Biomedical subjects

N Thatcher

Publications and source records attributed to N Thatcher.

At least 55 records · Page 3Linked to original sources

PubMed2000

Management of elderly patients with lung cancer.

Cancer management in the older patient is a growing concern, particularly with the increasing geriatric population and the high incidence of cancer among these individuals. Incidence of lung cancer in particular is known to rise with age. This article reviews prognosis, treatment options, and decision-making issues for both clinician and patient with respect to both non-small-cell and small-cell lung cancer in this population. Research findings dealing with response rates, survival rates, and symptom control in this age group are reviewed for radiotherapy, surgery, and for various chemotherapy agents, including gemcitabine, the taxanes, vinorelbine, and the topoisomerase 1 inhibitors. Quality- of-life issues are also addressed.

Age Factors↗

PubMed2000

Randomised phase II study of cisplatin-etoposide versus infusional carboplatin in advanced non-small-cell lung cancer and mesothelioma.

BACKGROUND: A randomised phase II study was performed to compare standard combination chemotherapy containing cisplatin and etoposide with infusional carboplatin. PATIENTS AND METHODS: One hundred twenty patients with locally advanced/metastatic non-small-cell lung cancer or mesothelioma were enrolled. All were chemotherapy-naïve and had a Karnofsky performance status of > or = 50. Patients were randomised to either four cycles of bolus therapy of cisplatin 80 mg/m2 day 1, etoposide 120 mg/m2 day 1-3, or continuous infusion of carboplatin 100/mg/m2/week for six weeks. RESULTS: No patients on infusional therapy incurred grade 3-4 toxicity while in the bolus arm, grade 3 and grade 4 leucopenia occurred in 17% and 35% of patients, respectively. Grade 4 thrombocytopenia occurred in 8% of patients and there were two instances of grade 3 renal toxicity. No responses occurred in the pump arm. Eight of forty-six patients with non-small-cell lung cancer responded to treatment (response rate 17.3%) with two complete responses and six partial responses. Only one patient with mesothelioma responded to bolus therapy. There was no difference in survival for the subset of NSCLC patients. Survival for mesothelioma patients in the pump arm was superior but this was likely to be a result of early deaths in the bolus arm. CONCLUSIONS: The pump arm was well-tolerated but not active, whilst combination platinum-based therapy demonstrated activity but significantly more toxicity than the pump arm. Further studies of infusional carboplatin with this schedule are not warranted.

Adult↗

PubMed2000

A randomized phase III study comparing dacarbazine, BCNU, cisplatin and tamoxifen with dacarbazine and interferon in advanced melanoma.

The purpose of this study was to compare the response rate, overall and 1-year survival in patients with advanced melanoma treated with a standard therapy, dacarbazine and interferon-alpha (DTIC/IFN), or combination chemotherapy, consisting of dacarbazine, BCNU, cisplatin and tamoxifen (DBCT). Treatment toxicity and time spent in hospital were secondary end points. One hundred and five patients (of whom 100 were eligible) were randomized to receive either DTIC/IFN or DBCT. The trial was designed to detect a 25% absolute difference in response rate or in 1-year survival with 80% power. There was no significant difference in response rate: this was 17.3% with DTIC/IFN and 26.4% with DBCT. Median overall survival was similar at 199 and 202 days respectively. One-year survival rate favoured standard treatment (30.6 vs 22.6%), but did not differ significantly between arms. DBCT was associated with significantly greater haematological toxicity, and a greater need for time spent in hospital (5.75 days/treatment cycle vs 2.29 with dacarbazine and interferon). DBCT combination therapy cannot be recommended as standard treatment for advanced melanoma. Dacarbazine remains the standard chemotherapy for this condition.

Adult↗

PubMed2000

Gemcitabine plus best supportive care (BSC) vs BSC in inoperable non-small cell lung cancer--a randomized trial with quality of life as the primary outcome. UK NSCLC Gemcitabine Group. Non-Small Cell Lung Cancer.

Three hundred patients with symptomatic, locally advanced or metastatic NSCLC not requiring immediate radiotherapy were enrolled into this randomized multicentre trial comparing gemcitabine + BSC vs BSC alone. Patients allocated gemcitabine received 1000 mg/m2 on days 1, 8 and 15 of a 28-day cycle, for a maximum of six cycles. The main aim of this trial was to compare patient assessment of a predefined subset of commonly reported symptoms (SS14) from the EORTC QLQ-C30 and LC13 scales. The primary end-points were defined as (1) the percentage change in mean SS14 score between baseline and 2 months and (2) the proportion of patients with a marked (> or = 25%) improvement in SS14 score between baseline and 2 months sustained for > or =4 weeks. The secondary objectives were to compare treatments with respect to overall survival, and multidimensional QL parameters. The treatment groups were balanced with regard to age, gender, Karnofsky performance status (KPS) and disease stage (40% had metastatic disease). The percentage change in mean SS14 score from baseline to 2 months was a 10% decrease (i.e. improvement) for gemcitabine plus BSC and a 1% increase (i.e. deterioration) for BSC alone (P = 0.113, two-sample t-test). A sustained (> or = 4 weeks) improvement (> or =25%) on SS14 was recorded in a significantly higher proportion of gemcitabine + BSC patients (22%) than in BSC alone patients (9%) (P = 0.0014, Pearson's chi-squared test). The QLQ-C30 and L13 subscales showed greater improvement in the gemcitabine plus BSC arm (in 11 domains) than in the BSC arm (one symptom item). There was greater deterioration in the BSC alone arm (six domains/items) than in the gemcitabine + BSC arm (three QL domains). Tumour response occurred in 19% (95% CI 13-27) of gemcitabine patients. There was no difference in overall survival: median 5.7 months (95% CI 4.6-7.6) for gemcitabine + BSC patients and 5.9 months (95% CI 5.0-7.9) (log-rank, P = 0.84) for BSC patients, and 1 -year survival was 25% for gemcitabine + BSC and 22% for BSC. Overall, 74 (49%) gemcitabine + BSC patients and 119 (79%) BSC patients received palliative radiotherapy. The median time to radiotherapy was 29 weeks for gemcitabine + BSC patients and 3.8 weeks for BSC. Patients treated with gemcitabine + BSC reported better QL and reduced disease-related symptoms compared with those receiving BSC alone. These improvements in patient-assessed QL were significant in magnitude and were sustained.

Adult↗

PubMed2000

Randomized phase III study of temozolomide versus dacarbazine in the treatment of patients with advanced metastatic malignant melanoma.

PURPOSE: To compare, in 305 patients with advanced metastatic melanoma, temozolomide and dacarbazine (DTIC) in terms of overall survival, progression-free survival (PFS), objective response, and safety, and to assess health-related quality of life (QOL) and pharmacokinetics of both drugs and their metabolite, 5-(3-methyltriazen-1-yl)imidazole-4-carboximide (MTIC). PATIENTS AND METHODS: Patients were randomized to receive either oral temozolomide at a starting dosage of 200 mg/m(2)/d for 5 days every 28 days or intravenous (IV) DTIC at a starting dosage of 250 mg/m(2)/d for 5 days every 21 days. RESULTS: In the intent-to-treat population, median survival time was 7.7 months for patients treated with temozolomide and 6.4 months for those treated with DTIC (hazards ratio, 1.18; 95% confidence interval [CI], 0.92 to 1.52). Median PFS time was significantly longer in the temozolomide-treated group (1.9 months) than in the DTIC-treated group (1.5 months) (P =.012; hazards ratio, 1.37; 95% CI, 1.07 to 1.75). No major difference in drug safety was observed. Temozolomide was well tolerated and produced a noncumulative, transient myelosuppression late in the 28-day cycle. The most common nonhematologic toxicities were mild to moderate nausea and vomiting, which were easily managed. Temozolomide therapy improved health-related QOL; more patients showed improvement or maintenance of physical functioning at week 12. Systemic exposure (area under the curve) to the parent drug and the active metabolite, MTIC, was higher after treatment with oral temozolomide than after IV administration of DTIC. CONCLUSION: Temozolomide demonstrates efficacy equal to that of DTIC and is an oral alternative for patients with advanced metastatic melanoma.

Adult↗

PubMed2000

Improving survival without reducing quality of life in small-cell lung cancer patients by increasing the dose-intensity of chemotherapy with granulocyte colony-stimulating factor support: results of a British Medical Research Council Multicenter Randomized Trial. Medical Research Council Lung Cancer Working Party.

PURPOSE: The treatment of small-cell lung cancer patients with good performance status aims to improve survival. Dose-intensification could be a way to achieve improved survival but can be limited by neutropenia and thrombocytopenia. Preliminary, nonrandomized feasibility studies showed that doxorubicin, cyclophosphamide, and etoposide (ACE) could be given every 2 (instead of the usual 3) weeks with granulocyte colony-stimulating factor (G-CSF) (lenograstim; Chugai-Rh¿one-Poulenc, Tokyo, Japan) support. The present multicenter randomized trial was designed to examine whether such dose-intensification improves survival while maintaining acceptable toxicity levels. PATIENTS AND METHODS: All patients were randomized to receive six cycles of ACE either every 3 weeks (control [C] group) or every 2 weeks with G-CSF (G group). The standard dose-intensity of ACE was increased by 50% in group G. RESULTS: Four hundred and three patients (G group: n = 201; C group: n = 202) were randomized. The received dose-intensity was 34% higher in the G group than in the C group. Complete response rates were 40% for the G group and 28% for the C group (P =.02), and overall rates were 78% for the G group and 79% for the C group. Survival was longer in the G group (hazard ratio = 0.80; 95% confidence interval, 0.65 to 0.99; P =.04), survival rates for the G and C groups being 47% and 39% at 12 months and 13% and 8% at 24 months, respectively. Metastasis-free survival, nonhematologic toxicity, and quality of life were similar in the two groups. In the G group, there was less neutropenia but more thrombocytopenia and more frequent blood and platelet transfusions. CONCLUSION: Increasing the dose-intensity of ACE with G-CSF support improved survival while maintaining acceptable toxicity.

Adult↗

PubMed2000

Phase II study of oral topotecan in advanced non-small cell lung cancer.

This study was designed to assess the activity of oral topotecan (TPT) in patients with advanced non-small cell lung cancer previously untreated with chemotherapy. Eligible patients had inoperable stage III or stage IV non-small cell lung cancer and were chemotherapy-naive. Other inclusion criteria were Eastern Cooperative Oncology Group performance status 0, 1, or 2, adequate bone marrow, and renal and hepatic function. Of 30 patients, 29 were assessable for response. Oral TPT was administered for 5 days every 21 days for up to six cycles unless disease progression or unacceptable toxicity occurred. Patients received a dose of 2.3 mg/m2/day for the first cycle. Dose modification for subsequent cycles was based on tolerability. Patients completed symptom questionnaires every 3 weeks. Pharmacokinetics were evaluated in all patients during cycle 1. Three patients had radiological responses with a reduction in tumor size of 30-40%. No patients achieved complete or partial responses to treatment. Thirteen patients had a stable disease (43.3%), and the median survival was 39.9 weeks with a 1-year survival of 33.3%. At the time of analysis, 27 patients had died. Median time to progression was 12.3 weeks. Treatment was well tolerated. A total of 125 cycles of treatment were completed. Twelve patients (40%) experienced grade III/IV neutropenia. Five patients (16.6%) had grade III/IV anemia. There were two episodes of grade III/IV thrombocytopenia. The main nonhematological toxicities consisted of grade III nausea (13%) and grade III vomiting (13%). The most frequently reported disease-related symptoms at baseline were dyspnea, cough, and fatigue. There was a subsequent improvement in patient scores of dyspnea in 17% of patients, 31% showed improvement in cough, and 32% showed improvement in fatigue. The mean area under the curve of TPT following 2.3 mg/m2 p.o. was 51.6 ng.h/ml (%SD, 25%). The area under the curve of TPT on day 1 of the first cycle was correlated with the percentage fall in leukocytes. Although oral TPT at the applied dose and schedule showed modest activity as a single agent, almost one-half of the patients had a stable disease, and median time to progression was 12.3 weeks. The overall median survival was a promising 39.9 weeks, and useful palliation of symptoms was seen.

Administration, Oral↗

PubMed1999

Seroconversion after influenza vaccination in patients with lung cancer.

There are no data in the literature about the efficacy of influenza vaccination in lung cancer patients. Paired sera were available from 59 patients who received Fluvirin (Evans Medical). Of 41 patients susceptible to one or more influenza strains, 78% responded fully to vaccination. This response rate is comparable to that obtained from healthy volunteers.

Aged↗

PubMed1999

Epoetin alpha prevents anaemia and reduces transfusion requirements in patients undergoing primarily platinum-based chemotherapy for small cell lung cancer.

Anaemia commonly occurs in cancer patients receiving chemotherapy, often necessitating blood transfusion. This multicentre study was designed to evaluate the efficacy and safety of epoetin alpha in preventing the decline in haemoglobin (Hb) level, and to determine whether the transfusion requirement could be reduced, in patients receiving 4-6 cycles of primarily platinum-based combination cyclic chemotherapy for small cell lung cancer (SCLC). A total of 130 non-anaemic SCLC patients were randomized to receive no additional treatment (n = 44), epoetin alpha 150 IU kg(-1) subcutaneously (s.c.) three times a week (n = 42) or 300 IU kg(-1) s.c. three times a week (n = 44). Reductions in epoetin alpha dosage were made during the study if Hb level increased to >15 g dl(-1). The mean weekly dosage was 335 and 612 IU kg(-1), respectively, in the two active treatment groups. Significantly fewer (P < 0.05) epoetin alpha-treated patients experienced anaemia (Hb < 10 g dl(-1)) during the course of chemotherapy (300 IU kg(-1), 39%; 150 IU kg(-1), 48%; untreated, 66%). This was reflected in the significantly lower number of treated patients transfused [300 IU kg(-1), 20% (P< 0.001); 150 IU kg(-1), 45% (P< 0.05); untreated, 59%]. Epoetin alpha was well-tolerated, and there was no evidence of sustained, clinically significant, hypertension. In summary, epoetin alpha is effective and well-tolerated in maintaining Hb level and reducing transfusion requirement in patients undergoing cyclic chemotherapy for SCLC.

Adult↗

PubMed1999

Protection of committed murine haemopoietic progenitors against BCNU toxicity does not predict protection of primitive, multipotent spleen colony-forming cells - implications for chemoprotective gene therapy.

The effect of expression of an O6-benzylguanine (O6-beG)-resistant mutant (hATPA/GA) of human O6-alkylguanine-DNA alkyltransferase (ATase) on the in vivo toxicity and clastogenicity of the anti-tumour agent N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU) to murine bone marrow has been investigated. When compared with control animals, the bipotent granulocyte-macrophage colony-forming (GM-CFC) progenitor population of the hATPA/GA transduced mice were somewhat more resistant to BCNU (1.4-fold, P = 0.047) and this effect was more significant in the presence of the ATase inactivator O6-beG (3. 5-fold, P = 0.001). The polychromatic erythrocytes were also significantly protected against BCNU-induced clastogenicity both in the presence (P < 0.001) and absence of O6-beG (P < 0.05). The primitive, multipotent spleen colony-forming cells (CFU-S) in these animals also showed moderate (1.6-fold, P = 0.034) protection in the absence of O6-beG but in the presence of the inactivator they remained as sensitive to BCNU toxicity as those in the control animals (P = 0.133). This result contrasts with previous findings demonstrating significant hATPA/GA-mediated, O6-beG-resistant protection against the toxicity and clastogenicity of a number of O6-alkylating agents, including temozolomide, fotemustine and chlorozotocin. The possibility that our strategy for protective gene therapy may be highly agent and cell-type specific is unexpected and has possible implications for clinical trials of this approach using BCNU or related agents.

Animals↗

PubMed1999

Paclitaxel: a hope for advanced non-small cell lung cancer?

Recent studies have shown that paclitaxel (Taxol); Bristol-Myers Squibb Co., Princeton, NJ) is an active agent in the treatment of advanced non-small cell lung cancer (NSCLC). Early trials in patients with advanced NSCLC utilised a 24 h infusion schedule and reported objective tumour responses in 21 - 24% of patients. Shorter infusion schedules have equivalent efficacy, and combined results from 14 separate trials of single agent paclitaxel in advanced NSCLC show an overall tumour response rate of 26%. Alternative schedules of paclitaxel from the traditional regimen every three weeks are under active investigation, but it is premature to assess whether these will yield improved efficacy for patients with advanced NSCLC. A single multicentre randomised trial of paclitaxel versus best supportive care in advanced NSCLC showed a significant survival advantage for the chemotherapy arm. Two large randomised Phase III trials have shown that paclitaxel and cisplatin is modestly more effective than cisplatin and podophyllotoxin combinations. The addition of cisplatin or carboplatin to paclitaxel results in higher response rates than for each of the drugs as single agents, but it is unclear whether the combinations yield superior survival or quality of life compared to single agent paclitaxel, or to other paclitaxel-containing regimens.

Journal Article↗

PubMed1998

Expression of p16INK4a/p16alpha and p19ARF/p16beta is frequently altered in non-small cell lung cancer and correlates with p53 overexpression.

The CDKN2 locus expresses two different mRNA transcripts, designated alpha and beta. The protein product of the alpha transcript is the cell cycle inhibitor and tumour suppressor p16INK4a. The beta transcript is translated in an alternate reading frame (ARF) and in humans encodes a 15 kDa protein (p19ARF). Immunohistochemical and Western analysis of p16INK4a has shown that the protein is downregulated in a significant number of tumours, but less is known on the expression of the p19ARF. We have examined the expression of p16INK4a and p19ARF in resectable non-small cell lung cancer (NSCLC) by immunostaining (n=49) and multiplex RT-PCR (n=28). In order to investigate the mechanism responsible for p16INK4a downregulation, exon 1alpha methylation was analysed in a PCR-based assay. Of 49 tumours examined by immunostaining, 24 and 20 tumours expressed p16INK4a and p19ARF at nil to low levels, respectively. p19ARF was localized primarily to the nuclei of tumour cells, but was also seen to varying degrees in nuclei of lymphocytes, chondrocytes, fibroblasts, and epithelial cells. No tumour with normal p16INK4a had decreased p19ARF expression. Among 16 tumours with nil to low p16INK4a expression, 11 tumours exhibited full methylation of at least one site within exon 1alpha and these tumours showed normal p19ARF expression. In contrast, no methylation of exon 1alpha was observed in five tumours which also lacked p19ARF. In normal lung, p16INK4a and p19ARF were not expressed at detectable levels, the multiplex RT-PCR results were balanced, and sites within exon 1alpha were strongly methylated. In tumours, imbalanced multiplex RT-PCR data (p16INK4a<p19ARF) predicted methylation of exon 1alpha (P=0.0006) as well as downregulation of p16INK4a. p19ARF downregulation was inversely correlated with p53 overexpression (P=0.025), whilst negative immunostaining for p16INK4a was inversely correlated with pRb down-regulation (P=0.003) and directly correlated with p53 overexpression as assessed by immunostaining (P=0.015). Our results show that: (1) p16INK4a and p19ARF expression are altered in almost half of resectable NSCLC; (2) methylation within exon 1alpha is a frequent, but not the only mechanism of p16INK4a downregulation; and that (3) the inverse association of p19ARF and p53 alteration is consistent with a linked pathway.

Aged↗

PubMed1998

G- and GM-CSF.

Explore the source record for details and available documents.

Fever↗

PubMed1998

A randomized phase II trial of interleukin 2 and interleukin 2-interferon alpha in advanced renal cancer.

A randomized phase II trial was performed to compare the efficacy and toxicity of interleukin 2 (IL-2) with an IL-2 and interferon alpha (IFN-alpha) regimen for the treatment of metastatic renal carcinoma. Sixty patients with recurrent renal cell carcinoma (RCC) who had previously undergone a nephrectomy were randomized to receive three cycles of IL-2 or IL-2 with IFN-alpha2b. Eighteen MU of IL-2 were administered subcutaneously on Mondays-Fridays for 3 weeks out of 4. Those patients randomized to receive the combination received the same regimen of IL-2 with 9 MU of IFN-alpha2b subcutaneously on Mondays, Wednesdays and Fridays for 3 weeks out of 4. Thirty patients were randomized to receive each arm. Twenty-nine were evaluable in each arm. Twenty-two patients received three cycles of IL-2 but only 14 patients received three cycles of IL-2/IFN-alpha because of the greater toxicity of the combination. The principal toxicities included nausea, fatigue and fever. There were no complete responses in either arm and only two patients who were treated with IL-2 attained a partial response. Twelve patients in each arm had stable disease and 15 patients in the IL-2 arm and 16 patients in the IL-2/IFN-alpha arm progressed through treatment. There were no significant differences in survival. Ten patients who received IL-2 are alive with a median follow-up of 266 days, whereas six patients who received IL-2/IFN-alpha are alive after a median of 278 days. The median survival from the time of identification of metastatic disease is 444 days in the IL-2 arm and 381 days in the IL-2/IFN-alpha arm. The IL-2/IFN-alpha combination is more toxic than IL-2 alone and this resulted in a reduced number of cycles of treatment. However, the median survival of the two groups was the same, suggesting that further evaluation of the IL-2/IFN-alpha combination should be confined to large prospective randomized clinical trials.

Adult↗

PubMed1998

O6-methylguanine-DNA methyltransferase in pretreatment tumour biopsies as a predictor of response to temozolomide in melanoma.

Resistance of tumour cells to methylating and monochloroethylating agents in vitro and in vivo has been linked to levels of the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT). In a clinical trial of temozolomide in advanced malignant melanoma, the relationship between pretreatment MGMT levels in biopsies of cutaneous tumours and involved lymph nodes and clinical response to the drug has been studied. Among 50 evaluable patients, there were three complete responses (CR), four partial responses (PR), six with stable disease (SD) and 37 with progressive disease (PD), with an overall response rate of 14%. In 33 patients in whom MGMT level and clinical response could be evaluated, the tumour MGMT levels (fmol mg(-1) protein) were: CR, 158 +/- 119; PR, 607 +/- 481; NC, 171 +/- 101; PD, 185 +/- 42.3. Thus, measurements of pretreatment levels of MGMT in melanoma did not predict for response to temozolomide.

Adult↗

PubMed1998

Chemoprotective gene transfer I: transduction of human haemopoietic progenitors with O6-benzylguanine-resistant O6-alkylguanine-DNA alkyltransferase attenuates the toxic effects of O6-alkylating agents in vitro.

Retroviral transduction was used to introduce cDNAs encoding two mutants of human O6-alkylguanine-DNA alkyltransferase (hAT), one of which (hATPA) is 16 times more resistant to O6-benzylguanine (O6-beG), and the other (hATPA/GA) which is almost totally refractory to inactivation relative to the wild-type protein, into K562 human erythroleukaemic cells. A colony-forming assay was used to demonstrate significant protection (P < 0.001) against mitozolomide or temozolomide toxicity in K562 clones expressing either hAT mutant, as determined from an in vitro assay of activity. However, protection against these agents was reduced in hATPA expressing cells in the presence of 1 microM O6-beG and was lost in the presence of 20 microM O6-beG while cells expressing hATPA/GA retained protection even in the presence of 20 microM O6-beG (P < 0.001). Using primary human cord blood-derived CD34+ haemopoietic cells in which PCR analysis indicated that up to 70% of progenitors were transduced with retroviral constructs harbouring hATPA/GA, we observed significant protection of the granulocyte-macrophage colony-forming cells against mitozolomide (P < 0.05) and temozolomide (P < 0.001) induced toxicity in the presence of O6-beG. These findings indicate that retrovirus-mediated expression of hATPA/GA in primitive primary human haemopoietic cells is possible and does provide O6-beG-resistant protection for these cells. Using this strategy in patients may simultaneously permit attenuated myelosuppression and increased sensitivity of tumour cells to the effects of O6-alkylating agent chemotherapy. These data, taken together with the study reported by Chinnasamy et al in the accompanying article in this issue showing reduced toxicity and clastogenicity in murine haemopoietic progenitors, make a compelling case to test this strategy clinically.

Antigens, CD34↗

PubMed1998

Chemoprotective gene transfer II: multilineage in vivo protection of haemopoiesis against the effects of an antitumour agent by expression of a mutant human O6-alkylguanine-DNA alkyltransferase.

Murine bone marrow cells were transduced ex vivo with a retrovirus encoding an O6-benzylguanine (O6-beG) insensitive, double mutant form of the human DNA repair protein O6-alkylguanine-DNA alkyltransferase (hATPA/GA). In animals reconstituted with the transduced bone marrow, about 50% of cells in the multipotent spleen colony-forming cells (CFU-S) and lineage restricted granulocyte-macrophage (GM-CFC) haemopoietic progenitor populations were found to be carrying the transgene and this correlated with the frequency of bone marrow cells and spleen colonies which stained positive for hATPA/GA by immunocyto-chemistry. Expression of hATPA/GA was associated with significant in vivo protection of both CFU-S (P = 0.001) and GM-CFC (P < 0.024) against the toxicity of the antitumour methylating agent, temozolomide, given in combination with O6-beG. Expression of hATPA/GA also led to a reduction in the frequency of combined O6-beG/temozolomide-induced micronuclei seen in polychromatic erythrocytes (P < 0.003). This study is the first to demonstrate in vivo protection of multipotent haemopoietic progenitors against the toxic and clastogenic effects of an O6-alkylating agent in the presence of O6-beG. It also represents the first report of reduced clastogenesis as a consequence of expression of an O6-beG-resistant ATase. In the accompanying article we report hATPA/GA-mediated resistance of human CD34+ haemopoietic progenitors to combined O6-beG/O6-alkylating agent toxicity. Together these two reports suggest that a gene therapy strategy whereby protection of normal haemopoietic tissue may be combined with O6-beG-mediated tumour sensitisation may be efficacious in achieving an increase in therapeutic index.

Animals↗

PubMed1998

Effects of granulocyte-macrophage colony-stimulating factor and dose intensification of V-ICE chemotherapy in small-cell lung cancer: a prospective randomized study of 300 patients.

PURPOSE: To assess whether granulocyte-macrophage colony-stimulating factor (GM-CSF) reduces the toxicity of chemotherapy and alters delivered dose-intensity. To assess the feasibility of dose-intensification of chemotherapy in small-cell lung cancer (SCLC) and determine whether it has an impact on outcome. MATERIALS AND METHODS: Patients with good- or intermediate-prognosis SCLC entered a prospective multicenter study that involved a 2 x 2 factorial design with randomization to six cycles of chemotherapy with ifosfamide 5 g/m2, carboplatin 300 mg/m2, etoposide 120 mg/m2 intravenously (I.V.) on days 1 and 2 and 240 mg/m2 orally on day 3, and vincristine 0.5 mg/m2 I.V. on day 15 (V-ICE) every 3 weeks (intensified arm) or every 4 weeks (standard arm). A second double-blind randomization to subcutaneous GM-CSF (250 microg/m2/d) or placebo for 14 days between chemotherapy cycles was made. RESULTS: Three hundred patients were entered. Myelosuppression was the main toxicity, with no significant difference in the incidence or grade between treatment groups. The incidence of febrile neutropenia and bacteriologically confirmed sepsis was unaffected by chemotherapy schedule or use of GM-CSF. Twenty-six percent greater dose-intensity was delivered in the intensified arm, with a trend for greater dose-intensity for those who received GM-CSF. Eighty-three percent of patients achieved a response (51% complete response [CR] rate), with no significant difference in response rates between treatment groups. Survival was significantly increased in the intensified compared with the standard arm (P = .0014); median survival rates were 443 versus 351 days and 2-year survival rates were 33% versus 18%, respectively. CONCLUSION: GM-CSF does not reduce the incidence of complications from myelosuppression of aggressive chemotherapy. Dose intensification of V-ICE to a 3-week schedule in SCLC is not associated with increased toxicity, but appears to improve survival significantly. Future studies should aim to deliver chemotherapy in maximal-tolerated dose-intensities.

Adult↗