Alternating floxuridine and 5-fluorouracil hepatic arterial chemotherapy for colorectal liver metastases minimizes biliary toxicity

BACKGROUND

The goals of this study of a hepatic arterial infusion (HAI) regimen of alternating floxuridine and 5-fluorouracil were to evaluate the treatment-related toxic effects, the antitumor response rate, and patient survival.

METHODS

Fifty-seven consecutive patients were treated with implanted HAI pumps and received a regimen of alternating floxuridine (0.1 mg/kg/day continuous HAI for 7 days) followed by a weekly HAI pump bolus of 5-fluorouracil (15 mg/kg for 3 weeks). Any changes in treatment plan because of toxicity, antitumor response, and survival were recorded.

RESULTS

Thirty-one (54.4%) patients responded to this HAI regimen; 14 (24.5% )patients had stable disease, and 12 (21.1%) progressed during treatment. Responders or patients with stable disease had a significantly (P < 0.05) improved survival rate (19 months median) compared with patients in whom disease progressed (12 months median). Two (3.5%) patients developed biliary sclerosis and 12 (21.1%) had mild transient liver function abnormalities. The liver alone or in combination with another area was the site of first progression of disease in 40 (70.2%) patients.

CONCLUSIONS

This regimen had reversible or no hepatobiliary toxicity in more than 95% of patients. Tumor reduction or stabilization of disease was observed in 79% of the patients, who had a median survival of 19 months. Reduced toxicity and more effective chemotherapeutic regimens may increase the likelihood of survival after HAI chemotherapy for unresectable colorectal liver metastases.

Isolated lung perfusion with FUDR in the rat: pharmacokinetics and survival

BACKGROUND

Although surgical resection remains the mainstay of treatment for metastatic pulmonary colorectal cancer, 5-year survival approaches only 30% to 40%. We have developed a model of isolated left lung perfusion (ILP) with FUDR (2'-deoxy-5-fluorouridine) for the treatment of pulmonary colorectal metastases. FUDR ILP toxicity and pharmacokinetics were evaluated and compared with continuous intravenous infusion in the rat.

METHODS

Toxicity was first evaluated in F344 rats (n = 17) after left ILP (20-minute perfusion at 0.5 mL/min) with 21 mg/mL (n = 11), 28 mg/mL (n = 2), 35 mg/mL (n = 2), and 70 mg/mL (n = 2) of FUDR. Animals were followed up and weights recorded for 14 days postoperatively before a right pneumonectomy was performed to evaluate the effect of FUDR perfusion on left lung function. In the second study, 32 rats (n = 8/group) underwent: systemic FUDR (intravenous), or ILP with 7, 14, and 21 mg/mL respectively (ILP 7, ILP 14, and ILP 21 groups). Left lungs and serum were analyzed for FUDR and 5-fluorouracil by high-performance liquid chromatography.

RESULTS

Rats perfused with doses of FUDR greater than 21 mg/mL died perioperatively. All animals perfused at 21 mg/mL survived until day 14, and 8/11 survived a right pneumonectomy. Rats that survived ILP resumed normal weight gain and grooming habits within 1 week. Pharmacokinetic evaluation demonstrated that ILP at 21 mg/mL maximally elevated total lung FUDR and 5-fluorouracil levels (508.5 +/- 96.4 micrograms/g lung) in comparison with the ILP 14, ILP 7, and intravenous groups (299.1 +/- 44.8, 116.0 +/- 21.1, and 7.5 +/- 4.1 micrograms/g lung, respectively) (p < 0.05). Serum FUDR levels were 10.5 +/- 6.8, 1.3 +/- 0.5, 2.31 +/- 1.1, and 1.2 +/- 0.4 microgram/g lung (p = not significant) for intravenous, ILP 7, ILP 14, and ILP 21 groups, respectively.

CONCLUSIONS

Isolated left lung perfusion with FUDR is well tolerated to a maximum dose of 21 mg/mL and results in significantly higher FUDR and 5-fluorouracil lung levels with low serum levels compared with intravenous treatment. These higher pulmonary levels may offer advantages in the treatment of pulmonary colorectal metastases.

[Intra-arterial infusion chemotherapy for liver metastases from breast cancer]

Twelve patients with liver metastases of breast cancer were treated with hepatic arterial infusion chemotherapy using 20-30 mg/body of epi-adriamycin (epi-ADM) every 2 weeks and continuous infusion of 250 mg/body/day of 5-fluorouracil (5-FU). All patients were followed by systemic chemo-endocrine therapy with oral administration of 600-1,200 mg/day of me droxyprogesterone acetate (MPA) alone or with 600-800 mg/day of 5'-deoxy-5-flurouridine (5'-DFUR). The response rate was 41.7% (5/12 cases). Duration of response was 2-28 months (mean 10 months). At one year, the survival rate was 46.8% (Kaplan-Meier method). As for side effects, gastrointestinal disturbance, bone marrow depression and alopecia were mild. These results suggest that hepatic arterial infusion therapy in combination with MPA is safe and effective for controlling liver metastases of breast cancer.

[A case resectable hepatic metastases of breast cancer following intrahepatic arterial chemotherapy]

A 38-year-old woman who had undergone Patey's operation for left breast cancer in July 1990 was admitted in December 1992 for hepatic metastases. Due to bone metastasis (Th10), oophorectomy and hepatic arterial cannulation were performed. Hepatic arterial chemotherapy and oral chemoendocrine therapy yielded a partial response for liver and unclear metastasis of the bone. She had arterial and oral administration after a hepatectomy in October 1994. The patient has had no recurrent signs now (July 1996). We experienced 522 patients with breast carcinoma and 14 cases (2.7%) of all having hepatic metastases. Hepatic arterial chemotherapy was done in three patients. Although one of them had a complete response, she died after 35 months because of bone, brain and liver metastases. Another case was underwent hepatectomy after arterial chemotherapy, but recurrent liver and bone tumors soon appeared. The mean survival period of 15 hepatic metastases, including the case under study here was 9 months, and the one-year survival rate was 23.4%.

Preclinical studies of chemotherapy and radiation therapy for pancreatic carcinoma

The use of radiation therapy combined with 5-fluorouracil (5-FU) in the treatment of pancreatic cancer has been well established. It has been hypothesized that any benefit from combined 5-FU and radiation has been due to radiosensitization. Improved therapy could result from a better understanding of the mechanism of radiosensitization and the development of compounds capable of providing better radiosensitization. This article reviews preclinical findings on the mechanism of cytotoxicity and radiosensitization for 5-FU, fluorodeoxyuridine, thymidine analogs, and gemcitabine (2',2'-difluorodeoxycytidine) and discusses the clinical implications of these findings.

Gas chromatography-mass spectrometry identification of a novel N3-methylated metabolite of 5'-deoxy-5-fluorouridine in plasma of cancer patients undergoing chemotherapy

Evidence of in vivo biomethylation of the anticancer pro-drug 5'-deoxy-5-fluorouridine (5'-dFUR) is presented for the first time. Biomethylation seems to occur specifically at the N3 site on the pyrimidine ring. This novel metabolic product was detected by gas chromatography-mass spectrometry of the trimethylsilylated extract of plasma samples from cancer patients undergoing doxifluridine chemotherapy. Considering the observed electron impact fragmentation pattern, the metabolic product was tentatively identified as N3-Me-5'-dFUR. Definite confirmation of the proposed structure was achieved by comparison of the mass spectra and chromatographic characteristics of the suspected metabolite with those of a synthetically prepared reference standard.

Treatment of metastatic renal cell carcinoma with constant-rate floxuridine infusion plus recombinant alpha 2b-interferon

BACKGROUND

Floxuridine (FUDR) and alpha-interferon (IFN) are active agents in advanced renal cell carcinoma, with different dose-limiting toxic effects and antitumor synergism in experimental models. The main purpose of this phase II study was to assess the activity and toxic effects of a combination of FUDR and alpha 2b-IFN in metastatic renal cell carcinoma.

PATIENTS AND METHODS

Metastatic renal cell carcinoma patients with measurable disease entered the study. FUDR was administered as a constant-rate continuous infusion for 14 days every 28 days at a starting daily dose of 0.1 mg/kg and with dose escalations of 0.025 mg/kg/day at each subsequent cycle if WHO > or = 2 toxicity had not occurred. IFN-alpha 2b 10 x 10(6) I.U. was administered intramuscularly 3 times per week.

RESULTS

Forty-two patients entered the study and a total of 272 cycles of FUDR + alpha 2b-IFN were administered. In 41 evaluable patients WHO grade III-IV toxic effects included nausea and vomiting (22%), diarrhea (32%), stomatitis (12%), fatigue (27%) and anorexia (12%). It was possible to increase the initial FUDR does in 21 (50%) patients; the median FUDR dose intensity was 0.35 mg/kg/week (range 0.18-0.54). Among 39 evaluable patients, 3 (7.5%) complete and 10 (25.5%) partial responses were observed (response rate 33%, 95% confidence interval (CI) 19%-50%) which lasted a median of 13 months (5.5-40+). Responses also occurred in liver (2), in patients pretreated with systemic therapy (5) and in patients who had other unfavourable prognostic characteristics (7). Median progression-free and survival times were 9 and 16 months, respectively.

CONCLUSIONS

In this study FUDR + alpha 2b-IFN demonstrated interesting activity in metastatic renal cell carcinoma, showing promise also in patients with unfavourable prognostic characteristics. The antitumor activity of FUDR and alpha 2b-IFN seems to be cumulative, but cumulative toxicity is also observed. These results require confirmation in randomised trials.

[A case of recurrent breast cancer responding to long-term treatment with 5'-DFUR combined with MPA]

A 55-year-old woman with recurrent breast cancer treated with sequential mastectomies, chemo-and hormonal therapy of UFT, CPM and TAM, achieved remission. Six months later she was admitted with a diagnosis of carcinomatous pleurisy. A large pleural effusion was drained followed by administration of ADM, which improved her effusion and accompanying dyspnea. The effusion recurred but the patient desired outpatient treatment. Thus, we prescribed oral 5'-DFUR and MPA. One month later, her cough had improved and her sputum cytology was negative, while on chest radiograph the pleural effusion had decreased and the patch-like shadows in her right lung field had disappeared. She was considered as a case of PR. At one year and 3 months after starting concomitant 5'-DFUR and MPA the pleural effusion disappeared. The patient has received this outpatient treatment for 2 years without adverse reactions.

[A case of effective chemotherapy by combination of 5'-DFUR and MMC for recurrent colon cancer with multiple liver metastasis]

A 63-year-old male had multiple liver metastasis about 7 months after right hemicolectomy. Combination chemotherapy of 5'-DFUR and MMC was started about 2 months after the diagnosis of recurrence. The abdominal US showed a remarkable decrease in size and number of liver metastatic foci 4 weeks after the beginning of this therapy. As this response was continued for 18 weeks by abdominal CT, this was considered to be a case of partial response (PR). We consider that the combination chemotherapy of 5'-DFUR and MMC is available for patient having recurrent colon cancer with multiple liver metastasis.

Intraperitoneal mitoxantrone or floxuridine: effects on time-to-failure and survival in patients with minimal residual ovarian cancer after second-look laparotomy--a randomized phase II study by theSouthwest Oncology Group

A randomized phase II study of intraperitoneal (ip) mitoxantrone or floxuridine (FUDR) was performed for the treatment of minimal residual epithelial ovarian cancer found at second-look laparotomy after initial platinum-based chemotherapy. Entry was to take place within 30 days of reassessment laparotomies, with documentation of peritoneal metastases either microscopic or gross with cytoreduction to less than or equal to 1 cm in largest diameter. Patients were stratified by the site of the largest disease present (microscopic to 0.5 cm maximum diameter versus greater than 0.5 to 1 cm maximum diameter), by time of registration (< 14 days versus up to 30), and by serum CA-125 (< or = 35 versus >35 units/ml) prior to randomization to either ip mitoxantrone 10 mg/m2 every 2 weeks X 9 or ip floxuridine (FUDR) 3 g (total dose)/ day X 3 days every 3 weeks X 6 cycles. Implantable ip systems and 1.5-2 liters of normal saline were used to deliver the drugs of 83 patients registered between December 1988 and January 1994; there were 6 pathology exclusions and 9 surgical exclusions, and 1 nonevaluable patient for a total of 39 evaluable on mitoxantrone and 28 on FUDR being evaluable. FUDR is the choice for further study because of a progression-free survival exceeding 15% at 1 year over mitoxantrone and a median overall survival of 38 months. It should be emphasized again that the goal of a randomized phase II selection design is to select a winner for phase III testing should there be a substantial difference between the treatments with respect to the primary endpoint. Comparative conclusions between the treatment arms should not be attempted due to the inherently much smaller sample sizes. This should reemphasize the limitations in a comparison of efficacy; however, the toxicologic differences still emerge quite clearly.

[Combined chemotherapy with MMC, ADM, CDDP, etoposide (VP-16) and 5'-DFUR, (MACVD therapy) as a second-line chemotherapy for metastatic gastric cancer: three cases]

Three patients with chemotherapeutically pretreated metastatic gastric cancer were given MAC-VD therapy combining MMC, ADM, CDDP, Etoposide (VP-16) and 5'-DFUR. All were evaluable for their responses. Patients ranged in age from 49 to 61 years. Performance status scale (P.S.) grade 0 was two cases; and P.S. grade 1 was one case. The overall response rate, CR+PR, was 0+2/3 (66.7%). The response rate in the primary lesions was 0%, against 66.7% (2/3) in the liver, 100% (1/1) in the spleen, 100% (1/1) in the lung, and 0% in the abdominal lymph node metastasis. The chief manifestations of toxicity were hematologic, such as leukocytopenia, anemia and thrombocytopenia in 100% of the cases. Non-hematologic toxicity was seen in alopecia in 66.7%, diarrhea in 33.3%, fever in 33.3%, and pigmentation in 33.3%. Severe toxicity was not observed. From these data, the administration of MAC-VD therapy was considered tolerable and these data suggested that this therapy could be given as a second-line chemotherapy when initial treatment failed to obtain a response after a partial response.

[A randomized controlled study of maintenance therapy with (2"R)-4'-O-tetrahydropyranyladriamycin for advanced and recurrent breast cancer. Clinical Study Group of THP for Breast Cancer in Japan]

We conducted a randomized controlled study to evaluate the clinical usefulness of (2"R) -4'-O-Tetrahydropyranyladriamycin (THP)-based combination therapy subsequent to induction therapy which was consisted with THP, 5'-DFUR, and CPA in the treatment of advanced or recurrent breast cancer. In maintenance therapy, Arm C received CPA and TAM, and Arm T received these two drugs plus THP. Survival time of 50% for all cases in which maintenance therapy was conducted was 26.9 months in Arm T and 20.9 months in Arm C, showing no significant difference by the log-rank test (p = 0.64). Survival time in all cases in which therapy had been completed was 54.6 months in Arm T and 28.1 months in Arm C, showing a significant difference by the log-rank test (p = 0.03) although the number of cases was few. A few cases showed a decrease in total leukocyte count to below 2,000/mm3 at the time of induction therapy, but this was transient in all cases. No significant difference in count was noted between two arms at the time of maintenance therapy. However, many cases in Arm T showed decreased total leukocyte count and hemoglobin content, and thrombocytopenia. These results suggest that combination therapy including THP conducted as maintenance therapy after induction is useful in the prolongation of survival time in patients with advanced or recurrent breast cancer.

[A case of nonresectable advanced gastric cancer responding to combined chemotherapy with 5'-DFUR, CDDP, and MMC]

A 39-year-old man was referred for epigastric fullness and a mass in the umbilical region. A giant mass was palpated in the epigastric region, while a mass 1 cm in diameter with a hemorrhagic tendency was felt in the umbilical region. Fluoroscopy of the upper gastrointestinal tract and gastroscopy revealed a Borrmann 3 tumor in the upper part of the gastric corpus. The tumor was found by CT scanning to be growing clearly across the wall of the stomach, and the invasion to the transverse colon was suspected by the enema. The tumor was unresectable because of the extensive tumor invasion of the abdominal wall. Therefore, the patient received 2 courses of combined chemotherapy with 5'-DFUR, CDDP, and MMC. As a result, the tumor in the epigastric region was reduced dramatically, and it became unpalpable 6 months after treatment. At the same time, the tumor in the umbilical region disappeared. Both CT scanning and upper gastrointestinal radiography disclosed tumor reduction, and sufficient oral ingestion became possible. The administration of 5'-DFUR has since been continued as maintenance therapy. Aside from transient anorexia and slight leukopenia, the patient developed no symptoms during the treatment period. At present. 2 years and 9 months after starting chemotherapy, the patient is in good health.

Continuous non chronomodulated infusion of floxuridine in metastatic renal cell carcinoma (MRCC): report of 17 cases

AIMS AND BACKGROUND

MRCC responds poorly to usual treatments. Recently floxuridine (FUDR) has been administered by chronomodulated infusion, obtaining interesting results. In order to simplify the infusion, we used continuous non chronomodulated infusion.

METHODS

We treated 17 patients affected by MRCC with continuous non chronomodulated infusion of FUDR. Toxicity was evaluated according to WHO criteria. Responses were recorded as complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD).

RESULTS

Sixty-four courses of therapy were administered; 15/17 patients, treated with a median of 4 cycles, were evaluable for the response. Only 1 patient showed a grade 3 toxicity (mucositis and diarrhoea); 6 patients showed grade 1-2 diarrhoea; 2 grade 1-2 nausea and vomiting; 1 grade 2 anaemia and thrombocytopenia. No patient obtained CR; 2 PR (lasting 7 and 9 months respectively) and 4 SD (lasting 4,5,6 and 9 months) were observed.

CONCLUSIONS

In our experience continuous non chronomodulated infusion of FUDR did not show important general toxicity. The observed responses were not good enough. We think that a better selection of patients (good performance status) and the use of FUDR in an earlier stage of disease, can obtain better results.

[Successful combination chemotherapy for a post-operative gastric cancer patient with multiple liver metastases and elevated CEA]

A 75-year-old male was admitted one year after surgery for advanced gastric cancer. He was diagnosed as having multiple liver metastases with elevated serum CEA level. Combination chemotherapy consisting of THP-ADM, MMC and 5'-DFUR was done in the outpatient clinic. As a result, both multiple metastatic liver tumors and serum CEA level showed a remarkable response.

Role of fluoropyrimidine Schedule and (6R,S)leucovorin dose in a preclinical animal model of colorectal carcinoma

BACKGROUND

Fluorouracil (5-FU) and 5-fluoro-2'-deoxyuridine (FdUrd), used alone or in combination with other cytotoxic agents, exhibit limited efficacy in the treatment of advanced gastrointestinal cancer. (6R,S)leucovorin (LV), a source of reduced folate cofactor, can modulate (i.e., enhance) the therapeutic efficacy of treatment with these fluoropyrimidines (FPs). The role of FP schedule and lv dose in modulating FP antitumor activity, using clinically relevant drug doses and schedules, has not been fully documented.

PURPOSE

We evaluated the antitumor activities and the toxic effects of 5-FU and FdUrd, used either alone or in combination with LV, by following three clinically relevant treatment schedules in rats bearing advanced ward colorectal carcinomas.

METHODS

Maximum tolerated doses (MTDs), i.e., doses producing a reversible body weight loss of no more than 20% with no lethality, of 5-FU and FdUrd, either individually or in combination with LV, were used in the following treatment schedules: (I) 4 days of continuous intravenous FP infusion (with or without a daily 2-hour lv infusion); (II) a daily FP intravenous push for 4 days (LV, when given, was administered as a 2-hour infusion, with the FP push given after the first hour of LV treatment); and (III) an FP intravenous push given weekly for 3 weeks (the coadministration of LV and FP was performed as in schedule II). In these studies, LV was given at either a low dose (20 mg/kg [body weight] per day) or a high dose (200 mg/kg per day). The MTDs of 5-FU and FdUrd, with or without LV, were defined in normal rats. Antitumor activities were assessed in animals 12-14 days after they received subcutaneous tumor implants. Toxic effects at the MTD were evaluated in both normal and tumorbearing animals.

RESULTS

With schedules I and II, the MTD of 5-FU alone was 35 mg/kg per day; with schedule III, it was 100 mg/kg per week. For FdUrd alone, the MTD was 100 mg/kg per day with schedules I and II and 400 mg/kg per week with schedule III. Coadministration of LV reduced the MTD of both 5-FU and FdUrd by approximately 25%-30%, irrespective of the LV dose used. The dose-limiting toxic effects of treatment with 5-FU and FdUrd were diarrhea and/or stomatitis, the relative severity of which depended on the schedule of FP administration. The profile of toxic effects was not altered by LV when used at either dose. FP antitumor activity was modulated by LV in all three treatment schedules, but the greatest effects were seen using schedule III, where more complete tumor regression was seen with high-dose LV than with low dose LV. LV potentiated the antitumor activity of FdUrd to a greater extent than that observed with 5-FU.

CONCLUSIONS

In this rat model of colorectal carcinoma, the extent to which FP antitumor activity is modulated by LV depends on the schedule of FP administration and the dose of LV used.

Reappraisal of hepatic arterial infusion in the treatment of nonresectable liver metastases from colorectal cancer

BACKGROUND

Metastases confined to the liver cause substantial morbidity and mortality for patients with colorectal cancer. The results of several randomized clinical trials conducted to study the effectiveness of hepatic arterial infusion (HAI) of fluoropyrimidines for the treatment of such patients have suggested that this treatment, as compared with systemic administration of fluoropyrimidines, increases the likelihood of tumor response. However, the impact of HAI on survival is unclear.

PURPOSE

A meta-analysis was carried out to provide an objective and quantitative appraisal of the benefits of HAI in terms of tumor response rate and overall patient survival.

METHODS

The meta-analysis was based on individual data provided by the principal investigators of six individual trials and on summary data for one trial. Of the seven trials, five compared HAI with floxuridine (5-fluoro-2'-deoxyuridine; FUDR) and intravenous chemotherapy (IVC) with FUDR (three trials) or fluorouracil (5-FU) (two-trials), and two compared HAI with FUDR and an ad libitum control group in which some patients could be left untreated. Response data were analyzed by use of a Mantel-Haenszel test on all randomized patients. Survival data were analyzed by the use of stratified logrank test. Multivariate analyses were performed with use of the logistic regression model for tumor response and the Cox regression model for survival. All P values resulted from two-sided statistical tests. The analyses were performed by an independent secretariat and were reviewed by the collaborators.

RESULTS

The tumor response rate was 41% for patients allocated to HAI with FUDR or 5-FU (CR, 2%; PR, 12%). This difference was highly significant, with a response odds ratio of 0.25 (95% confidence interval = 0.16-0.40; P < 10 (-10)). Survival analyses showed a statistically significant advantage for HAI with FUDR compared with control when trials were taken into account (P = .0009) but not when the survival analysis was restricted to trials comparing HAI with FUDR and IVC with FUDR or 5-FU (P = .14).

CONCLUSION

These results confirm that HAI can achieve much higher tumor response rates than systemic chemotherapy in patients with liver metastases from colorectal cancer.

IMPLICATIONS

The therapeutic benefit of use of HAI with FUDR in these patients should be judged together, with an overall evaluation of this therapy in terms of convenience, toxicity, and costs. These end points should be considered in addition to tumor response and survival in further trials involving HAI.

[A case of hepatocellular carcinoma responding to oral administration of 5'-DFUR]

A 65-year-old female patient with liver cirrhosis complicated with hepatocellular carcinoma (HCC) was treated with oral administration of 5'-DFUR (600 mg/day). The titer of serum alpha-fetoprotein gradually decreased, and reduction of the hepatic tumor size was observed by abdominal computed tomography (CT) following 5'-DFUR treatment. HCC was obviously diminished since the start of 5'-DFUR administration and almost disappeared in fifteen months. This case suggests the treatment with 5'-DFUR for hepatocellular carcinoma is completely effective.

Regional chemotherapy for colorectal hepatic metastases: evidence for improved survival with new drug combinations

BACKGROUND

In patients with colorectal hepatic metastases, response rates with hepatic arterial infusion (HAI) FUdR (5-Fluoro-2-deoxyuridine) are significantly higher than with systemic fluoropyrimidines. We report a novel animal model of intrahepatic therapy for hepatic metastasis for the study of methods to increase response rates and improve survival. METHODS. BD-IX rats are injected intrasplenically with K12/TRb cells. When hepatic metastases are established, animals are treated with hepatic or systemic chemotherapy, and the response to treatment, survival, and cause of death is determined.

RESULTS

Significant responses were observed with low- and high-dose HAI FUdR (p = 0.03 and 0.001, respectively). Only high-dose FUdR controlled hepatic disease. HAI FUdR alone did not prolong survival compared with control, but combination systemic FUdR and HAI FUdR did (p = 0.04). Continuous HAI of either 5-fluorouridine or mitomycin C has not previously been reported. There was no significant difference in response to FUdR, 5-fluorouridine, or mitomycin C. However, combination HA bolus mitomycin C plus either HAI 5-fluorouridine or HAI mitomycin C showed synergy with improved survival compared with all treatment groups (p < 0.0001).

CONCLUSIONS

The combination of bolus hepatic artery mitomycin C with either HAI mitomycin C or HAI 5-fluorouridine yields significant response rates, and survival is improved by this novel combination therapy.

[Influence of intratumor administration of OK-432 on the tumor selectivity of 5'-DFUR]

The influence of intratumor administration of OK-432 on the tumor-selective antitumor effect of 5'-DFUR was studied in 49 patients with advanced gastric cancer. The patients were divided into 4 groups that received oral 5'-DFUR, intratumor OK-432, oral 5'-DFUR plus intratumor and intracutaneous OK-432, or no therapy before operation. Using surgical specimens, the PyNPase activity and 5-FU content were measured, and the localization of PyNPase was determined immunohistologically. The results were as follows: 1) 5'-DFUR therapy decreased intratumor PyNPase activity whereas administration of OK-432 increased it. 2) PyNPase activity was higher in cancer tissue than in normal tissue for all groups. 3) The 5-FU content of cancer tissue was higher in patients receiving OK-432 plus 5'-DFUR than in patients receiving 5'-DFUR alone. 4) In the resected tumors, PyNPase was mainly localized in the cancer cells of some patients and in the stromal cells of others. Thus, the localization of PyNPase showed two major patterns.

Characterization of organ-specific immunoliposomes for delivery of 3',5'-O-dipalmitoyl-5-fluoro-2'-deoxyuridine in a mouse lung-metastasis model

A previous study has shown that lipophilic prodrugs can be delivered efficiently to normal lung endothelium by incorporation into liposomes covalently conjugated to monoclonal antibody (mAb) 34A against the lung endothelial anticoagulant protein thrombomodulin. In the present study, the potential use of these lung-targeted immunoliposomes (34A-liposomes) for delivery of a lipophilic prodrug, 3',5'-O-dipalmitoyl-5-fluoro-2'-deoxyuridine (dpFUdR), to the tumor-bearing lung was examined using BALB/c mice bearing experimental lung metastasis induced by i.v. injection of EMT-6 mouse mammary tumor cells. Immunohistochemical examination of the tumor-bearing lung showed specificity of mAb 34A to lung endothelium. Tumor cells appeared to localize just outside of the normal blood vessels and were within a small diffusion distance from the mAb 34A-binding sites. 111In-labeled 34A-liposomes containing monosialoganglioside (GM1) were prepared that included [3H]-dpFUdR at 3.0 mol% in the lipid mixture. In vitro cell binding studies further demonstrated that 34A-liposomes bound specifically to normal mouse lung cells that expressed thrombomodulin but not to EMT-6 cells. Biodistribution study showed efficient and immunospecific accumulation of [3H]-dpFUdR incorporated into 34A-liposomes in the lung at a level parallel with that of 111In-labeled 34A-liposomes, indicating that the drug is delivered to the target organ in intact liposomes. Liposomal dpFUdR appeared to be metabolized in the lung to the parent drug FUdR at a rate slower than in the liver and spleen. Furthermore, treatment of lung-metastasis-bearing mice with dpFUdR incorporated into 34A-liposomes on days 1 and 3 after tumor cell injection resulted in a significant increase in the median survival time of treated mice as compared with control mice (%T/C value, 165%). dpFUdR either dispersed in emulsion or incorporated into antibody-free liposomes was ineffective in prolonging the survival of mice. These results indicate the potential effectiveness of organ-specific immunoliposomes containing a lipophilic prodrug for the targeted therapy of metastatic tumors.

[Augmentation of chemotherapeutic efficaciousness of UFT by oral l-leucovorin--growth-inhibitory activity of combination against human tumor xenograft]

Combination chemotherapy with FUra and LV has been reported as a useful treatment for patients suffering from colon carcinoma. Usually, both FUra and LV are administered by intravenous infusion, but not orally. UFT, an anti-neoplastic agent consisting of FT and uracil, is widely used for oral administration in Japan. Using human tumor xenografts of 10 cell lines, we evaluated the efficacy of UFT combined with l-LV, which is the active form of LV, by oral administration. Combined treatment of UFT with l-LV was more effective than UFT alone on the growth suppression of colon carcinoma (KM 20 C, Col-1) and mammary carcinoma (H-31, MX-1). When 1.85 mg/kg (5.55 mg/m2) of LV was given to tumor bearing mice, the antitumor activity of UFT was augmented and at a dose of 5.56 mg/kg (16.7 mg/m2) of LV, it was significantly augmented. Among various 5-FU derivatives, such as UFT, 5'-DFUR or FUra, combined treatment using UFT with l-LV was the most effective by oral administration. l-LV did not improve the anti-tumor efficacy or toxicity of 5'-DFUR. l-LV seemed to augment the anti-tumor activity of FUra, but not significantly. These results suggest that combination chemotherapy of UFT with LV is a promising approach for the clinical treatment of human colon cancer.