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Chinese Clinical Oncology Aug 2017Tumor treating fields (TTF, Optune®), one of the low-intensity alternating electric fields, have been demonstrated to disrupt mitosis and inhibit tumor growth with... (Review)
Review
BACKGROUND
Tumor treating fields (TTF, Optune®), one of the low-intensity alternating electric fields, have been demonstrated to disrupt mitosis and inhibit tumor growth with antimitotic properties in a variety of tumor types. The Food and Drug Administration (FDA) of the United States approved TTF for recurrent GBM and newly diagnosed GBM in 2011 and 2015, respectively.
METHODS
A systematic review was conducted regarding the relevant studies published between January 1, 2000, and May 31, 2017 in PubMed database. The search term included "Tumor Treating Fields", "Optune", "TTF", "Novocure", and "GBM". This review summarizes the mechanism of action, efficacy, and adverse events based on pre-clinical studies and clinical trials for TTF in GBM.
RESULTS
Pre-clinical studies showed that TTF could inhibit tumor growth in vitro and in vivo by disrupting mitosis, inducing cell cycle arrest and apoptosis. Two randomized phase III trials evaluated the efficacy and safety of TTF in GBM patients. It was revealed that the combination of TTF and standard chemotherapy (temozolomide) prolonged the progression-free survival (PFS) and overall survival (OS) without systemic safety issues in newly diagnosed GBM (EF-14 trial). For recurrent GBM, the efficacy of TTF monotherapy was shown to be equivalent in PFS and OS without systemic adverse events when compared to the control group that received best physicians-chosen chemotherapies (EF-11 trial).
CONCLUSIONS
The advantages of TTF in GBM treatment, including non-invasive antitumor effect, superior therapeutic benefit in combination with chemotherapy, and minimal systematic toxicity, have been demonstrated in pre-clinical data and randomized phased III clinical trials. Future investigations will be needed to explore combinations of chemotherapy, radiation therapy, targeted therapy, as well as immunotherapy with this novel anti-tumor treatment modality to achieve additive or synergistic therapeutic benefit for GBM and other solid tumors.
Topics: Antineoplastic Agents, Alkylating; Brain Neoplasms; Clinical Trials, Phase III as Topic; Combined Modality Therapy; Dacarbazine; Disease-Free Survival; Electric Stimulation Therapy; Glioblastoma; Humans; Randomized Controlled Trials as Topic; Safety; Temozolomide; Treatment Outcome; United States
PubMed: 28841803
DOI: 10.21037/cco.2017.06.29 -
International Journal of Molecular... Nov 2023Gliomas are aggressive malignant brain tumors, with poor prognosis despite available therapies, raising the necessity for finding new compounds with therapeutic action.... (Meta-Analysis)
Meta-Analysis Review
Gliomas are aggressive malignant brain tumors, with poor prognosis despite available therapies, raising the necessity for finding new compounds with therapeutic action. Numerous preclinical investigations evaluating resveratrol's anti-tumor impact in animal models of glioma have been reported; however, the variety of experimental circumstances and results have prevented conclusive findings about resveratrol's effectiveness. Several databases were searched during May 2023, ten publications were identified, satisfying the inclusion criteria, that assess the effects of resveratrol in murine glioma-bearing xenografts. To determine the efficacy of resveratrol, tumor volume and animal counts were retrieved, and the data were then subjected to a random effects meta-analysis. The influence of different experimental conditions and publication bias on resveratrol efficacy were evaluated. Comparing treated to untreated groups, resveratrol administration decreased the tumor volume. Overall, the effect's weighted standardized difference in means was -2.046 (95%CI: -3.156 to -0.936; -value < 0.001). The efficacy of the treatment was observed for animals inoculated with both human glioblastoma or rat glioma cells and for different modes of resveratrol administration. The combined administration of resveratrol and temozolomide was more effective than temozolomide alone. Reducing publication bias did not change the effectiveness of resveratrol treatment. The findings suggest that resveratrol slows the development of tumors in animal glioma models.
Topics: Humans; Rats; Mice; Animals; Temozolomide; Resveratrol; Cell Line, Tumor; Glioma; Brain Neoplasms; Models, Animal
PubMed: 38068922
DOI: 10.3390/ijms242316597 -
British Journal of Cancer Jan 2013Malignant glioma is an aggressive tumour commonly associated with a dismal outcome despite optimal surgical and radio-chemotherapy. Since 2005 temozolomide has been... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Malignant glioma is an aggressive tumour commonly associated with a dismal outcome despite optimal surgical and radio-chemotherapy. Since 2005 temozolomide has been established as first-line chemotherapy. We investigate the role of in vivo glioma models in predicting clinical efficacy.
METHODS
We searched three online databases to systematically identify publications testing temozolomide in animal models of glioma. Median survival and number of animals treated were extracted and quality was assessed using a 12-point scale; random effects meta-analysis was used to estimate efficacy. We analysed the impact of study design and quality and looked for evidence of publication bias.
RESULTS
We identified 60 publications using temozolomide in models of glioma, comprising 2443 animals. Temozolomide prolonged survival by a factor of 1.88 (95% CI 1.74-2.03) and reduced tumour volume by 50.4% (41.8-58.9) compared with untreated controls. Study design characteristics accounted for a significant proportion of between-study heterogeneity, and there was evidence of a significant publication bias.
CONCLUSION
These data reflect those from clinical trials in that temozolomide improves survival and reduces tumour volume, even after accounting for publication bias. Experimental in vivo glioma studies of temozolomide differ from those of other glioma therapies in their consistent efficacy and successful translation into clinical medicine.
Topics: Animals; Antineoplastic Agents, Alkylating; Brain Neoplasms; Dacarbazine; Disease Models, Animal; Glioma; Mice; Rats; Survival Analysis; Temozolomide; Treatment Outcome; Xenograft Model Antitumor Assays
PubMed: 23321511
DOI: 10.1038/bjc.2012.504 -
The Cochrane Database of Systematic... Nov 2018This is an updated version of the original Cochrane Review published in September 2014. The most common primary brain tumours in adults are gliomas. Gliomas span a... (Meta-Analysis)
Meta-Analysis
BACKGROUND
This is an updated version of the original Cochrane Review published in September 2014. The most common primary brain tumours in adults are gliomas. Gliomas span a spectrum from low to high grade and are graded pathologically on a scale of one to four according to the World Health Organization (WHO) classification. High-grade glioma (HGG) carries a poor prognosis. Grade IV glioma is known as glioblastoma and carries a median survival in treated patients of about 15 months. Glioblastomas are rich in blood vessels (i.e. highly vascular) and also rich in a protein known as vascular endothelial growth factor (VEGF) that promotes new blood vessel formation (the process of angiogenesis). Anti-angiogenic agents inhibit the process of new blood vessel formation and promote regression of existing vessels. Several anti-angiogenic agents have been investigated in clinical trials, both in newly diagnosed and recurrent HGG, showing preliminary promising results. This review was undertaken to report on the benefits and harms associated with the use of anti-angiogenic agents in the treatment of HGGs.
OBJECTIVES
To evaluate the efficacy and toxicity of anti-angiogenic therapy in people with high-grade glioma (HGG). The intervention can be used in two broad groups: at first diagnosis as part of 'adjuvant' therapy, or in the setting of recurrent disease.
SEARCH METHODS
We conducted updated searches to identify published and unpublished randomised controlled trials (RCTs), including the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 9), MEDLINE and Embase to October 2018. We handsearched proceedings of relevant oncology conferences up to 2018. We also searched trial registries for ongoing studies.
SELECTION CRITERIA
RCTs evaluating the use of anti-angiogenic therapy to treat HGG versus the same therapy without anti-angiogenic therapy.
DATA COLLECTION AND ANALYSIS
Review authors screened the search results and reviewed the abstracts of potentially relevant articles before retrieving the full text of eligible articles.
MAIN RESULTS
After a comprehensive literature search, we identified 11 eligible RCTs (3743 participants), of which 7 were included in the original review (2987 participants). There was significant design heterogeneity in the included studies, especially in the response assessment criteria used. All eligible studies were restricted to glioblastomas and there were no eligible studies evaluating other HGGs. Ten studies were available as fully published peer-reviewed manuscripts, and one study was available in abstract form. The overall risk of bias in included studies was low. This risk was based upon low rates of selection bias, detection bias, attrition bias and reporting bias. The 11 studies included in this review did not show an improvement in overall survival with the addition of anti-angiogenic therapy (pooled hazard ratio (HR) of 0.95, 95% confidence interval (CI) 0.88 to 1.02; P = 0.16; 11 studies, 3743 participants; high-certainty evidence). However, pooled analysis from 10 studies (3595 participants) showed improvement in progression-free survival with the addition of anti-angiogenic therapy (HR 0.73, 95% CI 0.68 to 0.79; P < 0.00001; high-certainty evidence).We carried out additional analyses of overall survival and progression-free survival according to treatment setting and for anti-angiogenic therapy combined with chemotherapy compared to chemotherapy alone. Pooled analysis of overall survival in either the adjuvant or recurrent setting did not show an improvement (HR 0.93, 95% CI 0.86 to 1.02; P = 0.12; 8 studies, 2833 participants; high-certainty evidence and HR 0.99, 95% CI 0.85 to 1.16; P = 0.90; 3 studies, 910 participants; moderate-certainty evidence, respectively). Pooled analysis of overall survival for anti-angiogenic therapy combined with chemotherapy compared to chemotherapy also did not clearly show an improvement (HR 0.92, 95% CI 0.85 to 1.00; P = 0.05; 11 studies, 3506 participants; low-certainty evidence). The progression-free survival in the subgroups all showed findings that demonstrated improvements in progression-free survival with the addition of anti-angiogenic therapy. Pooled analysis of progression-free survival in both the adjuvant and recurrent setting showed an improvement (HR 0.75, 95% CI 0.69 to 0.82; P < 0.00001; 8 studies, 2833 participants; high-certainty evidence and HR 0.64, 95% CI 0.54 to 0.76; P < 0.00001; 2 studies, 762 participants; moderate-certainty evidence, respectively). Pooled analysis of progression-free survival for anti-angiogenic therapy combined with chemotherapy compared to chemotherapy alone showed an improvement (HR 0.72, 95% CI 0.66 to 0.77; P < 0.00001; 10 studies, 3464 participants). Similar to trials of anti-angiogenic therapies in other solid tumours, adverse events related to this class of therapy included hypertension and proteinuria, poor wound healing, and the potential for thromboembolic events, although generally, the rate of grade 3 and 4 adverse events was low (< 14.1%) and in keeping with the literature. The impact of anti-angiogenic therapy on quality of life varied between studies.
AUTHORS' CONCLUSIONS
The use of anti-angiogenic therapy does not significantly improve overall survival in newly diagnosed people with glioblastoma. Thus, there is insufficient evidence to support the use of anti-angiogenic therapy for people with newly diagnosed glioblastoma at this time. Overall there is a lack of evidence of a survival advantage for anti-angiogenic therapy over chemotherapy in recurrent glioblastoma. When considering the combination anti-angiogenic therapy with chemotherapy compared with the same chemotherapy alone, there may possibly be a small improvement in overall survival. While there is strong evidence that bevacizumab (an anti-angiogenic drug) prolongs progression-free survival in newly diagnosed and recurrent glioblastoma, the impact of this on quality of life and net clinical benefit for patients remains unclear. Not addressed here is whether subsets of people with glioblastoma may benefit from anti-angiogenic therapies, nor their utility in other HGG histologies.
Topics: Angiogenesis Inhibitors; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Bevacizumab; Brain Neoplasms; Camptothecin; Dacarbazine; Glioblastoma; Humans; Hypertension; Irinotecan; Lomustine; Neoplasm Recurrence, Local; Neovascularization, Pathologic; Progression-Free Survival; Proteinuria; Randomized Controlled Trials as Topic; Snake Venoms; Temozolomide
PubMed: 30480778
DOI: 10.1002/14651858.CD008218.pub4 -
Apoptosis : An International Journal on... Dec 2018Autophagy is an evolutionarily conserved catabolic process that plays an essential role in maintaining cellular homeostasis by degrading unneeded cell components. When... (Review)
Review
Autophagy is an evolutionarily conserved catabolic process that plays an essential role in maintaining cellular homeostasis by degrading unneeded cell components. When exposed to hostile environments, such as hypoxia or nutrient starvation, cells hyperactivate autophagy in an effort to maintain their longevity. In densely packed solid tumors, such as glioblastoma, autophagy has been found to run rampant due to a lack of oxygen and nutrients. In recent years, targeting autophagy as a way to strengthen current glioblastoma treatment has shown promising results. However, that protective autophagy inhibition or autophagy overactivation is more beneficial, is still being debated. Protective autophagy inhibition would lower a cell's previously activated defense mechanism, thereby increasing its sensitivity to treatment. Autophagy overactivation would cause cell death through lysosomal overactivation, thus introducing another cell death pathway in addition to apoptosis. Both methods have been proven effective in the treatment of solid tumors. This systematic review article highlights scenarios where both autophagy inhibition and activation have proven effective in combating chemoresistance and radioresistance in glioblastoma, and how autophagy may be best utilized for glioblastoma therapy in clinical settings.
Topics: Antineoplastic Agents; Autophagosomes; Autophagy; Brain Neoplasms; Cell Death; Drug Resistance, Neoplasm; Glioblastoma; Humans; Radiation-Sensitizing Agents; Temozolomide
PubMed: 30171377
DOI: 10.1007/s10495-018-1480-9 -
Hormones (Athens, Greece) Apr 2017Pituitary tumors represent 10-15% of all intracranial tumors; of these, prolactinomas account for 40-50% of cases. Prolactinomas usually respond well to dopamine... (Review)
Review
Pituitary tumors represent 10-15% of all intracranial tumors; of these, prolactinomas account for 40-50% of cases. Prolactinomas usually respond well to dopamine agonists (DA) as first-line therapy. However, treatment resistance remains a concern. Temozolomide (TMZ) is an oral alkylating agent that has shown promise in treating aggressive pituitary adenomas and carcinomas that are resistant to other therapies. To date, no control trials have been undertaken and only single case reports of pituitary tumors treated with TMZ have been published. A systematic literature search was conducted for studies reporting the use of TMZ for the treatment of prolactinomas that were resistant to standard therapy. In total, 42 reported cases were identified and included in our analysis: 23 cases of prolactin-secreting adenomas and 19 of prolactin-secreting carcinomas. Prior to TMZ administration, patients had exhibited tumor progression and had previously undergone various treatments including surgery, radiotherapy, and drug therapy. Tumor shrinkage was reported in 76% of patients. Reduced prolactin levels were observed in 75% of patients, while normalization of prolactin was reported in 8%. TMZ failure occurred in 20.6% of cases. Most patients exhibited no serious adverse effects. In conclusion, TMZ has potential for the treatment of highly aggressive and resistant prolactin-secreting adenomas and carcinomas, as demonstrated by tumor shrinkage or complete response and normalization of hormone hypersecretion, and exhibits good tolerability and few side effects.
Topics: Antineoplastic Agents, Alkylating; Carcinoma; Dacarbazine; Humans; Pituitary Neoplasms; Prolactinoma; Temozolomide
PubMed: 28742502
DOI: 10.14310/horm.2002.1729 -
The Cochrane Database of Systematic... Sep 2017Efficacy and the risk of severe late effects have to be well-balanced in treatment of Hodgkin lymphoma (HL). Late adverse effects include secondary malignancies which... (Meta-Analysis)
Meta-Analysis Review
Optimisation of chemotherapy and radiotherapy for untreated Hodgkin lymphoma patients with respect to second malignant neoplasms, overall and progression-free survival: individual participant data analysis.
BACKGROUND
Efficacy and the risk of severe late effects have to be well-balanced in treatment of Hodgkin lymphoma (HL). Late adverse effects include secondary malignancies which often have a poor prognosis. To synthesise evidence on the risk of secondary malignancies after current treatment approaches comprising chemotherapy and/or radiotherapy, we performed a meta-analysis based on individual patient data (IPD) from patients treated for newly diagnosed HL.
OBJECTIVES
We investigated several questions concerning possible changes in the risk of secondary malignancies when modifying chemotherapy or radiotherapy (omission of radiotherapy, reduction of the radiation field, reduction of the radiation dose, use of fewer chemotherapy cycles, intensification of chemotherapy). We also analysed whether these modifications affect progression-free survival (PFS) and overall survival (OS).
SEARCH METHODS
We searched MEDLINE and Cochrane CENTRAL trials databases comprehensively in June 2010 for all randomised trials in HL since 1984. Key international trials registries were also searched. The search was updated in March 2015 without collecting further IPD (one further eligible study found) and again in July 2017 (no further eligible studies).
SELECTION CRITERIA
We included randomised controlled trials (RCTs) for untreated HL patients which enrolled at least 50 patients per arm, completed recruitment by 2007 and performed a treatment comparison relevant to our objectives.
DATA COLLECTION AND ANALYSIS
Study groups submitted IPD, including age, sex, stage and the outcomes secondary malignant neoplasm (SMN), OS and PFS as time-to-event data. We meta-analysed these data using Petos method (SMN) and Cox regression with inverse-variance pooling (OS, PFS) for each of the five study questions, and performed subgroup and sensitivity analyses to assess the applicability and robustness of the results.
MAIN RESULTS
We identified 21 eligible trials and obtained IPD for 16. For four studies no data were supplied despite repeated efforts, while one study was only identified in 2015 and IPD were not sought. For each study question, between three and six trials with between 1101 and 2996 participants in total and median follow-up between 6.7 and 10.8 years were analysed. All participants were adults and mainly under 60 years. Risk of bias was assessed as low for the majority of studies and outcomes. Chemotherapy alone versus same chemotherapy plus radiotherapy. Omitting additional radiotherapy probably reduces secondary malignancy incidence (Peto odds ratio (OR) 0.43, 95% confidence interval (CI) 0.23 to 0.82, low quality of evidence), corresponding to an estimated reduction of eight-year SMN risk from 8% to 4%. This decrease was particularly true for secondary acute leukemias. However, we had insufficient evidence to determine whether OS rates differ between patients treated with chemotherapy alone versus combined-modality (hazard ratio (HR) 0.71, 95% CI 0.46 to 1.11, moderate quality of evidence). There was a slightly higher rate of PFS with combined modality, but our confidence in the results was limited by high levels of statistical heterogeneity between studies (HR 1.31, 95% CI 0.99 to 1.73, moderate quality of evidence). Chemotherapy plus involved-field radiation versus same chemotherapy plus extended-field radiation (early stages) . There is insufficient evidence to determine whether smaller radiation field reduces SMN risk (Peto OR 0.86, 95% CI 0.64 to 1.16, low quality of evidence), OS (HR 0.89, 95% C: 0.70 to 1.12, high quality of evidence) or PFS (HR 0.99, 95% CI 0.81 to 1.21, high quality of evidence). Chemotherapy plus lower-dose radiation versus same chemotherapy plus higher-dose radiation (early stages). There is insufficient evidence to determine the effect of lower-radiation dose on SMN risk (Peto OR 1.03, 95% CI 0.71 to 1.50, low quality of evidence), OS (HR 0.91, 95% CI 0.65 to 1.28, high quality of evidence) or PFS (HR 1.20, 95% CI 0.97 to 1.48, high quality of evidence). Fewer versus more courses of chemotherapy (each with or without radiotherapy; early stages). Fewer chemotherapy courses probably has little or no effect on SMN risk (Peto OR 1.10, 95% CI 0.74 to 1.62), OS (HR 0.99, 95% CI 0.73 to1.34) or PFS (HR 1.15, 95% CI 0.91 to 1.45).Outcomes had a moderate (SMN) or high (OS, PFS) quality of evidence. Dose-intensified versus ABVD-like chemotherapy (with or without radiotherapy in each case). In the mainly advanced-stage patients who were treated with intensified chemotherapy, the rate of secondary malignancies was low. There was insufficient evidence to determine the effect of chemotherapy intensification (Peto OR 1.37, CI 0.89 to 2.10, low quality of evidence). The rate of secondary acute leukemias (and for younger patients, all secondary malignancies) was probably higher than among those who had treatment with standard-dose ABVD-like protocols. In contrast, the intensified chemotherapy protocols probably improved PFS (eight-year PFS 75% versus 69% for ABVD-like treatment, HR 0.82, 95% CI 0.7 to 0.95, moderate quality of evidence). Evidence suggesting improved survival with intensified chemotherapy was not conclusive (HR: 0.85, CI 0.70 to 1.04), although escalated-dose BEACOPP appeared to lengthen survival compared to ABVD-like chemotherapy (HR 0.58, 95% CI 0.43 to 0.79, moderate quality of evidence).Generally, we could draw valid conclusions only in terms of secondary haematological malignancies, which usually occur less than 10 years after initial treatment, while follow-up within the present analysis was too short to record all solid tumours.
AUTHORS' CONCLUSIONS
The risk of secondary acute myeloid leukaemia and myelodysplastic syndrome (AML/MDS) is increased but efficacy is improved among patients treated with intensified chemotherapy protocols. Treatment decisions must be tailored for individual patients. Consolidating radiotherapy is associated with an increased rate of secondary malignancies; therefore it appears important to define which patients can safely be treated without radiotherapy after chemotherapy, both for early and advanced stages. For early stages, treatment optimisation methods such as use of fewer chemotherapy cycles and reduced field or reduced-dose radiotherapy did not appear to markedly affect efficacy or secondary malignancy risk. Due to the limited amount of long-term follow-up in this meta-analysis, further long-term investigations of late events are needed, particularly with respect to secondary solid tumours. Since many older studies have been included, possible improvement of radiotherapy techniques must be considered when interpreting these results.
Topics: Adult; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Bleomycin; Chemoradiotherapy; Dacarbazine; Disease-Free Survival; Doxorubicin; Hodgkin Disease; Humans; Leukemia, Radiation-Induced; Middle Aged; Myelodysplastic Syndromes; Neoplasms, Second Primary; Radiotherapy; Radiotherapy Dosage; Randomized Controlled Trials as Topic; Vinblastine
PubMed: 28901021
DOI: 10.1002/14651858.CD008814.pub2 -
Medicine Nov 2018Autophagy is a mechanism which relies on lysosomes for clearance and recycling of abnormal proteins or organelles. Many studies have demonstrated that the deregulation... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Autophagy is a mechanism which relies on lysosomes for clearance and recycling of abnormal proteins or organelles. Many studies have demonstrated that the deregulation of autophagy is associated with the development of various diseases including cancer. The use of autophagy inhibitors is an emerging trend in cancer treatment. However, the value of autophagy inhibitors remains under debate. Thus, a meta-analysis was performed, aiming to evaluate the clinical value of autophagy-inhibitor-based therapy.
METHODS
We searched for clinical studies that evaluated autophagy-inhibitor-based therapy in cancer. We extracted data from these studies to evaluate the relative risk (RR) of overall response rate (ORR), 6-month progression-free survival (PFS) rate, and 1-year overall survival (OS) rate.
RESULTS
Seven clinical trials were identified (n = 293). Treatments included 2 combinations of hydroxychloroquine and gemcitabine, 1 combination of hydroxychloroquine and doxorubicin, 1 combination of chloroquine and radiation, 2 combinations of chloroquine, temozolomide, and radiation, and 1 hydroxychloroquine monotherapy. Autophagy-inhibitor-based therapy showed higher ORR (RR: 1.33, 95% confidence interval [CI]: 0.95-1.86, P = .009), PFS (RR: 1.72, 95% CI: 1.05-2.82, P = .000), OS (RR: 1.39, 95% CI: 1.11-1.75, P = .000) values than the therapy without inhibiting autophagy.
CONCLUSION
This meta-analysis showed that autophagy-inhibitor-based therapy has better treatment response compared to chemotherapy or radiation therapy without inhibiting autophagy, which may provide a new strategy for the treatment of cancers.
Topics: Antineoplastic Combined Chemotherapy Protocols; Autophagy; Chloroquine; Clinical Trials as Topic; Dacarbazine; Deoxycytidine; Doxorubicin; Humans; Hydroxychloroquine; Neoplasms; Risk; Temozolomide; Treatment Outcome; Gemcitabine
PubMed: 30431566
DOI: 10.1097/MD.0000000000012912 -
Health Technology Assessment... Nov 2007To assess the clinical and cost-effectiveness of adjuvant carmustine wafers (BCNU-W) and also of adjuvant and concomitant temozolomide (TMZ), compared with surgery with... (Review)
Review
The effectiveness and cost-effectiveness of carmustine implants and temozolomide for the treatment of newly diagnosed high-grade glioma: a systematic review and economic evaluation.
OBJECTIVES
To assess the clinical and cost-effectiveness of adjuvant carmustine wafers (BCNU-W) and also of adjuvant and concomitant temozolomide (TMZ), compared with surgery with radiotherapy.
DATA SOURCES
Electronic databases were searched up to August 2005.
REVIEW METHODS
Included trials were critically appraised for key elements of internal and external validity. Relevant data were extracted and a narrative synthesis of the evidence produced. Where possible, data on absolute survival at a fixed time point were meta-analysed using a random effects model. A Markov (state transition) model was developed to assess the cost-utility of the two interventions. The model compared BCNU-W or TMZ separately with current standard treatment with surgery and radiotherapy. The simulated cohort had a mean age of 55 years and was modelled over 5 years.
RESULTS
Two randomised controlled trials (RCTs) (n = 32, n = 240) and two observational studies of BCNU-W compared with placebo wafers as adjuvant therapy to surgery and radiotherapy for newly diagnosed high-grade glioma were identified. All the studies were in adults and provided data on 193 patients who had received BCNU-W. The RCT findings excluded under 65-year-olds and those with a Karnofsky Performance Status of less than 60. The largest multi-centre RCT suggested a possible survival advantage with BCNU-W among a cohort of patients with grade III and IV tumours, adding a median of 2.3 months [95% confidence interval (CI) -0.5 to 5.1]. However, analysis using per-protocol, unstratified methods shows this difference to be not statistically significant (HR 0.77, 95% CI 0.57 to 1.03, p = 0.08). Long-term follow-up suggests a significant survival advantage using unstratified analysis. No difference in progression-free survival (PFS) was demonstrated. Subgroup analysis of those with grade IV tumours also showed no significant survival advantage with BCNU-W [hazard ratio (HR) 0.82, 95% CI 0.55 to 1.11, p = 0.20, unstratified analysis]. It is estimated that the cost of surgery and radiotherapy, with follow-up, treatment of adverse effects and end of life care is around 17,000 pounds per patient. Treatment with BCNU-W adds an additional 6600 pounds. Across the modelled cohort of 1000 patients, use of BCNU-W costs an additional 6.6 million pounds and confers an additional 122 quality-adjusted life-years (QALYs). On average, that is 6600 pounds per patient for 0.122 QALYs (6.3 quality-adjusted life-weeks). The base-case incremental cost-effectiveness ratio (ICER) is 54,500 pounds/QALY. In probabilistic sensitivity analyses, BCNU-W was not cost-effective in 89% of the simulations assuming a willingness to pay threshold of 30,000 pounds/QALY. In 15% of simulations, BCNU-W was dominated (i.e. did more harm than good, conferring fewer QALYs at greater cost). The cost-effectiveness acceptability curve (CEAC) suggests that it is very unlikely to be the most cost-effective option at normal levels of willingness to pay (11% probability at 30,000 pounds/QALY), only becoming likely to be the most cost-effective option at much higher levels of willingness to pay (50% probability at 55,000 pounds/QALY). Two RCTs (n = 130, n = 573) and two observational studies were included, giving evidence for 429 adult patients receiving TMZ. Currently, TMZ is licensed for use in those with newly diagnosed grade IV gliomas only. The RCTs excluded those with lower performance status and, in the larger RCT, those older than 70 years. TMZ provides a small but statistically significant median survival benefit of 2.5 months (95% CI 2.0 to 3.8), giving an HR of 0.63 (95% CI 0.52 to 0.75, p < 0.001). At 2 years, 26.5% of patients treated with TMZ were alive compared with 10.4% of those in the control arm. Median PFS is also enhanced with TMZ, giving a median 1.9 months' advantage (95% CI 1.4 to 2.7, p < 0.001). No analysis of the subgroup of patients with confirmed grade IV tumours was undertaken. Subgroup analysis of patients by O6-methylguanine-DNA methyltransferase (MGMT) activity showed a significant treatment advantage for those with reduced MGMT activity but not for those with normal activity, although this analysis was based on a selected sample of patients and the test used has proved difficult to replicate. A median gain of 6.4 (95% CI 4.4 to 9.5) more life-months is seen with TMZ among those with reduced MGMT, giving an HR of 0.51 (p < 0.007). PFS is increased by a median of 4.4 months (95% CI 1.2 to 6.3), giving an HR of 0.48 (p = 0.001). The model shows a cost per patient for being treated with surgery, radiotherapy and including adverse effects of treatment and end of life care of around 17,000 pounds per patient. TMZ in the adjuvant and concomitant phase adds an additional cost of around 7800 pounds. Across the modelled cohort of 1000 patients, use of TMZ costs an additional 7.8 million pounds and confers an additional 217 QALYs. For the average patient this is 7800 pounds for an additional 0.217 QALYs (11 quality-adjusted life-weeks). The base-case ICER is 36,000 pounds/QALY. Probabilistic sensitivity analyses shows that TMZ was not cost-effective in 77% of the simulations. The CEAC suggests that there is a 23% chance that TMZ is the most cost-effective option at a willingness to pay level of 30,000 pounds/QALY, rising to be more cost-effective than no TMZ at slightly higher levels (50% probability at 35,000 pounds/QALY).
CONCLUSIONS
BCNU-W has not been proven to confer a significant advantage in survival for patients with grade III tumours when treated with the drug, compared with placebo. There does not appear to be a survival advantage for patients with grade IV tumours. No increase in PFS has been shown. Limited evidence suggests a small but significant advantage in both overall survival and PFS with TMZ among a mixed population with grade IV and grade III (7-8%) tumours. However, it remains unclear whether this is true in grade IV tumours alone. On the basis of best available evidence, the authors consider that neither BCNU-W nor TMZ is likely to be considered cost-effective by NHS decision-makers. However, data for the model were drawn from limited evidence of variable quality. Tumour type is clearly important in assessing patient prognosis with different treatments. Grade IV tumours are commonest and appear to have least chance of response. There were too few grade III tumours included to carry out a formal assessment, but they appear to respond better and drive results for both drugs. Future use of genetic and biomarkers may help identify subtypes which will respond, but current licensing indications do not specify these. Further research is suggested into the effectiveness of these drugs, and also into areas such as genetic markers, chemotherapy regimens, patient and carer quality of life, and patient views on survival advantages vs treatment disadvantages.
Topics: Age Factors; Aged; Antineoplastic Agents, Alkylating; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Carmustine; Chemotherapy, Adjuvant; Combined Modality Therapy; Cost-Benefit Analysis; Dacarbazine; Disease-Free Survival; Drug Implants; Female; Glioma; Humans; Male; Middle Aged; Models, Econometric; Neoplasm Staging; Quality of Life; Temozolomide
PubMed: 17999840
DOI: 10.3310/hta11450 -
Health Technology Assessment... 2001
Review
Topics: Antineoplastic Agents, Alkylating; Brain Neoplasms; Cost-Benefit Analysis; Dacarbazine; Evidence-Based Medicine; Glioma; Humans; Recurrence; Temozolomide; Treatment Outcome; United Kingdom
PubMed: 11359682
DOI: 10.3310/hta5130