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PubMed2001

Comparison of conventional dose and double dose carboplatin in patients receiving cyclophosphamide plus carboplatin for advanced ovarian carcinoma: a North Central Cancer Treatment Group Study.

Between March 1992 and November 1994, 91 patients with stage III and IV ovarian carcinoma were enrolled in a randomized comparative study of cyclophosphamide 600 mg/m2 plus carboplatin 300 mg/m2 vs. cyclophosphamide 600 mg/m2 plus carboplatin 600 mg/m2, each regimen given monthly for six cycles. Patients on the intensive regimen also received 10 micrograms/kg of granulocyte macrophage colony stimulating factor (GM-CSF) (molgramostim) daily for 14 days following each chemotherapy treatment. The study was closed prematurely because of very poor case accrual following the preliminary announcement (in May 1993) that paclitaxel appeared superior to cyclophosphamide in the platinum-based treatment of ovarian cancer. More than 4 years after our last case entry, we analyzed the survival results for the 44 eligible patients who received the conventional dose of carboplatin and the 43 eligible patients receiving our intensified dose of carboplatin. More than 90% of the treated patients receiving the conventional dose regimen received at least 75% of the planned doses at each of the six treatment intervals, whereas the percentage of treated patients able to receive at least 75% of the assigned intensive dose regimen had declined from 95% in cycle 2 to 53% by cycle 6. Furthermore, although 32 patients received all six planned cycles of treatment in the conventional regimen group, only 15 received all six cycles of the intensified regimen. Patients receiving the intensive regimen had more fever, dermatitis, lethargy, musculoskeletal pain, and pulmonary complications than did the conventional dose patients. Median survival times for the two treatment groups were very similar (38.5 and 38.1 months, respectively, for the conventional and intensive regimens), and we saw no evidence that the distribution of survival times differed between the treatment regimens (p = 0.95).

Adult↗
PubMed1968

The thymus and recovery from cyclophosphamide-induced tolerance to sheep erythrocytes.

Recovery from specific immunological tolerance to sheep erythrocytes induced with the drug cyclophosphamide was studied with the hemolytic plaque technique of Jerne. The base line plaque (19S antibody-forming cell of the unstimulated spleen) and the proliferative response to antigen, both of which had disappeared during tolerance induction, returned with the recovery of specific immunological reactivity. When cyclophosphamide is injected without sheep cells there is temporary immunological unreactivity and lymphoid depletion of the spleen, but specific tolerance is not induced. Recovery is largely complete at the end of 2 wk and does not require the participation of the thymus. When cyclophosphamide is injected together with sheep cells, 18 days after drug injection, tolerance is still complete. In nonthymectomized mice there is rapid recovery during the next 10 wk, followed by much slower restoration over the remaining 20-30 wk of observation. The entire recovery process evidently takes 40-50 wk. In thymectomized CBA mice only minimal recovery takes place in the first 10 wk and no further restoration occurs thereafter. Thymectomy performed 18 days after tolerance is induced, when tolerance is complete, is equally effective in preventing this recovery.

Animals↗
PubMed1975

Augmentation of delayed-type hypersensitivity by doses of cyclophosphamide which do not affect antibody responses.

Mice immunized with more SRBC than are required to produce optimal delayed-type hypersensitivity reactions, developed good antibody responses and poor delayed foot pad reactions. Cyclophosphamide treatment in low doses (20 mg/kg) before immunization, augmented the delayed-type hypersensitivity without affecting antibody responses. Cyclophosphamide did not augment delayed responses to optimal doses of SRBC (0.01%), but did augment the delayed hypersensitivity response of mice immunized with a suboptimal antigen dose (0.001%); which produced no detectable antibody response with or without cyclophosphamide pretreatment. These results suggest that antibody feedback is not the sole regulator of delayed reactions; the possibility that suppressor T cells may also be involved is discussed.

Animals↗
PubMed1992

Autoimmune syndromes in major histocompatibility complex (MHC) congenic strains of nonobese diabetic (NOD) mice. The NOD MHC is dominant for insulitis and cyclophosphamide-induced diabetes.

The development of autoimmune diabetes in the nonobese diabetic (NOD) mouse is controlled by multiple genes. At least one diabetogenic gene is linked to the major histocompatibility complex (MHC) of the NOD and is most likely represented by the two genes encoding the alpha and beta chains of the unique NOD class II molecule. Three other diabetogenic loci have recently been identified in the NOD mouse and are located on chromosomes 1, 3, and 11. In addition to the autoimmune diabetes which is caused by destruction of the insulin-producing beta cells in the pancreas, other manifestations of autoimmunity are seen in the NOD mouse. These include mononuclear cell inflammation of the submandibular and lacrimal glands, as well as the presence of circulating autoantibodies. To determine the effect of the non-MHC diabetogenic genes on the development of autoimmunity, we constructed the NOD.B10-H-2b (NOD.H-2b) strain, which possesses the non-MHC diabetogenic genes from the NOD mouse, but derives its MHC from the C57BL/10 (B10) strain. The NOD.H-2b strain does not develop insulitis, cyclophosphamide-induced diabetes, or spontaneous diabetes. It does, however, develop extensive lymphocytic infiltrates in the pancreas and the submandibular glands that are primarily composed of Thy 1.2+ T cells and B220+ B cells. In addition, autoantibodies are present in NOD.H-2b mice which recognize the "polar antigen" on the insulin-secreting rat tumor line RINm38. These observations demonstrate that the non-MHC genes in the NOD strain, in the absence of the NOD MHC, significantly contribute to the development of autoimmunity. The contribution of a single dose of the NOD MHC to autoimmunity was assessed with a (NOD x NOD.H-2b)F1 cross. Although only approximately 3% of F1 females developed spontaneous diabetes, approximately 50% of both female and male F1 mice developed insulitis, and 25% of females and 17% of males became diabetic after treatment with cyclophosphamide. These data demonstrate that the MHC-linked diabetogenic genes of the NOD mouse are dominant with decreasing levels of penetrance for the following phenotypes: insulitis greater than cyclophosphamide-induced diabetes greater than spontaneous diabetes.

Animals↗
PubMed2006

Somatostatin, retinoids, melatonin, vitamin D, bromocriptine, and cyclophosphamide in advanced non-small-cell lung cancer patients with low performance status.

BACKGROUND: The prognosis of low performance status (PS) patients with advanced non-small-cell-lung cancer (NSCLC) is dismal. In these patients, we have determined the survival, clinical benefits, and toxicity of a multidrug regimen, based on cyclophosphamide and biotherapeutical agents. METHODS: Patients with a diagnosis of stage IIIB or stage IV NSCLC, no previous surgery or chemoradiotherapy, and an Eastern Cooperative Oncology Group (ECOG) PS equal to or greater than 2 received a daily combination of somatostatin, retinoids, melatonin, vitamin D, bromocriptine, and cyclophosphamide. RESULTS: Twenty-eight (28) patients were enrolled. The median age was 64 years (range, 35-74). The PS was 2 and 3 in 78.6% and 21.4% of patients, respectively. The median overall survival (intent-to-treat analysis) was 12.9 months (range, 1.5-33.5 months), The overall survival rates at 1 and 2 years were 51.2% and 21.1%, respectively. The side-effects were very mild, mostly consisting of diarrhoea, nausea/vomiting, and drowsiness of grade 1-2. Most patients experienced an improvement of both respiratory (cough and dyspnoea) and general (pain, fatigue, and insomnia) symptoms. CONCLUSIONS: Low PS patients with advanced NSCLC may benefit from a combination of somatostatin, retinoids, melatonin, vitamin D, bromocriptine, and cyclophosphamide, in terms of survival and quality of life, with very low side-effects.

Adult↗
PubMed1984

Phase-I study of continuous infusion cyclophosphamide for protracted durations: a preliminary report.

The continuous infusion of cyclophosphamide with an ambulatory infusion pump was employed in 13 patients to establish the optimal daily dose rate for permitting prolonged treatment intervals. Four dose rates were studied: 25, 50, 75, and 100 mg/M2 X day and the median duration of therapy was 39, 13, 20, and 28 days, respectively, with a range of 10-50 days. Dose-limiting toxicity was observed in 4 of 13 patients manifested exclusively as thrombocytopenia. No other drug-related untoward effects were observed and no therapeutic effects were noted. The cumulative cyclophosphamide dose for 3 weeks of continuous infusion is comparable to that achieved by bolus schedules. Drug toxicity, however, is substantially altered with the infusion schedule. For good-risk patients, the recommended daily infusion rate for cyclophosphamide is 100 mg/M2 X day.

Adult↗
PubMed1996

Cyclophosphamide is neuroprotective in a gerbil model of transient severe focal cerebral ischemia: correlation with effects of tirilazad mesylate (U-74006F).

Using a gerbil model of severe, temporary focal ischemia (3 h unilateral carotid occlusion), preliminary experiments identified an involvement of neutrophils in the reperfusion injury to the ischemic hemisphere. The present experiments were designed to (1) quantitate the temporal accumulation of neutrophils in the gerbil model, (2) determine if cyclophosphamide-induced neutropenia provided cytoprotection to the ischemic hemisphere, and (3) attempt to correlate the cytoprotective efficacy of tirilazad mesylate with possible effects on postischemic neutrophil accumulation. Following 3 h of unilateral carotid occlusion, animals were collected at increasing times of reperfusion and the CA1 region of the hippocampus and the lateral cortex were assessed for postischemic neuronal damage using a semiquantitative index (N.D.I.) of 0 (no damage) to 4 (>75% neuronal loss). The extent of neutrophil accumulation was determined by counting intensely cytochrome oxidase-positive cells. Minimal neuronal death was evident after 2 h of reperfusion, mean N.D.I. = 0.36. However, between 2 and 4 h of reperfusion, neuronal death did not increase. By 6 h of reperfusion, the neuronal death began to proceed at an accelerated rate, N.D.I. = 0.78. By 12 h, the N.D.I. reached 3.20. The accelerated neuronal death coincided with parenchymal invasion of neutrophils. Cyclophosphamide administration delayed neuronal death in the hippocampus, but exhibited a more sustained protective effect in the lateral cortex. Administration of tirilazad mesylate also resulted in a significant reduction in neutrophil accumulation and significant neuronal protection in both brain areas. Thus, in this gerbil model of transient, but prolonged focal cerebral ischemia, neutrophils appear to play an active role in the reperfusion injury to brain tissue. Our experiments confirm the previously demonstrated neuroprotective efficacy of tirilazad mesylate in this model and provide evidence for a similar protective effect of cyclophosphamide. Although other effects of this antioxidant are also thought to contribute to the overall efficacy, the data are consistent with the hypothesis that one mechanism by which tirilazad acts involves limiting the ability of neutrophils to participate in the reperfusion phase of ischemic cerebral injury.

Animals↗
PubMed2005

A case study: surface contamination of cyclophosphamide due to working practices and cleaning procedures in two Italian hospitals.

The efficacy of preventive and organisational measures implemented in Italy to prevent the contamination of cytotoxic drug preparation rooms has been investigated, and oncologic wards of two Italian hospitals were examined. The sampling strategy was based not only on potential sources of contamination but also on responses to detailed questionnaires on workplace practices and work organisation. Wipe samples were taken from different surfaces of preparation rooms, before and after the work shift, over a span of a month. Cyclophosphamide was taken as the marker drug that reflects exposure to cytotoxic drugs, being measurable by GC/MS. In one of the two hospitals (Hospital A), a large amount of cyclophosphamide was found, both before and after shift, on the workbench (median value, 2.55 microg dm(-2), before shift), on the floor between the operator working position and the waste bin (>10 microg dm(-2), after shift), as also on door handles and storage shelves. No quantifiable levels of cytotoxic drug were detected in the second hospital investigated (Hospital B). These results could be attributed to the efficacy of cleaning procedures and working practices. In fact, both hospitals were provided with vertical-laminar airflow hoods and the (male) nurses had attended special training courses; but in Hospital A, cleaning procedures were carried out without substances used specifically for the cleaning of surfaces contaminated by cytotoxic drugs such as sodium hypochlorite. Working practices did not include Luer Lock devices. Cyclophosphamide concentrations found in both hospitals, compared with the quantities of drug handled, gave evidence of the importance of the correct handling of cytotoxic agents as a major tool in reducing contamination levels. The results reveal the insufficiency of the risk management measures which do not take into account working practices that are prevailing, and stress the necessity for periodic environmental monitoring, indispensable for evolving effective procedures to prevent antineoplastic drug exposure.

Antineoplastic Agents, Alkylating↗
PubMed2002

The feasibility of classical cyclophosphamide, methotrexate, 5-fluorouracil (CMF) for pre- and post-menopausal node-positive breast cancer patients in a Belgian multicentric trial: a study of consistency in relative dose intensity (RDI) and cumulative doses across institutions.

BACKGROUND: Classical cyclophosphamide, methotrexate, 5-fluorouracil (CMF) including oral cyclophosphamide is still considered an important adjuvant chemotherapy regimen in patients with early breast cancer (BC). Concern has been raised regarding the feasibility of this regimen, especially in postmenopausal patients. PATIENTS AND METHODS: 254 pre- and post-menopausal node-positive BC patients aged < or = 70 years received six cycles of CMF in the context of a Belgian multicentric phase III trial of adjuvant chemotherapy. CMF dose and schedule were as follows: cyclophosphamide 100 mg/m2 p.o. on days 1 to 14, methotrexate 40 mg/m2 intravenously (i.v.) on days 1 and 8, 5-fluorouracil 600 mg/ml i.v. on days 1 and 8; cycles q. 28 days. The relative dose intensity (RDI) was calculated as the ratio between the delivered DI and the planned DI. We also analysed the RDI in two subgroups of patients with age > or = 50 years or < 50 years. RESULTS: Overall, the percentage of patients ending the six cycles of the planned CMF regimen was 90%. The mean RDI achieved in the population of 254 patients was 90% (range 8% to 129%). The subgroup analysis of patients aged > or = 50 years and < 50 years showed that 81% and 76% of patients, respectively, received > or = 80% of the planned chemotherapy dose intensity (P = 0.33). No statistically significant difference was found between the percentage of patients who received a RDI < 80% and the participating institutions (P = 0.50). CONCLUSIONS: The classical CMF regimen was a feasible regimen in the context of a multicentric trial, in which academic institutions as well as community hospitals participated. No substantial differences in RDI and cumulative doses were found in relation to a patient's age and the participating institution.

Adult↗
PubMed2002

Relationship between exposure and toxicity in high-dose chemotherapy with cyclophosphamide, thiotepa and carboplatin.

BACKGROUND: High-dose chemotherapy in combination with peripheral blood progenitor cell transplantation is widely used in the treatment of several malignancies. The use of high-dose chemotherapy can be complicated by the occurrence of severe and sometimes life threatening toxicity. A wide interpatient variability in toxicity is encountered, which may be caused by variability in the pharmacokinetics of the agents. The aim of this study was to establish the pharmacokinetics of cyclophosphamide, thiotepa, carboplatin and all relevant metabolites in a widely used high-dose combination and to study possible relationships between the pharmacokinetics and toxicity. PATIENTS AND METHODS: Blood samples were collected from patients treated with modifications of the CTCb regimen consisting of cyclophosphamide (1000-1500 mg/m2/day), carboplatin (265-400 mg/m2/day) and thiotepa (80-120 mg/m2/day) as short infusions for four consecutive days. Thiotepa and its main metabolite tepa, ultrafilterable carboplatin, cyclophosphamide and its activated metabolites 4-hydroxycyclophosphamide and phosphoramide mustard were determined. Pharmacokinetics were assessed with the use of population pharmacokinetic analyses. Relationship between the area under the concentration-time curves (AUCs) of these compounds and toxicity were tested. RESULTS: A total of 46 patients (83 courses of chemotherapy) was included. Relationships were identified between elevation of transaminases and the thiotepa and tepa AUC, mucositis and the tepa AUC and ototoxicity and the carboplatin AUC. A strong trend between the 4-hydroxycyclophosphamide AUC and veno-occlusive disease was found. CONCLUSIONS: The complex pharmacokinetics of the different agents and their metabolites have been established and several relationships between the pharmacokinetics and toxicity were identified. These findings may form the basis for further treatment optimisation and dose-individualisation in this high-dose chemotherapy combination.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

The NHL-15 protocol for aggressive non-Hodgkin's lymphomas: a sequential dose-dense, dose-intense regimen of doxorubicin, vincristine and high-dose cyclophosphamide.

BACKGROUND: The NHL-15 protocol is a novel, dose-intense, dose-dense, sequential chemotherapy program developed to improve outcome in advanced, aggressive non-Hodgkin's lymphomas. PATIENTS AND METHODS: The phase II NHL-15 protocol comprised: (i) induction [doxorubicin 60 mg/m(2) i.v. on weeks 1, 3, 5 and 7 plus vincristine 1.4 mg/m(2) i.v. (no cap) on weeks 1, 2, 3, 5 and 7]; and (ii) consolidation (cyclophosphamide 3000 mg/m(2) i.v. on weeks 9, 11 and 13 plus granulocyte colony-stimulating factor 5 microg/kg subcutaneous on days 3-10 following each cyclophosphamide dose). Patients with aggressive non-Hodgkin's lymphomas (working formulation: intermediate grade or immunoblastic), bulky stage I and stages II-IV, were eligible. RESULTS: There are 165 eligible patients with a 6.9-year median follow-up (range 0.5-141 months) and a median age of 48 years. For the entire group, 72.1% achieved complete remission, and at 5 years disease-free survival was 57.8% and overall survival (OS) was 62.2%. Ideal dose delivery was >90%. Acute and late toxicities of treatment were manageable and acceptable. Toxic death on treatment was 2.4%. When the diffuse large cell lymphoma histologies were grouped according to the International Prognostic Index (IPI), complete remission and OS in the low-intermediate (LI), and high-intermediate (HI) risk groups were improved by 5%-15% compared with historical CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone). This improvement was also noted for LI and HI risk groups in the age-adjusted (aa)IPI analysis for patients < or =60 years of age. CONCLUSIONS: The NHL-15 program can be administered safely and effectively to achieve high rates of durable remission when used for the treatment of advanced stage, aggressive, non-Hodgkin's lymphomas. The 5%-15% improvement in 5-year OS compared with historical CHOP, according to the IPI/aaIPI model (in LI and HI risk groups), is encouraging. Further evaluation and prospective testing of the NHL-15 protocol appears to be warranted.

Adolescent↗
PubMed1999

Subclinical depletion of primordial follicular reserve in mice treated with cyclophosphamide: clinical importance and proposed accurate investigative tool.

Studies have shown that ovarian failure is a common side-effect of chemotherapy treatment; however, continuation of regular menses post-treatment does not necessarily imply that the ovaries have escaped damage. This animal study measures directly the primordial follicle (PMF) loss following exposure to chemotherapy and evaluates reproductive outcome following significant destruction of the PMF population. Inbred Balb/c mice aged 5-6 weeks were administered different doses of an alkylating agent, cyclophosphamide, and the total number of PMF remaining in both ovaries was counted. Results show that cyclophosphamide causes PMF destruction in proportion to increasing dose (P = 0.0001). Reproductive performance was assessed after exposure to 75 mg/kg cyclophosphamide, a dose which destroys approximately 50% of PMF reserve, by evaluation of ovulation, mating and pregnancy rates. Reproductive potential of treated mice was not affected compared with controls despite the significant loss of PMF. Our results indicate that reproductive performance is not an accurate parameter for assessing ovarian injury. Rather, histological counting of PMF number more directly reflects the damage caused by chemotherapy to the ovary. This method can be used as a sensitive, inexpensive tool to gauge the damage to fertility caused by new chemotherapy agents or protocols.

Animals↗
PubMed1991

Progressive murine cytomegalovirus disease after termination of ganciclovir therapy in mice immunosuppressed by cyclophosphamide treatment.

Treatment of mice with cyclophosphamide causes immunosuppression and an enhancement of murine cytomegalovirus infection. In chemotherapy experiments, animals received cyclophosphamide (100 mg/kg by intraperitoneal [ip] injection) every 3-4 days starting 1 day before viral challenge. Once-daily ip treatments with ganciclovir (12.5, 25, and 50 mg/kg) for 5 or 10 days starting 24 h after viral challenge delayed but did not prevent death. In each case the animals died 8-12 days after the last dose of drug was given. Murine cytomegalovirus titers in tissues were suppressed during ganciclovir treatments but rose with discontinuation of therapy. Concanavalin A (T cell blastogenic) responses and, to a lesser extent, lipopolysaccharide (B cell blastogenic) responses were increased in ganciclovir-treated mice compared with the placebo group. Because of the progressive nature of the infection after termination of drug treatment, this model mimics the situation encountered in AIDS patients. The cyclophosphamide model will be useful to study drug treatment regimens.

Animals↗
PubMed1996

Effect of granulocyte colony-stimulating factor on the course of infection with gram-positive bacteria in mice during granulocytopenia induced by sublethal irradiation or cyclophosphamide.

This study assesses the effect of granulocyte colony-stimulating factor (G-CSF) on the outcome of infection with Listeria monocytogenes or Staphylococcus aureus in mice during leukocytopenia induced by sublethal total body irradiation or cyclophosphamide treatment. The role of granulocytes during infection was assessed in the thigh muscle, spleen, and liver. G-CSF treatment in naive mice increased the number of blood granulocytes; upon infection, these numbers increased further, but G-CSF did not affect the outgrowth of bacteria in the tissues. Cyclophosphamide treatment and sublethal irradiation decreased the number of blood granulocytes, which was not affected by G-CSF treatment. However, during infection in cyclophosphamide-treated mice, G-CSF increased the number of granulocytes in the circulation and at the site of infection and decreased the number of bacteria in the tissues. Treatment with G-CSF did not affect the number of granulocytes or the course of infection in irradiated mice.

Agranulocytosis↗
PubMed1991

Phase I/II study of cyclophosphamide, doxorubicin, fluorouracil, and leucovorin for treatment of metastatic adenocarcinoma.

Leucovorin enhances the cytotoxicity of fluorouracil (5-FU) in patients with colorectal cancer and may increase the efficacy of combination chemotherapy regimens containing 5-FU. To determine the maximum tolerated dose of 5-FU with leucovorin for use in combination with cyclophosphamide and doxorubicin, we conducted a phase I/II trial in 20 patients. The doses of leucovorin (200 mg/m2 on days 1-5), cyclophosphamide (500 mg/m2 on day 1), and doxorubicin (40 mg/m2 on day 1) were held constant, while the dose of 5-FU was escalated in cohorts of patients beginning at 150 mg/m2 on days 1-5. Cycles were repeated every 3 weeks. Significant mucositis, diarrhea, and myelosuppression were infrequently observed in patients receiving up to 250 mg/m2 5-FU on days 1-5. In contrast, at a dose of 300 mg/m2 on days 1-5, three of six patients had granulocyte count nadirs of less than 500/microL during the first cycle of therapy, and two of these three had platelet counts of less than 25,000/microL. In addition, two patients treated at this dose had significant mucosal toxic effects, and three had insufficient recovery to permit a second course by day 22. Among 14 patients with assessable breast cancer, there were one complete and nine partial responses (response rate 71%). Leucovorin modulation of 5-FU can be safely incorporated into combination chemotherapy with cyclophosphamide and doxorubicin and provides a highly active regimen for treatment of metastatic breast cancer. Further study will be required to determine whether the addition of leucovorin significantly enhances the activity of this regimen.

Adenocarcinoma↗
PubMed1993

Comparison of adjuvant chemotherapy with methotrexate and fluorouracil with and without cyclophosphamide in breast cancer patients with one to three positive axillary lymph nodes.

BACKGROUND: Alkylating agents administered as single agents or in combination with antimetabolites or anthracyclines delay the appearance of metastases and prolong the survival of breast cancer patients after surgery. PURPOSE: This phase III clinical trial was designed to evaluate the therapeutic efficacy and toxicity of the alkylating agent cyclophosphamide in combination with the antimetabolites methotrexate and fluorouracil adjuvant to breast cancer surgery. METHODS: This study consisted of 255 breast cancer patients (a) with one to three histologically positive axillary lymph nodes and either no detectable primary tumor or operable primary tumors 5 cm or less (T0-T2) (95% of the patients) or (b) with tumors larger than 5 cm (T3) and with negative axillary nodes. Patients were randomly allocated to receive either methotrexate (60 mg/m2) and fluorouracil (600 mg/m2) (MF) intravenously on days 1 and 8 every 28 days for eight cycles or cyclophosphamide (100 mg/m2) orally on days 1-14 plus MF (CMF) every 28 days for the same duration. Median follow-up was 7.8 years, and maximum follow-up was 13 years. RESULTS: There were no statistically significant differences in time to treatment failure or overall survival for patients treated with MF or CMF. At 8 years after completion of treatment, time to treatment failure was 55% (95% confidence interval [CI] = 50%-60%) and 59% (95% CI = 54%-64%) and overall survival was 69% (95% CI = 65%-73%) and 67% (95% CI = 62%-72%) for MF- and CMF-treated patients, respectively. The hazard ratios (MF to CMF) for time to treatment failure and for survival, estimated with a proportional hazards model, were 1.02 (95% CI = 0.69-1.50) and 0.87 (95% CI = 0.56-1.34), respectively. Myelosuppression was significantly greater (P < .0001) in CMF-treated patients during cycles 1-6. Median white blood cell count nadirs were between 4.4 x 10(3)/microL and 3.5 x 10(3)/microL in patients receiving MF and between 3.0 x 10(3)/microL and 2.4 x 10(3)/microL in those receiving CMF. Dose reductions were more frequent in CMF-treated patients, which led to statistically significant differences (P < .0001) in amounts of methotrexate and fluorouracil administered. Primary cancers at other sites occurred in 14 patients (5.5%)--six treated with MF and eight treated with CMF. CONCLUSIONS: Our findings suggest that the addition of cyclophosphamide to adjuvant chemotherapy with MF offers no therapeutic advantage but results in increased myelosuppression. IMPLICATIONS: Future trials will define the possible advantages of antimetabolites in adjuvant therapy. Further information will also become available when results of the ongoing National Surgical Adjuvant Breast and Bowel Project trial comparing adjuvant MF to CMF in node-negative breast cancer patients are presented.

Adult↗
PubMed1995

Induction of micronuclei in metabolically competent rat hepatoma cell lines by the promutagens 7,12-dimethylbenz[a]anthracene, benzo[a]pyrene and cyclophosphamide.

The capability of two rat hepatoma cell lines, H4IIEC3/G- and 2sFou, to detect genotoxicity of xenobiotics, was evaluated in a micronucleus assay. In this system, the cells act as the activation source as well as the target cells for the DNA damage. The study was performed using 7,12-dimethylbenz[a]anthracene, benzo[a]pyrene and cyclophosphamide, as pro-mutagens and mitomycin C as a direct acting mutagen. In both cell lines a significant micronucleus induction was observed after exposure to each test compound, starting from 25 nM for 7,12-dimethylbenz[a]anthracene, 8 microM for benzo[a]pyrene, 0.5 mM for cyclophosphamide and 0.4 microM for mitomycin C. A period of 24 h treatment and 48 h growth was sufficient for induction and expression of micronuclei. The two hepatoma lines behave in a similar way with regard to the pro-mutagen activation. The results obtained in this study with these differentiated hepatoma lines demonstrate that they are metabolically competent to activate the promutagens 7,12-dimethylbenz[a]anthracene, benzo[a]pyrene and cyclophosphamide into their biologically active metabolites as measured by micronucleus induction in our experiments. However, the variable dose responses to 7,12-dimethylbenz[a]anthracene and benzo[a]pyrene in some of the repeated experiments, suggest unstable activity of enzymes involved in polycyclic aromatic hydrocarbons metabolism in these cell lines.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1994

Stobadine-inhibitor of cyclophosphamide-induced micronuclei in mice.

The potential antimutagenic effect of stobadine dipalmitate (STB) on the frequency of micronuclei in reticulocytes of peripheral blood in female ICR mice was studied. The cyclophosphamide model was used to verify this effect. Stobadine dipalmitate was administered orally in three concentrations: STB I, 7.07; STB II, 23.6; STB III, 70.07 mg/kg body wt 2 h prior to or 4 h after (STB II only) cyclophosphamide administration (intraperitoneally, twice 80 mg/kg body wt with a 24 h interval). The method designed by Hayashi et al. [(1990) Mutat. Res., 245, 245-249] was used to prepare and to stain the slides. The results of the experiment show that pretreatment with stobadine 2 h prior to cyclophosphamide administration significantly decreased its mutagenic effect, as manifested by the reduced frequency of micronucleated reticulocytes. This protective effect of stobadine was concentration-dependent with the highest concentration of stobadine inducing the most pronounced decrease of micronuclei. Analysis and identification of the exact mechanism of the protective effects of stobadine is the aim of our further studies.

Animals↗