Phase III study of gemcitabine plus docetaxel compared with capecitabine plus docetaxel for anthracycline-pretreated patients with metastatic breast cancer

Update on Classic and Novel Approaches in Metastatic Triple-Negative Breast Cancer Treatment: A Comprehensive Review

Triple-negative breast cancer (TNBC) accounts for almost 15% of all diagnosed breast cancers and often presents high rates of relapses and metastases, with generally poor prognosis despite multiple lines of treatment. Immunotherapy has radically changed the approach of clinicians towards TNBC in the last two to three years, even if targeted and specific therapeutic options are still missing; this unmet need is further justified by the extreme molecular and clinical heterogeneity of this subtype of breast cancer and by the weak response to both single-agent and combined therapies. In March 2023, the National Comprehensive Cancer Network (NCCN), the main association of cancer centers in the United States, released the last clinical practice guidelines, with an update on classic and novel approaches in the field of breast cancer. The purpose of this comprehensive review is to summarize the latest findings in the setting of metastatic TNBC treatment, focusing on each category of drugs approved by the Food and Drug Administration (FDA) and included in the NCCN guidelines. We also introduce part of the latest published studies, which have reported new and promising molecules able to specifically target some of the biomarkers involved in TNBC pathogenesis. We searched the PubMed and Scopus databases for free full texts reported in the literature of the last 5 years, using the words "triple-negative breast cancer" or "TNBC" or "basal-like". The articles were analyzed by the authors independently and double-blindly, and a total of 114 articles were included in the review.

Neoadjuvant docetaxel and capecitabine (TX) versus docetaxel and epirubicin (TE) for locally advanced or early her2-negative breast cancer: an open-label, randomized, multi-center, phase II Trial

PURPOSE

The combination of taxanes and anthracyclines is still the mainstay of chemotherapy for early breast cancer. Capecitabine is an active drug with a favorable toxicity profile, showing strong anti-tumor activity against metastatic breast cancer. This trial assessed the efficacy and safety of the TX regimen (docetaxel and capecitabine) and compared it with the TE (docetaxel and epirubicin) regimen in locally advanced or high risk early HER2-negative breast cancer.

PATIENTS AND METHODS

This randomized clinical trial was conducted at five academic centers in China. Eligible female patients were randomly assigned (1:1) to the TX (docetaxel 75 mg/m² d1 plus capecitabine 1000 mg/m² twice d1-14, q3w) or TE (docetaxel 75 mg/m² d1 plus epirubicin 75 mg/m² d1, q3w) groups for four cycles. The primary endpoint was a pathological complete response in the breast (pCR). Secondary endpoints included pCR in the breast and axilla, invasive disease-free survival (iDFS), overall survival (OS), and safety.

RESULTS

Between September 1, 2012, and December 31, 2018, 113 HER2-negative patients were randomly assigned to the study groups (TX: n = 54; TE: n = 59). In the primary endpoint analysis, 14 patients in the TX group achieved a pCR, and nine patients in the TE group achieved a pCR (25.9% vs. 15.3%), with a not significant difference of 10.6% (95% CI -6.0-27.3%; P = 0.241). In a subgroup with high Ki-67 score, TX increased the pCR rate by 24.2% (95% CI 2.2-46.1%; P = 0.029). At the end of the 69-month median follow-up period, both groups had equivalent iDFS and OS rates. TX was associated with a higher incidence of hand-foot syndrome and less alopecia, with a manageable toxicity profile.

CONCLUSION

The anthracycline-free TX regimen yielded comparable pCR and long-term survival rates to the TE regimen. Thus, this anthracycline-free regimen could be considered in selected patients.

TRIAL REGISTRATION

ACTRN12613000206729 on 21/02/2013, retrospectively registered.

The Present and Future of Clinical Management in Metastatic Breast Cancer

Regardless of the advances in our ability to detect early and treat breast cancer, it is still one of the common types of malignancy worldwide, with the majority of patients decease upon metastatic disease. Nevertheless, due to these advances, we have extensively characterized the drivers and molecular profiling of breast cancer and further dividing it into subtypes. These subgroups are based on immunohistological markers (Estrogen Receptor-ER; Progesterone Receptor-PR and Human Epidermal Growth Factor Receptor 2-HER-2) and transcriptomic signatures with distinct therapeutic approaches and regiments. These therapeutic approaches include targeted therapy (HER-2+), endocrine therapy (HR+) or chemotherapy (TNBC) with optional combination radiotherapy, depending on clinical stage. Technological and scientific advances in the identification of molecular pathways that contribute to therapy-resistance and establishment of metastatic disease, have provided the rationale for revolutionary targeted approaches against Cyclin-Dependent Kinases 4/6 (CDK4/6), PI3 Kinase (PI3K), Poly ADP Ribose Polymerase (PARP) and Programmed Death-Ligand 1 (PD-L1), among others. In this review, we focus on the comprehensive overview of epidemiology and current standard of care treatment of metastatic breast cancer, along with ongoing clinical trials. Towards this goal, we utilized available literature from PubMed and ongoing clinical trial information from clinicaltrials.gov to reflect the up to date and future treatment options for metastatic breast cancer.

Network meta-analysis of eribulin versus other chemotherapies used as second- or later-line treatment in locally advanced or metastatic breast cancer

BACKGROUND

Eribulin mesylate (ERI; Halaven®) is a microtubule inhibitor approved in the United States for metastatic breast cancer patients with at least two prior chemotherapy regimens for metastatic breast cancer, and in the European Union in locally advanced breast cancer or metastatic breast cancer patients who progressed after at least one chemotherapy for advanced disease. This network meta-analysis compared the efficacy and safety of ERI versus other chemotherapies in this setting.

METHODS

Systematic searches conducted in MEDLINE, Embase, and the Cochrane Central Register of Clinical Trials identified randomized controlled trials of locally advanced breast cancer/metastatic breast cancer chemotherapies in second- or later-line settings. Efficacy assessment included pre-specified subgroup analysis of breast cancer subtypes. Included studies were assessed for quality using the Centre for Reviews and Dissemination tool. Bayesian network meta-analysis estimated primary outcomes of overall survival and progression-free survival using fixed-effect models. Comparators included: capecitabine (CAP), gemcitabine (GEM), ixabepilone (IXA), utidelone (UTI), treatment by physician's choice (TPC), and vinorelbine (VIN).

RESULTS

The network meta-analysis included seven trials. Results showed that second- or later-line patients treated with ERI had statistically longer overall survival versus TPC (hazard ratio [HR]: 0.81; credible interval [CrI]: 0.66-0.99) or GEM+VIN (0.62; 0.42-0.90) and statistically longer progression-free survival versus TPC (0.76; 0.64-0.90), but statistically shorter progression-free survival versus CAP+IXA (1.40; 1.17-1.67) and CAP+UTI (1.61; 1.23-2.12). In triple negative breast cancer, ERI had statistically longer overall survival versus CAP (0.70; 0.54-0.90); no statistical differences in progression-free survival were observed in triple negative breast cancer.

CONCLUSIONS

This network meta-analysis suggests that ERI may provide an overall survival benefit in the overall locally advanced breast cancer/metastatic breast cancer populations and triple negative breast cancer subgroup compared to standard treatments. These findings support the use of ERI in second- or later-line treatment of patients with locally advanced breast cancer/metastatic breast cancer.

Capecitabine for hormone receptor-positive versus hormone receptor-negative breast cancer

BACKGROUND

Retrospective analyses suggest that capecitabine may carry superior activity in hormone receptor-positive relative to hormone receptor-negative metastatic breast cancer. This review examined the veracity of that finding and explored whether this differential activity extends to early breast cancer.

OBJECTIVES

To assess effects of chemotherapy regimens containing capecitabine compared with regimens not containing capecitabine for women with hormone receptor-positive versus hormone receptor-negative breast cancer across the three major treatment scenarios: neoadjuvant, adjuvant, metastatic.

SEARCH METHODS

On 4 June 2019, we searched the Cochrane Breast Cancer Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 5) in the Cochrane Library; MEDLINE; Embase; the World Health Organization International Clinical Trials Registry Platform; and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials looking at chemotherapy regimens containing capecitabine alone or in combination with other agents versus a control or similar regimen without capecitabine for treatment of breast cancer at any stage. The primary outcome measure for metastatic and adjuvant trials was overall survival (OS), and for neoadjuvant studies pathological complete response (pCR).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias and certainty of evidence using the GRADE approach. Hazard ratios (HRs) were derived for time-to-event outcomes, and odds ratios (ORs) for dichotomous outcomes, and meta-analysis was performed using a fixed-effect model.

MAIN RESULTS

We included 26 studies with outcome data by hormone receptor: 12 metastatic studies (n = 4325), 6 neoadjuvant trials (n = 3152), and 8 adjuvant studies (n = 13,457). Capecitabine treatment was added in several different ways across studies. These could be classified as capecitabine alone compared to another treatment, capecitabine substituted for part of the control chemotherapy, and capecitabine added to control chemotherapy. In the metastatic setting, the effect of capecitabine was heterogenous between hormone receptor-positive and -negative tumours. For OS, no difference between capecitabine-containing and non-capecitabine-containing regimens was observed for all participants taken together (HR 1.01, 95% confidence interval (CI) 0.98 to 1.05; 12 studies, 4325 participants; high-certainty evidence), for those with hormone receptor-positive disease (HR 0.93, 95% CI 0.84 to 1.04; 7 studies, 1834 participants; high-certainty evidence), and for those with hormone receptor-negative disease (HR 1.00, 95% CI 0.88 to 1.13; 8 studies, 1577 participants; high-certainty evidence). For progression-free survival (PFS), a small improvement was seen for all people (HR 0.89, 95% CI 0.82 to 0.96; 12 studies, 4325 participants; moderate-certainty evidence). This was largely accounted for by a moderate improvement in PFS for inclusion of capecitabine in hormone receptor-positive cancers (HR 0.82, 95% CI 0.73 to 0.91; 7 studies, 1594 participants; moderate-certainty evidence) compared to no difference in PFS for hormone receptor-negative cancers (HR 0.96, 95% CI 0.83 to 1.10; 7 studies, 1122 participants; moderate-certainty evidence). Quality of life was assessed in five studies; in general there did not seem to be differences in global health scores between the two treatment groups at around two years' follow-up. Neoadjuvant studies were highly variable in design, having been undertaken to test various experimental regimens using pathological complete response (pCR) as a surrogate for disease-free survival (DFS) and OS. Across all patients, capecitabine-containing regimens resulted in little difference in pCR in comparison to non-capecitabine-containing regimens (odds ratio (OR) 1.12, 95% CI 0.94 to 1.33; 6 studies, 3152 participants; high-certainty evidence). By subtype, no difference in pCR was observed for either hormone receptor-positive (OR 1.22, 95% CI 0.76 to 1.95; 4 studies, 964 participants; moderate-certainty evidence) or hormone receptor-negative tumours (OR 1.28, 95% CI 0.61 to 2.66; 4 studies, 646 participants; moderate-certainty evidence). Four studies with 2460 people reported longer-term outcomes: these investigators detected no difference in either DFS (HR 1.02, 95% CI 0.86 to 1.21; high-certainty evidence) or OS (HR 0.97, 95% CI 0.77 to 1.23; high-certainty evidence). In the adjuvant setting, a modest improvement in OS was observed across all participants (HR 0.89, 95% CI 0.81 to 0.98; 8 studies, 13,547 participants; moderate-certainty evidence), and no difference in OS was seen in hormone receptor-positive cancers (HR 0.86, 95% CI 0.68 to 1.09; 3 studies, 3683 participants), whereas OS improved in hormone receptor-negative cancers (HR 0.72, 95% CI 0.59 to 0.89; 5 studies, 3432 participants). No difference in DFS or relapse-free survival (RFS) was observed across all participants (HR 0.93, 95% CI 0.86 to 1.01; 8 studies, 13,457 participants; moderate-certainty evidence). As was observed for OS, no difference in DFS/RFS was seen in hormone receptor-positive cancers (HR 1.03, 95% CI 0.91 to 1.17; 5 studies, 5604 participants; moderate-certainty evidence), and improvements in DFS/RFS with inclusion of capecitabine were observed for hormone receptor-negative cancers (HR 0.74, 95% CI 0.64 to 0.86; 7 studies, 3307 participants; moderate-certainty evidence). Adverse effects were reported across all three scenarios. When grade 3 or 4 febrile neutropenia was considered, no difference was seen for capecitabine compared to non-capecitabine regimens in neoadjuvant studies (OR 1.31, 95% CI 0.97 to 1.77; 4 studies, 2890 participants; moderate-certainty evidence), and a marked reduction was seen for capecitabine in adjuvant studies (OR 0.55, 95% CI 0.47 to 0.64; 5 studies, 8086 participants; moderate-certainty evidence). There was an increase in diarrhoea and hand-foot syndrome in neoadjuvant (diarrhoea: OR 1.95, 95% CI 1.32 to 2.89; 3 studies, 2686 participants; hand-foot syndrome: OR 6.77, 95% CI 4.89 to 9.38; 5 studies, 3021 participants; both moderate-certainty evidence) and adjuvant trials (diarrhoea: OR 2.46, 95% CI 2.01 to 3.01; hand-foot syndrome: OR 13.60, 95% CI 10.65 to 17.37; 8 studies, 11,207 participants; moderate-certainty evidence for both outcomes).

AUTHORS' CONCLUSIONS

In summary, a moderate PFS benefit by including capecitabine was seen only in hormone receptor-positive cancers in metastatic studies. No benefit of capecitabine for pCR was noted overall or in hormone receptor subgroups when included in neoadjuvant therapy. In contrast, the addition of capecitabine in the adjuvant setting led to improved outcomes for OS and DFS in hormone receptor-negative cancer. Future studies should stratify by hormone receptor and triple-negative breast cancer (TNBC) status to clarify the differential effects of capecitabine in these subgroups across all treatment scenarios, to optimally guide capecitabine inclusion.

Efficacy and Safety of Capecitabine Alone or in Combination in Advanced Metastatic Breast Cancer Patients Previously Treated with Anthracycline and Taxane: A Systematic Review and Meta-Analysis

BACKGROUND

Capecitabine is frequently used alone or combined with other chemotherapy agents for the treatment of metastatic breast cancer in relapsed patients.

OBJECTIVE

The objective of this meta-analysis is to evaluate the effectiveness and safety of capecitabine monotherapy versus combination in the treatment of metastatic breast cancer patients pretreated with anthracycline and taxane.

METHODS

Eligible randomized controlled trials examining the efficacy and safety of capecitabine alone compared to capecitabine combination were systematically searched. Progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and grades 3-4 drug-related adverse events were the outcomes assessed.

RESULTS

A total of 6,714 patients of 9 trials were involved in the pooled analysis. Our findings demonstrated that capecitabine combination is significantly superior to capecitabine monotherapy in improving PFS (hazard ratio [HR] 1.32, 95% CI 1.13-1.54, p < 0.0001) and ORR (risk ratio [RR] 0.67, 95% CI 0.54-0.83, p < 0.001), but it was insignificant in OS (HR 1.09, 95% CI 0.98-1.22, p = 0.12). On the other hand, the incidence of non-hematological adverse events such as hand-foot syndrome and diarrhea was lower in capecitabine combination compared to capecitabine monotherapy.

CONCLUSION

Capecitabine-based combination chemotherapy showed superiority over capecitabine monotherapy in terms of PFS and ORR, with no significant difference in OS. Non-hematological adverse effects such as hand-foot syndrome were fewer with a combination regimen. However, hematological adverse events were fewer with capecitabine monotherapy regimen.

Quality of adverse event reporting in phase III randomized controlled trials of breast and colorectal cancer: A systematic review

BACKGROUND

Clinical trial reports often emphasize efficacy over harms, leading to misinterpretation of the risk-to-benefit ratio of new therapies. Clear and sufficiently detailed reporting of methods and results is especially important in the abstracts of trial reports, as readers often base their assessment of a trial on such information. In this study, we evaluated the quality of adverse event (AE) reporting and abstract quality in phase III randomized controlled trials (RCTs) of systemic therapies in breast and colorectal cancer.

METHODS

Medline, EMBASE, Cochrane Database of RCTs, and Cochrane Database of Systematic Reviews were searched from November 2005 to September 2018. Phase III RCTs evaluating systemic therapies in breast or colorectal cancer were included. Each article was independently reviewed by two investigators using a standardized data extraction form based on guidelines developed by the Consolidated Standards of Reporting Trials (CONSORT) group. Descriptive statistics, bivariate analysis, and multivariable linear regression were used to analyze data. All statistical tests were two-sided.

RESULTS

Of 166 RCTs identified, 99.4% reported harms in the manuscript body, and 59.6% reported harms in the abstract. Reporting was restricted to severe harms in 15.6% of RCTs. Statistical comparison of AE rates went unreported in 59.0% of studies. Information regarding AEs leading to dose reductions, treatment discontinuations, or study withdrawals went unreported in 59.3%, 18.7%, and 86.8% of studies, respectively. Recently published RCTs (P = .009) and those sponsored at least partially by for-profit companies (P = .003) had higher abstract quality scores.

CONCLUSIONS

Breast and colorectal cancer phase III RCTs inadequately report CONSORT-compliant AE data. Improved guideline adherence and abstract reporting is required to properly weigh benefits and harms of new oncologic therapies.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42019140673.

The evolving management of metastatic triple negative breast cancer

Advanced triple negative breast cancer (TNBC) is an incurable disease classified by its lack of expression of the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2. Due to its lack of therapeutic targets, it has historically been treated with single agent chemotherapy, with combination cytotoxic therapy typically reserved for patients with high disease burdens, symptomatic disease, and/or impending visceral crisis. Recent molecular analyses have revealed that this clinical group of TNBCs is in fact quite biologically heterogeneous, with multiple TNBC subtypes defined by distinct biology and clinical behavior. Building on this biology, 2 targeted strategies are now approved for selected patients with advanced TNBC: the poly (ADP-ribose) polymerase inhibitors for advanced TNBC with a germline mutation in BRCA1/2, and the combination of the programmed death ligand 1-specific antibody atezolizumab with nab-paclitaxel for advanced TNBC that expresses programmed death ligand 1 on immune cells within the tumor. These targeted agents tend to be associated with a more favorable side effect profile and longer disease control than standard chemotherapy. A number of other targeted therapies have shown promise in early clinical trials, and several are now in definitive phase 3 testing for advanced TNBC. These include the antiapoptotic kinase inhibitors ipatisertib and capivasertib, and the antibody-drug conjugate sacituzumab govitecan-hziy. Approved biomarker-driven treatment options for this disease are thus likely to expand in the near-term. Here we review current treatment options and emerging targeted therapies for advanced TNBC. For patients who do not meet criteria for approved targeted therapies, participation in clinical trials evaluating precision medicines with candidate predictive biomarkers in advanced TNBC should be encouraged.

A novel view of the separate and simultaneous binding effects of docetaxel and anastrozole with calf thymus DNA: Experimental and in silico approaches

DNA stands as the primary purpose of many anticancer drugs and according to the performed research on this field, some certain changes contain crucial functionalities in the regulated transcription of DNA. Therefore, the interaction between anticancer drugs and DNA play an important role in understanding their function and also provide a better groundwork for producing more efficient and newer drugs. Here, the interaction between Docetaxel (DO) and calf thymus DNA (ct DNA), in the presence and absence of Anastrozole (AN), has been examined through the usage of different methods that include isothermal titration calorimetry, multi-spectroscopic, viscometry, and molecular docking techniques. Interaction studies have been performed by preparing different molar ratios of DO with the constant ct DNA and AN concentration at pH = 6.8. The binding constants have been calculated to be 7.93 × 10⁴ M^-1 and 6.27 × 10⁴ M^-1, which indicate the strong binding of DO with ct DNA double helix in the absence and presence of AN, respectively. Thermodynamic parameters, which were obtained from fluorescence spectroscopy and isothermal titration calorimetry, have suggested that the binding of DO and AN to ct DNA as binary and ternary systems have been mainly driven by the electrostatic interactions. The relative viscosity of ct DNA has increased upon the addition of DO and AN, which confirms the interaction mode. A competitive binding study has reported that the enhanced emission intensity of ethidium bromide (EB) and acridine orange (AO), in the presence of ct DNA, have been quenched through the addition of DO and Anastrozole as binary and ternary systems. As it is indicated by these findings, DO is capable of displacing EB and AO from their binding site in ct DNA; hence, it can be concluded that DO and AN are able to intercalate into the base pairs of ct DNA in binary and ternary systems. Molecular docking studies have corroborated the mentioned experimental results.

The Multifunction Of miR-218-5p-Cx43 Axis In Breast Cancer

Background

Gemcitabine is proven to be the first-line standard treatment of breast cancers. Yet, little is known involving gemcitabine resistance and remains largely to be elucidated.

Materials and methods

We evaluated the expression of Cx43 in gemcitabine-resistant cells and parental cells by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analyses. Dual-luciferase reporter assay was applied to examine the epigenetic regulator of Cx43. The role of miR-218-5p-Cx43 axis on cell cytotoxicity, cell proliferation, colony formation, chemoresistance and migration was detected via mammalian expression vector and small short RNA (shRNA) transfection in vitro.

Results

In this study, we found that Cx43 expression levels were significantly lower in gemcitabine-resistant cells than in the parental cells. On deep investigation of the epigenetic regulation of Cx43, a few miRNA candidates targeting Cx43 were derived. Through dual-luciferase reporter assay, Cx43 was proved to be a direct target of miR-218-5p. Besides, qPCR, Western blot demonstrated an inverse correlation between miR-218-5p and Cx43 expression in breast cancer cells, thus forming the miR-218-5p-Cx43 axis. Notably, miR-218-5p-Cx43 axis was found to be involved in the process of gemcitabine chemoresistance, cell proliferation and migration in breast cancer cells.

Conclusion

Our findings suggested that miR-218-5p-Cx43 axis was versatile and indicated significant potency in breast cancer cells. More importantly, miR-218-5p-Cx43 axis might be valuable in translational medicine, with therapeutic and prognostic information.

Statistical analysis of patient-reported outcome data in randomised controlled trials of locally advanced and metastatic breast cancer: a systematic review

Although patient-reported outcomes (PROs), such as health-related quality of life, are important endpoints in randomised controlled trials (RCTs), there is little consensus about the analysis, interpretation, and reporting of these data. We did a systematic review to assess the variability, quality, and standards of PRO data analyses in advanced breast cancer RCTs. We searched PubMed for English language articles published in peer-reviewed journals between Jan 1, 2001, and Oct 30, 2017. Eligible articles were those that reported PRO results from RCTs of adult patients with advanced breast cancer receiving anti-cancer treatments with reported sample sizes of at least 50 patients-66 RCTs met the selection criteria. Only eight (12%) RCTs reported a specific PRO research hypothesis. Heterogeneity in the statistical methods used to assess PRO data was observed, with a mixture of longitudinal and cross-sectional techniques. Not all articles addressed the problem of multiple testing. Fewer than half of RCTs (28 [42%]) reported the clinical significance of their findings. 48 (73%) did not report how missing data were handled. Our systematic review shows a need to improve standards in the analysis, interpretation, and reporting of PRO data in cancer RCTs. Lack of standardisation makes it difficult to draw robust conclusions and compare findings across trials. The Setting International Standards in the Analyzing Patient-Reported Outcomes and Quality of Life Data Consortium was set up to address this need and develop recommendations on the analysis of PRO data in RCTs.

An update on the currently available and future chemotherapy for treating bone metastases in breast cancer patients

INTRODUCTION

Bone metastases in breast cancer patients are a common clinical problem. Many factors influence the treatment decision, including tumor characteristics, previous treatment and tumor burden in the treatment of metastatic breast cancer.

AREAS COVERED

This present review summarizes the new treatment strategies and the chemotherapeutic agents currently available in the management of metastatic breast cancer with bone metastases.

EXPERT OPINION

Patients with bone metastases more often have hormone receptor-positive tumours. Although new treatment agents for metastatic breast cancer have been investigated, endocrine therapy is still considered as the treatment of choice for patients with bone metastases although chemotherapy still has an important place. In recent years, new chemotherapeutic agents such as etirinotecan and nab-paclitaxel have been established though there are few studies that have looked at particular types of metastases. In the last decade, therapies for bone metastasis resistant to endocrine therapy have predominantly focused on radiotherapy, surgical resection, chemotherapy, bone-targeting radiopharmaceuticals and targeted therapeutics. New targeted agents include: Src inhibitors, cathepsin K inhibitors, CXCR4 inhibitors, TGF-B blockade and integrin antagonists while drug delivery systems for chemotherapy have also been developed. These new treatment options could be future treatment options for bone metastatic disease if early promising results are confirmed by clinical trials.

PEGylated lipid microspheres loaded with cabazitaxel for intravenous administration: stability, bioavailability, antitumor efficacy, and toxicity

This paper aimed to develop a novel lipid microsphere delivering cabazitaxel (CTX) using phosphatidylcholine combined with DSPE-PEG2000 as emulsifier, and evaluate its stability, pharmacokinetics, antitumor efficacy, and toxicity. The pegylated cabazitaxel-loaded lipid microspheres (CTX-PLMs) were prepared by high-pressure homogenization methods; the biological samples were analyzed by the UPLC-MS/MS method. CTX-PLMs had a drug concentration of 1.2 mg/ml and a mean particle size of 180.0 ± 51.119 nm. CTX-PLMs showed a superior physical stability as it could remain nearly intact after 1-year storage. The AUC_0-t of the CTX-PLMs was 1562.6 ± 520.1 μg h L^-1 compared with the CTX-solution of 860.734 ± 312.4 μg h L^-1. CTX-PLMs exhibited a strong antitumor efficacy against NCI-N87 and DU145 tumor models with tumor growth inhibition rates of 93.5 and 88.5%, respectively. The LD50 of CTX-PLMs in rats was 20.89 mg/kg. As for the long-term toxicity, the thymus, mesenteric lymph nodes, and bone marrow were the main toxic target organs and systemic toxicity induced by CTX-PLMs was alleviated relative to that of the CTX-solution. Safety assessment studies including hemolysis test, dermal sensitization test, systemic anaphylaxis, and vascular stimulation test indicated that CTX-PLMs is safe enough for intravenous administration. In a word, CTX-PLMs are a promising carrier for intravenous administration with satisfactory stability, stronger tumor inhibition, and superior safety profile.

Implication of linker length on cell cytotoxicity, pharmacokinetic and toxicity profile of gemcitabine-docetaxel combinatorial dual drug conjugate

The present study investigates effect of linkers [zero length (without linker), short length linker (glycine and lysine) and long length linker (PEG1000, PEG2000 and PEG3500)] on pharmacokinetics and toxicity of docetaxel (DTX) and gemcitabine (GEM) bio-conjugates. Conjugates were synthesized via carbodiimide chemistry and characterized by ¹H NMR and FTIR. Conjugation of DTX and GEM via linkers showed diverse physiochemical and plasma stability profile. Cellular uptake mechanism in MCF-7 and MDA-MB-231 cell lines revealed clathrin mediated internalization of bio-conjugates developed by using long length linkers, leading to higher cytotoxicity compared with free drug congeners. DTX-PEG3500-GEM and DTX-PEG2000-GEM demonstrated 4.21 and 3.81-fold higher AUC_(0-∞) of GEM in comparison with GEM alone. DTX-PEG2000-GEM and DTX-PEG3500-GEM exhibited reduced hepato-, nephro- and haemolytic toxicity as evident via histopathology, biochemical markers and SEM analysis of RBCs. Conclusively, PEG2000 and PEG3500 significantly improved pharmacokinetics without any sign of toxicity and hence can be explored further for the development of dual-drug conjugates for better therapeutic efficacy.

A phase II study of tipifarnib and gemcitabine in metastatic breast cancer

Background Tipifarnib is an orally active, competitive inhibitor of farnesyltransferase which has shown encouraging signs of activity either alone or when combined with other agents. Clinical studies of tipifarnib in combination with anti-estrogen therapy have yielded disappointing results. In contrast, tipifarnib appears to be synergistic in combination with anthracycline based chemotherapy. Here we report the results of the first prospective phase II trial evaluating the efficacy of the novel combination of tipifarnib and gemcitabine in the treatment of metastatic breast cancer. Patients and Methods 30 postmenopausal women with metastatic breast cancer were treated on a 21-day cycle with tipifarnib 300 mg PO twice daily from days 1 through 14. Gemcitabine was administered intravenously at a dose of 1000 mg/m² on days 1 and 8. Patients were treated until disease progression or unacceptable toxicity. Results There was one complete response and four partial responses yielding an objective response rate of 16.7%. Median progression-free survival and overall survival was 2.5 months (95% confidence interval: 1.6-5.7 months) and 13.1 months (95% confidence interval: 9.1-20.6 months), respectively. 40% of patients experienced grade 4 neutropenia in this study. Conclusion The combination of tipifarnib and gemcitabine is not well tolerated with high rates of myelosuppression and is not more effective than gemcitabine monotherapy in the treatment of metastatic breast cancer.

Gemcitabine-based chemotherapy as a viable option for treatment of advanced breast cancer patients: a meta-analysis and literature review

This meta-analysis was designed to compare the efficacy and safety of gemcitabine-based regimens for the treatment advanced breast cancer (ABC). Altogether 15 studies involving 8195 ABC patients were retrieved for analysis. Compared with non-gemcitabine-based chemotherapies, patients receiving gemcitabine-based therapy exhibited better overall survival (OS), progression free survival (PFS), and objective response rate (ORR) (HR = 1.12, 95% CI 1.05 to 1.19; HR = 1.16, 95% CI 1.03 to 1.30; HR = 1.14, 95% CI 1.04 to 1.24). Grade 3/4 hematologic toxicity was significantly high but manageable in gemcitabine-based groups. Subgroup analysis revealed that patients with first-line gemcitabine-based chemotherapy had better OS (HR = 1.19, 95% CI 1.07 to 1.32), PFS (HR = 1.17, 95% CI 1.08 to 1.27), and ORR (RR = 1.16, 95% CI 1.02 to 1.32). In addition, additional gemcitabine chemotherapy also showed better OS (HR = 1.17, 95% CI 1.06 to 1.30), PFS (HR = 1.20, 95% CI 1.11 to 1.30) and ORR (RR = 1.23, 95% CI 1.06 to 1.42) than gemcitabine replacement therapy. Furthermore, patients receiving gemcitabine-taxanes-based regimens had better OS (HR = 1.17, 95% CI 1.06 to 1.28), PFS (HR = 1.12, 95% CI 1.04 to 1.20) and ORR (RR = 1.17, 95% CI 1.01 to 1.35) than patients with non-gemcitabine-taxanes-based chemotherapy. These findings indicate that gemcitabine combination regimens could serve as a promising regimen for ABC patients, though increased hematologic toxicity should be considered with caution.

Combination of using prodrug-modified cationic liposome nanocomplexes and a potentiating strategy via targeted co-delivery of gemcitabine and docetaxel for CD44-overexpressed triple negative breast cancer therapy

In this study, novel prodrug-modified cationic liposome nanocomplexes (Combo NCs) were reported for gemcitabine (GEM) and docetaxel (DTX) co-delivery. This nanoplatform exhibited multiple favorable characteristics, such as a 'green' fabrication with a one-step chemical reaction, appropriate size (∼200nm) and distribution (PDI<0.2), low zeta potential (-31.1mv), high drug-loading efficiency (9.3% GEM plus 3.1% DTX, wt%) and pH and enzymatic dual-stimulus-responsive release properties. Immunofluorescence and cellular uptake studies showed that Combo NCs efficiently targeted overexpressed CD44 in MDA-MB-231 carcinoma. In vitro studies revealed that Combo NCs played a critical role in the synergistic induction of cytotoxicity, apoptosis and inhibition of wound healing. Combo NCs were confirmed to exhibit great potency for increasing S phase arrest and remodeling the CDA and dCK balance by decreasing the mRNA expression of CDA down to 0.09-fold and increasing the mRNA expression of dCK by 1.36-fold, remarkably increasing the dCK/CDA ratio to 15.3-fold compared with the blank control. The biodistribution results obtained in vivo revealed an effective accumulation in tumor foci. All of these advantages of Combo NCs contributed to their remarkable anti-tumor efficacy without systemic toxicity as well as their apoptosis-enhancing and anti-proliferative capacities, as determined by TUNEL and Ki67 immunohistochemistry in vivo. Consequently, such a rationally contemplated co-delivery system demonstrated the promising potential of clinical applications for triple-negative breast cancer therapy.

STATE OF SIGNIFICANCE

The Combo NCs were innovatively applied for co-delivery of hydrophilic GEM and hydrophobic DTX. The ester bond linking and shielding effect of HA-GEM made the carriers achieve synchronous release properties, which was determined in in vitro release study. Due to the HA modification, the vectors own great potency for positive targeting to CD44 overexpressed triple-negative breast cancer cells MDA-MB-231. Cytotoxicity and apoptosis studies confirmed the targeting effect and synergism between two drugs. Interestingly, we found in cell cycle study, drug combinations (free combination or Combo NCs) didn't show a rise in G2M phase, which was significantly higher when treated DTX alone. We further discovered the role of DTX in combinations may involve in modulating GEM associated enzymes thus enhancing the efficacy of GEM. Consequently, this nanoplatform provided a novel solution for achieving targeted co-delivery and potentiating effect in cancer therapy.

Drug delivery approaches for breast cancer

Breast cancer is one of the most common cancers affecting women worldwide. The controlled release of drugs to the precise site of the disease using a nanocarrier vehicle increases the therapeutic efficiency of the drugs. Nanotechnology-based approaches used to endorse clinical improvement from a disease also help to understand the interaction of malignant cells with their microenvironment. Receptor-based targeting is another approach for drug delivery which is undergoing clinical trials. Nanoparticles (NPs) delivery has been proven to promise high loading capacity, less toxicity, and stability of the drugs or biomolecules compared to traditional chemotherapeutic drugs. The goal of this review is to present the current problems of breast cancer therapy and discuss the NP-based targeting to overcome the hurdles of conventional drug therapy approach.

Clinical pharmacology and clinical trials of ribonucleotide reductase inhibitors: is it a viable cancer therapy?

PURPOSE

Ribonucleotide reductase (RR) enzymes (RR1 and RR2) play an important role in the reduction of ribonucleotides to deoxyribonucleotides which is involved in DNA replication and repair. Augmented RR activity has been ascribed to uncontrolled cell growth and tumorigenic transformation.

METHODS

This review mainly focuses on several biological and chemical RR inhibitors (e.g., siRNA, GTI-2040, GTI-2501, triapine, gemcitabine, and clofarabine) that have been evaluated in clinical trials with promising anticancer activity from 1960's till 2016. A summary on whether their monotherapy or combination is still effective for further use is discussed.

RESULTS

Among the RR2 inhibitors evaluated, GTI-2040, siRNA, gallium nitrate and didox were more efficacious as a monotherapy, whereas triapine was found to be more efficacious as combination agent. Hydroxyurea is currently used more in combination therapy, even though it is efficacious as a monotherapy. Gallium nitrate showed mixed results in combination therapy, while the combination activity of didox is yet to be evaluated. RR1 inhibitors that have long been used in chemotherapy such as gemcitabine, cladribine, fludarabine and clofarabine are currently used mostly as a combination therapy, but are equally efficacious as a monotherapy, except tezacitabine which did not progress beyond phase I trials.

CONCLUSIONS

Based on the results of clinical trials, we conclude that RR inhibitors are viable treatment options, either as a monotherapy or as a combination in cancer chemotherapy. With the recent advances made in cancer biology, further development of RR inhibitors with improved efficacy and reduced toxicity is possible for treatment of variety of cancers.

Capecitabine in Combination with Docetaxel in First Line in HER2-Negative Metastatic Breast Cancer: an Observational Study

Due to the limited experience with capecitabine plus docetaxel (XT) combination in the first-line treatment of metastatic breast cancer in Hungary, the main objective of the study was to analyze the effectiveness and tolerability of XT therapy. A prospective, open-label, non-randomized, single-arm, multicenter, observational study was designed. All female patients were eligible whose metastatic breast cancer could be treated with the XT protocol according to the summary of product characteristics of the drugs. The median progression free survival was 9.9 ± 3.0 months. Time to treatment failure was 4.6 ± 5.1 months on average. The overall response rate was 28.9 %, the clinical benefit rate was 73.3 %. The treatment was discontinued in 35.6 % of patients due to disease progression and in 20.0 % due to adverse events (AE). 33 patients with a total of 73 AEs have been reported, and 13 of them had serious adverse events (SAE). The efficacy and the safety profile of XT chemotherapy proven in the study are consistent with the results demonstrated in randomized trials. First-line XT chemotherapy effectively improves the PFS in metastatic breast cancer.

A Review of Systemic Treatment in Metastatic Triple-Negative Breast Cancer

Patients with breast cancer along with metastatic estrogen and progesterone receptor (ER/PR)- and human epidermal growth factor receptor 2 (HER2)-negative tumors are referred to as having metastatic triple-negative breast cancer (mTNBC) disease. Although there have been many new treatment options approved by the Food and Drug Administration for ER/PR-positive and Her2/neu-amplified metastatic breast cancer, relatively few new agents have been approved for patients with mTNBC. There have been several head-to-head chemotherapy trials performed within the metastatic setting, and much of what is applied in clinical practice is extrapolated from chemotherapy trials in the adjuvant setting, with taxanes and anthracyclines incorporated early on in the patient's treatment course. Select synergistic combinations can produce faster and more significant response rates compared with monotherapy and are typically used in the setting of visceral threat or symptomatic disease. Preclinical studies have implicated other possible targets and mechanisms in mTNBC. Ongoing clinical trials are underway assessing new chemotherapeutic strategies and agents, including targeted therapy and immunotherapy. In this review, we evaluate the standard systemic and future treatment options in mTNBC.

The prognostic values of CYP2B6 genetic polymorphisms and metastatic sites for advanced breast cancer patients treated with docetaxel and thiotepa

This study investigated interactive effects of CYP2B6 genotypes and liver metastasis on the prognosis of metastatic breast cancer patients who received combined chemotherapy of docetaxel and thiotepa. Totally 153 patients were retrospectively genotyped rs8192719 (c.1294 + 53C > T) and rs2279343 (c.785A > G). Kaplan-Meier method and Cox Proportional Hazard Regression model were used to estimate the survival. Patients with liver metastasis had worsen prognosis, conferring a 2.26-fold high risk of progression and 1.93-fold high risk of death (p < 0.05). Both CT/TT genotype of rs8192719 (c.1294 +  3C > T) and AG genotype of rs2279343 (c.785A > G) prolonged survival (p < 0.05). Furthermore, among liver metastatic patients, AG genotype of rs2279343 (c.785A > G) was associated with a 47% reduced risk of death and a 6-month-longer overall survival (p < 0.05). Among non-liver metastatic patients, hazard ratios of CT/TT genotype of rs8192719 (c.1294 + 53C > T) were 0.45 for progression and 0.40 for death; and the corresponding survival was improved by 6 months and 16 months, respectively (p < 0.05). Genotypes of CYP2B6 had an interaction with clinical efficacy of docetaxel and thiotepa on metastatic breast cancer patients; and metastatic sites also affected clinical responses. Further therapies should take into account of chemotherapy regimen, genotypes of metabolizing enzymes and metastatic sites for the particular subpopulation.

Efficacy and safety of capecitabine-based first-line chemotherapy in advanced or metastatic breast cancer: a meta-analysis of randomised controlled trials

We sought to evaluate the efficacy and safety of capecitabine-based therapy as first-line chemotherapy in advanced breast cancer. Randomised controlled trials of capecitabine monotherapy or combined treatment were included in the meta-analysis. PubMed, EMBASE, the Cochrane Library database and important meeting summaries were searched systematically. Outcomes were progression-free survival (PFS), overall survival (OS), overall response rate (ORR) and grades 3-4 drug-related adverse events.Nine trials with 1798 patients were included. The results indicated a significant improvement with capecitabine-based chemotherapy compared with capecitabine-free chemotherapy in ORR (relative risk [RR] 1.14, 95% confidence interval [CI] 1.03 to 1.26, P = 0.013) and PFS (hazard ratio [HR] 0.77, 95% CI 0.69 to 0.87, P < 0.0001). Overall survival favoured capecitabine-based chemotherapy, but this was not significant. There were more incidences of neutropenia and neutropenic fever in the capecitabine-free chemotherapy group and more vomiting, diarrhoea and hand-foot syndrome in the capecitabine-based chemotherapy group. There were no significant differences in nausea, fatigue, cardiotoxicity or mucositis/stomatitis between the two treatment regimens.Capecitabine-based chemotherapy significantly improves ORR and PFS in patients with advanced breast cancer, but has no demonstrable impact on OS. Capecitabine-based regimens are suitable as first-line treatment for patients with advanced breast cancer.

Phase I dose-escalation study of cabazitaxel administered in combination with gemcitabine in patients with metastatic or unresectable advanced solid malignancies

Supplemental Digital Content is available in the text.

Taxane–gemcitabine combinations have demonstrated antitumor activity. This phase I study (NCT01001221) aimed to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of cabazitaxel plus gemcitabine and to assess the preliminary efficacy of this combination. The patients included had metastatic or unresectable solid tumors and had exhausted standard treatment. Cohorts of three to six patients received cabazitaxel (15–20 mg/m²) before (part 1a) or after (part 1b) gemcitabine (700–1000 mg/m²) on Day 1 and gemcitabine alone on Day 8. Prophylactic growth factors were not allowed in cycle 1. In part 1a (n=12), five patients received 20 mg/m² cabazitaxel plus 1000 mg/m² gemcitabine (20/1000), five received 15/900, two received 15/700. In part 1b, all six patients received the lowest dose (700/15). At all doses, two or more patients experienced a DLT, regardless of administration sequence, including febrile neutropenia (n=4), grade 4 neutropenia (n=2), grade 4 thrombocytopenia (n=2), and grade 3 aspartate transaminase increase (n=1). The MTD was not established as all cohorts exceeded the MTD by definition. All patients experienced an adverse event; the most frequent all-grade nonhematologic events were fatigue (66.7%), decreased appetite (50.0%), and diarrhea (44.4%). The most frequent grade 3–4 hematologic abnormalities were neutropenia (83.3%), leukopenia (77.8%), and lymphopenia (72.2%). Toxicity was sequence-independent but appeared worse with gemcitabine followed by cabazitaxel. Durable partial responses were observed in three patients (prostate cancer, appendiceal cancer, and melanoma). The unacceptable DLTs with cabazitaxel plus gemcitabine, at doses reduced more than 25% from single-agent doses, preclude further investigation.

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.

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.

Liver kinase B1 enhances chemoresistance to gemcitabine in breast cancer MDA-MB-231 cells

Liver kinase B1 (LKB1) is a well-known tumor suppressor gene in a variety of human cancers, including breast cancer. However, its role in gemcitabine resistance is unclear. Since gemcitabine in combination with other chemotherapeutic reagents is the first-line treatment in advanced breast cancer, the aim of the present study was to determine the effect of ectopic expression of LKB1 on chemosensitivity to gemcitabine in the breast cancer MDA-MB-231 cell line. Increasing the expression of LKB1 was found to directly correlate with gemcitabine chemoresistance. Although LKB1 suppressed the cell proliferation rate and clonogenicity in the absence of gemcitabine, it increased the median inhibitory concentration of gemcitabine and clonogenicity of cells in the presence of gemcitabine. Mechanistic analysis indicated that LKB1 was able to protect cells from DNA damage caused by gemcitabine. Furthermore, it was found that LKB1 induced a significant upregulation of cytidine deaminase expression, an important enzyme that accelerates gemcitabine catabolization. Overall, dual characteristics of LKB1 were identified: Suppressing cell growth in normal conditions and enhancing chemoresisitance to gemcitabine, possibly by accelerating degradation of gemcitabine, and protecting cells from DNA damage caused by gemcitabine.

A systematic review of gemcitabine and taxanes combination therapy randomized trials for metastatic breast cancer

Purpose

Gemcitabine/taxanes-based combination shows anti-tumor activity for the treatment of metastatic breast cancer, but there is a debate regarding the advantages of gemcitabine and taxanes regimens as a first-line or second-line treatment for metastatic breast cancer. Here we conducted a systematic review and meta-analysis to compare the efficacy and toxicity for patients receiving chemotherapy with or without GT-based regimens.

Methods

The randomized controlled trials were performed by searching Pubmed, MEDLINE, EMBASE, and conference proceedings. We identified eight randomized controlled trials and then extracted and combined the data using to calculate hazard ratios (HR). The primary outcomes were progression-free survival (PFS) and time to progression (TTP). The secondary outcomes were overall survival (OS) and acute toxicity. A meta-analysis was performed using Review Manager Version 4.2.

Results

Eight eligible trails were identified. These studies involved 2234 patients with metastatic breast cancer, (1122 patients received GT-based combination regimen and 1112 patients received a regimen without the combination). A fixed-effects model meta-analysis showed that ORR and TTP are superior for GT-treated patients ORR (OR = 1.28, 95% CI 1.07-1.53), TTP (HR = 0.80; 95% CI 0.71-0.89). And GT-based combination significantly improved OS in the first-line subgroup (HR = 0.84; 95% CI 0.71-0.99). However, there were significant differences regarding acute hematological toxicity, particularly thrombocytopenia.

Conclusion

Gemcitabine/taxanes-treated patients with metastatic breast cancer showed a significant improvement in the ORR, TTP and OS (first-line background) compared to patients not treated with the combination regimen.

A pooled analysis of gemcitabine plus docetaxel versus capecitabine plus docetaxel in metastatic breast cancer

In two randomized phase III trials of patients with metastatic breast cancer (MBC), gemcitabine-docetaxel (GD) and capecitabine-docetaxel (CD) had similar efficacy, but distinct safety profiles. Methods. Data from two GD versus CD studies were pooled; overall survival (OS), progression-free survival (PFS), and overall response rate (ORR) were determined. Cox proportional hazards models identified prognostic factors associated with improved OS and PFS. Using a multivariate prognostic model incorporating identified adverse prognostic factors, we grouped MBC patients into low-, intermediate-, and high-risk categories. Hazard ratios (HRs) of GD over CD for OS and PFS were determined for subsets of patients. Results. Baseline demographics of the pooled population were mostly well balanced. In the pooled population, there were no significant differences between GD versus CD for OS (HR = 1.02; p = .824), PFS (HR = 1.15; p = .079), and ORR (p = .526). In the pooled crossover population, there were trends toward improved OS (HR = 0.82; p = .171) and PFS (HR = 0.93; p = .557) with GD. Several prognostic factors (including prior adjuvant taxane) for improved OS or PFS were identified; however, there were no significant interactions between treatment arms and prognostic factors for PFS or OS, except number of metastatic sites. In the prognostic model, median OS and PFS were numerically lower in the high-risk group versus the intermediate- and low-risk groups. Conclusion. This analysis confirms the lack of efficacy difference between GD and CD in the pooled population, crossover population, and almost all subpopulations. Several prognostic factors were associated with improved outcomes in the pooled population.

Biweekly combination of trastuzumab, docetaxel and gemcitabine for HER2-positive metastatic breast cancer: results of a Phase II GOIM study

ABSTRACT: 

Aims: Clinical activity of chemotherapy plus trastuzumab in HER2 overexpressing advanced breast cancer has been documented. We report the activity and safety results of biweekly combination of trastuzumab, docetaxel and gemcitabine as first-line therapy in HER2-positive advanced breast cancer. Patients & methods: Patients were biweekly treated with trastuzumab (4 mg/kg), gemcitabine (1000 mg/m2) and docetaxel (50 mg/m2). The primary end point was overall response rate, secondary time to progression, clinical benefit rate (partial response plus complete response plus stable disease for ≥ 24 weeks) and tolerability. Results: A total of 65 patients with HER2-positive advanced breast cancer have been enrolled. In total, 47 patients responded (73%; 95% CI, 60–84), 11 achieved complete response (17%; 95% CI: 8.9–28.7), 36 achieved partial response (56%; 95% CI: 43–68.6). The clinical benefit rate was 87.5% (95% CI: 77–94). Three patients (4.7%) experienced progressive disease. The median time to progression was 14.2 months (95% CI: 10.6–17.8), the median overall survival was 39.3 months and the 36-month survival rate was 55.5% (95% CI: 58–73). The worst toxicities were grade 3 neutropenia (12%), thrombocytopenia (6%) and diarrhea (6%). No cardiac toxicity was reported. Conclusion: As first-line therapy, this combination allowed the delivery of polychemotherapy in association to targeted therapy, with clinical activity and mild toxicity. The promising results should be further explored in Phase III randomized clinical trials.

Efficacy of gemcitabine-based chemotherapy in metastatic breast cancer: a meta-analysis of randomized controlled trials

OBJECTIVES

To compare the effects of gemcitabine-based chemotherapy and gemcitabine-free regimens, a meta-analysis of all relevant randomized controlled trials was performed to investigate the improvement in overall response rate (ORR), time to progression (TTP), and overall survival (OS). A subgroup of gemcitabine-based doublet compared with single agent was also analyzed.

METHODS

The PubMed and Embase databases were searched for relevant publications reporting randomized controlled trials comparing gemcitabine-based chemotherapy and gemcitabine-free regimens between January 1990 and December 2012. Hazard ratios (HRs) with their 95% confidence intervals (CIs), or data for calculating HRs with 95% CI were derived.

RESULTS

Nine trials with a total of 2651 patients were included in this meta-analysis. Compared with gemcitabine-free chemotherapy, gemcitabine-based therapy demonstrated no improvement in terms of ORR (HR 1.09, 95% CI 0.73-1.62; P = 0.67), TTP (HR 0.91, 95% CI 0.72-1.15; P = 0.44) and OS (HR 1.05, 95% CI 0.88-1.25; P = 0.60). In a subgroup including patients who received adjuvant chemotherapy containing anthracyclines or taxanes, sub-analysis assessment revealed that gemcitabine-based doublets were superior to monotherapy in ORR (HR 1.64, 95% CI 1.26-2.12; P = 0.0002) and TTP (HR 0.71, 95% CI 0.62-0.81; P < 0.00001), but no benefit was observed for OS (HR 0.90, 95% CI 0.79-1.03; P = 0.14). The rates of grade 3 and 4 anemia (HR 2.02, 95% CI 1.35-3.02; P = 0.006), neutropenia (HR 2.33, 95% CI 1.37-3.63; P = 0.01), and thrombocytopenia (HR 8.31, 95% CI 5.00-13.82; P < 0.0001) were significantly higher in the gemcitabine-based arm.

CONCLUSIONS

The present study suggests that gemcitabine-based chemotherapy was as effective as gemcitabine-free chemotherapy in patients with metastatic breast cancer with increased hematological toxicity. Subgroup analysis indicated that adding gemcitabine to monotherapy might be more effective.

Use of neostigmine in capecitabine-induced paralytic ileus

Paralytic ileus is a recognised side effect of the oral agent capecitabine. We present this report on a patient with metastatic colorectal cancer who was treated with capecitabine and presented with persistent paralytic ileus which did not respond to standard conservative measures. Neostigmine was administered safely, resulting in resolution of the paralytic ileus. This approach merits further investigation.

Drug resistance and the role of combination chemotherapy in improving patient outcomes

Resistance to cancer chemotherapy is a common phenomenon especially in metastatic breast cancer (MBC), a setting in which patients typically have had exposure to multiple lines of prior therapy. The subsequent development of drug resistance can result in rapid disease progression during or shortly after completion of treatment. Moreover, cross-class multidrug resistance limits patient treatment choices, particularly in a setting where treatments options are few. One attempt to minimize the impact of drug resistance has been the concurrent use of two or more chemotherapy agents with unrelated mechanisms of action and differing modes of drug resistance, with the intent of blocking the development of multiple intracellular escape pathways essential for tumor survival. Within the past decade, an array of mechanistically diverse agents has augmented the list of combination regimens that may be both synergistic and efficacious in pretreated MBC. The aim of this paper is to review mechanisms of resistance to common chemotherapy agents and to consider current combination treatment options for heavily pretreated and/or drug-resistant patients with MBC.

Phase III, multicenter, randomized trial of maintenance chemotherapy versus observation in patients with metastatic breast cancer after achieving disease control with six cycles of gemcitabine plus paclitaxel as first-line chemotherapy: KCSG-BR07-02

PURPOSE

The primary purpose of our study was to evaluate whether maintenance chemotherapy with paclitaxel/gemcitabine (PG) was superior to observation in improving progression-free survival (PFS) in patients with metastatic breast cancer (MBC) who achieved disease control with an initial six cycles of PG as their first-line treatment.

PATIENTS AND METHODS

The study was a prospective, randomized, multicenter, phase III trial. Patients MBC with who achieved disease control after six cycles of PG chemotherapy were randomly assigned to maintenance chemotherapy or observation until progression.

RESULTS

Of 324 patients from 10 centers enrolled, 231 patients with MBC exhibited disease control (complete response + partial response + stable disease) with first-line PG and were randomly assigned to maintenance chemotherapy (n = 116) or observation (n = 115). The median age was 48 years (range, 28 to 76 years), median follow-up was 33 months, and median number of chemotherapy cycles in the maintenance group after random assignment was six. The median PFS time after random assignment was longer in the maintenance group than in the observation group (7.5 v 3.8 months, respectively; P = .026). The median overall survival (OS) time was longer in the maintenance group than in the observation group (32.3 v 23.5 months, respectively; P = .047). The rate of grade 3 or higher neutropenia after random assignment was higher in the maintenance group than in the observation group (61% v 0.9%, respectively; P < .001).

CONCLUSION

In patients with MBC who achieved disease control with an initial six cycles of PG chemotherapy, maintenance PG chemotherapy resulted in better PFS and OS compared with observation.

Randomised phase 3 open-label trial of first-line treatment with gemcitabine in association with docetaxel or paclitaxel in women with metastatic breast cancer: a comparison of different schedules and treatments

Background

This open-label study compared docetaxel/gemcitabine vs. paclitaxel/gemcitabine and a weekly (W) vs. 3-weekly (3 W) schedule in metastatic breast cancer (MBC).

Methods

Patients relapsed after adjuvant/neoadjuvant anthracycline-containing chemotherapy were randomized to: A) gemcitabine 1000 mg/m² Day 1,8 + docetaxel 75 mg/m² Day 1 q3W; B) gemcitabine 1250 mg/m² Day 1,8 + paclitaxel 175 mg/m² Day 1 q3W; C) gemcitabine 800 mg/m² Day 1,8,15 + docetaxel 30 mg/m² Day 1,8,15 q4W; D) gemcitabine 800 mg/m² Day 1,15 + paclitaxel 80 mg/m² Day 1,8,15 q4W. Primary endpoint was time-to-progression (TTP). Secondary endpoints were overall survival (OS) and overall response rate (ORR).

Results

Interim analysis led to accrual interruption (241 patients enrolled of 360 planned). Median TTP (months) was 8.33 (95% CI: 6.19-10.16) with W and 7.51 (95% CI: 5.93-8.33) with 3 W (p=0.319). No differences were observed in median TTP between docetaxel and paclitaxel, with 85.6% and 87.0% of patients progressing, respectively. OS did not differ between regimens/schedules. ORR was comparable between regimens (HR: 0.882; 95% CI: 0.523-1.488; p=0.639), while it was significantly higher in W than in the 3 W (HR: 0.504; 95% CI: 0.299-0.850; p=0.010) schedule. Grade 3/4 toxicities occurred in 69.2% and 71.9% of patients on docetaxel and paclitaxel, and in 65.8% and 75.2% in W and 3 W.

Conclusions

Both treatment regimens showed similar TTP. W might be associated with a better tumour response compared with 3 W.

Trial registration

Clinicaltrial.gov ID NCT00236899

The triterpenoid cucurbitacin B augments the antiproliferative activity of chemotherapy in human breast cancer

Despite recent advances in therapy, breast cancer remains the second most common cause of death from malignancy in women. Chemotherapy plays a major role in breast cancer management, and combining chemotherapeutic agents with nonchemotherapeutic agents is of considerable clinical interest. Cucurbitacins are triterpenes compounds found in plants of the Cucurbitaceae family, reported to have anticancer and anti-inflammatory activities. Previously, we have shown antiproliferative activity of cucurbitacin B (CuB) in breast cancer, and we hypothesized that combining CuB with chemotherapeutic agents can augment their antitumor effect. Here, we show that a combination of CuB with either docetaxel (DOC) or gemcitabine (GEM) synergistically inhibited the proliferation of MDA-MB-231 breast cancer cells in vitro. This antiproliferative effect was accompanied by an increase in apoptosis rates. Furthermore, in vivo treatment of human breast cancer orthotopic xenografts in immunodeficient mice with CuB at either low (0.5 mg/kg) or high (1 mg/kg) doses in combination with either DOC (20 mg/kg) or GEM (12.5mg/kg) significantly reduced tumor volume as compared with monotherapy of each drug. Importantly, no significant toxicity was noted with low-dose CuB in combination with either DOC or GEM. In conclusion, combination of CuB at a relatively low concentration with either of the chemotherapeutic agents, DOC or GEM, shows prominent antiproliferative activity against breast cancer cells without increased toxicity. This promising combination should be examined in therapeutic trials of breast cancer.

Metronomic chemotherapy for metastatic breast cancer to prolong time to treatment failure to 12 months or more

The objective of treatment for metastatic breast cancer (MBC) is to control the disease or disease-related symptoms. Prolonged survival has also often been achieved by chemotherapeutic regimens in this setting. Long-term administration of one therapeutic regimen is essential for prolonging survival as well as for maintaining quality of life in these patients. In this study, we focused on time to treatment failure (TTF) as a parameter that predicts patient survival and we retrospectively compared clinical outcomes of patients with MBC who showed TTF of ≥12 months (26 patients) and <12 months (29 patients). The proportion of hormone receptor-positive tumors and the number of prior chemotherapy regimens for MBC were significantly higher and tumor grade was lower in patients with TTF ≥12 months compared to those with TTF <12 months. With regard to clinical outcomes, the objective response rate (ORR) in patients with TTF ≥12 months was significantly higher and median time to progression (TTP) and overall survival (OS) were longer compared to those with TTF <12 months. Of note, the proportion of patients who received metronomic regimens was significantly higher in patients with TTF ≥12 months compared to those with TTF <12 months (80.8 vs. 24.1%, P=0.00003). To assess the clinical benefit of metronomic regimens, the efficacy in patients receiving metronomic and those receiving non-metronomic regimens was compared. Although there was no difference in ORR between the two groups, median TTP and OS were significantly longer in the metronomic compared to the non-metronomic group (TTP: 30 vs. 4 months, P=0.0017; OS: 68 vs. 28 months, P=0.0005). The results suggested that metronomic chemotherapy is useful for palliative care and also improved clinical outcomes as a regimen for which long-term administration may be expected.

Efficacy and toxicity of capecitabine-based chemotherapy in patients with metastatic or advanced breast cancer: results from ten randomized trials

OBJECTIVE

The efficacy and adverse effects of capecitabine-based chemotherapy versus other regimens reported in previous trials were discordant. The aim of the present study was to determine the efficacy and toxicity profiles of capecitabine-based chemotherapy versus capecitabine-free regimens in patients with metastatic and/or advanced breast cancer.

METHODS

Randomized trials in which capecitabine-based chemotherapy was compared with capecitabine-free chemotherapy were included by searching the PubMed database. Differences in efficacy and grade 3-4 toxicities between capecitabine-based chemotherapy and other chemotherapy were compared.

RESULTS

Ten randomized controlled trials were included in our meta-analysis. Compared to patients treated with capecitabine-free chemotherapy, patients treated with capecitabine-based chemotherapy did not have a significantly different complete response (odds ratio (OR): 1.25, 95% confidence interval (CI): 0.87-1.79, p = 0.231), partial response (OR: 1.16, 95% CI: 0.95-1.41, p = 0.147), and overall response (OR: 1.21, 95% CI: 1.00-1.47, p = 0.053). Compared to the capecitabine-free group, less hematological toxicity and more gastrointestinal toxicity occurred in patients treated with capecitabine-based chemotherapy, including neutropenia (OR: 0.34, 95% CI: 0.19-0.59, p <0.001), anemia (OR: 0.41, 95% CI: 0.20-0.85, p = 0.016), leukocytopenia (OR: 0.50, 95% CI: 0.32-0.78, p = 0.002), and diarrhea (OR: 2.35, 95% CI: 1.62-3.42, p < 0.001). Furthermore, patients in the capecitabine group exhibited a significantly higher rate of grade 3 hand-foot syndrome than the capecitabine-free group (OR: 25.16, 95% CI: 12.27-51.58, p < 0.001).

CONCLUSIONS

The present study suggests that capecitabine-based chemotherapy is as effective as capecitabine-free chemotherapy in patients with metastatic and/or advanced breast cancer with different toxicity profiles. Capecitabine-based chemotherapy may be better tolerated than capecitabine-free chemotherapy. Due to several limitations in our study, future large randomized trials are needed.

A multicenter phase II trial of docetaxel and capecitabine as salvage treatment in anthracycline- and taxane-pretreated patients with metastatic breast cancer

OBJECTIVE

To evaluate the efficacy and safety of docetaxel plus capecitabine (DC) combination as salvage treatment in anthracycline- and taxane-pretreated patients with metastatic breast cancer (MBC).

PATIENTS AND TREATMENT

Patients with MBC who had disease progression after initial chemotherapy with anthracyclines (n = 29; 100 %) and taxanes (n = 11; 37.9 %) were treated with oral capecitabine 950 mg/m(2) twice daily on days 1-14 and docetaxel 75 mg/m(2) on day 1 every 3 weeks. Nineteen (65.5 %) patients received this regimen as second line and 10 (34.5 %) as ≥3rd line of therapy. All patients were evaluable for response and toxicity.

RESULTS

Complete response occurred in two (6.9 %) patients and partial response in eleven (37.9 %) for an overall response rate of 44.8 % (95 % CI 26.7-62.9 %). Eleven women (37.9 %) had stable disease and five (17.2 %) progressive disease. Of the eleven patients previously treated with anthracyclines and taxanes, five (45.5 %) responded to DC combination. The median duration of response was 5.7 months (range 3.4-64.2), the median time to disease progression 9.3 months (range 1.2-58), and the median overall survival 25.5 months. No toxic death occurred. Neutropenia grade 4 occurred in 58.6 % of patients and three of them (10.3 %) developed neutropenic fever. Non-hematological toxicities were manageable with grade 3 hand-foot syndrome occurring in 6.9 % of the patients, fatigue in 3.4 %, and neurotoxicity in 3.4 %.

CONCLUSION

The DC combination is a valuable regimen as salvage treatment in anthracycline- or anthracycline and taxane-pretreated patients with MBC.

Combination drug delivery approaches in metastatic breast cancer

Disseminated metastatic breast cancer needs aggressive treatment due to its reduced response to anticancer treatment and hence low survival and quality of life. Although in theory a combination drug therapy has advantages over single-agent therapy, no appreciable survival enhancement is generally reported whereas increased toxicity is frequently seen in combination treatment especially in chemotherapy. Currently used combination treatments in metastatic breast cancer will be discussed with their challenges leading to the introduction of novel combination anticancer drug delivery systems that aim to overcome these challenges. Widely studied drug delivery systems such as liposomes, dendrimers, polymeric nanoparticles, and water-soluble polymers can concurrently carry multiple anticancer drugs in one platform. These carriers can provide improved target specificity achieved by passive and/or active targeting mechanisms.

Phase II study of gemcitabine and docetaxel in recurrent platinum resistant ovarian cancer

To evaluate the activity of gemcitabine and docetaxel in patients with recurrent ovarian cancer.

METHODS

Patients with platinum-resistant disease and prior treatment with paclitaxel received treatment with docetaxel on day 1 and gemcitabine on days 1 and 8, repeated every three weeks.

RESULTS

Twenty patients, with a platinum-free interval of three months, were enrolled. Overall response rate was 25%. Treatment was associated with significant myelosuppression.

CONCLUSIONS

In chemotherapy-resistant patients, this regimen exhibited encouraging activity. Excessive myelosuppression led to early closure. This was prevented by administering docetaxel on day 8 (instead of day 1) and prophylactic use of G-CSF.