Paclitaxel-based versus docetaxel-based regimens in metastatic breast cancer: a systematic review and meta-analysis of randomized controlled trials

Comparison of paclitaxel and docetaxel in dual HER2 blockade: efficacy and safety in neoadjuvant treatment of HER2-positive breast cancer

BACKGROUND

Dual HER2 blockade with trastuzumab and pertuzumab combined with neoadjuvant chemotherapy improves outcomes in HER2-positive breast cancer. The optimal taxane backbone (paclitaxel vs. docetaxel) remains unclear.

METHODS

This retrospective study included 220 HER2-positive breast cancer patients treated with anthracycline-based chemotherapy followed by dual HER2 blockade with trastuzumab, pertuzumab, and either paclitaxel (80 mg/m2 for 12 weeks) or docetaxel (75 mg/m2 every three weeks for four cycles). Pathological complete response (pCR), disease-free survival (DFS), overall survival (OS), and toxicity profiles were analyzed.

RESULTS

At the time of diagnosis, 6% of the patients included in the study were at stage I, 70.4% were at stage II, and 23.6% were at stage III. The overall pCR rate was 55%, with no significant difference between the paclitaxel (57.9%) and docetaxel (52.2%) groups (p = 0.418). Higher pCR rates were associated with grade 3 tumors, ER/PR negativity, and Ki- 67 ≥ 20%. Patients achieving pCR had significantly lower relapse rates (2.5% vs. 16.2%, p < 0.001). These factors were significantly associated with pCR in univariate analysis but did not remain independent predictors in multivariate analysis. DFS and OS were higher in the paclitaxel group compared to the docetaxel group (DFS: 96.3% vs. 83.2%, p = 0.025; OS: 100% vs. 95.5%, p = 0.042). Grade 3-4 anemia was more frequent with docetaxel (23% vs. 9%, p = 0.007).

CONCLUSION

Both paclitaxel and docetaxel are effective in neoadjuvant dual HER2 blockade regimens. Paclitaxel demonstrated better DFS, OS, and a favorable safety profile, supporting its use as a preferred option.

DNA Damage Response in Early Breast Cancer: A Phase III Cohort in the Phobos Study

We assessed the impact of DNA damage response and repair (DDR) biomarker expressions in 222 node-positive early breast cancer (BC) patients from a previous Phase III GOIM 9902 trial of adjuvant taxanes. At a median follow-up of 64 months, the original study showed no disease-free survival (DFS) or overall survival (OS) differences with the addition of docetaxel (D) to epirubicine-cyclophosphamide (EC). Immunohistochemistry was employed to assess the expression of DDR phosphoproteins (pATM, pATR, pCHK1, γH2AX, pRPA32, and pWEE1) in tumor tissue, and their association with clinical outcomes was evaluated through the Cox elastic net model. Over an extended follow-up of 234 months, we confirmed no significant differences in DFS or OS between patients treated with EC and those receiving D → EC. A DDR risk score, inversely driven by ATM and ATR expression, emerged as an independent prognostic factor for both DFS (HR = 0.41, p < 0.0001) and OS (HR = 0.61, p = 0.046). Further validation in a public adjuvant BC cohort was possible only for ATM, confirming its protective role. Overall, our findings confirm the potential role of the DDR pathway in BC prognostication and in shaping treatment strategies advocating for an integrated approach, combining molecular markers with clinical-pathological factors.

Preparation of Erlotinib hydrochloride nanoparticles (anti-cancer drug) by RESS-C method and investigating the effective parameters

The size of the drug particles is one of the essential factors for the proper absorption of the drug compared to the dose of the drug. When particle size is decreased, drug uptake into the body increases. Recent studies have revealed that the rapid expansion of supercritical solution with cosolvent plays a significant role in preparing micron and submicron particles. This paper examines the preparation of Erlotinib hydrochloride nanoparticles using a supercritical solution through the cosolvent method for the first time. An examination of the parameters of temperature (318-338 K), pressures (15-25 MPa) and nozzle diameter (300-700 μm) was investigated by Box-Behnken design, and their respective effects on particle size revealed that the nozzle diameter has a more significant impact on particle size than the other parameters. The smallest particles were produced at temperature 338 K, pressure 20 MPa, and nozzle diameter 700 μm. Besides, the ERL nanoparticles were characterized using SEM, DLS, XRD, FTIR, and DSC analyses. Finally, the results showed that the average size of the ERL particles decreased from 31.6 μm to 200-1100 nm.

The Association Between Taxane Use and Lacrimal Disorders

PURPOSE

The current study seeks to investigate the association between lacrimal disorders and the use of docetaxel and paclitaxel.

METHODS

A disproportionality analysis was conducted using the United States FDA Adverse Event Reporting System (FAERS). All adverse event reports containing the term docetaxel or paclitaxel were selected. Lacrimal adverse events were identified using the lacrimal disorders Standardized MedDRA Query (SMQ), which includes disorders that affect lacrimal gland and drainage system including blockage of nasolacrimal duct, occlusion/stenosis of punctum, lacrimal gland neoplasms, and inflammations and infections.

RESULTS

The proportionate reporting ratio (PRR) comparing lacrimal events among docetaxel to paclitaxel users was 2.47 (95% CI, 2.03-3.02). With respect to specific lacrimal events, dacryostenosis (PRR 19.54 [95% CI, 7.19-53.13]), increased lacrimation (PRR 3.2 [95% CI, 2.42-4.23]), lacrimation disorder (p = 0.02), and xeropthalmia reports (p > 0.001) were significantly more common.

CONCLUSIONS

The growing body of epidemiologic, clinical, and pathophysiologic research supports the case that docetaxel leads to adverse lacrimal events in certain patients and should be taken into consideration when oncologists consider docetaxel vs. paclitaxel.

Long Noncoding RNAs in Taxane Resistance of Breast Cancer

Breast cancer is a common cancer in women and a leading cause of mortality. With the early diagnosis and development of therapeutic drugs, the prognosis of breast cancer has markedly improved. Chemotherapy is one of the predominant strategies for the treatment of breast cancer. Taxanes, including paclitaxel and docetaxel, are widely used in the treatment of breast cancer and remarkably decrease the risk of death and recurrence. However, taxane resistance caused by multiple factors significantly impacts the effect of the drug and leads to poor prognosis. Long noncoding RNAs (lncRNAs) have been shown to play a significant role in critical cellular processes, and a number of studies have illustrated that lncRNAs play vital roles in taxane resistance. In this review, we systematically summarize the mechanisms of taxane resistance in breast cancer and the functions of lncRNAs in taxane resistance in breast cancer. The findings provide insight into the role of lncRNAs in taxane resistance and suggest that lncRNAs may be used to develop therapeutic targets to prevent or reverse taxane resistance in patients with breast cancer.

RAD6 inhibition enhances paclitaxel sensitivity of triple negative breast cancer cells by aggravating mitotic spindle damage

Background

Paclitaxel (PTX), a first-line therapy for triple negative breast cancers (TNBC) induces anti-tumor activity by microtubule stabilization and inhibition of cell division. Its dose-limiting toxicity and short half-life, however, pose clinical challenges underscoring the need for strategies that increase its efficiency. RAD6, a E2 ubiquitin conjugating enzyme, is associated with centrosomes at all phases of cell cycle. Constitutive overexpression of the RAD6B homolog in normal breast cells induces centrosome amplification and multipolar spindle formation, indicating its importance in centrosome regulation.

Methods

TNBC centrosome numbers were scored by pericentrin immunostaining. PTX sensitivities and interactions with SMI#9, a RAD6-selective small molecule inhibitor, on TNBC cell survival were analyzed by MTT and colony forming assays and an isogenic MDA-MB-468 TNBC model of PTX resistance. The molecular mechanisms underlying PTX and SMI#9 induced cytotoxicity were determined by flow cytometry, immunoblot analysis of cyclin B1 and microtubule associated protein TAU, and dual immunofluorescence staining of TAU and α-tubulin.

Results

Our data show aberrant centrosome numbers and that PTX sensitivities are not correlated with TNBC BRCA1 status. Combining PTX with SMI#9 synergistically enhances PTX sensitivities of BRCA1 wild-type and mutant TNBC cells. Whereas SMI#9/PTX combination treatment increased cyclin B1 levels in MDA-MB-468 cells, it induced cyclin B1 loss in HCC1937 cells with accumulation of reproductively dead giant cells, a characteristic of mitotic catastrophe. Cell cycle analysis revealed drug-induced accumulation of tetraploid cells in S and G2/M phases, and robust increases in cells with 4 N DNA content in HCC1937 cells. TAU overexpression is associated with reduced PTX efficacy. Among the six TAU isoforms, both SMI#9 and PTX downregulated 1N3R TAU in MDA-MB-468 and HCC1937 cells, suggesting a common mechanism of 1N3R regulation. Dual TAU and α-tubulin immunostaining showed that SMI#9 induces monopolar mitotic spindles. Using the isogenic model of PTX resistance, we show that SMI#9 treatment restores PTX sensitivity.

Conclusions

These data support a common mechanism of microtubule regulation by SMI#9 and PTX and suggest that combining PTX with RAD6 inhibitor may be beneficial for increasing TNBC sensitivities to PTX and alleviating toxicity. This study demonstrates a new role for RAD6 in regulating microtubule dynamics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10119-z.

The Place of Chemotherapy in The Evolving Treatment Landscape for Patients With HR-positive/HER2-negative MBC

Endocrine therapy (ET) for the treatment of patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR-positive/HER2-negative) metastatic breast cancer (MBC) has changed markedly over recent years with the emergence of new ETs and the use of molecularly targeted agents. Cytotoxic chemotherapy continues, however, to have an important role in these patients and it is important to maximize its efficacy while minimizing toxicity to optimize outcomes. This review examines current HR-positive/HER2-negative MBC clinical guidelines and addresses key questions around the use of chemotherapy in the face of emerging therapeutic options. Specifically, the indications for chemotherapy in patients with HR-positive/HER2-negative MBC and the choice of optimal chemotherapy are discussed.

Impact of the COVID-19 Pandemic on Breast Cancer Management in Portugal: A Cross-Sectional Survey-Based Study of Medical Oncologists

INTRODUCTION

Cancer care providers have faced many challenges in delivering safe care for patients during the COVID-19 pandemic. This cross-sectional survey-based study investigated the impact of the pandemic on clinical practices of Portuguese medical oncologists caring for patients with breast cancer.

METHODS

An anonymous online survey comprising 42 questions gathered information regarding COVID-19 testing, treatment in (neo)adjuvant and metastatic settings, and other aspects of breast cancer management. Practices before and during the pandemic were compared, and potential differences in outcomes according to respondents' regions, case volumes, and practice type were explored.

RESULTS

Of 129 respondents, 108 worked in the public health system, giving a representative national picture of the impact of the COVID-19 pandemic on breast cancer management. Seventy-one percent of respondents reported a reduction in visits for new cases of breast cancer, and there was a shift towards increased use of telemedicine. Clinical decision-making was largely unaffected in the most aggressive indications (i.e., triple-negative, HER2-positive, visceral crisis). The use of neoadjuvant therapy increased when access to surgery was difficult, whereas dose-dense regimens decreased, and cyclin-dependent kinase 4/6 inhibitor treatment decreased for less aggressive disease and increased for more aggressive disease. The use of oral formulations and metronomic chemotherapy regimens increased, and clinical trial participation decreased. Some differences by respondents' region and case volume were noted.

CONCLUSION

Medical oncologists in Portugal implemented many changes during the COVID-19 pandemic, most of which were logical and reasonable responses to the current healthcare emergency; however, the true impact on patient outcomes remains unknown.

Patient preferences for breast cancer treatments: a discrete choice experiment in France, Ireland, Poland, Spain

Aim: To understand breast cancer patients' trade-offs when choosing treatments and to identify the most important treatment attributes which drive decisions. Materials & methods: A discrete choice experiment was conducted in France, Ireland, Poland and Spain. Progression-free survival, febrile neutropenia, pain, functional well-being and out-of-pocket payment were the treatment attributes. Results: 371 patients were willing to pay €6896 per year for 1 additional year of progression-free survival, €17,288 per year for perfect functional well-being and €15,138 for one pain-free year. Patients are willing to trade off progression-free survival months for better functional abilities and less pain. Conclusion: Patient preferences should be considered by regulatory agencies, reimbursement bodies, payors and clinicians for best treatment choices for the individuals.

A Meta-Analysis of the Efficacy of Albumin Paclitaxel versus Docetaxel in the Treatment of Breast Cancer

Objective

To use meta-analysis to systematically compare the efficacy and adverse reaction rates of albumin paclitaxel and docetaxel in the treatment of breast cancer.

Methods

This study included Chinese and English literature studies on clinical controlled studies of albumin paclitaxel and docetaxel in the treatment of breast cancer by searching CNKI, Weipu, Wanfang, PubMed, Embase, and Cochrane Library. Two researchers participated in the screening of the literature, used the inclusion and exclusion criteria as reference indicators, extracted relevant data, and used the software RevMan5.3 to conduct quality evaluation and meta-analysis of the literature.

Results

4 literature stuides were retrieved that met the inclusion criteria, with 243 study subjects. The included literature had a lower risk of bias. Meta-analysis results showed that compared with the docetaxel group, the protein paclitaxel group had significant differences in objective effective rate (ORR) (OR = 1.56, 95% CI (0.80, 3.03), P=0.19), complete remission (CR) (OR = 1.79, 95% CI (0.96, 3.35), P=0.07), partial remission (PR) (OR = 0.88, 95% CI (0.53, 1.47), P=0.62), nausea (OR = 0.87, 95% CI (0.51, 1.74), P=0.84), and vomiting (OR = 0.62, 95% CI (0.45, 1.78) P=0.76). The reason may be that the number of literatures included in this study is small or the sample size is insufficient. However, it had an advantage in the incidence of neutropenia (OR = 0.38, 95% CI (0.16, 0.88), P=0.02), and the difference between the two groups was statistically significant.

Conclusion

Albumin paclitaxel treatment can better reduce the incidence of neutropenia in breast cancer patients and is of great significance to the safety of breast cancer patients.

The Role of Non-Coding RNAs in Breast Cancer Drug Resistance

Breast cancer (BC) is one of the commonly occurring malignancies in females worldwide. Despite significant advances in therapeutics, the mortality and morbidity of BC still lead to low survival and poor prognosis due to the drug resistance. There are certain chemotherapeutic, endocrine, and target medicines often used for BC patients, including anthracyclines, taxanes, docetaxel, cisplatin, and fluorouracil. The drug resistance mechanisms of these medicines are complicated and have not been fully elucidated. It was reported that non-coding RNAs (ncRNAs), such as micro RNAs (miRNA), long-chain non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) performed key roles in regulating tumor development and mediating therapy resistance. However, the mechanism of these ncRNAs in BC chemotherapeutic, endocrine, and targeted drug resistance was different. This review aims to reveal the mechanism and potential functions of ncRNAs in BC drug resistance and to highlight the ncRNAs as a novel target for achieving improved treatment outcomes for BC patients.

Chemotherapeutic effects on breast tumor hemodynamics revealed by eigenspectra multispectral optoacoustic tomography (eMSOT)

Non-invasive monitoring of hemodynamic tumor responses to chemotherapy could provide unique insights into the development of therapeutic resistance and inform therapeutic decision-making in the clinic.

Methods: Here, we examined the longitudinal and dynamic effects of the common chemotherapeutic drug Taxotere on breast tumor (KPL-4) blood volume and oxygen saturation using eigenspectra multispectral optoacoustic tomography (eMSOT) imaging over a period of 41 days. Tumor vascular function was assessed by dynamic oxygen-enhanced eMSOT (OE-eMSOT). The obtained in vivo optoacoustic data were thoroughly validated by ex vivo cryoimaging and immunohistochemical staining against markers of vascularity and hypoxia.

Results: We provide the first preclinical evidence that prolonged treatment with Taxotere causes a significant drop in mean whole tumor oxygenation. Furthermore, application of OE-eMSOT showed a diminished vascular response in Taxotere-treated tumors and revealed the presence of static blood pools, indicating increased vascular permeability.

Conclusion: Our work has important translational implications and supports the feasibility of eMSOT imaging for non-invasive assessment of tumor microenvironmental responses to chemotherapy.

Use of Taxanes in Metastatic HER2-negative Breast Cancer - a Status Report

The most important goal of treatment of patients with metastatic breast cancer is maintenance or even improvement of quality of life. In this setting, chemotherapy should be used with as much restraint as possible. If palliative chemotherapy is indicated, the taxane drug class is an established treatment option. The updated guidelines of the Gynaecological Oncology Working Group (AGO), Breast Committee, of the German Society for Gynaecology and Obstetrics (DGGG) and the German Cancer Society e. V. (DKG) provide recommendations with the greatest possible evidence on which of the licensed taxanes can be used in which treatment situation in the metastatic setting.

Role of nab-paclitaxel in metastatic breast cancer: a meta-analysis of randomized clinical trials

Whether nab-paclitaxel and conventional taxanes are equally effective for metastatic breast cancer (MBC) remains unclear. We conducted meta-analysis of trials that compared nab-paclitaxel-based chemotherapy with solvent-based paclitaxel (sb-paclitaxel) and docetaxel-based chemotherapy. A literature search was performed to identify articles that compared nab-paclitaxel-based chemotherapy with sb-paclitaxel or docetaxel-based chemotherapy for MBC. Four randomized controlled trials (1,506 patients) were identified from 1,268 reports. We detected equivalent overall response, overall survival, and survival probability (one-year, two-year). Grade 3 to 4 hematological and non-hematological toxicities were also comparable except that sensory neuropathy was more prominent for nab-paclitaxel-based chemotherapy (16.9% vs. 10%, odds ratio = 1.89, 95% confidence interval = 1.36–2.61, P < 0.001). No significant publication bias was detected. Consistent results stratified by treatment arm, study phase, treatment line, and study location were observed, except that overall response rate to nab-paclitaxel-based chemotherapy was significantly higher in the subgroup of randomized phase II trials, non-first-line treatment, and East Asian population. This meta-analysis failed to demonstrate advantages of nab-paclitaxel compared with sb-paclitaxel and docetaxel in patients with MBC. The newer agent was associated with increased sensory neuropathy, equivalent survival, and possibly increased overall response for some specific patients.

Antitumor activity and safety profile of weekly carboplatin plus paclitaxel in metastatic breast cancer: a ten-year, monocentric, retrospective study

BACKGROUND

Taxanes are a mainstay in the treatment of metastatic breast cancer (mBC). Combination chemotherapy, including platinum-taxens doublets, can improve tumor responses and progression-free survival (PFS), but is associated with more toxicities and an uncertain benefit in terms of overall survival (OS).

METHODS

We performed a retrospective study on 274 consecutive patients with mBC treated at the Division of Medical Oncology of Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy, during the decade 2007-2016 with the combination of carboplatin AUC 2 plus paclitaxel 80 mg/m², both given on days 1 and 8 in every 21-day cycle.

RESULTS

264 patients were evaluable for treatment safety and activity. The objective response rate (ORR) was 44.7%. Median PFS and OS were 8.6 and 23.7 months, respectively. Triple-negative breast cancer (TNBC) patients had significantly lower PFS and OS times compared to other biology groups. At multivariable analysis, previous exposure to taxanes, HR-positive HER2-negative biology, a higher number of metastatic sites, and de novo metastatic disease at diagnosis were associated with reduced PFS, while receiving maintenance therapy correlated with improved PFS. Overall, the treatment was quite well tolerated, with 10.2% of patients discontinuing one or both drugs because of adverse events (AEs). G3-G4 neutropenia occurred in 16.8% of patients, while the incidence of febrile neutropenia was 2.3%.

CONCLUSIONS

Weekly carboplatin-paclitaxel regimen is active and well tolerated in mBC treatment. Prospective studies should be conducted to compare its efficacy and tolerability with standard single-agent paclitaxel or docetaxel treatment schedules, as well as with more recent combination regimens.

Micro-RNAs as Potential Predictors of Response to Breast Cancer Systemic Therapy: Future Clinical Implications

Despite advances in diagnosis and new treatments such as targeted therapies, breast cancer (BC) is still the most prevalent tumor in women worldwide and the leading cause of death. The principal obstacle for successful BC treatment is the acquired or de novo resistance of the tumors to the systemic therapy (chemotherapy, endocrine, and targeted therapies) that patients receive. In the era of personalized treatment, several studies have focused on the search for biomarkers capable of predicting the response to this therapy; microRNAs (miRNAs) stand out among these markers due to their broad spectrum or potential clinical applications. miRNAs are conserved small non-coding RNAs that act as negative regulators of gene expression playing an important role in several cellular processes, such as cell proliferation, autophagy, genomic stability, and apoptosis. We reviewed recent data that describe the role of miRNAs as potential predictors of response to systemic treatments in BC. Furthermore, upon analyzing the collected published information, we noticed that the overexpression of miR-155, miR-222, miR-125b, and miR-21 predicts the resistance to the most common systemic treatments; nonetheless, the function of these particular miRNAs must be carefully studied and further analyses are still necessary to increase knowledge about their role and future potential clinical uses in BC.

Mechanisms of breast cancer resistance to anthracyclines or taxanes: an overview of the proposed roles of noncoding RNA

PURPOSE OF REVIEW

Anthracyclines and taxanes are the two most active classes of cytotoxic agents that are commonly used for the treatment of breast cancer. However, resistance to these agents has become a major clinical obstacle. The aim of the present review is to define the roles of noncoding RNA (ncRNA) in breast cancer progression and the development of chemotherapy resistance. The ultimate goal is to exploit ncRNAs as new therapeutic tools to overcome resistance.

RECENT FINDINGS

Two important types of ncRNA include microRNA (miRNA) and long noncoding RNA (lncRNA). Both miRNA and lncRNA have recently impacted the field of breast cancer research as important pieces in the mechanistic puzzle of the genes and pathways involved in breast cancer development and progression.

SUMMARY

Herein, we review the roles of miRNA and lncRNA in breast cancer progression and the development of chemotherapy resistance. Future research should include identification of ncRNAs that could be potential therapeutic targets in chemotherapy-resistant tumors, as well as ncRNA biomarkers that facilitate more tumor-specific treatment options for chemotherapy-resistant breast cancer patients.

Dicer Elicits Paclitaxel Chemosensitization and Suppresses Cancer Stemness in Breast Cancer by Repressing AXL

Paclitaxel is a standard-of-care chemotherapy for breast cancer, despite the increasing recognition of its poor effectiveness in the treatment of patients with advanced disease. Here, we report that adenovirus-type 5 E1A-mediated elevation of the miRNA-processing enzyme Dicer is sufficient to enhance paclitaxel sensitization and reduce cancer stem-like cell properties in this setting. Elevating Dicer expression increased levels of the AXL kinase targeting miRNA miR-494, thereby repressing AXL expression to increase paclitaxel sensitivity. We found that Dicer expression was regulated at the transcription level by E1A, through activation of an MAPK14/CEBPα pathway. Our findings define a mechanism of E1A-mediated chemosensitization for paclitaxel, which is based upon the suppression of breast cancer stem-like cells, with potential implications for the diagnosis and treatment of breast cancer patients. Cancer Res; 76(13); 3916-28. ©2016 AACR.

Treatment regimens of classical and newer taxanes

The classical taxanes (paclitaxel, docetaxel), the newer taxane cabazitaxel and the nanoparticle-bound nab-paclitaxel are among the most widely used anticancer drugs. The taxanes share the characteristics of extensive hepatic metabolism and biliary excretion, the need for dose adaptation in patients with liver dysfunction, and a substantial pharmacokinetic variability even after taking into account known covariates. Data from clinical studies suggest that optimal scheduling of the taxanes is dependent not only on the specific taxane compound, but also on the tumor type and line of treatment. Still, the optimal dosing regimen (weekly vs 3 weekly) and optimal dose of the taxanes are controversial, as is the value of pharmacological personalization of taxane dosing. In this article, an overview is given on the pharmacological properties of the taxanes, including metabolism, pharmacokinetics-pharmacodynamics and aspects in the clinical use of taxanes. The latter includes the ongoing debate on the most active and safe regimen, the recommended initial dose and the issue of therapeutic drug dosing.

Chemotherapy for Metastatic Breast Cancer - An Anachronism in the Era of Personalised and Targeted Oncological Therapy?

Based on the findings of modern molecular biology, breast cancer is nowadays considered to be a heterogeneous disease. This leads to the objective of an individualised, more patient-oriented therapy. A series of target molecules for this purpose has already been identified. The principle of targeted oncological therapy was realised decades ago with the introduction of endocrine therapy for patients with hormone receptor-positive tumours. The modern therapy for HER2-positive tumours is a further example for the translation of targeted therapy into clinical routine. For patients with HER2-negative metastatic breast cancer, to date two targeted drugs, bevacizumab and everolimus, are available for routine clinical use. Many other substances are still undergoing clinical development. However, validated predictive markers to aid in therapeutic decision-making and therapy control are still lacking. Chemotherapy constitutes an effective palliative therapy with proven efficacy for the patients. In this process strategies have also been realised for a targeted therapy against tumour cells with the help of chemotherapeutic agents such as, for example, the intracellular activation of the prodrug capecitabine or the active albumin-mediated transport of nab-paclitaxel which leads to higher peri- and intratumoural enrichments. The continuing unchanged relevance of chemotherapy is often underestimated in the current discussions and will be comprehensively evaluated in this review.

Taxane-containing regimens for metastatic breast cancer

BACKGROUND

It is generally accepted that taxanes are among the most active chemotherapy agents in the management of metastatic breast cancer. This is an update of a Cochrane review first published in 2003.

OBJECTIVES

The objective of this review was to compare taxane-containing chemotherapy regimens with regimens not containing a taxane in the management of women with metastatic breast cancer.

SEARCH METHODS

In this review update, we searched the Cochrane Breast Cancer Group Specialised Register, MEDLINE, EMBASE, the World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP), and ClinicalTrials.gov on 14 February 2013 using keywords such as 'advanced breast cancer' and 'chemotherapy'. We searched reference lists of articles, contacted study authors, and did not apply any language restrictions.

SELECTION CRITERIA

Randomised controlled trials comparing taxane-containing chemotherapy regimens to regimens without taxanes in women with metastatic breast cancer. We included published and unpublished studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We derived hazard ratios (HRs) for overall survival, time to progression, and time to treatment failure where possible, and used a fixed-effect model for meta-analysis. We represented objective tumour response rates and toxicity as risk ratios (RRs). We extracted quality of life data where present.

MAIN RESULTS

This review included 28 studies. The updated analysis included 6871 randomised women, while the original review had 3643 women. Of the 28 included studies, we considered 19 studies to be at low risk of bias overall; however, some studies failed to report details on allocation concealment and methods of outcome assessment for those outcomes that are more likely to be influenced by a lack of blinding (for example tumour response rate). Studies varied in the taxane-containing chemotherapy backbone, and the comparator arms and were categorised into three groups: Regimen A plus taxane versus Regimen A (2 studies); Regimen A plus taxane versus Regimen B (14 studies); and single-agent taxane versus Regimen C (13 studies). Thirteen studies used paclitaxel, 14 studies used docetaxel, and 1 study allowed the investigator to decide on the type of taxane; the majority of studies delivered a taxane every 3 weeks. Twenty studies administered taxanes as first-line treatment, and 21 studies involved anthracycline naïve women in the metastatic setting. The combined HR for overall survival and time to progression favoured the taxane-containing regimens (HR 0.93, 95% confidence interval (CI) 0.88 to 0.99, P = 0.002, deaths = 4477; and HR 0.92, 95% CI 0.87 to 0.97, P = 0.002, estimated 5122 events, respectively) with moderate to substantial heterogeneity across trials. If the analyses were restricted to studies of first-line chemotherapy, this effect persisted for overall survival (HR 0.93, 95% CI 0.87 to 0.99, P = 0.03) but not for time to progression (HR 0.96, 95% CI 0.90 to 1.02, P = 0.22). Tumour response rates appeared to be better with taxane-containing chemotherapy in assessable women (RR 1.20, 95% CI 1.14 to 1.27, P < 0.00001) with substantial heterogeneity across studies. Taxanes were associated with an increased risk of neurotoxicity (RR 4.84, 95% CI 3.18 to 7.35, P < 0.00001, 24 studies) and hair loss (RR 2.37, 95% CI 1.45 to 3.87, P = 0.0006, 11 studies) but less nausea/vomiting compared to non-taxane-containing regimens (RR 0.62, 95% CI 0.46 to 0.83, P = 0.001, 26 studies). Leukopaenia and treatment-related death did not differ between the two groups (RR 1.07, 95% CI 0.97 to 1.17, P = 0.16, 28 studies; and RR 1.00, 95% CI 0.63 to 1.57, P = 0.99, 23 studies, respectively). For quality of life measures, none of the individual studies reported a difference in overall or any of quality of life subscales between taxane-containing and non-taxane chemotherapy regimens.

AUTHORS' CONCLUSIONS

Taxane-containing regimens appear to improve overall survival, time to progression, and tumour response rate in women with metastatic breast cancer. Taxanes are also associated with an increased risk of neurotoxicity but less nausea and vomiting compared to non-taxane-containing regimens. The considerable heterogeneity encountered across studies probably reflects the varying efficacy of the comparator regimens used in these studies and indicates that taxane-containing regimens are more effective than some, but not all, non-taxane-containing regimens.

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.

Systemic treatment approaches in her2-negative advanced breast cancer-guidance on the guidelines

Despite advancements in the treatment of early-stage breast cancer, many patients still develop disease recurrence; others present with de novo metastatic disease. For most patients with advanced breast cancer, the primary treatment intent is noncurative-that is, palliative-in nature. The goals of treatment should therefore focus on maximizing symptom control and extending survival. Treatments should be evaluated on an individualized basis in terms of evidence, but also with full respect for the wishes of the patient in terms of acceptable toxicity. Given the availability of extensive reviews on the roles of endocrine therapy and her2 (human epidermal growth factor receptor 2)-targeted therapies for advanced disease, we focus here mainly on treatment guidelines for the non-endocrine management of her2-negative advanced breast cancer in a Canadian health care context.

Metabolism of the taxanes including nab-paclitaxel

INTRODUCTION

The classical taxanes (paclitaxel, docetaxel), the newer taxane cabazitaxel and the nanoparticle-bound nab-paclitaxel are among the most widely used anticancer drugs. Despite years of research, the optimal dosing regimen (weekly vs 3-weekly) and optimal dose is still controversial, as is the value of pharmacological personalization of taxane dosing.

AREAS COVERED

This review provides an overview of the pharmacological properties of the taxanes, including metabolism, pharmacokinetics-pharmacodynamics and aspects in the clinical use of taxanes. The latter includes the ongoing debate on the most active and safe regimen (paclitaxel, docetaxel, nab-paclitaxel), the recommended initial dose (cabazitaxel) and pharmacological dosing individualization.

EXPERT OPINION

Taxanes share the characteristics of extensive hepatic metabolism and biliary excretion, the need for dose adaptation in patients with liver dysfunction, and substantial pharmacokinetic variability even after taking into account known covariates. Data from clinical studies suggest that optimal scheduling of the taxanes is dependent not only on the specific taxane compound, but also on the tumor type and line of treatment. Finally, treating oncologists should be aware of the substantial risk for drug-drug interactions that is a direct consequence of the complex hepatic metabolism of the taxanes.

Paclitaxel-based regimens as first-line treatment in advanced gastric cancer

The aim of this study was to evaluate the efficacy and safety of paclitaxel-based regimens as first-line treatments in advanced gastric cancer. We reviewed 397 previously untreated patients with advanced gastric cancer, who non-randomly received one of three paclitaxel-based regimens: paclitaxel plus fluorouracil/leucovorin (PF), paclitaxel plus oxaliplatin (PO), and paclitaxel plus oxaliplatin plus fluorouracil/leucovorin (POF) between January 2003 and December 2010. The PF, PO, and POF response rates were 47.13, 52.08, and 63.78%, respectively. Overall survivals (OS) were 11.2, 11.7, and 11.7 months, respectively. Progression-free survivals (PFS) were 6.6, 7.2, and 7.1 months, respectively. Leucopenia was higher on the triplet regimen than the doublet regimens. The paclitaxel-based regimens appeared to be effective in patients with advanced gastric cancer. The triplet regimen produced a higher response rate than either doublet regimen with more side effects, while survivals were similar among all three treatments.