An experimental model of tumor dormancy therapy for advanced head and neck carcinoma.

An experimental model of tumor dormancy therapy for advanced head and neck carcinoma was developed. After transplantation of KB cells into nude mice, the mice were given tiracoxib, a selective cyclooxygenase (COX)-2 inhibitor, probucol, an antioxidant, and S-1, an oral pro-drug of 5-fluorouracil (5-FU), or combinations of two of them. The combined administration of tiracoxib with probucol significantly inhibited the tumor growth. The angiogenesis in this group was markedly reduced. Tiracoxib and probucol did not affect the intratumoral concentration of 5-FU when coadministered with S-1. The combined use of tiracoxib and probucol is thus a candidate for use in maintenance therapy after the primary therapy for patients with advanced head and neck carcinoma.     

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.     

Hypercalcemia in head and neck squamous-cell carcinoma

Hypercalcemia was previously considered a terminal phenomenon in advanced head and neck squamous-cell carcinoma. We report on six patients with head and neck carcinoma and hypercalcemia refractory to conventional measures. Three patients had stage IV tumor not amenable to surgery or radiation therapy and three others had carcinoma recurrent after surgery and/or radiation therapy. Five of the six patients had paraneoplastic hypercalcemia and one had extensive bone metastases. One refused chemotherapy and died in 2 months. Five treated with cisplatin 100 mg/m2 i.v. and 5-fluorouracil (5-FU) 960 mg/m2/day x 5, on days 2-7 as a continuous infusion, had prolonged control of hypercalcemia and required no other therapy to maintain eucalcemia. All three patients with no prior therapy, and one of the two patients with recurrent cancer, had a partial response after chemotherapy. The survivals of the patients with recurrent cancer were 1 and 3 months. The survivals in the patients with no prior antitumor therapy were 10, 11+, and 23 months, respectively. In conclusion, hypercalcemia in head and neck carcinoma can be well controlled by cisplatin and 5-FU chemotherapy for a prolonged period. The impact of chemotherapy on survival was minimal in patients with recurrent cancer. In contrast, patients with hypercalcemia at initial presentation of an advanced head and neck cancer have a high likelihood of tumor control and prolongation of survival by chemotherapy.     

Combination therapy with S-1 and CDDP for head and neck cancer

The combination with cisplatin (CDDP) and 5-FU is considered the first choice chemotherapy for squamous cell carcinoma of the head and neck (HNSCC). S-1, a modulation of tegafur developed in Japan, is an active agent for HNSCC. Some clinical phase I/II studies about the combination with CDDP and S-1 have been reported. The combination showed a good response rate of 67.6% for advanced and recurrent HNSCC in our clinical phase I/II study. The regimens of S-1 combined with carboplatin or nedaplatin have also been reported. Regimens containing S-1 appear to have been effective for HNSCC. Multi-institutional phase II studies with a large sample size are needed in the future. The compliance for patients is better than a 5-FU injection because S-1 is orally administrated. The adverse effect, especially for bone mallow toxicity, is equal or upgraded compared with a 5-FU injection. The efficacy and adverse effects of CDDP plus S-1 should be studied in carefully designed phase II/III trials. S-1 will be one of the key drugs for HNSCC in the future.     

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.     

Adjuvant chemotherapy for high-risk squamous-cell carcinoma of the head and neck

A prospective clinical trial was developed to evaluate efficacy, toxicity, and patient compliance to adjuvant chemotherapy following surgery and postoperative radiation therapy in patients with squamous-cell carcinoma of the head and neck with extracapsular spread of tumor in cervical metastases. Following postoperative radiation therapy, 18 courses of methotrexate (MTX) and 5-fluorouracil (5-FU) were administered over 6 months. Fifty patients were registered. A total of 771 doses were administered. Dose reduction was required 72 times. Therapy was stopped in one patient (2%) because of toxicity. Three patients (6%) refused to complete the adjuvant therapy. Adjusted 2-year no evidence of disease (NED) survival is 66%. This study demonstrates that patients with advanced squamous-cell carcinoma of the head and neck can undertake an aggressive program of adjuvant MTX/5-FU with acceptable compliance and toxicities. Preliminary data generated in this nonrandomized study support the call for a prospective randomized multiinstitutional trial of this program.     

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.     

Gimeracil, a component of S-1, may enhance the antitumor activity of X-ray irradiation in human cancer xenograft models in vivo

Chemoradiotherapy is a useful treatment strategy in patients with locally advanced cancers. In particular, combination of 5-fluorouracil (5-FU) with X-ray irradiation is effective for the treatment of some types of gastrointestinal cancers. We investigated the antitumor effects of combination treatment with X-ray and S-1, a unique formulation of 5-FU, on human cancer xenografts in nude mice and compared the efficacy of this treatment to that of radiotherapy combined with cisplatin, UFT, another oral 5-FU prodrug, and intravenous 5-FU. Tumors implanted into the left hind legs of mice were treated with a dose of 2 or 5 Gy X-ray irradiation on days 1 and 8, and S-1, UFT and 5-FU were administered for 14 days. The efficacy of combined treatment with 8.3 mg/kg S-1 and 2 Gy X-ray irradiation in treating non-small cell lung cancer xenografts (Lu-99 and LC-11) was significantly higher than that of treatment with S-1 alone or 2 Gy X-ray irradiation alone, and the antitumor activity of combined treatment was similar to that of 5 Gy X-ray irradiation alone. Although 8.3 mg/kg S-1 and 17.5 mg/kg UFT had equivalent antitumor activity; the antitumor efficacy of combination treatment with S-1 and 2 Gy X-ray irradiation on LC-11 tumors was significantly higher than that of combination treatment with UFT and 2 Gy X-ray irradiation. Combination treatment with S-1 and X-ray irradiation was also more effective against pancreatic tumors than combination treatment with intravenous 5-FU and X-ray irradiation. To elucidate the reason for the increased antitumor efficacy of combination treatment with S-1 and X-ray irradiation, the antitumor effect of gimeracil, one of the components of S-1, was tested in combination with 2 Gy X-ray irradiation. These experiments demonstrated that gimeracil enhanced the efficacy of X-ray irradiation against lung as well as head and neck cancer xenografts in a dose-dependent manner. Furthermore, we observed decreased expression of γ-H2AX protein, a marker of DNA repair, in LC-11 tumors treated with X-ray irradiation and gimeracil compared to that observed in tumors treated with X-ray irradiation alone, suggesting that gimeracil may inhibit rapid repair of X-ray-induced DNA damage in tumors. The present study suggests that chemoradiotherapy using S-1 acts through a novel mechanism and may prove useful in treating patients with locally advanced cancers whose disease progression is difficult to control using chemotherapy alone.     

Combined therapy with a thymidylate synthase-inhibiting vector and S-1 has effective antitumor activity against 5-FU-resistant tumors

High levels of intratumoral thymidylate synthase (TS) expression are associated with resistance to 5-fluorourcil (5-FU). In order to establish a new treatment method for 5-FU-resistant tumors, the efficacy of gene therapy was investigated using an adenoviral vector expressing short hairpin RNA (shRNA) targeting TS. A replication-deficient recombinant adenoviral vector expressing shRNA targeting TS was constructed under the control of the human U6 promoter (Ad-shTS). Three 5-FU-resistant cancer cell lines, DLD-1/5FU, KM12C/5FU and NUGC-3/5FU, were used. Transduction with Ad-shTS effectively downregulated TS expression in all three 5-FU-resistant tumor cells. MTT assays demonstrated that treatment with Ad-shTS significantly inhibited the growth of all three 5-FU-resistant tumor cells. Furthermore, combined treatment with Ad-shTS and 5-FU demonstrated significantly greater inhibition of tumor cell growth in comparison to 5-FU treatment alone and Ad-shTS treatment alone. S-1, a combination of tegafur, gimeracil and oteracil potassium, was used for the 5-FU treatment by in vivo experiments. The combined treatment of Ad-shTS and S-1 was found to have the strongest antitumor effect against 5-FU-resistant DLD-1/5FU xenografts in nude mice in comparison to S-1 treatment alone and Ad-shTS treatment alone. Furthermore, the apoptotic index in tumors treated with combined Ad-shTS and S-1 was significantly higher in comparison to that in tumors treated with S-1 alone and that in tumors treated with Ad-shTS alone. Consequently, the combined treatment of the TS-inhibiting adenoviral vector and S-1 has effective antitumor activity against 5-FU-resistant tumors.     

S-1, an oral fluoropyrimidine, enhances radiation response of DLD-1/FU human colon cancer xenografts resistant to 5-FU

S-1, a novel oral fluoropyrimidine, is increasingly used for the treatment of human cancer including gastrointestinal carcinomas. Using the 5-FU resistant DLD-1/FU human colon cancer cell xenografts, the present study investigated whether S-1 enhances the therapeutic efficacy of radiation and if so what are the underlying mechanisms. Nude mice bearing tumor xenografts were treated with radiation, S-1, or both. Tumor growth delay was the treatments' endpoint. To determine whether S-1 enhances intrinsic cell radiosensitivity, we performed clonogenic cell survival assay. Also we assessed the expression of thymidylate synthase (TS) using immunohistochemistry assay. While S-1 or 5 Gy were only slightly effective as single agents in delaying tumor growth, the combined treatment was highly effective. Clonogenic cell survival showed that S-1 strongly enhanced cell radiosensitivity. Immunohistochemistry showed that the expression of TS was down-regulated in tumors treated by S-1 plus radiation. Combined S-1 plus radiation treatment resulted in a synergistic effect in the therapy of 5-FU resistant human colon carcinoma xenografts (EF = 2.06). The effect could be attributed to the ability of S-1 to increase cell radiosensitivity (EF = 1.9) and to the down-regulation of TS involved in cellular processes leading to radio- and (or) chemo-resistance.     

Severe advanced lower gingival carcinoma effectively reduced by chemoradiation with S-1--report of a case

Severe advanced head and neck carcinoma which can not be removed via surgical procedure combined with a large lymph node metastasis has a poor prognosis. We administered concurrent chemoradiotherapy with S-1 for a lower gingival carcinoma. As a direct result, we discovered that the treatment greatly reduced the size of tumor, and we consider that this treatment prolonged the patient.s life. The treatment results suggest that the so-called dormancy state of the tumor was continued. In this case study, radiotherapy with S-1 showed a highly effective response from the viewpoint of QOL improvement.     

Prevention of peritoneal metastasis of human gastric cancer cells in nude mice by S-1, a novel oral derivative of 5-Fluorouracil

OBJECTIVE: Recent clinical trials have suggested that oral administration of a new anti-cancer agent, S-1, seems a promising therapy for advanced gastric cancer. In this study, we assessed the efficacy of S-1 against peritoneal dissemination of gastric cancer in a newly developed animal model and investigated the efficacy of S-1 from a pharmacokinetic angle. METHODS: Human gastric cancer cells (MKN-45) were injected into the peritoneal cavity of nude mice. The cancer cells were transduced using an enhanced green fluorescent protein (EGFP)-expressing plasmid vector, enabling micrometastatic foci to be accurately assessed with a high level of detection sensitivity. To investigate pharmacokinetics, the concentration of 5-FU was determined in tumor, peritoneum and plasma. RESULTS: Fourteen and 21 days after intraperitoneal injection, a significant difference in the number of fluorescent foci was observed between the control group and the S-1 group (p = 0.02 and p = 0.0024, respectively. The therapeutic effect of S-1 was significantly greater than that of 5-FU. Furthermore, S-1 treatment greatly improved the survival time and cachexia. The area under the curve of 5-FU in tumor was higher than in the peritoneum and plasma. CONCLUSION: Oral S-1 is a promising chemotherapy for peritoneal dissemination of gastric cancer.     

Intra arterial infusion chemotherapy combined with interferon-alpha following palliative hepatic resection against advanced hepatoma with portal venous tumor thrombus in the major trunk and multiple nodules--a preliminary study

Recently, we reported the beneficial effects of intra arterial 5-FU infusion chemotherapy combined with interferon-alpha (IFN-alpha/5-FU combined chemotherapy) for advanced hepatocellular carcinoma (HCC). This report describes the preliminary results of treatment of IFN-alpha/5-FU combined chemotherapy following palliative hepatic resection for advanced hepatocellular carcinoma with tumor thrombus in the main trunk of the portal vein with multiple nodules in the whole liver. The 15 patients of HCC with portal venous tumour thrombi (PVTT) and multiple intra-hepatic multiple nodules (IM3) were treated with IFN-alpha/5-FU combined chemotherapy following palliative surgery in this study. No leukopenia, thrombocytopenia, or myelosuppression was observed in any of the 15 patients. Other adverse effects were, in general, clinically manageable. Concerning the anti-tumor effect, 6 showed an objective response and 9 showed a progressive disease; the response rate was 40.0% (6/15). The 1-year and 3-year survival rates were 48% and 21% in all 15 cases, respectively. In conclusion, IFN-alpha/5-FU combined therapy may be a promising modality for advanced HCC with tumor thrombi in the major trunk with multiple nodules after following palliative surgery.     

Antitumor effects of bevacizumab in combination with fluoropyrimidine drugs on human oral squamous cell carcinoma

Vascular endothelial growth factor (VEGF) serves an important role in new blood vessel formation or angiogenesis, which is a critical event in tumor growth and metastasis. Bevacizumab is a humanized monoclonal antibody against VEGF-A, whereas S-1 is a fluoropyrimidine antineoplastic agent that induces apoptosis in various types of cancer cells. The present study evaluated the antitumor effects of bevacizumab in combination with 5-fluorouracil (5-FU) or S-1 against oral squamous cell carcinoma (OSCC) in vitro and in vivo. Two human OSCC cell lines were used, namely the high VEGF-A-expressing HSC-2 cells and the low VEGF-A-expressing SAS cells. MTT assay was used to evaluate the effect of bevacizumab and/or 5-FU against HSC-2 and SAS cell proliferation. Additionally, the antitumor effect of bevacizumab was evaluated alone and in combination with S-1 against HSC-2 tumors in nude mice. S-1 (6.9 mg/kg/day) was administered orally every day for 3 weeks, and bevacizumab (5 ml/kg/day) was injected intraperitoneally twice per week for 3 weeks. Apoptotic cells in mouse tumors were detected using the TUNEL method, and cell proliferation and microvessel density (MVD) were determined by immunohistochemical staining of Ki-67 and CD31, respectively. Bevacizumab alone did not inhibit OSCC cell proliferation in vitro, and did not exhibit any synergistic inhibitory effect in combination with 5-FU in vitro. However, combined bevacizumab and S-1 therapy exerted synergistic and significant antitumor effects in vivo on HSC-2 tumor xenografts, and induced apoptosis in tumor cells. Furthermore, this combination therapy led to decreased MVD and cell proliferative abilities, as well as increased apoptosis in residual tumors. The present findings suggested that the bevacizumab plus S-1 combination therapy may exert antitumor effects in high VEGF-A-expressing OSCC cells.     

Radiation Therapy With 5-fluorouracil in Head and Neck Cancer

5-Fluorouracil (5-FU) alone or combined with other drugs, most frequently cisplatin, has been used concurrently or as induction or adjuvant therapy with radiotherapy with or without surgery in the treatment of head and neck cancer. Improved local-regional control and disease-free survival or overall survival have been shown in several randomized trials using a concurrent approach. However, acute mucositis is usually increased with simultaneous 5-FU and radiation administration, especially when other drugs are used in addition to 5-FU. Alternating radiotherapy with 5-FU and cisplatin was shown to improve the local-regional relapse-free, progression-free, and overall survival of unresectable squamous cell carcinoma of the head and neck compared with radiotherapy alone in one randomized trial. Further evaluation of the alternating chemotherapy and radiotherapy approach is needed, however, before one can accept this as a standard of practice. Induction chemotherapy with 5-FU infusion and cisplatin followed by definitive radiotherapy in the chemotherapy responders in an alternative treatment option for patients with locally advanced resectable squamous cell carcinoma of the larynx or hypopharynx who wish to preserve organ function. Induction or adjuvant chemotherapy with 5-FU infusion and cisplatin may also decrease or delay the occurrence of distant metastasis. Induction chemotherapy, however, has not been shown to improve local-regional control or overall survival. Further clinical trials combining 5-FU and its biochemical modulators using innovative radiation and drug dose schedules and other treatment modifiers are needed to improve the therapeutic ratio.     

S-1 eliminates MDSCs and enhances the efficacy of PD-1 blockade via regulation of tumor-derived Bv8 and S100A8 in thoracic tumor

Myeloid-derived suppressor cells (MDSCs) have been known to play a pivotal role in the induction of immune tolerance, which limits the benefits of immune checkpoint inhibitors (ICIs). Recent studies revealed that several chemotherapeutic agents decreased tumor-infiltrating MDSCs. Therefore, combination therapy with cytotoxic chemotherapeutic agents and ICIs was approved for first-line treatment for lung cancer. However, the impact of chemotherapeutic agents on MDSCs and an optimal partner of ICIs has not been fully investigated in thoracic tumors, including lung cancer and malignant pleural mesothelioma. In the present study, we found that treatment with 5-FU and its oral formulation, S-1, suppressed tumor progression and inhibited the accumulation of MDSCs in thoracic tumor-bearing mice. Tumor-infiltrating T cells and dendritic cells were significantly expanded in S-1-treated mice. 5-FU suppressed the ability of tumor cells to recruit MDSCs, while it did not suppress the survival and differentiation of mouse MDSCs in vitro. We also revealed that 5-FU or S-1 significantly downregulated the expression of tumor-derived Bv8 and S100A8. The knockdown of Bv8 or S100A8 in tumor cells suppressed tumor growth and MDSC recruitment in vivo. Furthermore, in comparison with pemetrexed, administration of S-1 improved the synergistic therapeutic efficacy of anti-PD-1 antibodies with or without carboplatin. Our findings revealed a novel mechanism wherein S-1 primed a favorable tumor microenvironment to provide the rationale for combination therapy with S-1 and ICIs as the optimal therapy for thoracic cancer.     

Timeline from discovery of 5-FU to development of an oral anticancer agent S-1 and its drug concept

C. Heidelberger et al left great gifts to us. Approximately 50 years have elapsed since their discovery of 5-FU in 1957 before eventually elucidating the mechanisms by which the drug exerts its pharmacological actions and provokes its adverse reactions. Namely, 5-FU is a typical antimetabolite with strong time dependency, and continuous venous infusion(CVI) is considered to be its optimal regimen. The following facts may be mentioned to explain why such a long period of time has been spent to reach this level of research: 1) 5-FU, when administered to the living individual, is mostly inactivated by hepatic catabolic enzymes without delay and is then excreted in the urine, thus making it difficult to precisely analyze the relationship of blood 5-FU concentrations with concentration persistence, anticancer activity, and adverse reactions; and 2) unlike other anticancer agents, an antimetabolite 5-FU separately generates metabolites which show anticancer activity and adverse reactions, as well as metabolites which show adverse reactions only. For the last 30 years, we paid attention especially to 5-FU among chemotherapeutic agents for cancer and have sought for a long-lasting therapeutic modality which maintains quality of life of the patient and patient compliance by considering the balancing between its effects and adverse reactions. Consequently, we concretized an innovative therapeutic drug, TS-1 (S-1). We have a long history of research before developing S-1, which is represented by a series of investigations consisting in the developments of Futrafur (FT)--an oral anticancer agent of a 5-FU derivative (prodrug)-in 1970 subsequent to the above discovery of 5-FU, of UFT(FT: Ura=1 : 4) in 1976, and of S-1 in 1999. To date, we took the initiative in the world to devise S-1, the first self-rescuing concept(SRC)-based anticancer agent with dual actions, i.e., enhancement of pharmacological actions of 5-FU and reduction of its adverse reactions, by making use of the biochemical and enzymological properties of 5-FU and by combining FT, which is gradually converted to 5-FU in the body, with a 5-FU's effect-enhancing substance and a 5-FU's adverse reaction-reducing substance. S-1 is an oral anticancer agent in capsule, in which the following 2 modulators for 5-FU are combined to FT: one is CDHP(5-chloro-2,4-dihydroxypyridine) which increases blood concentrations and enhances pharmacological actions of 5-FU by potently inhibiting the degradation of 5-FU; and another is Oxo(potassium oxonate) which is localized in the mucosa of the gastrointestinal (GI) tract after oral administration and reduces GI toxicities provoked by 5-FU. S-1 is an oral anticancer agent in which these 3 components, FT, CDHP, and Oxo, are combined at a molar ratio of 1 : 0.4 : 1. Our conception to develop an SRC-based therapeutic drug and the preclinical concepts validated by numerous basic studies were demonstrated also in the clinical trials. In January 1999, S-1 was approved for the treatment of advanced and recurrent gastric cancers through the priority review system. From 2001 to 2005, S-1 was approved for the treatment of head and neck cancer, colon cancer, non-small cell lung cancer, and breast cancer. S-1 has been applied to acquire its expanded indications for the treatment of pancreatic cancer and biliary tract cancer. We are confident that the combined regimen of S-1 with other anticancer agents and with other therapeutic modalities will contribute to the routine medical practice of cancer treatment in the future.     

Combination therapy with methotrexate and 5-fluorouracil: a prospective randomized clinical trial of order of administration

Because of biochemical and tissue culture evidence casting doubt on the physiologic relevance of reported synergy afforded by sequential administration of methotrexate (MTX) followed by 5-fluorouracil (5-FU), a randomized controlled clinical trial was conducted in 108 patients with advanced cancer, including 70 with squamous cell carcinoma (SCC) of the head and neck, nine with SCC of other primary sites, 24 with colorectal, and five with gastric adenocarcinomas. Patients were randomized to receive weekly therapy consisting of MTX followed one hour later by 5-FU, or 5-FU followed one hour later by MTX. There was a trend to higher tumor response rates in patients treated with MTX before 5-FU (45% v 33% overall; 65% v 39% in patients with previously untreated head and neck cancer), but these differences were not significant, either by chi-square test or by multivariate stepwise logistic regression. The trend in survival favoring the reverse sequence of 5-FU before MTX was not significant in univariate analyses. Stepwise multivariate Cox model analysis showed that Eastern Cooperative Oncology Group performance status at study entry was the major prognostic factor for survival (P less than 0.001), but among the 70 patients with head and neck cancer, the sequence of drug administration was the only other significant prognostic factor for survival, and favored the sequence of 5-FU followed by MTX (P less than 0.025).     

S-1 treatment against advanced HCC

We have reported a remarkably high anti-tumor efficacy using intra arterial 5-FU infusion chemotherapy combined with subcutaneous interferon-alpha injection to treat advanced hepatocellular carcinoma (HCC) with portal vein thrombus. However, we have been confirming distant metastases along with a prognosis extension as hepatic lesions could possibly be controlled to a certain extent. Even though there has been no effective chemotherapy against hepatocellular carcinoma with distant metastases, we performed S-1 and interferon-alpha combination chemotherapy for the cases where good results were exhibited from interferon-alpha combined with arterial 5-FU infusion. As a result, we confirmed CR in the anti-tumor effect against distant metastases with no severe adverse effects. It was suggested that a combination therapy of S-1 and interferon-alpha may be one of the most effective treatment modalities against advanced HCC with distant metastases.     

Cisplatin and 5-fluorouracil chemotherapy in advanced or recurrent squamous cell carcinoma of the head and neck

Fifty-three patients with advanced or recurrent squamous cell carcinoma of the head and neck (SCCHN) were treated with bolus cisplatin (CDDP) and 96-hour infusion of 5-fluorouracil (5-FU). Twenty-six patients with advanced disease (21 T4 and/or N3) and no prior therapy (NPT) received 2 to 3 cycles of chemotherapy prior to surgery and/or radiation. There were four complete responses (CR) and 12 partial responses (PR) to chemotherapy for an overall response rate of 61%. In 20 patients with locally recurrent or disseminated disease there was one CR and six PR for an overall response rate of 35%. All but one responding patient in both groups showed clear evidence of tumor response after the initial cycle of chemotherapy. Two of the five complete responders required at least three courses to achieve CR. Disease-free survival was poor: only five of 26 patients in the NPT group remain alive and free of disease 8 to 28 months from initial therapy. CDDP and 5-FU is an active combination for SCCHN, but survival benefit remains to be proven.