A phase II study of combination therapy with 5'-deoxy-5-fluorouridine and cisplatin in the treatment of advanced gastric cancer with primary foci

PTBPs: An immunomodulatory-related prognostic biomarker in pan-cancer

Background: The polypyrimidine tract-binding protein (PTBP) nuclear ribonucleoprotein family of proteins, including PTBP1, PTBP2 and PTBP3, regulate the process of cell proliferation, differentiation, apoptosis and carcinogenesis. PTBPs exhibit oncogenic effects in certain tumors. However, the role of PTBPs in pan-cancer remains unclear. Our study examined the clinical significance and mechanism of PTBPs in pan-cancer.

Methods: We compared the expression of PTBPs in paired and unpaired tissue samples from the Cancer Genome Atlas (TCGA) database. Univariate and multivariate Cox regression, Kaplan–Meier curves, and time-dependent receiver operating characteristic (ROC) curves were used to assess the prognostic significance of PTBPs in pan-cancer. The cBioPortal database also identified genomic abnormalities in PTBPs. TISIDB, TCGA, and Cellminer were used to investigate the relationship between PTBP expression and immune subtypes, immune checkpoint (ICP) genes, tumor mutational burden (TMB), microsatellite instability (MSI), tumor-infiltrating immune cells, and chemosensitivity. cBioPortal was used to search for PTBP co-expressing genes in pan-cancer, and GO and KEGG enrichment analyses were performed to search for PTBP-related signaling pathways.

Results:PTBPs were shown to be widely upregulated in human tumor tissues. PTBP1 showed good prognostic value in ACC, KIRP, and LGG; PTBP2 in ACC and KICH; and PTBP3 in ACC, LGG, and PAAD, with AUC >0.7. PTBPs were differentially expressed in tumor immune subtypes and had a strong correlation with tumor-infiltrating lymphocytes (TILs) in the tumor microenvironment (TME). In addition, PTBP expressions were related to ICP, TMB, and MSI, suggesting that these three PTBPs may be potential tumor immunotherapeutic targets and predict the efficacy of immunotherapy. Enrichment analysis of co-expressed genes of PTBPs showed that they may be involved in alternative splicing, cell cycle, cellular senescence, and protein modification.

Conclusion: PTBPs are involved in the malignant progression of tumors. PTBP1, PTBP2 and PTBP3 may be potential biomarkers for prognosis and immunotherapy in pan-cancer and may be novel immunotherapeutic targets.

Co-operative groups in the development of chemotherapy for gastric cancer

In the multimodality treatment strategy for gastric cancer, chemotherapy has an important role in conferring survival benefit. For the last three decades, great progress has been achieved in adjuvant and palliative chemotherapy. Powerful combination regimens using doublet or triplet cytotoxic agents have been developed and new molecular targeted drugs, including trastuzumab and ramucirumab, have been introduced in clinical practice. These advances have resulted from the accumulation of many clinical trials. A well-designed phase III trial can change standard treatment; however, such a trial is hard to complete due to its huge cost and need to recruit many patients. Some co-operative groups have actively made efforts at fundraising and patient recruitment, which can make implementation of high-quality and large-scale phase III trials possible. This review summarizes the development of chemotherapy for gastric cancer with focus on co-operative groups around the world, considering effective treatment developments in gastric cancer. We studied 11 active co-operative groups, including six in Europe, two in the United States, and three in Japan, that have completed one or more phase III trials cited in the major guidelines. Each co-operative group had its own characteristics and contributed to the establishment of standard treatment in each region. International collaboration in the development of gastric cancer treatment may be difficult due to regional differences in standards of care, particularly for resectable gastric cancer. Whereas, intergroup collaboration within each region is a reasonable method to effectively develop treatments for resectable and advanced gastric cancer.

Global chemotherapy development for gastric cancer

To combat the dismal mortality rates from metastatic gastric adenocarcinoma (GAC), new drugs and treatment strategies are needed. Today, metastatic GAC is predominantly treated by empiric chemotherapy. Combination of two cytotoxic agents has become commonplace in North America, Europe, and Asia. Human epidermal growth factor 2 (HER2) overexpression (protein or gene copy numbers) has resulted in the addition of trastuzumab in the first-line chemotherapy combination in patients whose tumor is HER2 positive. The addition of trastuzumab in this select population has provided a modest survival advantage. In this review we trace the global development of systemic therapy in patients with metastatic GAC and ponder what lies in the future.

Sanguisorba officinalis L synergistically enhanced 5-fluorouracil cytotoxicity in colorectal cancer cells by promoting a reactive oxygen species-mediated, mitochondria-caspase-dependent apoptotic pathway

Sanguisorba officinalis L. radix is a widely used herb called DiYu (DY) in China and has an extensive range of bioactivities, including anti-cancer, anti-inflammatory, and anti-oxidative activities. However, there is little evidence to support its anti-cancer effects against colorectal cancer (CRC). The first-line chemotherapeutic agent 5-fluorouracil (5-FU) is used to treat CRC, but its efficiency is hampered by acquired drug resistance. This study found that a water extract of DY exerted anti-proliferative effects against two CRC cell lines (HCT-116 and RKO), and it sensitized CRC cells to 5-FU therapy by activating a reactive oxygen species (ROS)-mediated, mitochondria-caspase-dependent apoptotic pathway. Co-treatment of DY and 5-FU significantly elevated ROS levels, up-regulated Bax/Bcl-2 ratio and triggered mitochondrial dysfunction, followed by a release of cytochrome c and up-regulation of proteins such as cleaved-caspase-9/3 and cleaved-PARP. Additionally, the induction of autophagy may be involved in mediating synergism of DY in HCT-116 cells. Gallic acid (GA), catechinic acid (CA) and ellagic acid (EA) were identified as the potential chief constituents responsible for the synergistic effects of DY. In conclusion, co-treatment of DY, specifically GA, CA and EA, with 5-FU may be a potential alternative therapeutic strategy for CRC by enhancing an intrinsic apoptotic pathway.

Acquired resistance to 5-fluorouracil via HSP90/Src-mediated increase in thymidylate synthase expression in colon cancer

5-fluorouracil (5-FU), one of the first-line chemotherapeutic agents for the treatment of gastrointestinal malignancies, has shown limited efficacy. The expression of thymidylate synthase (TYMS) has been reported to be associated with the resistance to 5-FU. Here, we demonstrate that the enhanced HSP90 function and subsequent activation of Src induce expression of TYMS and acquired resistance to 5-FU in colon cancer. We show that the persistent 5-FU treatment granted 5-FU-sensitive HCT116 colon cancer cells morphologic, molecular, and behavioral characteristic of the epithelial-mesenchymal transition (EMT), contributing to emergence of acquired resistance to 5-FU. HCT116/R, a HCT116 colon cancer cell subline carrying acquired resistance to 5-FU, showed increased expression and activation of HSP90's client proteins and transcriptional up-regulation of TYMS. Forced overexpression of HSP90 or constitutive active Src in HCT116 cells increased TYMS expression. Conversely, pharmacological blockade of HSP90 or Src in HCT116/R cells effectively suppressed the changes involved in 5-FU resistance in vitro and xenograft tumor growth, hematogenous spread, and metastatic tumor development in vivo. This study suggests a novel function of HSP90-Src pathway in regulation of TYMS expression and acquisition of 5-FU resistance. Thus, therapeutics targeting this pathway may be an effective clinical strategy to overcome 5-FU resistance in colon cancer.

Past and present achievements, and future direction of the Gastrointestinal Oncology Study Group (GIOSG), a Division of Japan Clinical Oncology Group (JCOG)

Initially, Gastrointestinal Study Group in Japan Clinical Oncology Group (GIOSG/JCOG) focused on gastric cancer. In 1980s, fluoropyrimidine, cisplatin and mitomycin C were key drugs. A randomized Phase II trial (JCOG8501) comparing futrafur plus mitomycin C and uracil plus futrafur and mitomycin C showed a higher response rate of uracil plus futrafur and mitomycin C than futrafur plus mitomycin C. From the results of two Phase II trials of etoposide, adriamycin and cisplatin, and cisplatin plus 5-fluorouracil, uracil plus futrafur and mitomycin C and cisplatin plus 5-fluorouracil were adopted for the test arms of the Phase III trial (JCOG9205) comparing with continuous infusion of 5-fluorouracil as a control arm. Neither cisplatin plus 5-fluorouracil nor uracil plus futrafur and mitomycin C showed a survival benefit over continuous infusion of 5-fluorouracil. In late 1990s, new agents, irinotecan and S-1, were developed for gastric cancer in Japan. GIOSG conducted a Phase III trial (JCOG9912) investigating superiority of irinotecan plus cisplatin and non-inferiority of monotherapy with S-1 compared with continuous infusion of 5-fluorouracil, and S-1 succeeded in showing non-inferiority. Then, SPIRITS trial showed a survival benefit of S-1 plus cisplatin over S-1, resulting in the establishment of a standard care for advanced gastric cancer in Japan. GIOSG have merged with Gastric Cancer Study Group as the Stomach Cancer Study Group (SCSG) from 2011. Recent progress in the development of new drugs has been remarkable. From the point of the roles shared with many other study groups for clinical trials, including registration trials of new drugs conducted by pharmaceutical companies, SCSG should recognize its role and conduct clinical trials with high quality for establishing new standard treatment.

Phase I study of cediranib in combination with cisplatin plus fluoropyrimidine (S-1 or capecitabine) in Japanese patients with previously untreated advanced gastric cancer

PURPOSE

The primary objective of this Phase I study was to assess the safety and tolerability of the vascular endothelial growth factor signalling inhibitor cediranib in combination with cisplatin plus an oral fluoropyrimidine, in Japanese patients with previously untreated advanced gastric cancer.

METHODS

Patients received continuous, once-daily oral doses of cediranib 20 mg in combination with either cisplatin (60 mg/m(2) iv day 1) plus S-1 (40-60 mg bid, days 1-21) every 5 weeks for a maximum of eight cycles [Arm A]; or cisplatin (80 mg/m(2) iv, day 1) plus capecitabine (1,000 mg/m(2) bid, days 1-14) every 3 weeks for a maximum of six cycles [Arm B]. In both arms, the assessment period for dose-limiting toxicities (DLTs) was the first 21 days of cycle 1.

RESULTS

Fourteen patients (Arm A, n = 6; Arm B, n = 8) were enrolled and received at least one dose of cediranib. One patient in each arm experienced a DLT (Arm A; decreased appetite, grade 3; Arm B, decreased appetite, fatigue and hyponatraemia, all grade 3). Overall, the most common adverse events were decreased appetite, fatigue and nausea (all n = 13 [92.9%]). Preliminary efficacy evaluation showed one confirmed (Arm A) and three unconfirmed (Arm A, n = 1; Arm B, n = 2) partial responses that were ongoing at data cut-off.

CONCLUSIONS

Cediranib 20 mg/day in combination with cisplatin and S-1 or capecitabine was tolerable, with no new toxicities identified, and showed preliminary evidence of antitumour activity.

Salvage chemotherapy with biweekly irinotecan, plus 5-fluorouracil and leucovorin in patients with advanced gastric cancer previously treated with fluoropyrimidine, platinum, and taxane

OBJECTIVES

We retrospectively assessed the combination of biweekly irinotecan with 5-fluorouracil (5-FU), and leucovorin (LV) as salvage chemotherapy in patients with advanced gastric cancer (AGC) previously treated with fluoropyrimidine (F), platinum (P), and taxane (T).

METHODS

Between October 2003 and February 2006, all 131 patients with AGC were treated with irinotecan (150 mg/m(2) on day 1), along with either FOLFIRI-1 (ie, LV (20 mg/m(2) bolus) before 5-FU (1000 mg/m(2) continuous infusion over 6-hour) on days 1-2), or FOLFIRI-2 (ie, LV (20 mg/m(2) bolus) before 5-FU (400 mg/m(2) bolus) followed by 22-hour continuous infusion of 600 mg/m(2) on days 1-2), or FOLFIRI-3 (ie, 5-FU (400 mg/m(2) bolus) followed by 46-hour continuous infusion of 2400 mg/m(2) 5-FU and 100 mg/m(2) LV). Cycles were repeated every 2 weeks.

RESULTS

The median age of the patients was 52 years (range, 19-70 years). Patients received a median of 4 cycles of chemotherapy (range, 1-21 cycles). Of the 97 patients with measurable disease, 1 (1.0%) achieved a complete response, and 11 (11.3%) achieved partial responses, making the overall response rate 12.3%. The median time to progression (TTP) was 2.2 months (95% CI, 1.9-2.6 months) and the median overall survival (OS) was 6.2 months (95% CI, 5.6-6.9 months). Good performance status (P = 0.046), fewer metastatic sites (P < 0.001), and longer time to progression of previous chemotherapy (P = 0.006) were independent prognostic factors affecting OS. OS was longer with the FOLFIRI-1 regimen but not with statistical significance (P = 0.064). The treatments were generally well tolerated.

CONCLUSIONS

In actual clinical practice, biweekly irinotecan with 5-FU and LV had modest activity and tolerability in AGC patients previously treated with F, P, and T.

Multicenter phase II trial of combination chemotherapy with weekly paclitaxel and 5-fluorouracil for the treatment of advanced or recurrent gastric carcinoma

The aim of this study was to investigate the efficacy and safety of combination chemotherapy with weekly paclitaxel and 5-fluorouracil (5-FU) as first-line treatment in patients with advanced or recurrent gastric carcinoma. A total of 65 patients were treated with the following regimen, administered every 28 days; 5-FU 600 mg/m2 by 24-hour continuous infusion from days 1 through 5, and weekly paclitaxel 80 mg/m2 by 3-hour intravenous infusion on days 8, 14, and 21. A total of 272 cycles were conducted with a median of 4 (2-13) cycles per case. Out of 57 patients with measurable disease by RECIST criteria, there were 2 complete responses (3.5%), 20 partial responses (35.1%) and 25 cases with stable disease (43.9%). The overall response rate was 38.6% (95%CI: 26.0-51.2%). The median survival time and 1-year survival rates were 329 days and 47.4%, respectively. Both hematologic and non-hematologic toxicities were well tolerated.

A phase II study of epirubicin, cisplatin and capecitabine combination chemotherapy in patients with metastatic or advanced gastric cancer

OBJECTIVES

The purpose of this study was to evaluate the antitumor activity and safety of an epirubicin, cisplatin, and capecitabine (ECX) combination in patients with metastatic or advanced gastric cancer.

PATIENTS AND METHODS

Patients with metastatic or advanced measurable gastric adenocarcinoma received ECX combination chemotherapy. Epirubicin 50 mg/m2 and cisplatin 60 mg/m2 were administered on day 1 by intravenous injection. Capecitabine 1,000 mg/m2 twice daily was administered orally on day 1-14. The cycle was repeated every 3 weeks.

RESULTS

Fifty-four patients were enrolled in this study. Fifty patients were assessable for responses and 53 for toxicity. A total of 250 cycles were administered. The overall best response rate by intent-to-treat analysis was 59% including 52% partial responses and 7% complete responses. Median response duration and time to progression was 5.8 and 6 months, respectively. Median survival for all patients was 9.6 months (95% CI, 8.7-10.5 months). The most common grade 3/4 hematological adverse event was neutropenia in 31% (76 cycles) including febrile neutropenia in 4.8% (11 cycles). Non-hematological toxicity was generally mild and reversible. Grade 3/4 nausea, vomiting and stomatitis occurred in 8, 9, and 8% of the patients, respectively. Hand-foot skin reactions developed in 51% of patients, but most were self-limited. Grade 3 occurred in only 4%. One patient died of neutropenic sepsis.

CONCLUSIONS

ECX combination regimen showed high anti-tumor activity with a tolerable toxicity pattern as a front-line chemotherapy for patients with metastatic or advanced gastric cancer.

Available options in chemotherapy for advanced gastric cancer: the current developments in Japan

Although techniques for early diagnosis and treatment of gastric cancer have been established, standard treatment for advanced gastric cancer has not. 5-Flourouracil (5-FU) plus cisplatin containing regimens, including 5-FU plus cisplatin, epirubicin plus cisplatin and 5-FU, and docetaxel plus cisplatin and 5-FU, are considered to be the most effective regimens for advanced gastric cancer in US, Europe and Korea. In Japan, oral fluoropyrimidine S-1 is currently considered to be the first-line treatment for advanced gastric cancer. S-1-based combination therapies with other promising drugs, including cis-platin, irinotecan and taxanes, are expected to yield good results. Above all, S-1 plus cisplatin therapy showed high efficacy and expected to be a standard therapy for advanced gastric cancer. Further evaluation by well-controlled clinical trials is still required.

The ratio of thymidine phosphorylase to dihydropyrimidine dehydrogenase in tumour tissues of patients with metastatic gastric cancer is predictive of the clinical response to 5'-deoxy-5-fluorouridine

The aim of this work was to determine whether intratumour contents of thymidine phosphorylase (TP), which converts 5'-deoxy-5-fluorouridine (5'-DFUR) to 5-fluorouracil, and dihydropyrimidine dehydrogenase (DPD), which degrades 5-fluorouracil to inactive molecules, could be useful in predicting the response of patients with metastatic gastric cancer to chemotherapy using 5'-DFUR. Endoscopic biopsy specimens for the measurement of TP and DPD were obtained from the primary lesions before the start of combination chemotherapy, in which 5'-DFUR, cisplatin and mitomycin C were administered. TP and DPD were measured by enzyme-linked immunosorbent assays after the objective responses to chemotherapy had been confirmed. Twenty five patients were enrolled in this study and data for 22 patients in whom responses were confirmed were analysed. The median levels (ranges) of TP and DPD were 80 (4.9-360) and 44 (15-82) U/mg protein, respectively. The median value (range) of TP to DPD ratios was 1.9 (0.25-5.1). Eight patients with a complete or partial response to chemotherapy had significantly higher TP to DPD ratios than did the remaining patients with stable or progressive disease (P = 0.014). When a cut-off level of TP to DPD ratio was defined as the median value, the high-ratio group (n = 11) showed a significantly higher response rate (64% vs. 9.1%, P = 0.024) than the low-ratio group (n = 11). Overall survival of the high-ratio group was significantly longer than that of the low-ratio group (the median survival time; 300 days vs. 183 days, P = 0.047). The efficacy of 5'-DFUR could be optimised by preselecting patients with high TP/ DPD ratios in their tumour tissues, and this would be applicable to the treatment with capecitabine.

Randomized phase III trial of fluorouracil alone versus fluorouracil plus cisplatin versus uracil and tegafur plus mitomycin in patients with unresectable, advanced gastric cancer: The Japan Clinical Oncology Group Study (JCOG9205)

PURPOSE

To compare fluorouracil (FU) alone with FU plus cisplatin (FP) and with uracil and tegafur plus mitomycin (UFTM) for patients with advanced gastric cancer in a prospective, randomized, controlled trial.

PATIENTS AND METHODS

A total of 280 patients with advanced gastric cancer were randomly allocated and analyzed for survival, response, and toxicity. The survival curves were compared between groups by log-rank test on an intent-to-treat basis.

RESULTS

At the interim analysis, the UFTM arm showed a significantly inferior survival with higher incidences of hematologic toxic effects than did control arm FU alone, and the registration to UFTM was terminated. Both investigational regimens, FP and UFTM, had a significantly higher incidence of hematologic toxic effects than FU alone, although the effects were manageable. The overall response rates of the FU-alone, FP, and UFTM arms were 11%, 34%, and 9%, respectively. The median progression-free survival was 1.9 months with FU alone, 3.9 months with FP, and 2.4 months with UFTM, respectively. Although FP demonstrated a higher response rate (P <.001) and longer progression-free survival than did FU alone (P <.001), no differences in overall survival were observed between the arms. The median survival times and 1-year survival rates were 7.1 months and 28% with FU, 7.3 months and 29% with FP, and 6.0 months and 16% with UFTM, respectively.

CONCLUSION

Neither investigational regimen, FP nor UFTM, showed a survival advantage as compared with FU alone. FU alone will remain a reference arm in our future trial for advanced gastric cancer.

Phase II study of capecitabine plus cisplatin as first-line chemotherapy in advanced gastric cancer

BACKGROUND

A phase II study was conducted to assess the efficacy and tolerability of combination therapy with capecitabine and cisplatin in patients with advanced gastric cancer.

PATIENTS AND METHODS

Patients with previously untreated metastatic or unresectable measurable gastric adenocarcinoma received oral capecitabine 1250 mg/m(2) twice daily, days 1-14, and i.v. cisplatin 60 mg/m(2) on day 1. This cycle was repeated every 3 weeks.

RESULTS

Forty-two patients were enrolled in this study. Of these, 38 patients were assessable for efficacy and 40 were assessable for toxicity. One patient achieved a complete response and 22 patients had partial responses, giving an overall response rate of 54.8% in the intention-to-treat population (95% confidence interval 39.8% to 69.8%). The median time to progression was 6.3 months and the median overall survival was 10.1 months. The principal adverse events were neutropenia and hand-foot syndrome. Grade 3/4 adverse events were neutropenia (32.5% of patients), thrombocytopenia (10%), stomatitis (2.5%) and diarrhea (5%). Grade 2 and 3 hand-foot syndrome occurred in 20% and 7.5% of patients, respectively. There were no treatment-related deaths.

CONCLUSIONS

The combination of capecitabine and cisplatin is active and well tolerated in patients with advanced gastric cancer.

Tumor treatment by sustained intratumoral release of 5-fluorouracil: effects of drug alone and in combined treatments

PURPOSE

To evaluate an intratumoral polymer implant for sustained delivery of 5-fluorouracil (5-FU) in a mouse tumor model.

METHODS AND MATERIALS

5-FU was incorporated into a polyanhydride-based polymer, bis(p-carboxyphenoxy)propane sebacic acid (CPP:SA) and implanted in RIF-1 mouse fibrosarcoma growing s.c. The effectiveness of treatment was evaluated by tumor growth delay. External beam radiation was 60Co gamma rays, and the source of interstitial radiation was implanted 125I seeds. A second drug, cis-diamminedichloroplatinum (cis-DDP), was administered by intraperitoneal injection or by osmotic pump.

RESULTS

For drug/polymer implant alone, the tumor growth delay was proportional to the amount of drug in the implant. The 5-FU polymer implant was most effective when combined with cis-DDP or with acute or fractionated radiation, and in some cases, the effects of combined treatments were greater than additive. The most effective combination was intratumoral 5-FU and low-dose-rate radiation delivered from an interstitial radiation source.

CONCLUSION

Results indicate that 5-FU can be effectively delivered by polymer implant and that this mode of delivery is particularly appropriate for combined treatments.

Hepatic arterial infusion of 5-fluorouracil and cisplatin for unresectable or recurrent hepatocellular carcinoma with tumor thrombus of the portal vein

BACKGROUND AND OBJECTIVES

This study was designed to evaluate the efficacy of hepatic arterial infusion of 5-fluorouracil (5-FU) and cisplatin (CDDP) for unresectable or recurrent hepatocellular carcinoma (HCC) with tumor thrombus of the trunk or first branches of the portal vein (PVTT).

METHODS

Seven unresectable or recurrent HCC patients with PVTT were enrolled in this study. A one-week course of chemotherapy consisted of intraarterial administration of CDDP (10 mg on days 1-5) for 1 h and 5-FU (250 mg on days 1-5) for 24 h, followed by cessation of administration for the subsequent 2 days (days 6 and 7). Three or more sequential courses of chemotherapy were given through an implanted reservoir.

RESULTS

Serum alpha-fetoprotein (AFP) levels before the chemotherapy were >20 ng/ml in six of the seven patients. Serum AFP levels were decreased in four of the six patients after chemotherapy, including two patients (cases 1 and 7) whose AFP levels later returned to normal. Six of the seven patients had measurable lesions in the liver, with a response rate of 33%. In three of the seven patients (43%), PVTTs decreased in size or disappeared after chemotherapy. The mean and median survival periods of all patients were 8.0 and. 7.5 months, respectively.

CONCLUSIONS

The chemotherapy described in this report is beneficial in terms of survival for HCC patients with PVTT for whom transcatheter arterial embolization or surgical treatment is contraindicated.

Metastatic urothelial cancer showing an efficacy by low-dose cisplatin

A 69-year-old man who had developed multiple distant metastases on retrocaval lymph nodes after four courses of Methotraxate, Vinblastine, Adriamycin, Cisplatin (MVAC) chemotherapy was successfully treated by intravenous infusion of low-dose cisplatin (CDDP) (10 mg/time, once per week) and oral administration of 600 mg/day 5'-deoxy-5-fluorouridine (5'-DFUR), a pro-drug of 5-FU, in an outpatient setting. A partial response (62% reduction rate) was confirmed by abdominal computed tomography (CT) scan after 7 months. Although the CDDP dosage had been reduced to 5 mg/week 1 year previously, the tumor was still reducing in size in November 2000. Combination therapy of 5'-DFUR with low-dose CDDP could become an option for advanced bladder cancer that compromises the patient's quality of life, especially when used in an outpatient setting.

Plasma, intestine and tumor levels of 5-fluorouracil in mice bearing L1210 ascites tumor following oral administration of 5-fluorouracil, UFT (mixed compound of tegafur and uracil), carmofur and 5'-deoxy-5-fluorouridine

Several 5-fluorouracil (5-FU) derivatives, 1-hexylcarbamoyl-5-fluorouracil (HCFU), 5'-deoxy-5-fluorouridine (5'-DFUR) and UFT (mixed compound of tegafur and uracil), have been developed and clinically widely used. However, comparative pharmacokinetic studies of the parent compound and other fluorinated drivatives have not been precisely reported. The dosage of the oral clinical use for human cancer of 5-FU, HCFU, 5'-DFUR and UFT as tegafur (FT) is 200-300mg/d, 600mg/d, 800-1,200mg/d and 300-600mg/d respectively. These amounts of the drugs are almost equimolar. Previously, we reported the effect of oral equimolar administration of each four drugs on thymidilate synthase activity, deoxyribonucleotide metabolism and cell cycle progression in L1210 ascites tumor. (1,2) In this study, we examined the antitumor effect and 5-FU concentration in the plasma, intestine and tumor after oral equimolar administrations of each drug using BDF1 mice bearing L1210 ascites tumor. In our study, UFT showed the best life prolongation among these four drugs. The intestine 5-FU level was highest by treatment with 5-FU during the initial 4 h. The plasma 5-FU level was highest by treatment with HCFU for 4 h. But the tumor 5-FU level was highest by treatment with UFT over the 24 h. In spite of the high plasma 5-FU concentration after the treatment with HCFU, the 5-FU concentration in the tumor was below the detectable level until 24 h. These findings suggested that the highest specific accumulation of 5-FU in tumor cells may explain the best therapeutic results of UFT.

Effectiveness of immunochemotherapy for gastric cancer: a review of the current status

Currently, the most effective treatment of gastric cancer is surgical resection of the tumor with lymphadenectomy, which is the standard treatment in Japan. It is important to determine whether chemotherapy or immunochemotherapy regimens may prolong the survival of patients with gastric cancer. Although gastric cancer cells, in general, have a low sensitivity to chemotherapy and a low immunogenicity related to stimulation of immune competent cells, a new method including biochemical modulation and nonspecific immunopotentiation with biological response modifiers (BRMs) has permitted us to augment the clinical efficacy of immunochemotherapy for gastric cancer. Further, promising new drugs are being developed and await testing for their possible benefit in an adjuvant setting, and recent advances in molecular biology may open a new avenue for tumor antigen-specific immunotherapy for gastric cancer. We will review the current status of immunochemotherapy for gastric cancer and examine its clinical benefit for survival.

Late phase II study of novel oral fluoropyrimidine anticancer drug S-1 (1 M tegafur-0.4 M gimestat-1 M otastat potassium) in advanced gastric cancer patients

S-1 is a novel oral anticancer drug, composed of tegafur (FT), gimestat (CDHP) and otastat potassium (Oxo) in a molar ratio of 1:0.4:1, based on the biochemical modulation of 5-fluorouracil (5-FU). CDHP inhibits dihydropyrimidine dehydrogenase (DPD), an enzyme which degrades 5-FU, and maintains prolonged 5-FU concentrations in the blood and tumours. Oxo is distributed in the gastrointestinal tract at a high concentration after oral administration and alleviates gastrointestinal toxicity due to 5-FU. S-1 improves the tumour-selective toxicity of 5-FU by the actions of two modulators, CDHP and Oxo. We conducted a late phase II clinical trial of S-1 as an open trial in patients with advanced gastric cancer, to confirm its antitumour effect and adverse reactions. 51 patients with advanced gastric cancer were enrolled in the trial. S-1 was administered orally twice daily after meals, at a standard dose of 80 mg/m2/day. One course consisted of consecutive administration for 28 days and 14 days' rest. Administration was repeated over four courses. A complete response was obtained in 1 patient and partial responses in 24 patients, producing a response rate of 49% (25/51) (95% confidence interval (CI) 35.9-62.3%). The incidence of adverse reactions was 78% (40/51) and that of adverse reactions of grades 3 and 4 was 20%. Adverse reactions of grades 3 and 4 included a decrease in the haematocrit, leucopenia, granulocytopenia, diarrhoea, malaise and proteinuria. No serious unexpected adverse reactions were observed. In conclusion, S-1 was effective and well tolerated in patients with advanced gastric cancer.

Clinical trials for advanced gastrointestinal cancers in Japan. Japan Clinical Oncology Group Gastrointestinal Oncology Study Group

No standard chemotherapy regimen for the treatment of advanced gastrointestinal cancer exists. However, 5-fluorouracil (5-FU) is being used more frequently as a key component of combination therapy regimens for this disease, and including cisplatin (CDDP) in combination therapy regimens produces significant tumor shrinkage. Although oral formulations of 5-FU are widely used in Japan, their clinical activity and toxicity have not been thoroughly evaluated. In 1992, the Japan Clinical Oncology Group initiated a phase III study in which the survival rates of patients treated with 5-FU 800 mg/m2/day for 5 days by continuous infusion (5-FUci), 5-FUci with CDDP 20 mg/ m2/day for 5 days by infusion, or oral uracil/Ftorafur 375 mg/m2/day with weekly MMC 5 mg/m2 i.v. were compared. This study was closed with 280 patients accrued in 1997, and final analysis was made in early 1998. Irinotecan and paclitaxel are new drugs with activity against gastric cancer. Combination chemotherapy consisting of irinotecan with CDDP has also been evaluated. For treatment of metastatic colorectal cancer, the only active drug previously available in Japan was 5-FU, although 5-FU + leucovorin is the international standard regimen. Irinotecan is now approved in Japan, Europe, and the USA and is the most effective drug for 5-FU-refractory patients. The optimal irinotecan and 5-FU combination regimen is being extensively examined but further trials aimed at accumulating basic data are warranted.

Japan Clinical Oncology Group (JCOG)

The Japan Clinical Oncology Group (JCOG) is a cooperative oncology group with the aims of conducting, developing, coordinating and stimulating clinical research in Japan on the treatment of cancer and related problems. The purpose of JCOG is to establish and improve the standard of cancer treatment, mainly in solid cancer, through the testing of new therapeutic regimens or combined modalities, using drugs that are newly-approved or already commercially available. Research sponsored by JCOG is accomplished mainly through the execution of large, prospective, randomized, multicenter, clinical trials. In this way, JCOG facilitates the passage of new clinical trial discoveries into state-of-the-art treatment.

Pharmacokinetics of cisplatin in combined cisplatin and 5-fluorouracil therapy: a comparative study of three different schedules of cisplatin administration

BACKGROUND

Cisplatin is widely used in combination chemotherapy against a variety of tumors; however, the optimal administration schedule of cisplatin is still controversial. To clarify the pharmacokinetic differences according to the administration schedules of cisplatin, we compared three different administration schedules of cisplatin such as single short-term infusion, daily short-term infusion and daily continuous infusion in combination with 5-fluorouracil. Preliminary clinical responses and toxicities were also investigated.

METHODS

A total of 12 courses in combination of cisplatin and 5-fluorouracil therapy was studied. The schedules of cisplatin tested were as follows: single short-term infusion (80 mg/m2, day 1,2 h div., n = 4), daily short-term infusion (20 mg/m2, days 1 to 5, 2 h div., n = 4), daily continuous infusion (100 mg/m2, 120 h, n = 4). In all schedules, 5-fluorouracil was continuously administered at a dose of 800 mg/m2/day on days 1 to 5. The area under the time-concentration curve (AUC) and the maximum concentration (Cmax) of total and free Pt were investigated.

RESULTS

The highest AUC of total and free Pt and the lowest Cmax of free Pt were observed in the daily continuous infusion (total AUC; 162.53 +/- 18.39 micrograms h/ml, free AUC; 5.50 +/- 0.9 micrograms h/ml, free Cmax; 0.07 +/- 0.01 microgram/ml, mean +/- SEM). Two patients in the single short-term infusion and one patient in the daily continuous infusion indicated partial responses clinically. No nephrotoxicity or ototoxicity was observed. All toxicities were mild and tolerable in all regimens; however, the incidence of GI toxicity in daily continuous infusion seemed to be relatively higher.

CONCLUSIONS

Daily continuous infusion of cisplatin gave the best pharmacokinetic results and to evaluate the clinical advantage of this schedule a prospective randomized trial should be conducted with sufficient numbers of patients.

Adenocarcinoma of the gastric cardia

One hundred and ninety-five patients operated on for adenocarcinoma of the gastric cardia during the years 1961-90 were analysed and the present data indicate that the more enthusiastic attitude adopted towards resective surgery led to a significant increase in operative explorations performed and in resectability rate, from 50% (44/88) and 35% (28/88) during the years 1961-75 to 84% (90/107) and 56% (60/107) during the years 1976-90, respectively. The difference between radical resections, 54% (15/28) and 67% (34/60), remained non-significant. The overall postoperative mortality and morbidity after resective surgery were 14% and 35% and these rates did not rise with time. The anastomotic leakage rate was 15%. Anastomotic leakage was, in fact, not only the most common postoperative complication but also the most common cause of death. Overall cumulative survivals at 1, 3 and 5 years were 47%, 11% and 5%. Comparison of the cumulative survival rates between the 15-year periods indicated that there were no differences in overall survival or in survival after resective surgery. We regard these results disappointing, because over half of the patients died in 1 year and because the long-term survival remained dismal.