Combination therapy with TS-1

The combination with cisplatin (CDDP) and 5-FU is considered the chemotherapy of choice for squamous cell carcinoma of the head and neck (HNSCC). TS-1, a modulation of tegafur developed in Japan, is an orally administered active agent for HNSCC. Some clinical phase I/II studies on the combination of CDDP and TS-1 have been reported. The combination showed a good response rate, 67.6% for both advanced and recurrent HNSCC, in our clinical phase II study. Regimens of TS-1 combined with carboplatin or nedaplatin are also reported.TS-1 containing regimens appear to be effective for HNSCC, and multi-institutional phase II studies with large sample size are needed in future.The combination TS-1 and radiotherapy, its dose and schedule,are being studied in phase I trials for advanced HNSCC. Patient compliance is better than with 5-FU injection because TS-1 is orally administered.The adverse effect, especially in terms of bone marrow toxicity, is equal or better than with 5-FU injection. The TS-1 combination with radiotherapy is a useful regimen for outpatients. The efficacy and adverse effects should be studied in carefully designed phase I/II trials. TS-1 will be one of the key drugs for HNSCC in future.     

S-1 for gastric cancer-S-1 monotherapy and its progress

Two pivotal phase II studies of S-1 in advanced gastric cancer showed response rates of 44% and 49%, and the overall survival time was 207 and 250 days, respectively. The response rate of S-1 exceeded the response rates of other approved drugs, and was comparable to that of combination chemotherapies such as 5-fluorouracil (5-FU) plus cisplatin (CDDP). These data suggested that S-1 could be used as a first-line drug for gastric cancer with a great advantage in quality of life (QOL), because it is an oral drug and can be used at an outpatient clinic. The overall incidences of adverse reactions in the phase II studies were 74.3%, and that of grade 3 or worse were 14.9%. The main adverse reactions were myelosuppression and GI toxicities. As hematological toxicity was more common than other oral fluoropyrimidine derivatives such as UFT, a careful hematological monitoring is necessary. To confirm the survival benefit of S-1 in advanced gastric cancer, a phase III trial of S-1 vs 5-FU vs CDDP plus irinotecan (CPT-11) has been conducted by the Japan Clinical Oncology Group (JCOG), and these results have been awaited. Furthermore, the combination of S-1 with CDDP, CPT-11 or taxane for the treatment of gastric cancer is feasible and active, and phase III studies of S-1 vs several combination therapies including S-1 are also in progress. The effect of S-1 in adjuvant setting is also promising. Currently, a phase III study of surgery alone vs S-1 in patients with a curative resection of gastric cancer has been developed. Further therapeutic benefits are also expected by combining S-1 with other chemotherapeutic agents such as molecular targeted agents.     

S-1 in gastric cancer: a comprehensive review

The current basic and clinical studies of S-1 (TS-1^®) were reviewed. S-1 is a novel oral dihydropyrimidine dehydrogenase (DPD) inhibitory fluoropyrimidine (DIF) based on a biochemical modulation of 5-fluorouracil (5-FU); S-1 contains tegafur (FT) and two types of enzyme inhibitor; 5-chloro-2,4-dihydroxypyridine (CDHP) and potassium oxonate (Oxo) in a molar ratio of 1?:?0.4?:?1. In pharmacokinetic studies, S-1 showed high 5-FU concentration in blood for long periods of time. In a combined analysis of two pivotal late phase II studies in gastric cancer, the overall response rate was 44.6% (45/101), and median survival time and 1-year survival rate were 244 days and 37%, respectively. A postmarketing survey was conducted, and in the interim analysis, tolerability and safety profiles were shown in 3294 patients with gastric cancer. The oral dose form and low incidence of adverse reactions permit treatment on an outpatient basis. To evaluate the survival benefit of S-1 in advanced gastric cancer, a phase III study of S-1 vs 5-FU vs cisplatin (CDDP) plus irinotecan (CPT-11) has been conducted. The effect of S-1 in adjuvant chemotherapy is also promising. Currently, a phase III study of surgery alone vs S-1 in patients with curative resection of gastric cancer is in progress. Further therapeutic benefits are expected to be gained by combining S-1 with other chemotherapeutic agents. Several preliminary results of combination phase I/II studies of S-1 with CDDP or CPT-11 have recently been obtained, and phase II studies are in progress. Thus, S-1 is currently the first candidate as the standard anticancer drug for gastric cancer. Further evaluations by well-controlled clinical trials are still needed.     

Concurrent chemoradiotherapy (CRT) with S-1 and cisplatin (CDDP) in patients (pts) with locally advanced head and neck cancer (HNC)

The standard care for unresectable locally advanced head and neck cancer (HNC) is concurrent chemoradiotherapy (CRT). Although there is no standard regimen of CRT, a platinum-based regimen has shown a better survival benefit than other regimens. The control arm in a randomized trial for unresectable locally advanced HNC is radiotherapy concurrent with CDDP (100 mg/m2, every 3 weeks), which has been considered to be too toxic for clinical practice in Western countries and has required frequent dose modifications. Because the Japanese also have been considered unable to tolerate this regimen, no prospective study of it has been conducted in Japan. Most Japanese patients with locally advanced head and neck cancer have received concurrent chemoradiotherapy with 5-FU and CDDP (70-80 mg/m2). S-1 has shown high activity in HNC with a response rate of 34%. Furthermore, a combination of cisplatin and S-1 therapy for HNC has been reported to have good efficacy. With this rationale in mind, we conducted a phase I study of CRT with S-1 and CDDP for unresectable locally advanced squamous cell carcinoma of the head and neck. The CR rate was very promising, though preliminary, and warrants further investigation. The Japan Clinical Oncology Group (JCOG) is planning a multicenter phase II study of concurrent chemoradiotherapy with S-1 and CDDP for locally advanced unresectable HNC.     

Chemotherapy for metastatic disease: review from JCOG trials

The Gastrointestinal Oncology Study Group of Japan Clinical Oncology Group (GIOSG/JCOG) has conducted several clinical trials to establish standard chemotherapy for unresectable or recurrent gastric cancer. From the late 1980s to early 1990s, two phase II studies by JCOG evaluated oral fluoropyrimidines, and others introduced Western chemotherapy regimens. Thereafter, the first phase III study (JCOG9205), comparing 5-fluorouracil (5-FU), 5-FU plus ciplatin (CDDP) (FP), and uracil and tegafur (UFT) plus mitomycin (UFTM), could not show a survival benefit of either FP or UFTM over 5-FU alone. In the late 1990s, new active agents such as irinotecan (CPT-11) and S-1 (new oral fluoropyrimidine) showed promising results in their phase II trials. The latest phase III study (JCOG9912), comparing 5-FU, CPT-11 plus CDDP, and S-1, showed significant noninferiority of S-1 to 5-FU in overall survival, associated with a better response rate and progression-free survival and acceptable toxicities, and concluded that S-1 should be considered for the standard chemotherapy of unresectable or recurrent gastric cancer. Simultaneously, another Japanese phase III trial comparing S-1 with S-1 plus CDDP showed a survival benefit of S-1 plus CDDP. At present, S-1 plus CDDP is recognized as standard chemotherapy for unresectable or recurrent gastric cancer, and new treatment with molecular target agents is under development.     

Effect of combination chemotherapy with nedaplatin and 5-FU for head and neck squamous cell carcinoma

Nedaplatin (254-S), which is a cisplatin (CDDP) analog, is an effective agent for head and neck squamous cell carcinoma (HNSCC). 254-S is expected to play an important role in neo-adjuvant chemotherapy (NAC) for HNSCC in place of CDDP. We have been using combination chemotherapy including CDDP, 5-FU, MTX and LV. The response rate and CR rate of this 4-drug combined chemotherapy are 87% and 33%. Thirty-six patients with HNSCC were treated with 5-FU, 800 mg/m2/day for 5 days and 254-S, 100 mg/m2 on day 4. Chemotherapy was discontinued in one patient because of allergic shock. Three patients showed a CR and 10 patients showed a PR. The response rate and CR rate of 254-S plus 5-FU chemotherapy were 37.1% and 8.6%. These were inferior to those with the 4-drug combined chemotherapy. Fourteen percent of patients showed grade 3 leukocytopenia, and 17% showed more than grade 3 thrombocytopenia. The effect of combination chemotherapy of 254-S and 5-FU was inferior to that of the previous chemotherapy including CDDP, 5-FU, MTX and LV. Further study or another combination therapy including 254-S will be essential for improving efficacy against HNSCC.     

Complete recovery obtained with combined S-1 + CDDP therapy in a patient with multiple lung metastases from esophageal cancer

PURPOSE: There are numerous reports on the subject of effectiveness in radio-chemotherapy with regard to esophageal cancer, suggesting especially the combination therapy of 5-FU + CDDP aimed for recovery. Treatment becomes difficult when distal metastases appear during an adjuvant therapy followed by surgery. Our report here is a case in which a complete recovery was obtained after changing to S-1, a prodrug of 5-FU, in response to multiple lung metastases which appeared during the combined 5-FU + CDDP therapy followed by surgery for esophageal cancer. CASE: The patient was a 71-year-old male. Endoscopy during a physical examination showed a Type 1 tumor 27-30 cm from the anterior teeth. Detailed tests provided a preoperative diagnosis of esophageal cancer: Ut Type 1, T2-T3, N2, MO, IMO. A right thoracolaparotomic subtotal esophagectomy and retrosternal reconstruction were performed. Pathological findings showed well-differentiated squamous cell carcinoma, pT1b (sm), pN1 (106-rec R), pStage II. Postoperative combination of 5-FU + CDDP (day 1-5, 5-FU 500 mg; CDDP 10 mg/body) was started. Because of the appearance of multiple lung metastases after the completion of 3 courses, 2 courses of S-1 + CDDP (S-1 120 mg/body day 1-14; CDDP 5 mg/body day 1-5, day 8-12) were performed. After completing the chemotherapy, CT revealed the resolution of the lung metastases and complete recovery was diagnosed. Following this, a treatment with S-1 alone was continued until the appearance of bone metastases at which time radiotherapy was performed. The treatment is currently ongoing and no recurrence of the lung metastases has been shown. CONCLUSION: There have been numerous reports of the combination of S-1 + CDDP in esophageal cancer for NAC or in inoperable cases. However, our report suggests that this method may be effective in cases of recurrence or distal metastases.     

Conceptual changes in cancer chemotherapy--biochemical modulation of 5-FU

Recently, the demand for more useful therapies for cancer patients has increased. We describe in this paper a therapeutic modality based on a self-rescuing concept (SRC), and which features dual activity, i.e., an effect-enhancing activity and an adverse reaction-reducing activity. We present the theory and practice of S-1, a novel oral fluoropyrimidine anticancer agent designed to enhance anticancer activity and reduce gastrointestinal toxicity through the deliberate combination of the following components: the oral fluoropyrimidine agent tegafur; a DPD inhibitor (CDHP) which is more potent than uracil, which is used in UFT; and an ORTC inhibitor (Oxo) which localizes in the gastrointestinal tract. S-1 is a combination drug with a molar ratio of 1:0.4:1 in FT, CDHP, and Oxo, respectively. A clinical pharmacology study was conducted to examine blood concentrations of 5-FU after twice-a-day administration of S-1 at a dose of 40 mg/m2. Blood concentrations of 5-FU were found to be 60 to 200 ng/ml in all twelve patients examined. The overall response rate was 44.6% (45/101). In addition, the incidence of adverse reactions judged to be grade 3 or higher was 10% or less. We have also reported a combination therapy with 5-FU (civ) (5-FU: 250 to 350 mg/body, 24-hour cvi, consecutive days) and low-dose cisplatin (CDDP: 3 to 5 mg/body, i.v., 5 days/week), in which CDDP was used as a modulator of 5-FU. Low-dose FP therapy provided response rates as high as 40 to 60% in 163 patients with various gastrointestinal cancers other than pancreas cancer. The incidence of the adverse reactions of nausea and vomiting which were judged to be grade 3 or higher was 2.5% (4/163). The incidences of other adverse reactions were 1% or less. In line with the theory and practice of combination therapy with 5-FU (cvi) 24 hr cvi; 5-FU: 750 to 1,000 mg/body/day on Monday, Wednesday, and Friday (withdrawal on Tuesday, Thursday, Saturday and Sunday) intermittent administration and low-dose CDDP (3 to 5 mg/body/day day 1-5/w) consecutive administration was utilized in which there was a difference in cell cycle between gastrointestinal mucosal cell and tumor cell, or between bone marrow cell and tumor cell. Few adverse reactions, e.g., diarrhea and stomatitis, were observed despite the overall response rate being as high as 52.4% (22/42). The incidence of adverse reaction judged to be grade 3 or higher was as low as 9.3% (5/54), with an incidence of 9.3% (5/54) in Grade 3 or higher myelotoxicity. We intend in the future to combine the abovementioned therapeutic modalities, which provoke fewer adverse reactions and are easy on patients with cancer in an effort to further increase their life expectancy.     

JCOG trials of systemic chemotherapy for unresectable or recurrent gastric cancer

From the late 1980s to the early 1990s, the Gastrointestinal Oncology Study Group of the Japan Clinical Oncology Group (GIOSG/JCOG) conducted several phase II studies, some of which evaluated oral fluoropyrimidines and others of which introduced Western regimens to Japanese patients. Thereafter, in the phase III study JOCG9205 comparing 5-fluorouracil (5-FU), 5-FU plus cisplatin (CDDP) (FP), and uracil and tegafur (UFT) plus mitomycin (UFTM), neither FP nor UFTM showed a survival benefit over 5-FU alone. Whereas irinotecan (CPT-11) and S-1 (new oral fluoropyrimidine) were developed with promising action against gastric cancer in the late 1990s, these agents cannot be used for patients with impaired oral intake and bowel passage caused by severe peritoneal metastasis. Sequential methotrexate (MTX) and 5-FU (MF) therapy showed substantial action against peritoneal metastasis. Thus, GIOSG/JCOG followed different treatment strategies according to the presence or absence of severe peritoneal metastasis. The phase III study JCOG9912, comparing 5-FU, CPT-11 plus CDDP, and S-1, showed a highly significant noninferiority of S-1 to 5-FU in overall survival associated with acceptable toxicities and concluded that S-1 should be considered for the standard chemotherapy for gastric cancer without severe peritoneal metastasis. For patients with severe peritoneal metastasis, the phase III study JCOG0106 compares MF to 5-FU. In that study, patient enrollment has been completed and a final analysis is planned at the end of 2008. The randomized phase II study JCOG0407 compares the best available 5-FU with weekly paclitaxel after failure in first-line chemotherapy containing 5-FU.     

Chemotherapy for metastatic gastric cancer in Japan

Until the 1990s, there were no chemotherapy regimens with old-generation anticancer agents showing a survival benefit over 5-fluorouracil (FU) alone, and standard chemotherapy for metastatic gastric cancer had not been established. In the late 1990s, several new active agents were developed and some phase III trials with these agents were conducted; the new agent S-1 showed noninferiority to 5-FU in these trials. S-1 plus cisplatin is the first doublet chemotherapy to have shown a survival benefit over monotherapy with S-1. It has been demonstrated that capecitabine and oxaliplatin (OHP) can replace 5-FU and cisplatin (CDDP), offering more convenient treatment options. Thus, combination chemotherapy with an oral fluoropyrimidine (S-1 or capecitabine) and platinum (CDDP or OHP) has been recognized as standard chemotherapy for metastatic gastric cancer all over the world. However, it can be said that none of these new combination chemotherapies have shown remarkable progress from 5-FU plus cisplatin regimens. It is expected that triplet chemotherapy with a taxane; the use of molecular targeting agents; and the establishment of treatment strategies including second line chemotherapy, will lead to remarkable progress in personalized medicine in the near future.     

A phase I study of sorafenib in combination with S-1 plus cisplatin in patients with advanced gastric cancer

Background

Sorafenib inhibits several receptor tyrosine kinases involved in tumor progression and angiogenesis. S-1, an oral fluorouracil antitumor drug, plus cisplatin (CDDP) is the standard regimen for advanced gastric adenocarcinoma (AGC) in Japan. The purpose of this phase I study was to evaluate the safety, pharmacokinetics, and preliminary efficacy of sorafenib in combination with S-1 plus CDDP.

Methods

Patients with histologically confirmed previously untreated AGC were evaluated for eligibility and treated with sorafenib (400 mg bid, days 1–35), S-1 (40 mg/m² bid, days 1–21), and CDDP (60 mg/m², day 8). Treatment was continued until disease progression or unacceptable toxicity. Pharmacokinetics for sorafenib, 5-FU, and CDDP were investigated in cycle 1.

Results

Thirteen patients were enrolled and received at least one dose of the study treatment. No specific or serious adverse event was newly reported in this study. Five patients had partial response and 8 had stable disease as the best response. Pharmacokinetic analysis showed no significant differences in the exposures of sorafenib when administered alone or in combination with S-1 and CDDP.

Conclusions

The present phase I study demonstrates the acceptable toxicity and preliminary efficacy of combined treatment with S-1, CDDP, and sorafenib.     

Clinical efficacy of administration with S-1 alone for head and neck carcinoma

Most head and neck carcinomas are squamous cell carcinomas (HNSCCs). The combination of cisplatin with a continuous infusion of 5-fluorouracil (5-FU) has been a standard chemotherapy regimen for HNSCC. Based on basic and clinical studies, the critical plasma concentration of 5-FU is suspected to be about 0.1 microg/ml. The administration of the conventional dose of S-1 including dihydropyrimidine dehydrogenase (DPD), an metabolic inhibitor of 5-FU, results in exceeding the critical plasma concentration of 5-FU, and the long-term administration with high plasma concentration of 5-FU is considered to show clinical effectiveness in head and neck cancer. The results of early and late phase II studies on head and neck carcinoma were also described in the present paper.     

Combination chemotherapy with S-1 and carboplatin for head and neck cancers

Chemotherapy plays an important role in the treatment of head and neck cancer (HNC) patients with recurrent and/or metastatic unresectable disease. The standard regimen for HNC has been a combination of cisplatin (CDDP) and 5-fluorouracil (5-FU). We planned to develop a new outpatient regimen that could be carried out safely and had an antitumor activity equivalent to the regimen of CDDP plus 5-FU. For this purpose, we selected a combination of S-1 and carboplatin. The overall response rate of 40.9% in this study was almost equivalent to the study previously reported on 5-FU plus CDDP. This regimen of S-1 plus carboplatin has the possibility of yielding tumor responses equivalent to a conventional regimen of 5-FU combined with CDDP in patients with recurrent and/or metastatic head and neck carcinoma as a second-line palliative chemotherapy.     

Combination therapy with molecular targeting drugs for head and neck cancer

Concurrent chemoradiotherapy (CCRT) is one of the standard treatments for advanced head and neck cancer (HNC). Intensive combination chemotherapy has been re-considered for neo-adjuvant chemotherapy in functional preservation protocol. Molecular targeting drugs (MTG) have proved effective for HNC not only in basic study but in many clinical phase II trials. Cetuximab, an anti-EGFR monoclonal antibody, is a key drug for regimens including MTG. Phase III trials with CDDP/carboplatin+5-FU vs CDDP/carboplatin+5-FU+cetuximab proved the combination with cetuximab was statistically effective for survival of patients with recurrent/metastatic HNC. Combination with cetuximab prolonged survival from 7.4 months to 10.1 months in this report. A good response rate and survival rate are reported in phase II study for chemoradiotherapy with CDDP and cetuximab. The three-year overall survival and local control rate were 76% and 71%, respectively. The combination with MTG will be important in CCRT for advanced HNC. It may well be considered the standard treatment for recurrent/metastatic HNC patients in future.     

Conceptual changes in cancer chemotherapy--biochemical modulation of 5-FU from bench to clinic

Recently, a demand for therapy of higher usefulness in cancer patients has increased. We described in this paper a therapeutic modality which is based on SRC (self-rescuing concept) featuring dual activity, i.e., effect-enhancing activity and adverse reaction-reducing activity. We presented the theory and practice of S-1, a novel oral fluoropyrimidine anti-cancer agent designed to enhance anticancer activity and reduce gastrointestinal toxicity through the deliberate combination of the following components: an oral fluoropyrimidine agent tegafur; a DPD inhibitor (CDHP) which is more potent than uracil used in UFT; and an ORTC inhibitor (Oxo) which localizes in the gastrointestinal tract. S-1, as a combination drug with a molar ratio of 1:0.4:1 in FT, CDHP, and Oxo, respectively. A clinical pharmacology study to examine blood concentrations of 5-FU after twice-a-day administration of S-1 at a dose 40 mg/m2. Consequently , blood concentrations of 5-FU were 60 to 200 ng/m/ in all twelve patients examined. The overall response rate was 44.6% (45/101). In addition, the incidence of adverse reactions judged to be G3 or higher was 10% or less. Furthermore, we referred to combination therapy with 5-FU (CIV)(5-FU: 250 to 350 mg/body, 24-hour CVI, consecutive days) and low-dose cisplatin (CDDP: 3 to 5 mg/body, iv, 5 days/week) in which CDDP was used as modulator of 5-FU. Low-dose FP therapy provided response rates as high as 40 to 60% in 163 patients with sorts of gastrointestinal cancers except pancreas cancer. The incidence of adverse reactions which were judged to be G3 or higher was 2.5% (4/163) in nausea and vomiting. The incidences of other adverse reactions were 1% or less. And to the theory and practice of combination therapy with 5-FU (CVI) 24-hour CVI; 5-FU: 750 to 1000 mg/body/day on Monday, Wednesday, and Friday; withdrawal on Tuesday, Thursday, Saturday, and Sunday) intermittent administration and low-dose CDDP (3 to 5 mg/body/day day 1-5/w) consecutive administration in which a difference in cell cycle between gastrointestinal mucosal cel l and tumor cell or between bone marrow cell and tumor cell was utilized . Little adverse reactions, e.g., diarrhea and stomatitis, were observed despite the overall response rate which was as high as 52.4% (22/42). We intend in the future to combine the above mentioned therapeutic modalities provoking less adverse reactions and being gentle to patients with cancer in an effort to further increase their life expectancy.     

S-1+Low-Dose CDDP

A review of the published literature was undertaken to ascertain the trends in treatment schedules of combination of an oral fluorouracil derivative S-1 with low-dose CDDP (25 mg/m2 or less) for un-resectable and recurrent gastric cancer. The case reports demonstrated as follows: S-1 was given as standard doses of 80-120 mg/body. With regard to CDDP administration, 4 mg/m2 or less was given for 4-consecutive weeks following 2-weeks rest and 6-10 mg/m2 was given for 3-consecutive weeks following 2-weeks rest in the case of 5-day/week CDDP administration. There have been reports of 6-8 mg/m2 CDDP given once or twice a week and weekly CDDP of 10-25 mg/m2 without grade 3 or more adverse events. A phase I study demonstrated the recommend dose of CDDP in the case of 5-day/week was 4 mg/m2 in the regimen of 4-consecutive weeks and 2-weeks rest with a standard dose of S-1. Three phase I studies on weekly low-dose CDDP with S-1 showed the recommend doses were 20-25 mg/m2. S-1+low-dose and a high-dose (30-90 mg/m2) CDDP have come into wide use in Japan. There have been no differences between the case reports and the clinical studies in quantity and quality for both regimens. The unified regimen of S-1+low-dose CDDP as an outpatient based chemotherapy should be developed.     

Clinical development of S-1 (TS-1) for advanced gastric cancer

The 5-FU plus cisplatin containing regimen like FP, ECF and DCF, is considered to be the most effective treatment for advanced gastric cancer in the United States, Europe, and Korea. In Japan, oral fluoropyrimidine S-1 (TS-1) is currently considered to be the first candidate as the standard drug for advanced gastric cancer. S-1 based combination therapies with other promising drugs like cisplatin, irinotecan and taxanes, are expected to yield good results. Above all, S-1+CDDP therapy showed a high efficacy and expected to be a standard therapy for advanced gastric cancer. Two large phase III studies, JCOG 9912 5-FU vs S-1 vs CPT-11 +CDDP and S-1 vs S-1+CDDP, are now on going to establish an acceptable frontline standard for patients with AGC. We therefore need to develop new agents and combination chemotherapy regimens to achieve a greater survival benefit in AGC.     

Relationship between expression of vascular endothelial growth factor in tumor tissue from gastric cancers and chemotherapy effects: comparison between S-1 alone and the combination of S-1 plus CDDP

BACKGROUND: We have reported that vascular endothelial growth factor (VEGF) expression in gastric cancers might be a selective marker between 5-fluorouracil (5-FU) and a combination of 5-FU plus cisplatin (CDDP). In this study, the relationship between VEGF expression and effects of S-1 with and without CDDP is investigated. METHODS: The subjects were 44 patients treated with S-1 (40 mg/m2, twice daily, days 1-28, repeated every 6 weeks) and 24 patients treated with S-1 plus CDDP (S-1 40 mg/m2, twice daily, days 1-21, CDDP, 60 or 70 mg/m2, day 8, repeated every 5 weeks). VEGF expression in pretreatment endoscopic biopsy samples was assessed immunohistochemically. RESULTS: Median survival times (MST) of the patients treated with S-1 and S-1 plus CDDP were 344 and 388 days. Among evaluable patients, the response rates of patients with VEGF (+) and (-) tumors to S-1 were 40% (6/15) and 54% (13/24), and to S-1 plus CDDP, 79% (15/19) and 80% (4/5). While the survival of patients with VEGF (-) tumors was slightly longer than those with VEGF (+) tumors in the S-1 group (MST, 425 versus 308 days, P = 0.42), patients with VEGF (+) tumors survived remarkably longer than those with VEGF (-) tumors in the S-1 plus CDDP group (MST, 570 versus 333 days, P = 0.19). CONCLUSION: Similarly to our previous study, it is suggested that the effects of adding CDDP to S-1 might be more remarkable in gastric cancer patients with VEGF (+) tumors than in those with VEGF (-) tumors. These results should be confirmed in a large phase III study.     

Combination chemotherapy with S-1 and cisplatin for non-small cell lung cancer

S-1 is a newly developed oral anti-tumor agent, which contains 5-chloro-2, 4-dihydroxypyridine and potassium oxonate to strengthen biological activities of 5-fluorouracil. Response rate of S-1 for advanced non-small cell lung cancer was reported to be 12.5-22%. Response rate of combination chemotherapy with S-1 plus cisplatin (CDDP) was reported to be 47%, and the median survival time was 11 months. Adverse events of the combination chemotherapy were milder than other combination chemotherapy described before. Therefore, S-1 plus CDDP combination chemotherapy is a future candidate for phase III clinical study.