Search PubMed⌕ Search

Biomedical subjects

D Crowther

Publications and source records attributed to D Crowther.

At least 73 records · Page 4Linked to original sources
PubMed1993

A phase I study of intravenous bryostatin 1 in patients with advanced cancer.

Bryostatin 1 is a novel antitumour agent derived from Bugula neritina of the marine phylum Ectoprocta. Nineteen patients with advanced solid tumours were entered into a phase I study to evaluate the toxicity and biological effects of bryostatin 1. Bryostatin 1 was given as a one hour intravenous infusion at the beginning of each 2 week treatment cycle. A maximum of three treatment cycles were given. Doses were escalated in steps from 5 to 65 micrograms m-2 in successive patient groups. The maximum tolerated dose was 50 micrograms m-2. Myalgia was the dose limiting toxicity and was of WHO grade 3 in all three patients treated at 65 micrograms m-2. Flu-like symptoms were common but were of maximum WHO grade 2. Hypotension, of maximum WHO grade 1, occurred in six patients treated at doses up to and including 20 micrograms m-2 and may not have been attributable to treatment with bryostatin 1. Cellulitis and thrombophlebitis occurred at the bryostatin 1 infusion site of patients treated at all dose levels up to 50 micrograms m-2, attributable to the 60% ethanol diluent in the bryostatin 1 infusion. Subsequent patients treated at 50 and 65 micrograms m-2 received treatment with an intravenous normal saline flush and they did not develop these complications. Significant decreases of the platelet count and total leucocyte, neutrophil and lymphocyte counts were seen in the first 24 h after treatment at the dose of 65 micrograms m-2. Immediate decreases in haemoglobin of up to 1.9g dl-1 were also noted in patients treated with 65 micrograms m-2, in the absence of clinical evidence of bleeding or haemodynamic compromise. No effect was observed on the incidence of haemopoietic progenitor cells in the marrow. Some patients' neutrophils demonstrated enhanced superoxide radical formation in response to in vitro stimulation with opsonised zymosan (a bacterial polysaccharide) but in the absence of this additional stimulus, no bryostatin 1 effect was observed. Lymphocyte natural killing activity was decreased 2 h after treatment with bryostatin 1, but the effect was not consistently seen 24 h or 7 days later. With the dose schedule examined no antitumour effects were observed. We recommend that bryostatin 1 is used at a dose of 35 to 50 micrograms m-2 two weekly in phase II studies in patients with malignancies including lymphoma, leukaemia, melanoma or hypernephroma, for which pre-clinical investigations suggest antitumour activity.

Adult↗
PubMed1993

A randomised dose intensity study in ovarian carcinoma comparing chemotherapy given at four week intervals for six cycles with half dose chemotherapy given for twelve cycles.

BACKGROUND: The importance of dose intensity has not been clearly defined in ovarian cancer and we present a prospectively randomised trial of dose intensity in patients with ovarian cancer. PATIENTS AND METHODS: Ninety-nine patients with FIGO stage Ic, II, III and IV epithelial ovarian cancer were randomised to receive cycles of standard dose cyclophosphamide (600 mg/m2) and carboplatin (300 mg/m2) alternating with adriamycin (50 mg/m2) and ifosfamide (5 G/m2) for 6 cycles at monthly intervals (49 patients) or cycles of half dose cyclophosphamide (300 mg/m2) and carboplatin (150 mg/m2) alternating with adriamycin (25 mg/m2) and ifosfamide (2.5 G/m2) for 12 cycles at monthly intervals (50 patients). Patients in each arm were well balanced for major prognostic factors. RESULTS: The combined clinical response rate (complete response and partial response) on the 6 month arm was 76% compared with 48% on the low dose intensity arm (p = 0.009). With a median follow up of 25.7 months the median survival on the low dose intensity arm is 20.9 months. The median survival point on the 6 month arm has not yet been reached. The median progression free interval on the 12 month arm was 19.8 months, the median value has not yet been reached on the standard arm. The amount of residual tumour following initial laparotomy was the only significant independent variable affecting survival (p = 0.0001). The mean received dose intensity of each drug was greater than 80% of the planned dose intensity. More patients had clinical disease progression during treatment on the low dose intensity arm (42%) when compared to the standard dose intensity arm (8%) (p = 0.0003). Fifteen patients on the standard dose arm experienced a total of 18 delays and 5 patients on the low dose arm experienced 17 delays. Nausea, vomiting and diarrhoea were similar for both standard and low dose cycles of chemotherapy with a consequent benefit for patients receiving fewer cycles even though these were of higher dose. CONCLUSIONS: The combination studied was more effective when given at the higher dose intensity and the improved response and survival was not accompanied by a significant increase in toxicity.

Adenocarcinoma↗
PubMed1993

Granulocyte-macrophage colony-stimulating factor allows safe escalation of dose-intensity of chemotherapy in metastatic adult soft tissue sarcomas: a study of the European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group.

PURPOSE: This study was designed to test the feasibility of administering doxorubicin at an optimal dose-intensity (> 70 mg/m2 per 21 days) in combination with ifosfamide under recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) cover in patients with metastatic soft tissue sarcomas. PATIENTS AND METHODS: One hundred four eligible patients (of 111 entered) in 16 centers received doxorubicin 75 mg/m2 plus ifosfamide 5 g/m2 every 3 weeks for up to seven cycles. rhGM-CSF (250 micrograms/m2) was administered once or twice daily by subcutaneous injections for up to 14 days between cycles of chemotherapy. RESULTS: Full protocol dose-intensity of chemotherapy was administered to the majority of patients with only 15 of 293 cycles being complicated by febrile episodes that required hospitalization. There were two treatment-related deaths: one from septicemia and one from cardiac failure. The main toxicities attributed to rhGM-CSF were pruritus and rash. A 45% response rate (10% complete remission [CR]) was seen, with a median response duration of 9 months and median survival of 15 months. CONCLUSION: This high-dose regimen of chemotherapy was feasible under rhGM-CSF cover and produced a higher response rate and median survival than previously seen by the European Organization for Research and Treatment of Cancer (EORTC) Soft Tissue Sarcoma Group. A randomized phase III study is now underway comparing this regimen with conventional-dose doxorubicin/ifosfamide to test the dose-response relationship.

Adult↗
PubMed1993

The use of recombinant human granulocyte-macrophage colony-stimulating factor with combination chemotherapy in the treatment of advanced adult soft-tissue sarcomas: early results from the EORTC Soft-Tissue and Bone Sarcoma Group.

We gave the "optimal" dose of doxorubicin (75 mg/m2) with ifosfamide (5 g/m2), the two most active agents against metastatic soft-tissue sarcomas, in an attempt to determine the feasibility of administration of these doses in combination. To offset complications arising from the myelosuppression associated with this regimen, recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF, 250 micrograms/m2 daily) was given by subcutaneous injection during the intervals between courses of chemotherapy. In all, 111 patients with progressive metastatic soft-tissue sarcoma were entered, 104 of whom were eligible for preliminary analysis. Use of rhGM-CSF allowed full doses of chemotherapy to be given to the majority of patients, although cumulative thrombocytopenia became a dose-limiting toxicity during subsequent courses. Two treatment-related deaths occurred, one from presumed septicemia while the patient was at home and one as a result of cardiac failure. An overall response rate of 45% was achieved. The activity of this high-dose combination (with rhGM-CSF) will be compared with that of standard treatment doses in a future phase III randomized trial.

Adult↗
PubMed1992

Granulocyte colony-stimulating factor to prevent dose-limiting neutropenia in non-Hodgkin's lymphoma: a randomized controlled trial.

The effect of granulocyte colony-stimulating factor (G-CSF) on neutropenia, infection, and cytotoxic chemotherapy administration was studied in a randomized trial in patients receiving intensive weekly chemotherapy for non-Hodgkin's lymphoma (NHL). Eighty patients (aged 16 to 71 years) with high-grade NHL (Kiel) of any stage were randomized to receive VAPEC-B chemotherapy alone (39 patients) or with G-CSF administered as a daily subcutaneous dose of 230 micrograms/m2 (41 patients). Prophylactic ketoconazole and cotrimoxazole were administered to all patients throughout treatment. The protocol specified identical dose modification and antibiotic treatment criteria bor both groups. Neutropenia (absolute neutrophil count [ANC] less than 1.0 x 10(9)/L) occurred in 15 of 41 (37%) of the G-CSF-treated patients and in 33 of 39 (85%) of the controls, giving a relative risk for control patients of 2.31 (95% confidence interval [CI], [1.51, 3.54]; P = .00001). Fever (greater than or equal to 37.5 degrees C) with neutropenia (ANC less than 1.0 x 10(9)/L) occurred in 9 of 41 (22%) of the G-CSF group and in 17 of 39 (44%) of the controls (relative risk for control, 2.26; 95% CI [1.01, 5.06]; P = .04). There were fewer treatment delays, with shorter duration (P = .01) in patients receiving G-CSF. Chemotherapy doses were reduced in 4 of 41 (10%) of the G-CSF patients and 13 of 39 (33%) of the controls (P = .01). The dose intensity of cytotoxic chemotherapy was significantly increased in patients receiving G-CSF (median of 95% in G-CSF group compared with 83% in control patients). Three vascular deaths occurred in the G-CSF group. Delays in the control group most commonly resulted from neutropenia (19 patients, compared with 2 patients in the G-CSF-treated group, P = .000007). Severe mucositis was the major dose-limiting toxicity in G-CSF-treated patients, but did not occur more frequently than in controls (15 patients in each group). Overall, patients randomized to receive G-CSF achieved a greater dose intensity than control patients, but this did not result in significant differences in drug toxicity (other than neutropenia), intravenous antibiotic usage, or hospitalization between the two groups.

Adolescent↗
PubMed1992

Haemopoietic cell kinetics in humans treated with rGM-CSF.

We have investigated the kinetics of myeloid cell proliferation in the marrow of patients with small-cell lung cancer and treated with 10 daily subcutaneous injections of granulocyte/macrophage colony-stimulating factor (GM-CSF). Bone marrow, obtained before and during treatment with the growth factor, was labelled in vitro with tritiated thymidine (3H-TdR). A 3rd bone-marrow sample was obtained 1 hr following an intravenous injection of 3H-TdR. Subsequent daily blood samples were also collected, and 3H-TdR labelling was assessed on these and the marrow preparations by autoradiography. GM-CSF treatment increased the peripheral granulocytic cells nearly 5-fold, but this included significant eosinophilia, so that the neutrophilic granulocytes increased only 3.3-fold. These cells were released from the marrow over a normal time scale, but their peripheral half-life was about 6 times longer than normal and they were probably functionally defective. Furthermore, significant numbers of immature cells were released from the marrow. Neutrophil production stimulated by GM-CSF was thus overestimated by measurement of the apparent peripheral granulocytosis. Increased labelling indices and grain counts in the proliferating granulocytic cells of the marrow indicate shortened cell-cycle times, and the excess granulocyte production appears to be the result of extra amplification divisions in the proliferative compartments.

Carcinoma, Small Cell↗
PubMed1992

In vivo depletion of O6-alkylguanine-DNA-alkyltransferase in lymphocytes and melanoma of patients treated with CB 10-277, a new DTIC analogue.

There is increasing evidence to suggest that alkylation of guanine residues in DNA at the O6 position is the critical cytotoxic event following treatment with dacarbazine (DTIC) and related drugs and that endogenous O6-alkylguanine-DNA alkyltransferase (ATase) gene expression may be a major factor in resistance to such agents. 1-p-Carboxyl-3,3-dimethylphenyltriazene (CB10-277) was recently selected for clinical evaluation as a DTIC analogue with improved solubility, stability and (possibly) metabolic activation. Serial ATase levels were measured in peripheral blood lymphocytes of nine patients and in biopsied melanoma samples of two patients undergoing treatment with 24-h continuous infusion of CB10-277 (12 g/m2). Wide individual variations in pre-treatment levels as well as in the post-treatment depletion of lymphocyte ATase were seen. Progressive depletion of lymphocyte ATase was seen during continuous infusion of CB10-277 in all patients. Complete suppression of lymphocyte ATase activity occurred in two patients whose pre-treatment ATase levels were low. Immediately following completion of the CB10-277 infusion, the median ATase activity was 17% of pre-treatment levels (range, 0-67%). At 24 h after the end of the infusion, no recovery of lymphocyte ATase activity was observed in six patients, but significant recovery to 50%, 100% and 102% of pre-treatment activity occurred in the other three. In three patients who returned for subsequent cycles of chemotherapy at 4 weeks after the first dose, pre-treatment ATase levels showed a 3- to 4-fold increase relative to the original pre-treatment values. A significant correlation was found between the extent of ATase depletion and the initial lymphocyte ATase levels (r = 0.725, P < 0.05). Haematological toxicity developed in two patients and was associated with low pre-treatment ATase activity. Depletion of tumour ATase activity was noted in these patients, with residual activity amounting to 8% and 11% of pre-treatment levels, respectively, in the biopsies melanoma tissues. These results indicate extensive metabolism of CB10-277 to a methylating agent capable of mediating alkylation of DNA and subsequent depletion of lymphocyte and tumour ATase levels and further indicate that the effects on lymphocytes may reflect effects on the target tumour.

Adult↗
PubMed1992

Phase I/II study of intraperitoneal iproplatin in patients with minimal residual disease following platinum-based systemic therapy for epithelial ovarian carcinoma.

13 patients with minimal residual disease following platinum-based systemic therapy for epithelial ovarian cancer were treated with intraperitoneal iproplatin. A total of three cycles were given at monthly intervals. All patients had minimal residual disease (defined as less than 2 cm in diameter) or positive cytology documented at second look laparotomy following systemic chemotherapy. Iproplatin was administered via a temporary dialysis catheter (n = 11) or a semi permanent Tenckhoff peritoneal dialysis catheter (n = 2). The dose of iproplatin ranged from 150 to 450 mg/m2. No responses to therapy were documented. In this trial the major toxic side effects of iproplatin were thrombocytopenia, diarrhoea, nausea and vomiting. The maximum tolerated dose was 300 mg/m2.

Adult↗
PubMed1992

Cyclophosphamide decreases O6-alkylguanine-DNA alkyltransferase activity in peripheral lymphocytes of patients undergoing bone marrow transplantation.

O6-alkylguanine-DNA-alkyltransferase (ATase) levels were measured in extracts of peripheral blood lymphocytes taken at various times during chemotherapy from 19 patients with various haematological malignancies. Seven patients with advanced Hodgkin's disease received preparative treatment consisting of cyclophosphamide (1.5 g m-2, daily) administered on days 1 to 4 and BCNU (600 mg m-2) on day 5 prior to autologous bone marrow rescue (ABMR) delivered on day 7. Treatment in the remaining 12 patients consisted of cyclophosphamide (1.8 g m-2, daily) given on days 1 and 2 followed at day 4 with total body irradiation (TBI) administered in six fractions over the subsequent 3 days to a total dose of 1200 cGy prior to bone marrow transplantation. In the Hodgkin's group, significant decreases in ATase activity were seen during the cyclophosphamide treatment, and the median ATase nadir was 32% (range 0% to 57%) of pretreatment levels following 4 days of cyclophosphamide. In one patient, no ATase activity was detectable following the 4th cyclophosphamide treatment. ATase activities decreased further after BCNU administration to a median of 19% (range 0% to 32%) of pretreatment levels. Extensive cyclophosphamide-induced reduction of lymphocyte ATase levels was also seen in the other group of 12 patients treated with cyclophosphamide/TBI: postcyclophosphamide median ATase nadir was 35% (range 12% to 78%) of the pretreatment levels. No ATase depletion was seen when cyclophosphamide (up to 10 mM) was incubated for 2 h with pure recombinant human ATase in vitro whereas ATase activity was reduced by 90% on preincubation with 100 microns acrolein or with greater than 1 mM phosphoramide mustard. This suggests that a cyclophosphamide-induced decrease in ATase levels in human peripheral lymphocytes in vivo may be due to depletion mediated by the production of intracellular acrolein. Since ATase appears to be a principal mechanism in cellular resistance to the cytotoxic effects of BCNU and related alkylating agents, these observations suggest that a cyclophosphamide-induced reduction in ATase activity may be an additional factor in the effectiveness of the combined sequential therapy.

Acrolein↗
PubMed1992

Glutathione S-transferase activity and isoenzyme distribution in ovarian tumour biopsies taken before or after cytotoxic chemotherapy.

A study involving the measurement of glutathione S-transferase activities and isoenzyme distributions in human ovarian tumours has been carried out. These tumours have been obtained either at initial debulking surgery, prior to cytotoxic chemotherapy, or at second look laparotomy following chemotherapy. The response rates of these two groups to chemotherapy differ markedly, with patients who have relapsed following initial chemotherapy showing a reduction in response rates to subsequent chemotherapy. Analysis of these data show no statistically significant differences between the glutathione S-transferase activity or isoenzyme distribution in these two groups of patients. Significant differences were observed in the glutathione-S-transferase activities (GST) between tumours and normal ovaries. GST activities in pre-chemotherapy tumours (n = 33, P = 0.01) and post-chemotherapy tumours (n = 20, P = 0.001) where significantly higher than the GST activity in normal ovaries (n = 15). One feature was the expression of the basic isoenzyme which is expressed more in normal ovaries than in tumours. No differences in these parameters were observed in normal peritoneal tissue taken from patients before or after chemotherapy. These data do not support the hypothesis that changes in glutathione S-transferase enzyme activity or isoenzyme expression are major determinants of response to chemotherapy in ovarian tumours.

Adult↗
PubMed1991

p53 germline mutations in Li-Fraumeni syndrome.

Germline mutations within a defined region of the p53 gene have recently been found in families with the Li-Fraumeni syndrome (LFS). In the present study this region of p53 was sequenced in affected individuals from 8 families with LFS. In only 2 of them were such mutations detected. Our findings suggest that the p53 mutation could be the primary lesion in some but not all families with LFS, and confirm that there is a "hot spot" for these mutations at the CpG dinucleotide moiety of codon 248. Assigning risks and counselling families on the basis of presence of p53 mutations should be approached with caution.

Adolescent↗
PubMed1991

Interferon-alpha 2b in the treatment of follicular lymphoma: preliminary results of a trial in progress.

Since 1985 the combination of chlorambucil (10 mg daily, initially for six weeks, then alternating fortnights for 12 weeks) and interferon-alpha 2b (Schering-Plough; 2 x 10(6) U/m2 three times weekly by subcutaneous injection for 18 weeks) has been compared in a randomised trial with chlorambucil alone in previously untreated patients with stage III or IV follicular lymphoma. Responding patients have subsequently been randomised to receive maintenance interferon-alpha 2b or no further treatment. Of the 124 treated patients, 108 are evaluable for response with a median follow-up of 30 months. The major toxicity was myelosuppression which was more frequent with chlorambucil and IFN alpha 2b in combination than with chlorambucil alone (P less than 0.01). There was no treatment-related mortality. Actuarial survival at three years is 75% for all patients, regardless of therapy. There was no significant difference in response rate according to initial therapy. For the 60 patients achieving a good response to initial therapy who have entered the second part of the trial, there has been a significant prolongation of remission duration in favour of maintenance IFN-alpha 2b (median not yet reached versus two years for the 'no treatment' arm, P less than 0.015). Fewest relapses have been seen in patients who received IFN-alpha 2b throughout. Accrual to this trial continues; this preliminary analysis indicates that maintenance IFN-alpha 2b may extend remission duration in follicular lymphoma.

Adult↗
PubMed1991

Workshop on growth factors.

The 'Workshop on Growth Factors' which took place at the Lugano Lymphoma Conference on June 8, 1990, included a presentation by Michael Sporn on the concept that loss of inhibitory control mechanisms may be important in the development and growth of human cancer. Examples illustrating this were taken from current experimental biology research into transforming growth factor beta (TGF-beta) interactions. Brian Durie presented recent data on the biology of interleukin-6 (IL-6) and its putative role in plasma cell diseases. These studies have culminated in the first clinical study of the role of an antibody to a growth factor as therapy for a human cancer (anti-IL-6 antibody as therapy for patients with myeloma). Derek Crowther presented data concerning the current clinical role of the haematopoietic growth factors in patients undergoing chemotherapy for cancer. Recent clinical research has established the role of granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in improving the safety of high-dose or accelerated chemotherapy, and their use is associated with enhanced neutrophil recovery following ablative therapy and bone marrow rescue. This session was followed by the presentation of three papers concerning the use of G-CSF and GM-CSF in association with chemotherapy for patients with malignant lymphoma.

Animals↗
PubMed1991

A randomised study of adjuvant MVPP chemotherapy after mantle radiotherapy in pathologically staged IA-IIB Hodgkin's disease: 10-year follow-up.

One hundred fifteen untreated patients with supra-diaphragmatic, pathologically staged (PS) IA-IIB Hodgkin's disease (HD) were entered into a randomised study comparing treatment using mantle radiotherapy followed by adjuvant treatment with mustine, vinblastine, prednisolone, and procarbazine (MVPP) with mantle radiotherapy alone. Fifty-six patients were randomised to receive radiotherapy alone (RT) and 59 to radiotherapy followed by six cycles of adjuvant MVPP (RT + MVPP). One hundred fourteen patients achieved a complete remission (CR) with radiotherapy. One patient achieved a partial remission. The overall 10-year survival after correction for intercurrent death was 92% with no difference between the two treatment groups (90% for RT alone and 95% for RT + MVPP P = 0.66). There were 9 (8%) deaths from HD (5 patients had received RT alone), and 10 (9%) intercurrent deaths. Eight (7%) patients have developed a second malignancy, and two of them are alive. No patient has developed secondary acute myelogenous leukaemia. The 10-year relapse-free survival (RFS) was 79% overall, 67% in the RT group, and 91% in the RT + MVPP group (P = 0.0004). There were 25 relapses; 20 patients had received RT alone and 5 had received adjuvant MVPP. Of the relapsed patients, 13 (52%) have received successful salvage therapy and are in CR. In the RT alone group, 45 (80%) patients are alive in CR, 5 (9%) died of HD, and 6 (11%) died of intercurrent causes. In the adjuvant MVPP group, 51 (86%) are alive in CR, 4 (7%) died of HD, and 4 (7%) died of intercurrent causes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗