A literature-based meta-analysis taxane-based doublet versus single-agent taxane chemotherapy in patients with advanced breast cancer

A network meta-analysis of everolimus plus exemestane versus chemotherapy in the first- and second-line treatment of estrogen receptor-positive metastatic breast cancer

The goal of this study was to compare the efficacy and toxicity of chemotherapy to exemestane plus everolimus (EXE/EVE) through a network meta-analysis (NMA) of randomized controlled trials. NMA methods extend standard pairwise meta-analysis to allow simultaneous comparison of multiple treatments while maintaining randomization of individual studies. The method enables "direct" evidence (i.e., evidence from studies directly comparing two interventions) and "indirect" evidence (i.e., evidence from studies that do not compare the two interventions directly) to be pooled under the assumption of evidence consistency. We used NMA to evaluate progression-free survival (PFS) and time to progression (TTP) curves in 34 studies, and response rate (RR) and the hazard ratios (HRs) of the PFS/TTP in 36 studies. A number needed to treat (NNT) analysis was also performed as well as descriptive comparison of reported toxicities. The NMA for PFS/TTP curves and for HR shows EXE/EVE is more efficacious than capecitabine plus sunitinib, CMF, megestrol acetate and tamoxifen, with an average of related-PFS/TTP difference ranging from about 10 months for capecitabine plus sunitinib to more than 6 months for tamoxifen. The NMA for overall RR shows that EXE/EVE provides a better RR than bevacizumab plus capecitabine, capecitabine, capecitabine plus sorafenib, capecitabine plus sunitinib, CMF, gemcitabine plus epirubicin plus paclitaxel, EVE plus tamoxifen, EXE, FEC, megestrol acetate, mitoxantrone, and tamoxifen. Finally, the NMA for NNT shows that EXE/EVE is more beneficial as compared to BMF, capecitabine, capecitabine plus sunitinib, CMF, FEC, megestrol acetate, mitoxantrone, and tamoxifen. The combination of EXE/EVE as first- or second-line therapy for ER+ve/HER2-ve metastatic breast cancer is more efficacious than several chemotherapy regimens that were reported in the literature. Toxicities also favored EXE/EVE in most instances.

Deviation from intention to treat analysis in randomised trials and treatment effect estimates: meta-epidemiological study

OBJECTIVE

To examine whether deviation from the standard intention to treat analysis has an influence on treatment effect estimates of randomised trials.

DESIGN

Meta-epidemiological study.

DATA SOURCES

Medline, via PubMed, searched between 2006 and 2010; 43 systematic reviews of interventions and 310 randomised trials were included.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

From each year searched, random selection of 5% of intervention reviews with a meta-analysis that included at least one trial that deviated from the standard intention to treat approach. Basic characteristics of the systematic reviews and randomised trials were extracted. Information on the reporting of intention to treat analysis, outcome data, risk of bias items, post-randomisation exclusions, and funding were extracted from each trial. Trials were classified as: ITT (reporting the standard intention to treat approach), mITT (reporting a deviation from the standard approach), and no ITT (reporting no approach). Within each meta-analysis, treatment effects were compared between mITT and ITT trials, and between mITT and no ITT trials. The ratio of odds ratios was calculated (value <1 indicated larger treatment effects in mITT trials than in other trial categories).

RESULTS

50 meta-analyses and 322 comparisons of randomised trials (from 84 ITT trials, 118 mITT trials, and 108 no ITT trials; 12 trials contributed twice to the analysis) were examined. Compared with ITT trials, mITT trials showed a larger intervention effect (pooled ratio of odds ratios 0.83 (95% confidence interval 0.71 to 0.96), P=0.01; between meta-analyses variance τ(2)=0.13). Adjustments for sample size, type of centre, funding, items of risk of bias, post-randomisation exclusions, and variance of log odds ratio yielded consistent results (0.80 (0.69 to 0.94), P=0.005; τ(2)=0.08). After exclusion of five influential studies, results remained consistent (0.85 (0.75 to 0.98); τ(2)=0.08). The comparison between mITT trials and no ITT trials showed no statistical difference between the two groups (adjusted ratio of odds ratios 0.92 (0.70 to 1.23); τ(2)=0.57).

CONCLUSIONS

Trials that deviated from the intention to treat analysis showed larger intervention effects than trials that reported the standard approach. Where an intention to treat analysis is impossible to perform, authors should clearly report who is included in the analysis and attempt to perform multiple imputations.

Chemotherapy and targeted therapy for women with human epidermal growth factor receptor 2-negative (or unknown) advanced breast cancer: American Society of Clinical Oncology Clinical Practice Guideline

PURPOSE

To identify optimal chemo- and targeted therapy for women with human epidermal growth factor 2 (HER2)- negative (or unknown) advanced breast cancer.

METHODS

A systematic review of randomized evidence (including systematic reviews and meta-analyses) from 1993 through to current was completed. Outcomes of interest included survival, progression-free survival, response, quality of life, and adverse effects. Guideline recommendations were evidence based and were agreed on by the Expert Panel via consensus.

RESULTS

Seventy-nine studies met the inclusion criteria, comprising 20 systematic reviews and/or meta-analyses, 30 trials on first-line treatment, and 29 trials on second-line and subsequent treatment. These trials form the evidence base for the guideline recommendations.

RECOMMENDATIONS

Endocrine therapy is preferable to chemotherapy as first-line treatment for patients with estrogen receptor-positive metastatic breast cancer unless improvement is medically necessary (eg, immediately life-threatening disease). Single agent is preferable to combination chemotherapy, and longer planned duration improves outcome but must be balanced against toxicity. There is no single optimal first-line or subsequent line chemotherapy, and choice of treatment will be determined by multiple factors including prior therapy, toxicity, performance status, comorbid conditions, and patient preference. The role of bevacizumab remains controversial. Other targeted therapies have not so far been shown to enhance chemotherapy outcome in HER2-negative breast cancer.

Taxane chemotherapy treatment for metastatic breast cancer

SUMMARY The taxanes, paclitaxel, docetaxel and nab-paclitaxel, are among the most active cytotoxic agents for treatment of breast cancer. Significant progress has been made in addressing taxane dose and schedule in both early-stage and metastatic disease. Several studies have clarified the role of retreatment with taxanes in recurrent breast cancer patients previously treated with taxane-containing regimens. In addition, the advent of nab-paclitaxel, designed to reduce allergic reactions and enhance drug delivery to tumor cells, has provided additional therapeutic options. This article summarizes the uses of taxanes in the treatment of metastatic breast cancer.

Meta-analysis of phase III trials of docetaxel alone or in combination with chemotherapy in metastatic breast cancer

PURPOSE

Whether combination chemotherapy offers an advantage over sequential therapy in metastatic breast cancer (MBC) is still an unsettled issue. Polychemotherapy regimens containing taxanes has been shown to increase overall survival (OS), time to tumor progression (TTP), and overall response rate (ORR) when compared with regimens that did not contain a taxanes, while taxane-based doublets have a statistically significant benefit over single-agent taxane only for progression-free survival. However, the term "taxanes" generally includes both paclitaxel and docetaxel, drugs with different clinical activity. Aim of this work is to compare OS, TTP, and ORR in patients with MBC receiving docetaxel alone or in combination with chemotherapy using a formal meta-analysis.

METHODS

We performed a systematic review of all published trials comparing docetaxel alone or in combination with other chemotherapeutic agents in MBC.

RESULTS

Three randomized clinical trials including 1,313 patients were retrieved. A significant reduction of risk ratio was found in TTP (P ≤ 0.0001) but not in OS (P = 0.48) or ORR (P = 0.10) for patients treated with a chemotherapy agent plus docetaxel compared with docetaxel alone. Treatment with docetaxel alone is associated with a lower incidence of grade 3 diarrhea and stomatitis (diarrhea, P = 0.011; stomatitis, P = 0.0004).

CONCLUSION

Combination chemotherapy regimens with docetaxel show a statistically significant advantage for TTP, but not for OS and ORR in MBC. This review confirms that it is unlikely that any single agent or combination chemotherapy regimen will emerge as superior in MBC, due to its heterogeneous nature.