Vinorelbine and capecitabine in anthracycline- and/or taxane-pretreated metastatic breast cancer: sequential or combinational?

Cabazitaxel exhibits more favorable molecular changes compared to other taxanes in androgen-independent prostate cancer cells

Taxane-based chemotherapy drugs (cabazitaxel, docetaxel, and paclitaxel) are microtubule inhibitors, which are effectively and frequently used to treat metastatic prostate cancer (PCa). Among these, cabazitaxel is offered as a new therapeutic option for patients with metastatic castration-resistant PC as that are resistant to other taxanes. Here, we investigated the cellular and molecular changes in response to cabazitaxel in comparison with docetaxel and paclitaxel in androgen-independent human PCas. The androgen-independent human PCa cell lines, PC3 and DU145, were treated with 1 to 5nM cabazitaxel, docetaxel, or paclitaxel, and assessed for cell viability (MTT assay), colony forming ability and migration (scratch assay). The induction of apoptosis was determined through measurement of mitochondrial membrane potential (JC-1 assay) and caspase-3 activity assay. The protein expression changes (caspase-3, caspase-8, Bax, Bcl-2, β-tubulin, nuclear factor-κB [NF-κB/p50, NF-κB/p65], vascular endothelial growth factor, WNT1-inducible signaling pathway protein-1 [WISP1], transforming growth factor β [TGF-β]) in response to drug treatment were screened via western blotting. Under our experimental conditions, all taxanes significantly reduced WISP1 and TGF-β expressions, suggesting an anti-metastatic/antiangiogenic effect for these drugs. On the other hand, cabazitaxel induced more cell death and inhibited colony formation compared to docetaxel or paclitaxel. The highest fold change in caspase-3 activity and Bax/Bcl-2 ratio was also detected in response to cabazitaxel. Furthermore, the induction of β-tubulin expression was lower in cabazitaxel-treated cells relative to the other taxanes. In summary, cabazitaxel shows molecular changes in favor of killing PCa cells compared to other taxanes, at least for the parameters analyzed herein. The differences with other taxanes may be important while designing other studies or in clinical settings.

Vinorelbine plus Capecitabine (Vinocap): a retrospective analysis in heavily pretreated HER2 negative metastatic breast cancer patients

PURPOSE

Metastatic breast cancer is regarded as an incurable entity. In heavily pretreated patients with increasingly limited options for palliative management, ensuring proper quality of life continues is to be an elusive issue. With this in mind, the authors evaluated the efficacy and safety of the Vinorelbine/Capecitabine doublet (VINOCAP).

PATIENTS AND METHODS

The investigators retrospectively analyzed a cohort of 67 women with HER2 negative MBC treated at a large breast cancer practice and a local cancer center with Vinorelbine 22.5 mg/m2 IV on days 1 and 8 combined with Capecitabine 1 g PO BID for 14 consecutive days of 21 day cycles. Patients had been treated with an average of 4 prior lines of chemotherapy. Patient characteristics and outcomes were evaluated.

RESULTS

A total of 67 patients received VINOCAP, and an additional 2 underwent repeat exposure yielding a cohort of 69. Clinical benefit rate, defined as complete response (CR), partial response (PR) or stable disease ≥ 6 months (SD), was 55.07%. Complete response was seen in 4.34%, PR in 18.8% and SD ≥ 6 months in 31.9%. Median progression-free survival was 6.2 months and overall survival 35.47 months after VINOCAP exposure. The most common grade 3-4 toxicity was neutropenia in 10% of cases. Dose had to be reduced in 18% of cases due to toxicity of any type. The regimen was well tolerated, and serious side effects were uncommon.

CONCLUSION

Vinorelbine/Capecitabine appears to be an active and well-tolerated regimen in women with MBC. In particular, encouraging was the efficacy of VINOCAP as fourth or greater line of chemotherapy.

Development and validation of a quantitative method for thymidine phosphorylase activity in peripheral blood mononuclear cells

The enzyme thymidine phosphorylase (TP) is important for activation of capecitabine and 5-fluorouracil. Assessment of TP phenotype might be suitable for identification of patients at risk of fluoropyrimidine-induced toxicity. In this paper, we describe the development and validation an assay for TP activity in peripheral blood mononuclear cells (PBMCs). The assay was based on ex vivo conversion of the TP substrate thymidine to thymine. The amount of thymine formed was determined by high-performance liquid chromatography - ultraviolet detection (HPLC-UV) with 5-bromouracil as internal standard. Lymphocytes and monocytes were purified from isolated PBMCs to examine cell-specific TP activity. TP activity in PBMCs demonstrated Michaelis-Menten kinetics. The lower limit of quantification was 2.3 µg PBMC protein and assay linearity was demonstrated up to 22.7 µg PBMC protein. Within-day and between-day precisions were ≤9.2% and ≤6.0%, respectively. Adequate stability TP activity was demonstrated after long-term storage of PBMC dry pellets and lysates at -80 °C. In monocytes, TP activity was approximately 3 times higher than in lymphocytes. Clinical applicability was demonstrated in samples that were collected from five cancer patients. A simple, precise and sensitive HPLC-UV assay for quantification of TP activity in PBMCs was developed that can be applied for clinical research.

Metastatic and triple-negative breast cancer: challenges and treatment options

The major current conventional types of metastatic breast cancer (MBC) treatments include surgery, radiation, hormonal therapy, chemotherapy, or immunotherapy. Introducing biological drugs, targeted treatment and gene therapy can potentially reduce the mortality and improve the quality of life in patients with MBC. However, combination of several types of treatment is usually recommended. Triple negative breast cancer (TNBC) accounts for 10-20% of all cases of breast carcinoma and is characterized by the low expression of progesterone receptor (PR), estrogen receptor (ER), and human epidermal growth factor receptor 2 (HER2). Consequently, convenient treatments used for MBC that target these receptors are not effective for TNBC which therefore requires special treatment approaches. This review discusses the occurrence of MBC, the prognosis and predictive biomarkers of MBC, and focuses on the novel advanced tactics for treatment of MBC and TNBC. Nanotechnology-based combinatorial approach for the suppression of EGFR by siRNA and gifitinib is described.

Deciphering molecular mechanisms of arginine deiminase-based therapy - Comparative response analysis in paired human primary and recurrent glioblastomas

Arginine auxotrophy constitutes the Achilles' heel for several tumors, among them glioblastoma multiforme (GBM). Hence, arginine-depleting enzymes such as arginine deiminase (ADI) from Streptococcus pyogenes are promising for treatment of primary and maybe even refractory GBM. Based on our previous study in which ADI-susceptibility was shown on a panel of patient-derived GBM cell lines, we here aimed at deciphering underlying molecular mechanisms of ADI-mediated growth inhibition. We found that ADI (35 mU/mL) initially induces a cellular stress-response that is characterized by upregulation of genes primarily belonging to the heat-shock protein family. In addition to autophagocytosis, we show for the first time that senescence constitutes another cellular response mechanism upon ADI-treatment and that this bacterial enzyme is able to act as radiosensitizer (¼ cases). Long-term treatment schedules revealed no resistance development, with treated cells showing morphological signs of cell stress. Next, several combination strategies were employed to optimize ADI-based treatment. Simultaneous and sequential S. pyogenes ADI-based combinations included substances acting at different molecular pathways (curcumin, resveratrol, quinacrine, and sorafenib, 2 × 72 h treatment). Adding drugs to GBM cell lines (n = 4, including a matched pair of primary and recurrent GBM in one case) accelerated and potentiated ADI-mediated cytotoxicity. Autophagy was identified as the main cause of tumor growth inhibition. Of note, residual cells again showed classical signs of senescence in most combinations. Our results suggest an alternative treatment regimen for this fatal cancer type which circumvents many of the traditional barriers. Using the metabolic defect in GBM thus warrants further (pre-) clinical evaluation.

Vinorelbine With Capecitabine, an Evergreen Doublet for Advanced Breast Cancer: A Systematic Literature Review and Pooled-Analysis of Phase II-III Studies

Metastatic breast cancer (MBC) is treated with cytotoxic drugs or endocrine agents according to the site and extent of the disease, biology, previous treatments, and the patient's condition, comorbidities, and wishes. In MBC, vinorelbine (VRB) and capecitabine (X; VRB + X) are chemotherapy drugs that hold activity as first or later lines of therapy. We conducted a systematic literature review and meta-analysis to quantify the efficacy of the VRB + X combination in HER2-negative (HER2^-) MBC. We searched PubMed, EMBASE, SCOPUS, Web of Science, the Cochrane Library, and CINAHL for phase II/III clinical trials that assessed VRB + X for patients with HER2^- MBC. Pooled estimates of the overall response rate (RR), median progression-free survival (PFS), and overall survival (OS) were computed using random or fixed effects models. Twenty-seven studies were included in the analysis, encompassing a total of 1356 MBC patients. All were phase II (n = 21) or prospective/pilot (n = 5) trials, except for 1 that was a phase III controlled trial. The pooled estimate for the RR in first-line therapy (n = 16 trials) was 52.9% (95% confidence interval [CI], 46.5%-59.2%). For second-line trials, data were available in n = 9 studies and the overall RR was 41% (95% CI, 31.2%-51.6%). The pooled estimates for median PFS and OS in first-line therapy were 7.3 (95% CI, 6.2-8.3) and 22.3 (95% CI, 20-24.5) months, respectively. Vinorelbine + X, with the dose and schedules currently used in clinical practice, appears to be an effective and feasible chemotherapy for MBC, for first- and also for second-line therapy.

Effect of CH-35, a novel anti-tumor colchicine analogue, on breast cancer cells overexpressing the βIII isotype of tubulin

The subunit protein of microtubules is tubulin, which has been the target for some of the most successful and widely used anti-tumor drugs. Most of the drugs that target tubulin bind to the β subunit. There are many isotypes of β-tubulin and their distributions differ among different tissues. The βIII isotype is over-expressed in many tumors, particularly those that are aggressive, metastatic, and drug resistant. We have previously reported the design and synthesis of a series of compounds to fit the colchicine site on βIII but not on the other isotypes. In the current study, we tested the toxicity and the anti-tumor activity of one of these compounds, CH-35, on the human breast tumor MDA-MB-231 over-expressing βIII in a xenogeneic mouse model. We found that CH-35 was as toxic as Taxol® in vivo. Although the βIII-over-expressing cells developed into very fast-growing tumors, CH-35 was more effective against this tumor than was Taxol. Our results suggest that CH-35 is a promising candidate for future drug development.

Combination versus sequential single agent chemotherapy for metastatic breast cancer

BACKGROUND

Combination chemotherapy can cause greater tumour cell kill if the drug dose is not compromised, while sequential single agent chemotherapy may allow for greater dose intensity and treatment time, potentially meaning greater benefit from each single agent. In addition, sequentially using single agents might cause less toxicity and impairment of quality of life, but it is not known whether this might compromise survival time.

OBJECTIVES

To assess the effect of combination chemotherapy compared to the same drugs given sequentially in women with metastatic breast cancer.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group Specialised Register, using the search terms "advanced breast cancer" and "chemotherapy", MEDLINE and EMBASE on 31 October 2013. The World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov were also searched (22 March 2012).

SELECTION CRITERIA

Randomised controlled trials of combination chemotherapy compared to the same drugs used sequentially in women with metastatic breast cancer in the first-, second- or third-line setting.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from published trials. Hazard ratios (HR) were derived from time-to-event outcomes where possible, and a fixed-effect model was used for meta-analysis. Response rates were analysed as dichotomous variables (risk ratios (RR)), and toxicity and quality of life data were extracted where available.

MAIN RESULTS

Twelve trials reporting on nine treatment comparisons (2317 patients randomised) were identified. The majority of trials (10 trials) had an unclear or high risk of bias. Time-to-event data were collected for nine trials for overall survival and eight trials for progression-free survival. All 12 trials reported results for tumour response. In the 12 trials there were 1023 deaths in 2317 women randomised. There was no difference in overall survival, with an overall HR of 1.04 (95% confidence interval (CI) 0.93 to 1.16; P = 0.45), and no significant heterogeneity. This result was consistent in the four subgroups analysed (risk of bias, line of chemotherapy, type of schema of chemotherapy, and relative dose intensity). In particular, there was no difference in survival according to the type of schema of chemotherapy, that is whether chemotherapy was given on disease progression or after a set number of cycles. In the eight trials that reported progression-free survival, 678 women progressed out of the 886 women randomised. The combination arm had a higher risk of progression than the sequential arm (HR 1.16; 95% CI 1.03 to 1.31; P = 0.01) with no significant heterogeneity. This result was consistent in all subgroups. Overall tumour response rates were higher in the combination arm (RR 1.13; 95% CI 1.03 to 1.24; P = 0.008) but there was significant heterogeneity for this outcome across the trials. In the seven trials that reported treatment-related deaths, there was no significant difference between the two arms, although the CIs were very wide due to the small number of events (RR 1.53; 95% CI 0.71 to 3.29; P = 0.28). The risk of febrile neutropenia was higher in the combination arm (RR 1.32; 95% CI 1.06 to 1.65; P = 0.01). There was no statistically significant difference in the risk of neutropenia, nausea and vomiting, or treatment-related deaths. Overall quality of life showed no difference between the two groups, but only three trials reported this outcome.

AUTHORS' CONCLUSIONS

Sequential single agent chemotherapy has a positive effect on progression-free survival, whereas combination chemotherapy has a higher response rate and a higher risk of febrile neutropenia in metastatic breast cancer. There is no difference in overall survival time between these treatment strategies, both overall and in the subgroups analysed. In particular, there was no difference in survival according to the schema of chemotherapy (giving chemotherapy on disease progression or after a set number of cycles) or according to the line of chemotherapy (first-line versus second- or third-line). Generally this review supports the recommendations by international guidelines to use sequential monotherapy unless there is rapid disease progression.

Combination versus sequential single agent chemotherapy for metastatic breast cancer

BACKGROUND

Combination chemotherapy can cause greater tumour cell kill if the drug dose is not compromised, while sequential single agent chemotherapy may allow for greater dose intensity and treatment time, potentially meaning greater benefit from each single agent. In addition, sequentially using single agents might cause less toxicity and impairment of quality of life, but it is not known whether this might compromise survival time.

OBJECTIVES

To assess the effect of combination chemotherapy compared to the same drugs given sequentially in women with metastatic breast cancer.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group Specialised Register, using the search terms "advanced breast cancer" and "chemotherapy", MEDLINE and EMBASE on 31 October 2013. The World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov were also searched (22 March 2012).

SELECTION CRITERIA

Randomised controlled trials of combination chemotherapy compared to the same drugs used sequentially in women with metastatic breast cancer in the first-, second- or third-line setting.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from published trials. Hazard ratios (HR) were derived from time-to-event outcomes where possible, and a fixed-effect model was used for meta-analysis. Response rates were analysed as dichotomous variables (risk ratios (RR)), and toxicity and quality of life data were extracted where available.

MAIN RESULTS

Twelve trials reporting on nine treatment comparisons (2317 patients randomised) were identified. The majority of trials (10 trials) had an unclear or high risk of bias. Time-to-event data were collected for nine trials for overall survival and eight trials for progression-free survival. All 12 trials reported results for tumour response. In the 12 trials there were 1023 deaths in 2317 women randomised. There was no difference in overall survival, with an overall HR of 1.04 (95% confidence interval (CI) 0.93 to 1.16; P = 0.45), and no significant heterogeneity. This result was consistent in the four subgroups analysed (risk of bias, line of chemotherapy, type of schema of chemotherapy, and relative dose intensity). In particular, there was no difference in survival according to the type of schema of chemotherapy, that is whether chemotherapy was given on disease progression or after a set number of cycles. In the eight trials that reported progression-free survival, 678 women progressed out of the 886 women randomised. The combination arm had a higher risk of progression than the sequential arm (HR 1.16; 95% CI 1.03 to 1.31; P = 0.01) with no significant heterogeneity. This result was consistent in all subgroups. Overall tumour response rates were higher in the combination arm (RR 1.13; 95% CI 1.03 to 1.24; P = 0.008) but there was significant heterogeneity for this outcome across the trials. In the seven trials that reported treatment-related deaths, there was no significant difference between the two arms, although the CIs were very wide due to the small number of events (RR 1.53; 95% CI 0.71 to 3.29; P = 0.28). The risk of febrile neutropenia was higher in the combination arm (RR 1.32; 95% CI 1.06 to 1.65; P = 0.01). There was no statistically significant difference in the risk of neutropenia, nausea and vomiting, or treatment-related deaths. Overall quality of life showed no difference between the two groups, but only three trials reported this outcome.

AUTHORS' CONCLUSIONS

Sequential single agent chemotherapy has a positive effect on progression-free survival, whereas combination chemotherapy has a higher response rate and a higher risk of febrile neutropenia in metastatic breast cancer. There is no difference in overall survival time between these treatment strategies, both overall and in the subgroups analysed. In particular, there was no difference in survival according to the schema of chemotherapy (giving chemotherapy on disease progression or after a set number of cycles) or according to the line of chemotherapy (first-line versus second- or third-line). Generally this review supports the recommendations by international guidelines to use sequential monotherapy unless there is rapid disease progression.