In vivo antitumor effects of fluoropyrimidines on colon adenocarcinoma 38 and enhancement by leucovorin

Antitumor effect and active metabolites of fluoropyrimidines were examined in mice with transplantable colon adenocarcinoma 38 (Co 38). 5-Fluoro-2'-deoxyuridine (FUdR) treatment resulted in a much higher level of free 5-fluoro-2'-deoxyuridine-5'-monophosphate in the tumor than 5-fluorouracil (5-FU) did, and thymidylate synthase was almost completely inhibited after FUdR treatment, but FUdR showed weaker antitumor activity than 5-FU did. Moreover, 5-fluorouridine (FUR) also hardly inhibited tumor growth. A more marked tumor inhibition was obtained when FUdR and FUR were administered together. The antitumor activity of 5-FU was similar to that of the combination of FUdR and FUR. In combination with 2,2'-anhydro-5-ethyluridine, a uridine phosphorylase inhibitor, FUdR lost its antitumor activity, but that of FUR was somewhat potentiated. On the other hand, in combination with leucovorin (LV), 5-FU showed markedly potentiated antitumor activity, while the antitumor activity of FUdR or FUR was not potentiated. Addition of LV to the combination of FUdR and FUR enhanced the inhibitory effect of the drugs. From these results, the combination of FUdR and FUR together with LV, and the combination of 5-FU and LV seem to be highly efficacious against Co 38.

A randomized trial of intrahepatic infusion of fluorodeoxyuridine with dexamethasone versus fluorodeoxyuridine alone in the treatment of metastatic colorectal cancer

To decrease the toxicity of hepatic arterial fluorodeoxyuridine (FUDR) administered through an Infusaid pump (Shiley Infusaid, Inc., Norwood, MA), 50 patients with liver metastases from colorectal cancer were selected randomly to receive FUDR, 0.3 mg/kg/d, for 14 of 28 days, with or without a total dose of 20 mg of hepatic arterial dexamethasone for 14 of 28 days. Patients were stratified according to the percentage of liver involvement by tumor and the perfusion pattern on macroaggrated albumin perfusion scan (MAA) scan. There was a trend toward decreased frequency of bilirubin levels in the group receiving dexamethasone plus FUDR versus the group receiving FUDR alone (9% and 30%, respectively, had a 200% or greater increase from baseline; P = 0.07). Patients in the group treated with dexamethasone and FUDR received higher doses of FUDR in the second, third, fifth, and sixth months than those receiving FUDR alone; however, this was statistically significant only in the fifth month (percentages of planned dose received: 42% and 19%, respectively; P = 0.05), and there was no overall difference for the total 6-month period. The complete and partial response rates were increased in patients receiving dexamethasone and FUDR versus FUDR alone (8% and 63% versus 4% and 36%, respectively; P = 0.03), and there was a trend toward increased survival with the addition of dexamethasone (median, 23 months and 15 months, respectively; P = 0.06). In conclusion, the use of hepatic arterial dexamethasone is associated with an increased response rate and a trend toward increased survival and decreased bilirubin levels. Therefore, the authors recommend additional investigation of the use of dexamethasone with chemotherapy to treat hepatic metastases.

Antitumor effect of 2'-deoxy-5-fluorouridine conjugates against a murine thymoma and colon carcinoma xenografts

The conjugation of antineoplastic drugs to monoclonal antibodies reactive with tumor associated antigens conveys selective cytotoxicity, overcoming the systemic toxicities caused by drugs during standard chemotherapy. 2'-Deoxy-5-fluorouridine, a more potent derivative of 5-fluorouracil, is an antimetabolite which exerts its cytotoxic action by inhibiting the enzyme thymidylate synthetase and as a result inhibits DNA synthesis. 2'-Deoxy-5-fluorouridine was successfully conjugated to anti-Ly-2.1 reactive with the murine thymoma ITT(1)75NS E3, I-1, and 250-30.6 reactive with human colon cancer cells using the active ester of 2'-deoxy-5-fluoro-3'-O-succinoyluridine (5FdUrdsucc). In vitro, 5Fd-Urdsucc-anti-Ly-2.1 was selectively cytotoxic against ITT(1)75NS E3 murine thymoma cells at nanomolar concentrations. The human colon carcinoma cell LIM1899 was inhibited by 5FdUrdsucc-I-1 conjugates in the range of 10(-7)-10(-8) M, as were Colo 205 cells by 5FdUrdsucc-250-30.6 conjugates. In vivo, 5FdUrdsucc conjugates were more effective than equivalent amounts of free 5FdUrdsucc. Against the ITT(1)75NS E3 murine thymoma, a single dose of 100 micrograms (5FdUrdsucc equivalents) 5FdUrdsucc-anti-Ly-2.1 resulted in 85% tumor inhibition compared to mean tumor size of control mice. Irrelevant 5FdUrdsucc conjugates failed to inhibit tumor growth. Multiple doses of 5FdUrdsucc-I-1 conjugate produced 50% growth inhibition of the moderately differentiated tumor LIM1899. In contrast, the human colon carcinoma Colo 205 was relatively resistant to free 5FdUrdsucc and 5FdUrdsucc-250-30.6 conjugates.

[Investigation of 5-fluorouracil (5-FU) levels and pyrimidine nucleoside phosphorylase activities in the tissues from patients with uterine cervical and ovarian cancers after oral administration of 5'-DFUR]

The usefulness of 5'-DFUR in both patients with uterine cervical and ovarian cancers was investigated by determining pyrimidine nucleoside phosphorylase (PyNPase) activities and 5-FU levels in cancerous and normal tissues resected from them after oral administration of 5'-DFUR. In uterine cervical cancer, each group of 9 cases administered single dose of 400 mg of 5'-DFUR and 7 cases administered 400 mg of 5'-DFUR 3 times a day continuously for 7 days was investigated. In ovarian cancer, all of 9 cases were administered 400 mg of 5'-DFUR 3 times a day continuously for 7 days. In conclusion, PyNPase activities in the tissues of uterine cervical and ovarian cancers were higher than those in the normal tissues. 5-FU tissue levels in the cancerous tissues were significantly higher than in the normal tissues and blood as well. This tendency was observed in each of the single and continuous administration groups. These results suggest that the tumor selectivity which is one of characteristics of 5'-DFUR could be expected also for cancer in the field of gynecology.

[Phase II study of 5'-DFUR in uterine cervical cancer and ovarian cancer]

A phase II study of 5'-DFUR was conducted in uterine cervical cancer and ovarian cancer by the cooperative study group consisting of 26 institutions. Forty-four cases with uterine cervical cancer and 40 cases with ovarian cancer were enrolled. A daily dose of 800-1,200 mg was administered orally for more than 8 weeks. In 34 evaluable cases with uterine cervical cancer, the overall efficacy rate was 20.6%: CR was shown in 2 cases, PR in 5 cases, MR in 2 cases, NC in 17 cases and PD in 8 cases. Histologically, the response rate was 27.3% in large cell non-keratinizing type, 20.0% in small cell non-keratinizing type and 15.4% in keratinizing type of squamous cell carcinoma. The overall response rate was 20.7% in squamous cell carcinoma, while 25.0% in adenocarcinoma. In 31 evaluable cases with ovarian cancer, the overall efficacy rate was 16.1%: PR was shown in 5 cases, MR in 3 cases, NC in 11 cases and PD in 12 cases. Histologically, the response rate was 16.7% in serous cystadenocarcinoma, 25.0% in endometrioid adenocarcinoma and 33.3% in undifferentiated carcinoma. No responses were observed in cases with mucinous cystadenocarcinoma, clear cell adenocarcinoma, mature cystic teratoma with malignant transformation and mesodermal mixed tumor. Some adverse effects were observed in 43.2% (32 out of 74 cases evaluated for adverse effects), but those of grade 4 were not observed. Most of them were gastro-intestinal disturbances such as diarrhea and anorexia. Diarrhea of grade 3 was observed in 12.2% and anorexia of grade 3 in 5.4%. Severe myelosuppression or hepatic toxicity was not observed. These results suggested that 5'-DFUR is a useful anticancer drug against uterine cervical cancer and ovarian cancer.

[Phase II study of 5'-DFUR treatment of the bladder and prostatic cancer]

Phase 2 study of 5'-DFUR in bladder and prostatic cancer was conducted at 15 collaborative institutions including Okayama University. 5'-DFUR was orally administered to patients at a daily dose of 800-1200 mg for more than 4 weeks. Forty-one patients with bladder cancer and 12 patients with prostatic cancer were evaluated. The response rate for bladder cancer was 31.7% (CR, 1 case: PR, 12 cases), against no response with prostatic cancer. Moreover, the concentration of 5-FU in bladder tumors was confirmed to be high. Adverse reactions such as diarrhea, anorexia, and nausea were observed. Thus, 5'-DFUR seems to be useful for the treatment of bladder cancer.

[Phase II study of 5'-DFUR (Furtulon) capsule for bladder cancer]

A cooperative phase II study of 5'-DFUR at a daily dose of 800 to 1,200 mg was performed on 18 patients with bladder cancer. The therapeutic responses were evaluated by Koyama-Saito's criteria in 13 out of 18 patients, and 3 PR, 1 MR, 6 NC and 3 PD were obtained. Adverse reactions were observed in three out of 15 cases (20.0%). These side effects were reversible gastrointestinal symptoms such as nausea-vomiting, anorexia and diarrhea. The results suggest that 5'-DFUR is a useful drug for bladder cancer treatment.

Circadian infusion of floxuridine in patients with metastatic renal cell carcinoma

A total of 42 patients with metastatic renal cell carcinoma received floxuridine infusion for 14 days at monthly intervals. The drug was delivered via an external programmable pump on a time-modified or circadian schedule; the highest dose of 68% was given between 3 and 9 p.m. Of the 42 patients 25 (60%) had undergone prior nephrectomy. Of the 40 evaluable patients 4 (10%, 95% confidential interval 3 to 24%) achieved a partial response: 3 of the 4 had undergone prior nephrectomy, while 1 had undergone renal angioinfarction. Another 4 patients (10%) had responses at metastatic sites but no response in the primary kidney tumor. The median duration of response for these 2 groups of patients was 65 and 27 weeks, respectively, and the most responsive site was the lungs. The treatment was generally well tolerated and could be administered on an outpatient basis. Our study confirms the limited but definite activity of floxuridine infused on a circadian schedule in patients with metastatic renal cell carcinoma. We observed responses in metastasis equally in patients with or without prior nephrectomy.

[Comparative studies on the antitumor activity of fluorinated pyrimidine derivatives against human bladder, cervical and ovarian cancer xenografts in nude mice]

Fluorinated pyrimidines given orally were examined for their antitumor activity with 11 human cancer xenograft models (4 bladder, 4 cervical and 3 ovarian cancers). The drugs were evaluated to be effective when they inhibited tumor growth over 58%. UFT was not effective against all of 11 cancer xenografts tested. 5-Fluorouracil (5-FU) was effective against only one bladder cancer xenograft among 6 cancer xenografts tested. On the other hand, 5'-deoxy-5-fluorouridine (5'-DFUR) was effective against one bladder, 3 cervical and one ovarian cancer xenografts. The Antitumor activity of 5'-DFUR was correlated with the enzyme activity of pyrimidine nucleoside phosphorylase, which is an essential enzyme for phosphorolysis of 5'-DFUR to 5-FU.

[Antitumor activity of T-506, a novel synthetic FUDR derivative, on murine colon cancer and its hepatic metastasis]

T-506 is a novel synthetic FUDR derivative which releases FUDR slowly in vivo. We studied antitumor activity of T-506 by i.v. injection against mouse colon cancer, colon 26. When T-506 was administrated to mice daily, from day 1 through day 10, or every 3 days, on days 1, 4, 7, and 11, after s.c. inoculation of the tumor, the survival period was expanded significantly. The subcutaneous tumor growth was also inhibited according to the dose levels. Then, we compared the therapeutic effects on the experimental hepatic metastasis of colon 26 between T-506, 5'-DFUR and UFT at each maximal tolerable dose; that is, T-506 (0.074 m mole/kg/day; i.v. on days 1, 4, 7, and 10), 5'-DFUR (1.0 m mole/kg/day; P. O. from day 1 to 7), UFT (0.1 m mole/kg/day; P. O. from day 1 to 7). T-506 and 5'-DFUR suppressed completely the metastases of 5 of 6 (83.3%) mice and 6 of 7 (85.7%), respectively. UFT did not show a significant inhibitory effect. However, since the loss of body weight was more marked in T-506 than in the other two drugs, the side effect was thought to be a serious problem. These data suggested that if the side effect could be overcome, T-506 would be useful clinically for the treatment of gastrointestinal cancers or hepatic metastases.

[Adjuvant chemotherapy]

The authors treated 10 advanced renal cell carcinoma with circadian venous continuous infusion of 5-Fluoro 2-Deoxyuridine (FUDR). The drug was delivered by Medtronic Synchromed implantable pump in 14-day cycles alternating with 14-day intervals of physiologic saline infusion. Of the patient observed for at least 8 months (range: 8-32, median: 22.1) 1 showed progression. Circadian continuous central venous infusion of FUDR is minimally toxic. The FUDR can be delivered safely and conveniently in this way for long spans. This therapy is administrated in on entirely out patient setting, and associated with a normal quality of life.

Phase II clinical trial of doxifluridine in patients with advanced ovarian cancer

35 evaluable patients were treated with 5'-deoxy-5-fluorouridine (doxifluridine), a fluoropyrimidine derivative. All patients had been heavily pretreated and had refractory disease. Treatment with doxifluridine at a dosage of 3000 mg/m2 given intravenously for 5 successive days at 3-week intervals led to 6 partial remissions (17%). The main side-effects were central neurotoxicity, stomatitis and myelotoxicity, resulting in 2 toxic deaths. In patients with renal function disturbances, toxicity proved to be more severe. We concluded that the drug should not be used in patients with renal impairment. Because responses have been encountered, further evaluation of the drug may be warranted in the less toxic oral form.

Effects of orally administered 5-fluorouracil and its derivative 5'-deoxy-5-fluorouridine on 7,12-dimethylbenz[a]anthracene-induced breast carcinomas in rats

Antitumour activity of 20 mg/kg 5-fluorouracil (5-FU) and 100 or 200 mg/kg 5'-deoxy-5-fluorouridine (5'-DFUR) was assessed by tumour regression, light and electron microscopic changes, and immunohistochemical variations in broxuridine labelling in 7,12-dimethyl-benz[a]anthracene- (DMBA-) induced breast carcinomas in rats. The relative regression of tumours was significantly (P less than 0.05) greater in animals receiving 5-FU or 5'-DFUR than in control animals. Light microscopic changes became apparent after 3 or 4 days' treatment and were more evident after 4-21 days. Electron microscopic degeneration of tumours was observed after 1 day. The broxuridine labelling index decreased significantly (P less than 0.05) in rats receiving 5-FU and especially in those receiving 5'-DFUR. Concentrations of 5-FU in DMBA-induced breast carcinomas were significantly (P less than 0.05) higher in rats treated with 5'-DFUR than in those treated with 5-FU, and the histological degeneration was significantly (P less than 0.05) more advanced in 5'-DFUR- than in 5-FU-treated animals, possibly due to the higher pyrimidine nucleoside phosphorylase activity in the former treatment group.

Treatment of cancers involving the liver and porta hepatis with external beam irradiation and intraarterial hepatic fluorodeoxyuridine

A Phase I/II clinical trial was designed for patients with malignancies of the liver and porta hepatis. This protocol employed three concepts: a) boost treatment to gross tumor within the liver for selected patients, determined by the dose-volume histogram (DVH) of the normal liver that would be irradiated by boost treatment; b) concurrent use of intraarterial hepatic 5-fluorodeoxyuridine (FdUrd) as a radiosensitizer; and c) hyperfractionation (1.5 Gy fractions given bid greater than 4 hr apart). This report describes the results of treatment of the first 33 patients entered onto this study, with a minimum follow-up of 1 year. Twenty patients received only whole liver irradiation (33 Gy). Thirteen patients were treated with whole liver irradiation (30 Gy) plus a 15 Gy (6 patients) or 30 Gy (7 patients) boost (total 45 Gy and 60 Gy to the tumor, respectively). Forty-eight percent of the evaluable patients (14/29) had an objective response, based on CT scan. The median duration of response was 8 months. The chief toxicities were fatigue, nausea, gastritis, and diarrhea, which were less than or equal to grade 2 in severity. Two patients developed mild radiation hepatitis which was treated successfully with diuretics. These data suggest that the treatment of intrahepatic malignancies can be guided by the concept of DVH analysis of the normal liver to allow the safe administration of doses of radiation that are potentially tumoricidal and are well above those that would be predicted to be tolerable for the whole liver.

5'-Deoxy-5-fluorouridine improves cachexia by a mechanism independent of its antiproliferative action in colon 26 adenocarcinoma-bearing mice

The cytostatic agent 5'-deoxy-5-fluorouridine (5'-dFUrd) improves cachexia and prolongs survival, suppressing tumor growth in mice bearing large burdens of colon 26 adenocarcinoma. To investigate the mode of this anticachectic action, we isolated colon 26 variants that were resistant to the anticachectic activity in vivo in tumor-bearing mice that initially responded to 5'-dFUrd in terms of tumor growth and cachexia but again became cachectic and refractory to the drug after prolonged treatment. The original line and variants were equally susceptible to the antiproliferative action of 5'-dFUrd, and their growth was stopped. However, 5'-dFUrd given to cachectic mice exhibiting large burdens of these variants could not reverse wasting and only slightly prolonged the survival period. These results indicate that the anticachectic activity of 5'-dFUrd is independent of its antiproliferative action and that the survival of colon 26-bearing mice is shorter when the size of the tumors is not reduced to levels below those that cause cachexia.

Complications of hepatic arterial infusion chemotherapy

Chemotherapy by direct hepatic arterial infusion (HAI) results in reduction in tumor mass in a large percentage of patients. The authors reviewed records for 45 patients with metastatic cancer of the gastrointestinal tract who underwent HAI chemotherapy with floxuridine, administrated via an implanted pump. Twenty-seven of the 45 patients suffered complications, including gastrointestinal ulceration (18%), hepatitis (24%), sclerosing cholangitis (7%), and abscess (2%). The complication rates in this series were similar to those previously reported. The toxicity of HAI chemotherapy continues to limit its efficacy.

Concomitant radiation therapy and constant infusion FUdR for unresectable hepatic metastases

Ten patients with unresectable liver metastases from intraabdominal primary malignancies were treated with combined hepatic irradiation and hepatic artery infusion with FUdR using an Infusaid pump. The median survival for the entire group was 10 months. Four (40%) demonstrated an objective response to treatment: Three patients had a decrease in tumor mass on computed tomography (CT) scan, and one patient had a reduction in liver size as measured by palpation. The survival of two of the three patients whose tumor size was observed to be reduced on CT scan was significantly longer than that of the rest of the group (23, 37, and 12 months). Treatment was generally well tolerated with only mild side effects. Morbidity from chemotherapy did not appear to be enhanced by combination with hepatic irradiation. This form of treatment, although it has not demonstrated improved survival compared with other treatments in this setting, may be considered for adjuvant therapy in patients with hepatic metastases.

[A study on pre-operative administration of 5'-DFUR in carcinomas of the gastric, breast, thyroid and colon]

Pre-operative chemotherapy for 7 days with 5'-DFUR (p.o.) were carried out in the patients with gastric, breast, thyroid and colon cancers. The concentration of 5-fluorouracil (5-FU) in tumor cells was higher than that in the normal tissue. In case of breast cancer, it was 10 times higher than normal tissue. The concentration of 5-FU at the metastatic lymph nodes in gastric cancer was considerably high. The pattern of DNA histogram changed when chemotherapy was applied, and we observed the G2 and M phase block.

[A resected case of gastric carcinoma with complete remission of Virchow's node metastasis by 5'-DFUR administration]

5'-DFUR was administered orally at 800 mg/day, for total dosage of 57.6 g to the gastric cancer patient, classified Borrmann Type 2, with Virchow's node metastasis. Gastric tumor had diminished in size on the fluoroscopy and the endoscopy. We then made distal gastrectomy. The resected stomach showed moderately differentiated tubular adenocarcinoma on the pathological examination. Side effect was diarrhea.

Development of a radioimmunoassay for neurone specific enolase (NSE) and its application in the study of patients receiving intra hepatic arterial streptozotocin and floxuridine

A radioimmunoassay has been developed for neurone specific enolase (NSE) and used to measure serum NSE levels in patients with neuroendocrine and non-neuroendocrine tumours following intra hepatic arterial chemotherapy. Ten patients were studied, 7 receiving streptozotocin and floxuridine for neuroendocrine tumours and three receiving cisplatinum for non-neuroendocrine neoplasms. All ten patients had liver metastases. In patients with tumours of neuroendocrine origin, a significant increase in serum NSE was recorded within 24 h of therapy. Slight increases in serum NSE levels were also recorded in three patients with non neuroendocrine tumours. These increases may reflect lysis of neuroendocrine cells within the tumour. Raised levels in non-neuroendocrine tumour patients may reveal damage done to healthy neuronal and neuroendocrine cells during treatment. NSE may be a useful marker of the extent of cell death following chemotherapy.

Anticachectic activity of 5'-deoxy-5-fluorouridine in a murine tumor cachexia model, colon 26 adenocarcinoma

Murine colon 26 adenocarcinoma causes a progressive weight loss and physiological changes associated with cachexia when it grows to a certain size. By the use of this tumor model several types of cytostatics were examined for their ability to alleviate cachexia. Among them, 5'-deoxy-5-fluorouridine could reverse a progressive weight loss and improve hypoglycemia, hyperglucocorticism, and hepatic malfunctions, as well as inhibiting the tumor growth. Cyclophosphamide, nimustine, and 2'-deoxy-5-fluorouridine were only slightly effective in reversing the wasting, while 5-fluorouracil, tegafur, mitomycin C, cis-platinum, and doxorubicin were not active. Within 3 days after 5'-deoxy-5-fluorouridine was administered to cachectic mice with large tumor burdens, the wasting was immediately reversed even at doses in which there was increase or no significant reduction in tumor growth. These results indicate that the anticachectic activity of 5'-deoxy-5-fluorouridine is independent of its antiproliferative activity.