provided prolonged TTP with low toxicity, and the results warrant a further phase III study to define the efficacy in improvement of survival in patients with advanced gastric cancer.

A multicenter phase II study of biweekly paclitaxel and S-1 combination chemotherapy for unresectable or recurrent gastric cancer

PURPOSE

This Phase II study assessed the activity and safety of biweekly paclitaxel and oral S-1 as treatment for unresectable and recurrent gastric cancer. The maximum tolerated dose for this regimen had been established previously in a Phase I study performed in Japanese patients.

PATIENTS AND METHODS

Chemotherapy was performed using two anticancer agents, S-1 and paclitaxel. Oral S-1 (80 mg/m(2)) was administered twice a day after meals for two consecutive weeks from Day 1 to 14, followed by a 2 week recovery period; paclitaxel (120 mg/m(2)) was administered intravenously, biweekly, on Days 1 and 15. The patient received cycles of this regimen every 4 weeks (q 28-day cycles). The primary end point was the response rate according to the Response Evaluation Criteria in Solid Tumors.

RESULTS

A total of 39 patients (median age, 65 years) were enrolled; 13 other patients were screened, but found to be ineligible. All patients had unresectable and recurrent gastric cancer. The most common treatment-related Grade 3/4 adverse events were neutropenia (37.5%), appetite loss, diarrhea, decreased sodium (each 5%), and anemia, increased alanine aminotransferase, general fatigue, and dizziness (each 2.5%). Almost all the patients experienced alopecia. Intent-to-treat analysis showed a response rate of 43.6%. With a median follow-up of 14 months (range 8-21 months), median survival was 256 days and the median time to progression was 4 months.

CONCLUSION

A combination regimen of biweekly paclitaxel and oral S-1 was well tolerated and showed promising activity against unresectable and recurrent gastric cancer.

Phase I/II study of a combination of S-1 and weekly paclitaxel in patients with advanced or recurrent gastric cancer

OBJECTIVE

A phase I/II study of a combination of S-1 and weekly paclitaxel was conducted to determine the maximum tolerated dose (MTD), recommended dose (RD), dose-limiting toxicities (DLTs) and objective response rate (RR) in patients with advanced or recurrent gastric cancer.

METHODS

S-1 was administered orally at a fixed dose of 80 mg/m(2) per day on days 1-14. Paclitaxel was injected intravenously on days 1, 8, and 15, starting with a dose of 50 mg/m(2). The dose was increased in a stepwise manner.

RESULTS

In phase I, level 2 (60 mg/m(2)) was considered the MTD, because 2 of 3 patients in level 2 developed DLTs (grade 3 neutropenia and anemia, and grade 4 diarrhea and stomatitis). Therefore, the RD was determined to be level 1 (50 mg/m(2)). In phase II, efficacy and safety were assessed in 18 patients treated with the RD. The RR was 64.7% and the median survival time was 13.5 months. The most severe toxicities were grade 3 leukopenia (5.5%) and grade 3 neutropenia (5.5%).

CONCLUSION

Our study showed that S-1 combined with 50 mg/m(2) paclitaxel is effective and safe in patients with advanced or recurrent gastric cancer.

Capecitabine in advanced gastric cancer

Since the routine introduction of chemotherapy for advanced gastric cancer in the early 1990 s, median survival for gastric cancer has improved from 3 months, with best supportive care alone, to > 11 months in recently reported Phase III trials of triplet chemotherapy. Capecitabine is an orally-active fluoropyrimidine, which is selectively metabolised to fluorouracil in tumour cells. The combinations of platinum compounds and capecitabine have been evaluated in two recent, large, Phase III trials demonstrating non-inferiority in efficacy compared with platinum plus continuous infusion fluorouracil. In view of the convenience and flexibility of patients in adjusting dosage when encountering toxicities, capecitabine is replacing continuous infusion fluorouracil as the backbone of combination chemotherapy in advanced gastric cancer patients. Future trials evaluating biologicals are now incorporating capecitabine combinations as control arms in both advanced disease and peri-operative settings in gastric cancer.

Alternative pharmacokinetics of S-1 components, 5-fluorouracil, dihydrofluorouracil and alpha-fluoro-beta-alanine after oral administration of S-1 following total gastrectomy

We studied whether total gastrectomy for gastric cancer would affect the pharmacokinetics of 5-fluorouracil (5-FU) and its degradation products, such as dihydrouracil (FUH(2)) and alpha-fluoro-beta-alanine (FBAL), after oral administration of the fluorouracil derivative S-1, composed of tegafur, 5-chloro-2,4-dihydroxypyridine (CDHP; a dihydropyrimidine dehydrogenase inhibitor) and potassium oxonate. Blood and urine samples were obtained, both preoperatively and at least 2 weeks postoperatively, from six patients with advanced gastric cancers who were undergoing total gastrectomy. Plasma levels of tegafur, 5-FU, CDHP, potassium oxonate, FUH(2) and FBAL were measured prior to and at 1, 2, 4, 6 and 10 h after oral administration of 40 mg/m(2) S-1. The total amounts of 5-FU, FUH(2) and FBAL excreted into urine during the 24-h period after S-1 administration were also measured. Total gastrectomy significantly increased the maximum concentration and the area under the curve until 10 h after administration (AUC(1-10h)) of plasma 5-FU. The plasma AUC(1-10h) of CDHP was significantly higher than the preoperative value. In terms of clinical efficacy, the higher AUC(1-10h) of 5-FU after total gastrectomy may be beneficial to S-1 administered as adjuvant chemotherapy, and might be caused by the higher postoperative AUC(1-10h) of CDHP relative to preoperative values. However, the dose of S-1 for patients who have undergone total gastrectomy might be diminished to avoid severe adverse events and to continue the treatment for a long period.

Phase I study of S-1, docetaxel and cisplatin combination chemotherapy in patients with unresectable metastatic gastric cancer

The aim of this dose escalation study was to determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLTs) and preliminary efficacy of docetaxel, S-1 and cisplatin combination chemotherapy in patients with unresectable metastatic gastric cancer. Seventeen patients received oral S-1 (40 mg m⁻² bid) on days 1–14, intravenous cisplatin (60 mg m⁻²) and docetaxel (60, 70 or 80 mg m⁻² depending on DLT) on day 8 every 3 weeks. The MTD of this combination was presumed to be docetaxel 70 mg m⁻². At this dose level, 40% of the patients (two of five) developed grade 4 neutropenia and 20% (one of five) exhibited grade 3 nausea during the first course. Therefore, the recommended dose of docetaxel was defined as 60 mg m⁻². The DLT was neutropenia. The response rate (RR) was 88.2% (15 of 17), consisting of one complete response and 14 partial responses. There were two stable diseases but no progressive disease. Of these 15 responders, four (23.5%) with high VEGF expression showed rapid tumour regression and achieved downstaging, leading to subsequent curative gastrectomy. Three of these have been disease free for about 3 years, suggesting a complete cure. In conclusion, this regimen was tolerable and showed a quite high RR, with an appreciable downstaging rate in metastatic gastric cancer.

Phase I/II study of S-1 combined with paclitaxel in patients with unresectable and/or recurrent advanced gastric cancer

Both paclitaxel and S-1 are effective against gastric cancer, but the optimal regimen for combined chemotherapy with these drugs remains unclear. This phase I/II study was designed to determine the maximum tolerated dose (MTD), recommended dose (RD), dose-limiting toxicity (DLT), and objective response rate of paclitaxel in combination with S-1. S-1 was administered orally at a fixed dose of 80 mg m-2 day-1 from days 1 to 14 of a 28-day cycle. Paclitaxel was given intravenously on days 1, 8, and 15, starting with a dose of 40 mg m-2 day-1. The dose was increased in a stepwise manner to 70 mg m-2. Treatment was repeated every 4 weeks unless disease progression was confirmed. In the phase I portion, 17 patients were enrolled. The MTD of paclitaxel was estimated to be 70 mg m-2 because 40% of the patients given this dose level (two of five) had DLT. The RD was determined to be 60 mg m-2. In the phase II portion, 24 patients, including five with assessable disease who received the RD in the phase I portion, were evaluated. The median number of treatment courses was six (range: 1-17). The incidence of the worst-grade toxicity in patients given the RD was 28 and 8%, respectively. All toxic effects were manageable. The response rate was 54.1%, and the median survival time was 15.5 months. Our phase I/II trial showed that S-1 combined with paclitaxel is effective and well tolerated in patients with advanced gastric cancer.