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(1/6112) Intensive weekly chemotherapy is not effective in advanced pancreatic cancer patients: a report from the Italian Group for the Study of Digestive Tract Cancer (GISCAD).

Twenty-two patients, with locally advanced unresectable and/or metastatic pancreatic carcinoma, received weekly administration of cisplatin 40 mg m(-2), 5-fluorouracil 500 mg m(-2), epidoxorubicin 35 mg m(-2), 6S stereoisomer of leucovorin 250 mg m(-2) and glutathione 1.5 mg m(-2), supported by a daily administration of lenograstim at a dose of 5 microg kg(-1). Nineteen patients were men and three were women. Median age was 63 years (range 47-70). At study entry, pain was present in 15 out of 22 patients (68%) with a mean value of Scott-Huskisson scale of 27.6+/-23.8, whereas a weight loss >10% was present in 15 patients. After eight weekly treatments, three partial responses were achieved for a response rate of 13% (95% CI 0-26%), five patients had stable disease and 14 progressed on therapy. Pain was present in 9 out of 22 patients (40%) with a mean value of Scott-Huskisson scale of 12.3+/-18.4. Eight patients (36%) (three partial response and five stable disease) had a positive weight change. Toxicity was mild: WHO grade III or IV toxicity was recorded in terms of anaemia in 7 out of 188 cycles (3.7%), of neutropenia in 9 out of 188 cycles (4.7%) and of thrombocytopenia in 3 out of 188 cycles (1.5%). Median survival of all patients was 6 months. The outcome of this intensive chemotherapy regimen does not support its use in pancreatic cancer.  (+info)

(2/6112) Is early post-operative treatment with 5-fluorouracil possible without affecting anastomotic strength in the intestine?

Early post-operative local or systemic administration of 5-fluorouracil (5-FU) is under investigation as a means to improve outcome after resection of intestinal malignancies. It is therefore quite important to delineate accurately its potentially negative effects on anastomotic repair. Five groups (n = 24) of rats underwent resection and anastomosis of both ileum and colon: a control group and four experimental groups receiving daily 5-FU, starting immediately after operation or after 1, 2 or 3 days. Within each group, the drug (or saline) was delivered either intraperitoneally (n = 12) or intravenously (n = 12). Animals were killed 7 days after operation and healing was assessed by measurement of anastomotic bursting pressure, breaking strength and hydroxyproline content. In all cases, 5-FU treatment from the day of operation or from day 1 significantly (P<0.025) and severely suppressed wound strength; concomitantly, the anastomotic hydroxyproline content was reduced. Depending on the location of the anastomosis and the route of 5-FU administration, even a period of 3 days between operation and first dosage seemed insufficient to prevent weakening of the anastomosis. The effects of intravenous administration, though qualitatively similar, were quantitatively less dramatic than those observed after intraperitoneal delivery. Post-operative treatment with 5-FU, if started within the first 3 days after operation, is detrimental to anastomotic strength and may compromise anastomotic integrity.  (+info)

(3/6112) Profound variation in dihydropyrimidine dehydrogenase activity in human blood cells: major implications for the detection of partly deficient patients.

Dihydropyrimidine dehydrogenase (DPD) is responsible for the breakdown of the widely used antineoplastic agent 5-fluorouracil (5FU), thereby limiting the efficacy of the therapy. To identify patients suffering from a complete or partial DPD deficiency, the activity of DPD is usually determined in peripheral blood mononuclear cells (PBM cells). In this study, we demonstrated that the highest activity of DPD was found in monocytes followed by that of lymphocytes, granulocytes and platelets, whereas no significant activity of DPD could be detected in erythrocytes. The activity of DPD in PBM cells proved to be intermediate compared with the DPD activity observed in monocytes and lymphocytes. The mean percentage of monocytes in the PBM cells obtained from cancer patients proved to be significantly higher than that observed in PBM cells obtained from healthy volunteers. Moreover, a profound positive correlation was observed between the DPD activity of PBM cells and the percentage of monocytes, thus introducing a large inter- and intrapatient variability in the activity of DPD and hindering the detection of patients with a partial DPD deficiency.  (+info)

(4/6112) Dihydropyrimidine dehydrogenase deficiency and fluorouracil-related toxicity.

Dihydropyrimidine dehydrogenase (DPD) is the initial and rate-limiting enzyme of 5-fluorouracil (5-FU) catabolism. We report lymphocytic DPD data concerning a group of 53 patients (23 men, 30 women, mean age 58, range 36-73), treated by 5-FU-based chemotherapy in different French institutions and who developed unanticipated 5-FU-related toxicity. Lymphocyte samples (standard collection procedure) were sent to us for DPD determination (biochemical method). Among the whole group of 53 patients, 19 had a significant DPD deficiency (DD; below 150 fmol min(-1) mg(-1) protein, i.e. less than 70% of the mean value observed from previous population study). There was a greater majority of women in the DD group (15 out of 19, 79%) compared with the remaining 34 patients (15 out of 34, 44%, P<0.014). Toxicity was often severe, leading to patient death in two cases (both women). The toxicity score (sum of WHO grading, theoretical range 0-20) was twice as high in patients with marked DD (below 100 pmol min(-1) mg(-1) protein, n = 11, mean score = 13.2) compared with patients with moderate DD (between 150 and 100 pmol min(-1) mg(-1) protein, n = 8, mean score = 6.8), P = 0.008. In the DD group, there was a high frequency of neurotoxic syndromes (7 out of 19, 37%). The two deceased patients both had severe neurotoxicity. The occurrence of cardiac toxicity was relatively rare (1 out of 19, 5%). These data suggest that women are particularly prone to DPD deficiency and allow a more precise definition of the DD toxicity profile.  (+info)

(5/6112) Antitumor agents. I. Effect of 5-fluorouracil and cyclophosphamide on liver microsomes and thymus of rat.

Effects of antitumor agents on rat liver microsomal drug-metabolizing enzyme activities and thymus lymphocytes were studied in male Wistar rats. High doses of 5-fluorouracil (5-FU) and cyclophosphamide (CP) given parenterally for 6 days caused a partial decrease in whole body weight and the microsomal enzyme content such as cytochrome P-450 and cytochrome b5. Aniline p-hydroxylase and aminopyrine N-demethylase activities also decreased in rats dosed for 5 days decreased compared with the control. Both compounds in the high concentrations produced spectral change of "modified type II". However, the magnitude of the spectral changes observed was independent of the the concentration of substrate added. The addition of NADPH to the microsomes-substrate mixture modified the spectral change. Both drugs caused a considerable decrease in thymus weight and the number of thymus lymphocytes, while the alkaline phosphatase activity was enhanced in 5-FU groups, indicating that the agents cause a significant involution of the thymus. Decrease in the total number of the lymphocytes was greater than that in the blood leucocytes.  (+info)

(6/6112) Persistent induction of apoptosis and suppression of mitosis as the basis for curative therapy with S-1, an oral 5-fluorouracil prodrug in a colorectal tumor model.

In an effort to improve the therapeutic selectivity of 5-fluorouracil (FUra) against colorectal cancer, S-1, a combination agent including a prodrug of FUra with two modulators, was recently developed by Taiho Pharmaceuticals Co. S-1 is a combination of tegafur (FT), 5-chloro-2,4-hydroxypyridine, and potassium oxonate in the molar ratio of 1.0:0.4:1.0, with the latter two components as inhibitors of dihydropyrimidine dehydrogenase and phosphoribosylpyrophosphate transferase, respectively. In this study, the therapeutic selectivity and efficacy of S-1 (oral) was compared with FT (oral) and FUra (i.v. infusion) in rats bearing advanced colorectal cancer by using clinically relevant schedules. The maximum tolerated doses (MTDs) of S-1, FT, and FUra were 31.5, 200, and 25 mg/kg/d for 7 days and 22.5, 150, and 12.5 mg/kg/d for 28 days, respectively. The therapeutic index of S-1 was 4- to 5-fold higher than that of either FT or FUra. S-1 achieved 100% complete tumor regression (CR) at its MTD in both 7-day and 28-day schedules. Furthermore, the high incidences of stomatitis, alopecia, and diarrhea observed with FUra and FT, were not observed with S-1. In an attempt to understand the basis for the observed superior therapeutic selectivity with S-1, we studied pharmacokinetic analysis of FUra, drug-induced apoptosis, suppression of mitosis, and inhibition of thymidylate synthase (TS) after S-1, FUra, or FT administration. The peak plasma FUra concentrations derived from FUra or S-1 (FT) at comparable MTDs were similar, but the plasma level of FUra was higher with S-1 than with FUra. Induction of high and sustained apoptosis was achieved with S-1. Although the initial level of apoptosis induced by FUra was comparable to S-1, it was not sustained. The sustained level of apoptosis appears to correlate with tumor growth inhibition. Mitotic figures were more greatly suppressed with S-1 treatment than with FUra. Studies on TS inhibition indicated that, although both S-1 and FUra caused a 4- to 6-fold induction of total TS protein, single oral administration of S-1 was superior to 24-h infusion of FUra in suppressing free TS. The data are consistent with the observation that the therapeutic efficacy of S-1 (100% cure) over FUra is associated with high and sustained levels of drug-induced apoptosis, greater suppression of mitosis, and inhibition of free TS in tumor tissues.  (+info)

(7/6112) Phase I study of eniluracil, a dihydropyrimidine dehydrogenase inactivator, and oral 5-fluorouracil with radiation therapy in patients with recurrent or advanced head and neck cancer.

5-Fluorouracil (5-FU) is an effective enhancer of radiation therapy (RT) in head and neck cancers. Due to rapid, predominantly hepatic metabolism by dihydropyrimidine dehydrogenase (DPD) and suggested clinical benefit from prolonged drug exposure, 5-FU is commonly given by continuous infusion. Eniluracil is a novel DPD-inactivator designed to prolong the half-life of 5-FU and provide sustained plasma concentrations of 5-FU with oral dosing. We conducted a Phase I study of the safety and efficacy of eniluracil given with oral 5-FU in patients receiving concurrent RT for recurrent or advanced squamous cell carcinomas of the head and neck. Thirteen patients with recurrent, metastatic, or high-risk (defined as an expected 2-year survival rate of <10%) head and neck cancer were enrolled and treated with concomitant chemoradiotherapy on an every-other-week schedule. Eniluracil at a fixed dose [20 mg twice a day (BID)] was given for 7 consecutive days (days 1-7). 5-FU and RT were given on 5 consecutive days (days 2-6). One patient was treated with once-daily RT (2.0 Gy fractions). The remaining patients received hyperfractionated RT (1.5-Gy fractions BID). The initial dose of 5-FU was 2.5 mg/m2 given BID. Dose escalation in patient cohorts was scheduled at 2.5-mg/m2 increments, with intrapatient dose escalation permitted. Lymphocyte DPD activity and serum 5-FU and uracil concentrations were monitored during two cycles. DPD activity was completely or nearly completely inactivated in all patients. Sustained, presumed therapeutic concentrations of 5-FU were observed at a dose of 5.0 mg/m2 given BID. Cumulative dose-limiting myelosuppression (both neutropenia and thrombocytopenia) was observed during the fourth and fifth cycles following administration of 5.0 mg/m2 5-FU BID. One patient died of neutropenic sepsis during cycle 4. Other late cycle toxicities included diarrhea, fatigue, and mucositis. Grade 3 mucositis was observed in 4 patients, but no grade 4 mucositis or grade 3 or 4 dermatitis was observed. A second patient death occurred during cycle 1 of treatment. No specific cause of death was identified. The study was subsequently discontinued. Cumulative myelosupression was the significant dose-limiting toxicity of oral 5-FU given with the DPD-inactivator eniluracil on an every-other-week schedule. Clinical radiation sensitization was not observed, based on the absence of dose-limiting mucositis and dermatitis. Alternative dosing schedules need to be examined to determine the most appropriate use of eniluracil and 5-FU as radiation enhancers.  (+info)

(8/6112) A Fas-dependent component in 5-fluorouracil/leucovorin-induced cytotoxicity in colon carcinoma cells.

We have shown previously (J. A. Houghton et al., Proc. Natl. Acad. Sci. USA, 94: 8144-8149, 1997) that thymineless death in thymidylate synthase-deficient (TS-) colon carcinoma cells is mediated via Fas/FasL interactions after deoxythymidine (dThd) deprivation, and that Fas-dependent sensitivity of human colon carcinoma cell lines may be dependent upon the level of Fas expressed. The objective of this study was to elucidate whether a Fas-dependent component exists in 5-fluorouracil (FUra)/leucovorin (LV)-induced cytotoxicity of colon carcinoma cells, and whether this may be potentiated by IFN-gamma-induced elevation in Fas expression, using the HT29 cell line as a model. The cytotoxic activity of FUra/LV was inhibited by dThd in HT29 cells and also, in part, by NOK-1+NOK-2 MoAbs that prevent Fas/FasL interactions. FUra/LV-induced cytotoxicity was significantly potentiated by IFN-gamma, reversed by exposure to NOK-1+NOK-2 antibodies, and correlated with a 4-fold induction of Fas expression in the presence of IFN-gamma and significant elevation in expression of FasL. Using five additional human colon carcinoma cell lines, FUra/LV-induced cytotoxicity was dThd-dependent in GC3/c1, VRC5/c1, and Caco2 but not in HCT8 or HCT116 cells. Like HT29 cells, this cytotoxicity was potentiated by IFN-gamma in GC3/c1 and VRC5/c1 but not in Caco2, which fails to express Fas, nor in HCT8 and HCT116, in which no dThd-dependent FUra-induced cytotoxicity was demonstrated. Data suggest that a Fas-dependent component, potentiated by IFN-gamma, exists in FUra/LV-induced cytotoxicity but requires FUra/LV-induced DNA damage for IFN-gamma-induced potentiation to occur.  (+info)