Cisplatin plus oral etoposide (EoP) combination is more effective than paclitaxel in patients with advanced breast cancer pretreated with anthracyclines: a randomised phase III trial of Turkish Oncology Group

Third-line Treatment for Metastatic Triple-negative Breast Cancer: A Systematic Review and Network Meta-analysis

OBJECTIVE

Metastatic triple-negative breast cancer (mTNBC) is an invasive histologic subtype with a poor prognosis and rapid progression. Currently, there is no standard therapy for the third-line treatment of mTNBC. In this study, we conducted a network meta-analysis to compare regimens and determine treatment outcomes.

METHODS

We performed a systematic search of PubMed, EMBASE, the Cochrane Central Register of Controlled Bases, and the minutes of major conferences. Progression-free survival, overall survival, and objective response rate were analyzed through network meta-analysis using the R software (R Core Team). The efficacy of the treatment regimens was compared using hazard ratios, odds ratios, and 95% CIs.

RESULTS

We evaluated 15 randomized controlled trials involving 6,010 patients. Compared with the physician's choice treatment, sacituzumab govitecan showed significant advantages in progression-free survival and overall survival, with hazard ratio values of 0.41 (95% CI: 0.32-0.52) and 0.48 (95% CI, 0.39-0.60). In terms of objective response rate, sacituzumab govitecan is the best-performing therapy (odds ratio: 10.82; 95% CI: 5.58-20.97). Adverse events among grades 3 to 5 adverse reactions, the incidence of neutropenia and leukopenia in each regimen was higher, whereas the incidence of fever, headache, hypertension, and rash was lower.

CONCLUSION

Compared with the treatment of the physician's choice, sacituzumab govitecan appears more efficacious and is the preferred third-line treatment for mTNBC.

Platinum-containing regimens for triple-negative metastatic breast cancer

BACKGROUND

In a previous Cochrane Review, we found that for women with metastatic breast cancer unselected for triple-negative disease, there is little or no survival benefit and excess toxicity from platinum-based regimens. In subgroup analyses, however, we found preliminary low-quality evidence of a survival benefit from platinum-based regimens for women with metastatic triple-negative breast cancer (mTNBC). This review updates the evidence from the mTNBC subgroup analyses in the previous Cochrane Review.

OBJECTIVES

To assess the effects of platinum-containing chemotherapy regimens with regimens not containing platinum in the management of women with mTNBC.

SEARCH METHODS

We obtained relevant studies published prior to 2015 and their extracted results from the mTNBC subgroup analysis in the previous Cochrane Review. We searched the Cochrane Breast Cancer Group's Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization's International Clinical Trials Registry Platform and ClinicalTrials.gov between 2015 and 27 September 2019. We identified further potentially relevant studies from previous trial reports, systematic reviews, and meta-analyses.

SELECTION CRITERIA

Randomised trials comparing platinum-containing chemotherapy regimens with regimens not containing platinum in women with mTNBC. Individual trials could compare one or more platinum-based regimens to one or more non-platinum regimens; hence there could be more 'treatment-comparisons' (i.e. platinum regimen versus non-platinum regimen comparison) than trials. Trial participants may have been purposely selected for mTNBC or inadvertently selected as a subgroup.

DATA COLLECTION AND ANALYSIS

At least two independent reviewers assessed studies for eligibility and quality, and extracted all relevant data from each study. We derived hazard ratios (HRs) for time-to-event outcomes, where possible, and used fixed-effect models for meta-analyses. We analysed objective tumour response rates (OTRRs) and toxicities as binary (dichotomous) outcomes with risk ratios (RRs) used as measures of effects. We extracted quality of life data, if available. We used GRADE to rate the quality of evidence for time-to-event and tumour response outcomes.

MAIN RESULTS

This review includes 13 treatment-comparisons involving 1349 women from 10 studies. Twelve of the 13 treatment-comparisons were included in one or more meta-analyses. Of the 13 treatment-comparisons, six and eight had published or provided time-to-event data on overall survival (OS) or progression-free survival/time to progression (PFS/TTP), respectively, that could be included in meta-analyses. Ten treatment-comparisons published or provided OTRR data that could be included in meta-analyses. Eight of the 13 treatment-comparisons were from studies that selected participants on the basis of mTNBC status, while the other five treatment-comparisons were from studies that reported mTNBC results as part of subgroup analyses. Analysis of six treatment-comparisons indicated that platinum-containing regimens may have provided a small survival benefit to mTNBC patients (HR 0.85, 95% CI 0.73 to 1.00; 958 women; moderate-quality evidence) with no evidence of heterogeneity (P = 0.41; I2 = 1%). Data from eight treatment-comparisons showed that platinum regimens may improve PFS/TTP (HR 0.77, 95% CI 0.68 to 0.88; 1077 women; very low-quality evidence). There was marked evidence of heterogeneity (P < 0.0001; I2 = 80%). There was also low-quality evidence of better tumour response for platinum recipients (RR 1.40, 95% CI 1.22 to 1.59; 1205 women) with some evidence of heterogeneity (P = 0.01; I2 = 58%). The observed heterogeneity for the PFS/TTP and OTRR outcomes may reflect between-study differences and general difficulties in assessing tumour response, as well as the varying potencies of the comparators. Compared with women receiving non-platinum regimens: rates of grade 3 and 4 nausea/vomiting were higher for platinum recipients (RR 4.77, 95% CI 1.93 to 11.81; 655 women; low-quality evidence) and rates of grade 3 and 4 anaemia were higher for platinum recipients (RR 3.80, 95% CI 2.25 to 6.42; 843 women; low-quality evidence). In general, however, relatively few intervention-comparisons could be included in meta-analyses for adverse events. None of the studies reported quality of life.

AUTHORS' CONCLUSIONS

For women with mTNBC, there was moderate-quality evidence of a small survival benefit from platinum-based regimens compared to non-platinum regimens. This finding is consistent with findings of a PFS/TTP benefit and improved tumour response from platinum-based regimens. These potential benefits, however, should be weighed against previously identified excess toxicities from platinum-based regimens, particularly regimens containing cisplatin. Further randomised trials of platinum-based regimens among women with mTNBC are required.

The role of chemotherapy in treatment of advanced breast cancer: an overview for clinical practice

This review aims to evaluate the role of chemotherapy-containing regimens in the treatment of advanced breast cancer (ABC), with the purpose to optimize selection, sequencing and duration of treatment with the currently available agents for clinical practice. Data from observational as well as randomized phase II and III studies were included. Chemotherapy yielded a median overall survival (OS) of 2 years in registration studies, with comparable efficacy of different agents. Combining chemotherapy agents did not yield OS improvement and caused greater toxicity compared with single-agent chemotherapy. Continuing chemotherapy till progression or unacceptable toxicity generated greater efficacy without detrimental impact on quality of life compared with a limited amount of cycles. In real-world studies, benefits after third-line chemotherapy were modest compared with first- and second-line. Furthermore, effects of previous chemotherapy predicted effects of next-line therapy in real-world. Physicians increasingly prescribed capecitabine or taxanes as first- or second-line chemotherapy over time.

Platinum-containing regimens for metastatic breast cancer

BACKGROUND

Studies have reported high tumour response rates for platinum-containing regimens in the treatment of women with metastatic breast cancer. Most of these studies were conducted prior to the 'intrinsic subtype' era, and did not specifically focus on metastatic triple-negative breast cancers (mTNBCs).

OBJECTIVES

To identify and review the evidence from randomised trials comparing platinum-containing chemotherapy regimens with regimens not containing platinum in the management of women with metastatic breast cancer.

SEARCH METHODS

For this review update, we searched the Cochrane Breast Cancer Group's Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization's International Clinical Trials Registry Platform and ClinicalTrials.gov on 28 May 2015. We identified further potentially relevant studies from handsearching references of previous trials, systematic reviews, and meta-analyses. Prior to this review update, the most recent search for studies was conducted in May 2003 for the original 2004 review.

SELECTION CRITERIA

Randomised trials comparing platinum-containing chemotherapy regimens with regimens not containing platinum in women with metastatic breast cancer.

DATA COLLECTION AND ANALYSIS

At least two independent reviewers assessed studies for eligibility and quality, and extracted all relevant data from each study. Hazard ratios (HRs) were derived for time-to-event outcomes, where possible, and fixed-effect models were used for meta-analyses. Objective tumour response rates (OTRRs) and toxicities were analysed as binary (dichotomous) outcomes with risk ratios (RRs) used as measures of effects. Quality of life data were extracted where available. GRADE was used to rate the quality of evidence for survival and tumour response outcomes at the level of subgroups selected and unselected for mTNBC, and for toxicity outcomes based on combining data from selected and unselected populations.

MAIN RESULTS

This update includes 15 new eligible treatment-comparisons from 12 studies. In total, 28 treatment-comparisons, involving 4418 women, from 24 studies are now included in one or more meta-analyses. Of the 28 treatment-comparisons, 19 and 16 had published or provided extractable time-to-event data on overall survival (OS) or progression-free survival/time to progression (PFS/TTP), respectively. All 28 treatment-comparisons provided OTRR data that could be included in meta-analyses. Most women recruited to the studies were not selected on the basis of mTNBC status.In a subgroup of three treatment-comparisons assessing women with mTNBC, platinum-containing regimens may have provided a survival benefit (HR 0.75, 95% CI 0.57 to 1.00; low-quality evidence). In women unselected for intrinsic subtypes such as mTNBC, there was little or no effect on survival (HR 1.01, 95% CI 0.92 to 1.12; high-quality evidence). This effect was similar to the combined analysis of survival data for both populations (HR 0.98, 95% CI 0.89 to 1.07; I² =39%, 1868 deaths, 2922 women; 19 trials). The difference in treatment effects between mTNBC women compared with unselected women was of borderline statistical significance (P = 0.05).Data from three treatment-comparisons with mTNBC participants showed that platinum regimens may improve PFS/TTP (HR 0.59, 95% CI 0.49 to 0.72; low-quality evidence). Thirteen treatment-comparisons of unselected metastatic participants showed that there was probably a small PFS/TTP benefit for platinum recipients, although the confidence interval included no difference (HR 0.92, 95% CI 0.84 to 1.01; moderate-quality evidence). Combined analysis of data from an estimated 1772 women who progressed or died out of 2136 women selected or unselected for mTNBC indicated that platinum-containing regimens improved PFS/TTP (HR 0.85, 95% CI 0.78 to 0.93). There was marked evidence of heterogeneity (P = 0.0004; I² = 63%). The larger treatment benefit in mTNBC women compared with unselected women was statistically significant (P < 0.0001).There was low-quality evidence of better tumour response in both subgroups of women with mTNBC and unselected women (RR 1.33, 95% CI 1.13 to 1.56; RR 1.11, 95% CI 1.04 to 1.19, respectively). Combined analysis of both populations was closer to the effect in unselected women (RR 1.15, 95% CI 1.08 to 1.22; 4130 women). There was considerable evidence of heterogeneity (P < 0.0001; I² = 64%), which may reflect between-study differences and general difficulties in assessing response, as well as the varying potencies of the comparators.Compared with women receiving non-platinum regimens: rates of grade 3 and 4 nausea/vomiting were probably higher among women receiving cisplatin- (RR 2.65, 95% CI 2.10 to 3.34; 1731 women; moderate-quality evidence) but the effect from carboplatin-containing regimens was less certain (RR 0.77, 95% CI 0.47 to 1.26; 1441 women; moderate-quality evidence); rates of grade 3 and 4 anaemia were higher among women receiving cisplatin- (RR 3.72, 95% CI 2.36 to 5.88; 1644 women; high-quality evidence) and carboplatin-containing regimens (RR 1.72, 95% CI 1.10 to 2.70; 1441 women; high-quality evidence); rates of grade 3 and 4 hair loss (RR 1.41, 95% CI 1.26 to 1.58; 1452 women; high-quality evidence) and leukopenia (RR 1.38, 95% CI 1.21 to 1.57; 3176 women; moderate-quality evidence) were higher among women receiving platinum-containing regimens (regardless of platinum agent).

AUTHORS' CONCLUSIONS

In women with metastatic breast cancer who do not have triple-negative disease, there is high-quality evidence of little or no survival benefit and excess toxicity from platinum-based regimens. There is preliminary low-quality evidence of a moderate survival benefit from platinum-based regimens for women with mTNBC. Further randomised trials of platinum-based regimens in this subpopulation of women with metastatic breast cancer are required.

Platinum salts in advanced breast cancer: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

The interest in platinum salts in breast cancer (BC) therapy has been recently renewed as inhibition of DNA damage response may enhance the effects of DNA-damaging agents in BC tumors with high genomic instability. The present systematic review and meta-analysis of randomized trials were performed to assess the efficacy and safety of therapy with platinum salts in patients with locally advanced or metastatic (hereinafter advanced) BC.

METHODS

We searched PubMed, EMBASE, SCOPUS, Web of Science, the Cochrane Library, and CINAHL for phase II/III clinical trials that assessed efficacy of platinum-based therapy in patients with advanced BC. Pooled estimates of overall response rate (RR), median progression-free survival (PFS) and overall survival (OS) were computed using random or fixed effects models.

RESULTS

Data on 4625 patients from 23 phase II and III trials (11 with cisplatin, 11 with carboplatin, and 1 with either agents respectively) were analyzed. Estimates for RR, PFS, and OS were obtained from 23, 13, and 15 studies, respectively. Although at the cost of significantly increased fatigue, hematological and gastrointestinal toxicity, compared with non-platinum schemas, cisplatin, and carboplatin prolonged OS (HR 0.91; 95 % CI 0.83-1.00, p = 0.04), PFS (HR 0.84; 95 % CI 0.73-0.97, p = 0.01), and RR (HR 1.27; 95 % CI 1.03-1.57, p = 0.03).

CONCLUSIONS

Despite some limitations of the studies examined, including partial information on hormonal receptor and HER2 status, the use of platinum salts significantly prolonged OS, and PFS of patients with advanced BC with no unexpected toxicity.

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.

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.

RAD50 targeting impairs DNA damage response and sensitizes human breast cancer cells to cisplatin therapy

In tumor cells the effectiveness of anti-neoplastic agents that cause cell death by induction of DNA damage is influenced by DNA repair activity. RAD50 protein plays key roles in DNA double strand breaks repair (DSBs), which is crucial to safeguard genome integrity and sustain tumor suppression. However, its role as a potential therapeutic target has not been addressed in breast cancer. Our aim in the present study was to analyze the expression of RAD50 protein in breast tumors, and evaluate the effects of RAD50-targeted inhibition on the cytotoxicity exerted by cisplatin and anthracycline and taxane-based therapies in breast cancer cells. Immunohistochemistry assays on tissue microarrays indicate that the strong staining intensity of RAD50 was reduced in 14% of breast carcinomas in comparison with normal tissues. Remarkably, RAD50 silencing by RNA interference significantly enhanced the cytotoxicity of cisplatin. Combinations of cisplatin with doxorubicin and paclitaxel drugs induced synergistic effects in early cell death of RAD50-deficient MCF-7, SKBR3, and T47D breast cancer cells. Furthermore, we found an increase in the number of DSBs, and delayed phosphorylation of histone H2AX after cisplatin treatment in RAD50-silenced cells. These cellular events were associated to a dramatical increase in the frequency of chromosomal aberrations and a decrease of cell number in metaphase. In conclusion, our data showed that RAD50 abrogation impairs DNA damage response and sensitizes breast cancer cells to cisplatin-combined therapies. We propose that the development and use of inhibitors to manipulate RAD50 levels might represent a promising strategy to sensitize breast cancer cells to DNA damaging agents.

Which patients with metastatic breast cancer benefit from subsequent lines of treatment? An update for clinicians

The outcome of patients with metastatic breast cancer (MBC) has clearly improved over the past decades and the proportion of women living with their disease for several years is increasing. However, the usefulness of multiple lines of treatment is still debated and under evaluation. The available data from both randomized trials and large retrospective series are reviewed and discussed in order to analyze management practices, with emphasis on potential prognostic and predictive factors for clinical outcome. At present, evidence-based medicine provides some support for the use of second-line and to a lesser degree and in selected cases, third-line chemotherapy in human epidermal growth factor receptor 2 (HER2) negative MBC. Beyond third-line treatment, messages from recently reported retrospective studies also suggest a clear potential gain for women receiving further therapies after disease progression, since each line can contribute to a longer survival. In HER2-positive disease, the data from observational and retrospective studies support a clinical benefit from the use of trastuzumab beyond disease progression and emerging evidences from randomized controlled trials are leading to the introduction of newer HER2-targeted therapies in multiple lines. The question 'How many lines of treatment should we give patients?' clearly needs further research through prospective, high-quality clinical trials, aiming for a better definition of factors with prognostic and predictive role. In the meantime, the 'optimal' treatment strategy should probably be to use as many therapeutic options as possible, either in sequence or combination, to keep the best efficacy/toxicity balance, considering MBC as a chronic disease.

Complete response and long-term remission to anti-HER2 combined therapy in a patient with breast cancer presented with bone marrow metastases

Presentation with bone marrow metastasis at diagnosis is a rare event in breast carcinoma. Here, we report a rare presentation of metastatic breast cancer patient with bone marrow metastases, who was successfully treated with trastuzumab combined chemotherapy. The regimens initially applied for bone marrow metastasis were docetaxel/adriamycin, gemcitabine/vinorelbine, epirubicin/cyclophosphamide, capecitabine, docetaxel, gemcitabine, and paclitaxel. But, the best response to these regimens was not satisfactory. Our patient was completely treated with etoposide-cisplatin and trastuzumab combination. She is still on remission after five years of metastatic breast cancer diagnosis using letrozole and trastuzumab without complication. Physicians should be careful in treating bone marrow metastases in breast cancer, since patients can show improved marrow function after chemotherapy and long-lasting survival is possible.

Differential gene and microRNA expression between etoposide resistant and etoposide sensitive MCF7 breast cancer cell lines

In order to develop targeted strategies for combating drug resistance it is essential to understand it’s basic molecular mechanisms. In an exploratory study we have found several possible indicators of etoposide resistance operating in MCF7VP cells, including up-regulation of ABC transporter genes, modulation of miRNA, and alteration in copy numbers of genes.

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.

Platinum-based compounds for the treatment of metastatic breast cancer

The role of platinum-based compounds (PBCs) in the treatment of metastatic breast cancer (MBC) has been extensively studied. As single agents, high response rates have been observed in first-line therapy, while results in pretreated patients were discouraging. Regimens containing cisplatin/carboplatin together with taxanes showed the highest efficacy and safety as both first-line and second-line therapy. When administered with vinorelbine, the combination was also active and well tolerated in anthracycline- and taxane-pretreated patients. Combining PBCs with etoposide or nucleoside analogues showed moderate activity, yet high toxicity in the case of etoposide. The overall results for the combination with anthracyclines were disappointing. Addition of trastuzumab to PBC combinations showed remarkable activity and good tolerability in patients with HER2/neu overexpression. The use of cisplatin or carboplatin alongside novel targeted therapeutics for patients with triple-negative MBC seems promising and is being further evaluated. The use of PBCs against MBC requires careful patient selection and combination with the right chemotherapeutic agent.

Filling in the gaps: reporting of concurrent supportive care therapies in breast cancer chemotherapy trials

BACKGROUND

Supportive care interventions can have a substantial impact on side effects of chemotherapy. Consequently, accurate reporting of such interventions is essential when interpreting clinical trial results. This study determined the prevalence and quality of reporting of supportive care treatment for common chemotherapy-induced toxicities in phase III, breast cancer chemotherapy trials.

METHODS

A systematic review of phase III trials of breast cancer trials incorporating chemotherapy published in the last 5 years was undertaken. Trials were identified through MEDLINE, EMBASE, BIOSIS, and the Cochrane Library. Supportive treatments evaluated were use of antiemetics, colony-stimulating growth factors, and antibiotics. Reporting quality was rated as "good", "fair", "poor", or "absent" using predetermined criteria.

RESULTS

Sixty-two trials met inclusion criteria. In 41 studies (66%), details regarding prophylactic antiemetic treatment were not provided. Growth factor use was not reported in 20 trials (32%). Instructions for the use of prophylactic antibiotics were absent in 45 trials (72%).

CONCLUSION

There are significant deficiencies in reporting of use of prophylactic supportive care agents in breast cancer trials. Omission of supportive care instructions may impact substantially on patient management and health care system expenditure. Recommendations for the type, dose, and frequency of supportive care drugs should be provided and reported on in trials.

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

PURPOSE

Clinical trials have reported conflicting results as to whether taxane-based doublet improves outcome over single-agent taxane in patients with advanced breast cancer.

METHODS

We performed a meta-analysis comparing primary and secondary end points of taxane-based doublet with single-agent taxane chemotherapy in patients with advanced breast cancer and prior anthracycline treatment. The event-based relative risk ratio (RR) with 95% confidence intervals (95% CI) was derived, and a test of heterogeneity was applied.

RESULTS

Four eligible trials (2,343 patients) were selected from 488 studies that initially were identified. A significant difference in favoring taxane-based doublet over single-agent taxane was observed in progression-free survival (PFS) (RR, 1.33; 95% CI, 1.02-1.75; P = 0.039) and partial response (PR) (RR, 1.43; 95% CI, 1.10-1.86; P = 0.008). The ORR was higher for patients receiving taxane-based doublet, although not statistically significant (RR, 1.17; 95% CI, 0.91-1.50; P = 0.220). Whereas there was no difference in 1-year survival rate (1-year SR) (RR, 1.05; 95% CI, 0.94-1.17; P = 0.422), clinical benefit (CB) (RR, 1.02; 95% CI, 0.95-1.09; P = 0.642), and complete response (CR) (RR, 0.75; 95% CI, 0.31-1.79; P = 0.512). Toxicities did not differ significantly except stomatitis and diarrhea.

CONCLUSION

Taxane-based doublet appeared to improve PFS and PR compared with single-agent taxane in the treatment of patients with advanced breast cancer. Further prospective, randomized, controlled trials will be necessary.

Preferential antitumor effect of the Src inhibitor dasatinib associated with a decreased proportion of aldehyde dehydrogenase 1-positive cells in breast cancer cells of the basal B subtype

BACKGROUND

Recent studies have suggested that the Src inhibitor dasatinib preferentially inhibits the growth of breast cancer cells of the basal-like subtype. To clarify this finding and further investigate combined antitumor effects of dasatinib with cytotoxic agents, a panel of breast cancer cell lines of various subtypes was treated with dasatinib and/or chemotherapeutic agents.

METHODS

Seven human breast cancer cell lines were treated with dasatinib and/or seven chemotherapeutic agents. Effects of the treatments on c-Src activation, cell growth, cell cycle, apoptosis and the proportion of aldehyde dehydrogenase (ALDH) 1-positive cells were examined.

RESULTS

The 50%-growth inhibitory concentrations (IC50s) of dasatinib were much lower in two basal B cell lines than those in the other cell lines. The IC50s of chemotherapeutic agents were not substantially different among the cell lines. Dasatinib enhanced antitumor activity of etoposide in the basal B cell lines. Dasatinib induced a G1-S blockade with a slight apoptosis, and a combined treatment of dasatinib with etoposide also induced a G1-S blockade in the basal B cell lines. Dasatinib decreased the expression levels of phosphorylated Src in all cell lines. Interestingly, dasatinib significantly decreased the proportion of ALDH1-positive cells in the basal B cell lines but not in the other cell lines.

CONCLUSIONS

The present study indicates that dasatinib preferentially inhibits the growth of breast cancer cells of the basal B subtype associated with a significant loss of putative cancer stem cell population. A combined use of dasatinib with etoposide additively inhibits their growth. Further studies targeting breast cancers of the basal B subtype using dasatinib with cytotoxic agents are warranted.

Single agent versus combination chemotherapy for metastatic breast cancer

BACKGROUND

Combination chemotherapy regimens are frequently favoured over single agents for the treatment of metastatic breast cancer, in an attempt to achieve superior tumour response rates. It is not known however whether giving more intensive chemotherapy regimens results in better health outcomes, when both survival and toxicity are considered, and whether better response rates and rates of progression free survival actually translate to better overall survival.

OBJECTIVES

To compare single agent with combination chemotherapy for the treatment of metastatic breast cancer.

SEARCH STRATEGY

We searched the Cochrane Breast Cancer Group Specialised Register November 2008. Handsearching of recent conference proceedings was also undertaken.

SELECTION CRITERIA

Randomised trials of single agent chemotherapy compared to combination therapy in metastatic breast cancer.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials for eligibility and quality, and extracted data. Hazard ratios were derived for reported time-to-event outcomes.Response rates were analysed as dichotomous variables. Toxicity and quality of life data were extracted where present.

MAIN RESULTS

Forty three eligible trials (48 comparisons) were identified. These included 9742 women, 55% of whom were receiving first-line treatment for metastatic disease. For overall survival there was a statistically significant difference in favour of the combination regimens with no heterogeneity (HR 0.88, 95% CI 0.83-0.93, p<0.00001). Results were very similar when trials of first-line treatment were analysed, and for analyses where the single agent was also included in the combination regimen. Combination regimens showed a statistically significant advantage for survival over single agent taxane (HR 0.82; 95% CI 0.75-0.89, p<0.00001), but not anthracycline (HR 0.94.86-1.02, p=0.15).Combination regimens were also associated with significantly better time to progression (HR 0.78, 95% CI 0.74 - 0.82, p<0.00001) and response (RR 1.29, 95% CI 1.14 -1.45, p<0.0001) although heterogeneity was statistically significant in both instances and probably due to clinical diversity of the participants and interventions.Women receiving combination regimens experienced a statistically significant detrimental effect on white cell count, increased alopecia and nausea and vomiting.

AUTHORS' CONCLUSIONS

Combination chemotherapy regimens show a statistically significant advantage for survival, tumor response and time to progression in women with metastatic breast cancer but they also produce more toxicity. An unresolved question is whether combination regimens are more effective than single agents given sequentially.

Multiple-treatments meta-analysis of chemotherapy and targeted therapies in advanced breast cancer

BACKGROUND

Many systemic nonhormonal regimens have been evaluated across several hundreds of randomized trials in advanced breast cancer. We aimed to quantify the relative merits of these regimens in prolonging survival.

METHODS

We performed a systematic review of all trials that compared different regimens involving chemotherapy and/or targeted therapy in advanced breast cancer (1973-2007). Regimens were categorized a priori into different treatment types. We performed multiple-treatments meta-analysis and calculated hazard ratios for each treatment category relative to monotherapy with old agents (ie, regimens not including anthracyclines, anthracenediones, vinorelbine, gemcitabine, capecitabine, taxanes, marimastat, thalidomide, trastuzumab, lapatinib, or bevacizumab).

RESULTS

We identified 370 eligible randomized trials (54,189 patients), of which 172 (31,552 patients) compared different types of treatment. Survival data from 148 comparisons pertaining to 128 of the 172 trials (26,031 patients, 22 different types of treatment) were available for inclusion in the multiple-treatments meta-analysis. Compared with single-agent chemotherapy with old nonanthracycline drugs, anthracycline regimens achieved 22%-33% relative risk reductions in mortality (ie, hazard ratio [HR] for standard-dose anthracycline-based combination: 0.67, 95% credibility interval [CrI] 0.57-0.78). Several newer regimens achieved further benefits (eg, HR [95% CrI] 0.67 [0.55-0.81] for single-drug taxane, 0.64 [0.53-0.78] for combination of anthracyclines with taxane, 0.49 [0.37-0.67] for taxane-based combination with capecitabine or gemcitabine), and similar benefits were seen with several regimens including molecular targeted treatments. Most regimens had very similar efficacy profiles (<5% difference in HR) as first- and subsequent-line therapies.

CONCLUSIONS

Stepwise improvements in efficacy of chemotherapy and targeted treatments cumulatively have achieved major improvements in the survival of patients with advanced breast cancer. Many options that can be used in first and subsequent lines of therapy have comparable efficacy profiles.

Treatment of MCF-7 cells with taxol and etoposide induces distinct alterations in the expression of apoptosis-related genes BCL2, BCL2L12, BAX, CASPASE-9 and FAS

We studied alterations in the mRNA expression levels of BCL2 (Bcl-2), BCL2L12, BAX, FAS and CASPASE-9 genes in the MCF-7 breast cancer cell line in response to treatment with two anticancer drugs. Cell toxicity was evaluated by the MTT method, trypan blue staining and DNA laddering, whereas the expression levels of the apoptosis-related genes were analysed by RT-PCR using gene-specific primers. In the case of etoposide, down-regulation of the BCL2L12-A gene variant and of CASPASE-9, as well as upregulation of BAX, was observed, whereas treatment of MCF-7 cells with taxol led to down-regulation of the mRNA levels of all genes examined. Our results support the idea that after long-term clinical studies, mRNA expression analysis of BCL2L12 and other members of the BCL2 gene family may serve as useful molecular markers predicting chemotherapy response in breast cancer.