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Biomedical subjects

R Bugat

Publications and source records attributed to R Bugat.

At least 55 records · Page 3Linked to original sources
PubMed1997

Sequence-dependent activity of the irinotecan-5FU combination in human colon-cancer model HT-29 in vitro and in vivo.

Irinotecan, a DNA-topoisomerase-I inhibitor, is active against metastatic colon carcinoma. We investigated the effects of irinotecan and 5FU combinations in human colon-carcinoma cell line HT-29, both in vitro and in vivo. Cytotoxicity of 24-hr exposure was evaluated by SRB technique and the nature of interactions were determined by median-effect analysis. Strong synergism between irinotecan and 5FU was observed after sequential exposure, and only additivity after simultaneous exposure. At 50% level of kill, the mean sums of fractional effects were 0.13 +/- 0.05 and 0.18 +/- 0.02 respectively for the 2 sequential schedules, indicating that the combined amount of the 2 drugs necessary to kill 50% cells was only 0.18 and 0.13 times respectively, as much as would be required if they demonstrated purely additive behavior. In nude-mice xenografts, schedule-dependent toxicity was observed: the schedule in which irinotecan was administered i.v. 6 hours before 5FU was the most toxic. Higher anti-tumoral activity was noted when 20 mg/kg/day of each drug was administered sequentially (a delay of 6 hr between the 2 drugs) to mice over 5 days, in comparison with simultaneous administration. In vivo data confirmed those obtained in vitro in the same human colon-cancer model. These results suggest that irinotecan and 5FU combinations are of clinical interest and that the schedule of administration is a critical parameter for chemotherapeutic efficacy.

Animals↗
PubMed1997

Incidence and cost of adverse drug reactions in a French cancer institute.

OBJECTIVES: The incidence and the cost of adverse drug reactions (ADR) in patients treated by cancer chemotherapy were assessed using hospital database records from 1993 in a French regional cancer institute. METHODS: Patients with ADRs were identified using a list of ICD-9 codes describing potential adverse events. Direct medical costs for treating these ADRs were assessed according to the hospital system of claims data. RESULTS: Among the 3429 in-patients hospitalized in 1993, we found 171 patients (5% of the population) who presented at least one ADR (3.5% of the total number of hospital stays). A total of 313 ADRs occurred in 256 hospital stays (3.5% of the hospital stays in 1993). Of the patients with ADRs 60.2% were female and their mean age was 51.5 years; 106 patients presented with at least one "serious" ADR according to the WHO definition. These ADRs occurred during 130 hospitalizations. In 7 cases, ADRs led to death. There was no relationship between age or sex and the seriousness of the ADR. Of the ADRs 91% was type "A" (predictable). We estimated that the cost of "serious" ADRs was 1.8% of the global budget of the hospital. The average cost of ADRs leading to hospitalization was 33 037 French Francs at the current rate in 1993. This cost represented an additional cost of 32% of the overall cumulative yearly cost per patient in the institution. CONCLUSION: This study emphasizes the medical and economic impact of the management of ADR in anticancer treatments.

Adolescent↗
PubMed1997

Simultaneous high-dose external irradiation and daily cisplatin in unresectable, non-metastatic adenocarcinoma of the pancreas: a phase I-II study.

BACKGROUND AND PURPOSE: Clinical trials have demonstrated that high dose radiation therapy and daily cisplatin (CDDP) could increase local control and survival in carcinoma from various sites. The present phase I-II study has combined high dose radiation therapy and daily CDDP at escalating dosages. METHODS: From August 1994 to December 1995, 23 patients with non-resectable carcinoma of the pancreas were enrolled in a phase I-II multicentric, pilot study to test the toxicity and the effectiveness of high dose radiotherapy and daily cisplatin (CDDP) at escalating dosages. A dose of 6 mg/sqm/day of CDDP was selected for the phase II step since no grade IV toxicity occurred in any patient in the phase I step. RESULTS: Toxicity was considered fairly acceptable. At the time of analysis, the 23 patients who entered the study had clear evidence of evolutive disease either locally or distantly in the liver. It is suggested that high dose radiotherapy (60 Gy continuously) and daily CDDP have little effect on local control of the tumor and survival, and only a moderate effect on pain. CONCLUSIONS: In unresectable, apparently non-metastatic cancers of the pancreas, there is an urgent need for new agents or new combinations of agents to be tested.

Adenocarcinoma↗
PubMed1997

How to predict carboplatin clearance from standard morphological and biological characteristics in obese patients.

BACKGROUND: We previously proposed a formula to predict carboplatin clearance (CL) from four patient characteristics: plasma creatinine level, body weight, age, and sex (J Natl Cancer Inst 1995; 87: 573). Its accuracy was studied in a subpopulation of obese patients. PATIENTS AND METHODS: Twenty-five patients (16 male and 9 female, 23 to 82 years old) were studied. They were 20% to 67% (median 36%) over the ideal weight which was calculated according to the Lorentz equation. Their actual CL was obtained individually by the Siphar program. The pharmacokinetic population program NONMEM was used to determine the best value of substitution for weight in the formula. RESULTS: By using the actual weight, CL was significantly over predicted (by more than 20% for 7 of 25 patients). By using the mean value between the ideal and the actual weight, a good prediction of CL was obtained: the percentage of error ranged from -21% to +22%. CONCLUSION: The formula is applicable to obese patients if both ideal and actual weights are taken into account.

Adult↗
PubMed1997

Multifactorial mechanism for the potentiation of cisplatin (CDDP) cytotoxicity by all-trans retinoic acid (ATRA) in human ovarian carcinoma cell lines.

All-trans retinoic acid (ATRA) has been previously shown to inhibit the proliferation of some human ovarian carcinoma cell lines, and this inhibition was accompanied by cellular changes that were indicative of differentiation (Caliaro et al, 1994). In this work, a pretreatment of these adenocarcinoma cells with ATRA, for their respective doubling time, enhanced cisplatin (CDDP) cytotoxicity in the cell ines that were sensitive to its antiproliferative effect, but not in the ATRA-resistant ones. Results were assessed using median effect analysis in two ATRA-sensitive cell lines (OVCCR1 and NIHOVCAR3 cells) and in one ATRA-insensitive cell line (IGROV1 cells). Synergy between these two agents was observed only in cells sensitive to ATRA, regardless of their relative sensitivity to CDDP. Potential mechanisms for this synergy were investigated. ATRA did not increase the cellular platinum content, did not decrease the cellular glutathione and had no influence on the metallothionein IIA mRNA levels in NIHOVCAR3 cells. Moreover, the protein kinase C (PKC) activity was modulated by this differentiating agent in all cell lines tested, indicating that this activity was not directly involved in this potentiation. However, an ATRA inhibition of glutathione-S-transferase activity associated with an increase in the total DNA adducts formation could explain the potentiation of the CDDP cytotoxicity observed in NIHOVCAR3 cells. Finally, the ATRA modulation of the epidermal growth factor (EGF) receptor mRNA level could also be implicated in this synergy.

Antineoplastic Agents↗
PubMed1997

Phase II study of irinotecan in the treatment of advanced colorectal cancer in chemotherapy-naive patients and patients pretreated with fluorouracil-based chemotherapy.

PURPOSE: To assess the efficacy of irinotecan (CPT-11) in the treatment of advanced colorectal cancer in both chemotherapy-naive and pretreated patients. PATIENTS AND METHODS: Two hundred thirteen patients (aged 18 to 75 years) with metastatic colorectal cancer, World Health Organization (WHO) performance status < or = 2, and life expectancy > or = 3 months were treated with CPT-11 350 mg/m2 every 3 weeks. All 178 patients eligible for efficacy analysis had not received more than one prior fluorouracil (5-FU)-based chemotherapy regimen (adjuvant or palliative) and had adequate hematologic, renal, and hepatic function. RESULTS: Primary tumor sites were the colon (71%) and rectum (28%). Sixty-six percent of the patients had > or = two metastatic sites. Ninety-eight percent of the patients had undergone previous surgery, and 77.5% had received prior chemotherapy. Thirty-two of 178 eligible patients achieved on objective response (four complete responses [CRs] and 28 partial responses [PRs]; response rate, 18%; 95% confidence interval, 12.6% to 24.4%), 65 were stable, and 59 progressed. The response rate was 17.7% in the pretreated group and 18.8% in the chemotherapy-naive group. Within the former subgroup, response rates of 16.1% were reported in patients who were progressive on prior 5-FU chemotherapy and 19.1% in patients who were progressive off such treatment. The median duration of objective response (9.1 months) and median time to achievement of a response (9.3 weeks) did not differ between chemotherapy-naive and pretreated patients. The most frequent adverse events were neutropenia, which developed in 80% of the patients, delayed diarrhea (87%), alopecia (88%), fatigue (81%), and nausea/vomiting (77%). All these adverse events were manageable. Severe (WHO grade 3 or 4) neutropenia was only observed in 18% of the cycles, leukopenia in 11%, delayed diarrhea in 11%, and nausea and vomiting in 3%. Development of simultaneous grade 3 or 4 neutropenia and delayed diarrhea during 4% of the cycles was the safety issue of greatest concern. CONCLUSION: CPT-11 has definite activity in the treatment of advanced metastatic colorectal cancer both in chemotherapy-naive and in pretreated patients who experienced disease progression on 5-FU, which suggests a lack of cross-resistance between CPT-11 and 5-FU. Diarrhea and neutropenia, the major toxicities of CPT-11, contribute to the risk to develop febrile neutropenic sepsis.

Adult↗
PubMed1997

High dose-intensity of irinotecan administered every 3 weeks in advanced cancer patients: a feasibility study.

PURPOSE: To assess, on a multicenter basis, the feasibility of treating advanced cancer patients with high-dose irinotecan. PATIENTS AND METHODS: Thirty-five patients who met the usual phase I criteria (26 men and nine women) were included. Primary tumor sites were colon, head and neck, unknown primary, kidney, liver, and others. All had been previously treated. Irinotecan was given at the maximum-tolerated dose (MTD) (600 mg/m2) or the level below (500 mg/m2) as a 30-minute infusion once every 3 weeks. RESULTS: Eighteen patients were entered in the four participating centers at the MTD of 600 mg/m2. This dose level was clearly shown not to be feasible: 14 patients (78%) had grade 3 to 4 neutropenia, with febrile episodes in 11 patients; grade 3 to 4 diarrhea was observed in nine patients; and one toxic death occurred. Subsequently, 17 not heavily pretreated patients were included at 500 mg/m2 and carefully monitored. The safety of this dose level was considered acceptable: 41% of patients had grade 3 to 4 neutropenia, 24% experienced grade 3 to 4 diarrhea, and no febrile granulocytopenia or toxic death occurred. Six partial responses were documented in metastatic colorectal cancer, all in patients who had previously received conventional chemotherapy, four in patients who had exhibited progressive disease under fluorouracil (5FU)-based chemotherapy. CONCLUSION: We plan to study the higher dose-intensity 500-mg/m2 level on good-risk and carefully monitored patients. This could enlarge the spectrum of tumors sensitive to irinotecan and improve the already good results observed in colorectal cancers.

Adult↗
PubMed1997

[Local treatment of "small cancers" of the rectum: excision is preferable to electrocoagulation].

From 1973 to 1990, 50 patients with a "small cancer" of the rectum were treated locally either by electrocoagulation or by local excision using an electrical scalpel. 20 patients were treated by electrocoagulation. Their 5-year actuarial survival was 78.3% and the local recurrence rate was 16.5%. 4 treated patients by local excision had a lesion which invaded the serosa and should have been amputated as primary procedure. Three of them relapsed. 26 patients were treated by local excision for a lesion confined to the rectal wall. Their 5-year actuarial survival was 94.4% and the local recurrence rate was 4.5%. The difference in survival and recurrence was significant between electrocoagulation and excision of a lesion confined to the rectal wall. These results suggest that excision is preferable to electrocoagulation as it allows prediction of the result by pathological examination of the operative specimen.

Actuarial Analysis↗
PubMed1996

Pharmacokinetics and pharmacodynamics of irinotecan during a phase II clinical trial in colorectal cancer. Pharmacology and Molecular Mechanisms Group of the European Organization for Research and Treatment of Cancer.

PURPOSE: A pharmacokinetic study was performed during a phase II clinical trial of irinotecan (CPT-11) to confirm the pharmacokinetic profile of this drug and its metabolite and to investigate interpatient and intrapatient pharmacokinetic variations and pharmacokinetic-pharmacodynamic relationships. PATIENTS AND METHODS: Twenty-six men and 21 women (mean age, 61 years) with metastatic colorectal cancer, performance status less than 3 (World Health Organization [WHO] scale), and normal renal and hepatic function were administered CPT-11 (350 mg/m2) by 30-minute intravenous (IV) infusion every 21 days. CPT-11 and its metabolites SN-38 and SN-38 glucuronide (SN-38G) were determined by high-performance liquid chromatography (HPLC) using fluorimetric detection. RESULTS: The mean CPT-11 clearance and area under the concentration-time curve (AUC) were 15.2 L/h. m2 and 24,769ng. h/mL, respectively. The large difference in SN-38 and SN-38G AUCs (559 v 2,283 ng. h/mL) was suggestive of extensive glucuronidation of SN-38. Interindividual variation in the metabolic ratio ([AUCSN-38 + AUCSN-38Gl/AUCCPT-11) was marked (coefficient of variation [CV] = 51.6%] compared with intrapatient variation in this variable (CV = 32.6%). A significant relationship existed between percentage reduction in neutrophil count and the AUC of CPT-11 (r = .597, P < .001) and SN-38 (r = .559, P < .001). No relationship was identified between any pharmacokinetic parameter and delayed diarrhea or therapeutic outcome. CONCLUSION: Interindividual variations in the metabolic ratio suggest interpatient variation in carboxylesterase activity. Furthermore, glucuronidation of SN-38 may also be in part responsible for the large interpatient variability in the total SN-38 AUC. Conversely, low intrapatient variation of this parameter was observed in this study, which indicates a lack of autoinduction of the carboxylesterase system. The relationship between neutropenia and both CPT-11 and SN-38 pharmacokinetic parameters confirms the results of previous studies.

Adult↗
PubMed1996

Intraperitoneal recombinant interferon gamma in ovarian cancer patients with residual disease at second-look laparotomy.

PURPOSE: The purpose of this study was to evaluate the efficacy and tolerance of recombinant human interferon gamma (rIFN-gamma) as second-line treatment in patients with persistent disease at second-look laparotomy. PATIENTS AND METHODS: One hundred eight patients with residual disease at second-look laparotomy were treated with rIFN-gamma (20 x 10(6) IU/m2) administered intraperitoneally (IP) twice a week for 3 to 4 months. In the absence of clinically assessable disease, response to rIFN-gamma was assessed with a third-look laparotomy. RESULTS: Of 98 assessable patients, 31 (32%) achieved a surgically documented response, including 23 patients (23%) with a complete response (CR). The age and size of residual tumor were significant prognostic factors for the response to rIFN-gamma. A 41% CR rate was observed in 41 patients younger than 60 years and with residual tumor less than 2 cm. The probability of response was independent of previous response to first-line chemotherapy. The median duration of response was 20 months and the 3-year survival rate in responders was 62%. Response to rIFN-gamma was the most significant prognostic factor for survival of patients with residual disease. Adverse events included fever, flu-like syndrome, neutropenia, and liver enzyme disturbances. No significant peritoneal fibrosis was noted. CONCLUSION: These results support the potential interest of IP rIFN-gamma as adjuvant treatment in ovarian cancer. Controlled prospective trials are required to determine its place in the therapeutic strategy of this malignancy.

Adult↗
PubMed1996

CPT-11 in the treatment of colorectal cancer: clinical efficacy and safety profile.

CPT-11 (irinotecan) is a promising anticancer agent with a novel mechanism of action dependent on the inhibition of the DNA eukaryotic enzyme, topoisomerase I. The clinical utility of CPT-11 in advanced colorectal cancer has been documented in more than 400 patients recruited in phase II clinical trials in Europe, Japan, and United States. Among 178 eligible patients in a multicenter European study, the overall response rate to CPT-11 on a once-every-3-weeks regimen was 18%, and the median duration of response was 9.1 months. Thirty-two percent of the patients had no evidence of disease progression at 6 months. These results were similar in chemotherapy-naive and pretreated patients. These findings are consistent with the results of other studies conducted in Japan and the United States in which a weekly CPT-11 regimen was associated with response rates of 15% to 32% in chemotherapy-naive or pretreated patients. The principal adverse events of CPT-11 are neutropenia and delayed diarrhea, which in the European studies developed as grade 3 or 4 toxicity in 21% and 12% of the cycles (47% and 38% of patients), respectively. Neutropenia did not appear to be cumulative, with total recovery by day 22 in most cases. Loperamide was considered the most effective agent for controlling delayed diarrhea. Other adverse events included an early cholinergic-like syndrome (consisting of diaphoresis, early diarrhea, and abdominal cramps), nausea and vomiting, fatigue, and alopecia. In conclusion, CPT-11 has shown promising antitumor activity in the treatment of patients with advanced colorectal cancer, including those refractory to 5-fluorouracil (5-FU)-based regimens, suggesting no cross-resistance to 5-FU. CPT-11 appears to have activity similar to that of 5-FU in first-line treatment and, moreover, remains active after failure of 5-FU therapy. The specific gastrointestinal toxicity is manageable, and a better control of this type of toxicity is expected in the future. CPT-11 would therefore appear a welcome addition to the oncology armamentarium for this difficult-to-treat malignancy.

Antineoplastic Agents, Phytogenic↗
PubMed1996

[A phase II study with mitoxantrone-vinorelbine association in the treatment of advanced breast cancer in elderly women].

To assess efficacy and toxicity of less toxic analogs for advanced breast cancer in elderly women, we performed a phase II study using the combination mitoxantrone (MTZ)-vinorelbine (VNR). From January 1991 to May 1993, 25 women older than 70 years received a chemotherapy consisting in 10 mg/m2 of MTZ on day 1, followed by 20 mg/m2 of VNR on day 1 and 8. Cycles were repeated every 21 days for a maximum of ten cycles in the case of an objective response. Sixteen women previously received first line hormonotherapy, eight with only one metastatic site. Twenty-three patients are evaluable for response and toxicity. An objective response was observed in five cases (22%), with a median time to progression of 13 months. More than 75% of the planned dose-intensity, for MTZ and VNR was received by 90 and 57.2% of patients, respectively. Dose-limiting toxicity was myelosuppression but no febrile neutropenia was observed. Extra haematologic toxicities were unfrequent. This combination is well tolerated by elderly women, but best results could be achieved by increasing delivered dose intensity.

Aged↗
PubMed1995

Mechanism of interaction between cisplatin and human recombinant interferon gamma in human ovarian-cancer cell lines.

Human ovarian carcinoma cells (2008 and its cisplatin-resistant sub-line 2008/C13*) were sensitized to cisplatin by treatment with human recombinant gamma interferon (IFN gamma). IFN gamma produced no significant change in the uptake of CDDP. Exposure of 2008 and 2008/C13* cells to IFN gamma resulted in a time-dependent decrease of cellular glutathione and total glutathione-S-transferase activity, principally the pi isoform. By contrast, the treatment of 2008 and 2008/C13* cell lines with IFN gamma induced rather than suppressed metallothionein IIA mRNA levels. IFN gamma changed neither the formation of total platinum-DNA adducts, nor DNA repair. A significant decrease in c-erbB-2 expression was observed both in sensitive and in resistant cell lines after treatment with IFN gamma, and this decrease was dose-dependent. Our results indicate that the mechanism of IFN gamma-induced sensitization in human ovarian-cancer cell lines is multifactorial.

Cisplatin↗
PubMed1995

Prediction of carboplatin clearance from standard morphological and biological patient characteristics.

BACKGROUND: Hematologic toxicity of an antineoplastic drug, carboplatin, is largely dependent on its pharmacokinetics. Its therapeutic efficacy may be related to plasma drug exposure. Dosage adjustment based on isotopic determination of glomerular filtration rate has been proposed, but its ambulatory use is not yet conceivable. The dosage adjustment based on a patient's creatinine clearance relies on accurate measurement of urine volume per unit time and can be done with ease. PURPOSE: A population pharmacokinetics study was undertaken to determine a relationship between carboplatin clearance and patient characteristics. A predictive formula was derived that was then prospectively evaluated, and its outcome was compared with that obtained by other methods available to predict carboplatin clearance. METHODS: Plasma carboplatin pharmacokinetics determined as ultrafilterable platinum in 70 patients (age range, 23-84 years) treated with different combination regimens that included carboplatin at doses ranging from 184 mg to 950 mg (1-hour intravenous infusion) for various tumor types. Data were analyzed using the nonlinear mixed effects model (NONMEM). The data from 34 patients (46 cycles) were utilized to derive the most predictive formula. The reliability of the formula was subsequently evaluated by analyzing the data obtained from 36 other patients (49 cycles). RESULTS: Carboplatin clearance (mL/min) was found to be best predicted by the following formula: 0.134.weight + [218.weight.(1-0.00457.age).(1-0.314.sex)]creatinine expressed in micromolar concentration (with weight in kg, age in years, and sex = 0 if male and sex = 1 if female). Prospectively, this formula predicted the carboplatin clearance with good precision (median absolute percent error of 10% [range, 0% to 30%]) and minimal bias (median percent error of 2% [range, -25% to 30%]). This method of prediction was as accurate as the one derived from the measurement of glomerular filtration rate following the injection of 51 chromium-EDTA. CONCLUSION: This formula for the determination of carboplatin clearance can permit individualized determination of carboplatin dosage in adults by simply multiplying the calculated carboplatin clearance by the area under the curve for the desired dosage administration.

Adult↗
PubMed1995

Pharmacokinetics of irinotecan and its metabolites in human blood, bile, and urine.

Two patients were treated with CPT-11 for colorectal cancer and had a percutaneous biliary catheter for extrahepatic biliary obstruction. The first patient was treated with CPT-11 according to the 100-mg/m2 weekly therapeutic schedule, and the second patient was treated every 3 weeks, with a dose of 350 mg/m2 being given at the first course, after which it was decreased to 300 mg/m2 for the following courses. In plasma, the active identified metabolite of CPT-11, SN-38, occurred mainly in the form of a glucuronide conjugate. CPT-11 was mainly excreted in bile and urine as CPT-11. The cumulative biliary and urinary excretion of CPT-11 and its metabolites (SN-38 and SN-38 glucuronide conjugate) over a period of up to 48 h ranged from 25% (100 mg/m2 weekly) to 50% (300 mg/m2 every 3 weeks). This means that CPT-11 can be excreted under other, not yet identified metabolite forms.

Antineoplastic Agents, Phytogenic↗
PubMed1995

A pharmacologically guided phase I study of carboplatin in combination with methotrexate and vinblastine in advanced urothelial cancer.

Carboplatin is an alternative for cisplatin in the treatment of urothelial cancers. A pharmacologically guided phase I study of carboplatin in combination with methotrexate (30 mg/m2) and vinblastine (4 mg/m2) was conducted in ten patients by increment of the area under the plasma concentration versus time curve (AUC) for ultrafilterable carboplatin using the Calvert formula. The maximal tolerated AUC was 5 mg ml-1 min, with neutropenia being the dose-limiting toxicity. There was a significant linear correlation between the percentage of decrease in neutrophil count and the carboplatin AUC. Determination of the glomerular filtration rate by the isotopic method allowed us to adapt the dose of carboplatin given to patients suffering from urothelial cancer, who frequently have impaired renal function. The recommended AUC for phase II study is 4 mg ml-1 min.

Antineoplastic Combined Chemotherapy Protocols↗