Taxanes: optimizing adjuvant chemotherapy for early-stage breast cancer

Differential response of immunohistochemically defined breast cancer subtypes to anthracycline-based adjuvant chemotherapy with or without paclitaxel

Background

The aim of the present study was to investigate the efficacy of adjuvant dose-dense sequential chemotherapy with epirubicin, paclitaxel, and CMF in subgroups of patients with high-risk operable breast cancer, according to tumor subtypes defined by immunohistochemistry (IHC).

Materials and Methods

Formalin-fixed paraffin-embedded (FFPE) tumor tissue samples from 1,039 patients participating in two adjuvant dose-dense sequential chemotherapy phase III trials were centrally assessed in tissue micro-arrays by IHC for 6 biological markers, that is, estrogen receptor (ER), progesterone receptor (PgR), HER2, Ki67, cytokeratin 5 (CK5), and EGFR. The majority of the cases were further evaluated for HER2 amplification by FISH. Patients were classified as: luminal A (ER/PgR-positive, HER2-negative, Ki67^low); luminal B (ER/PgR-positive, HER2-negative, Ki67^high); luminal-HER2 (ER/PgR-positive, HER2-positive); HER2-enriched (ER-negative, PgR-negative, HER2-positive); triple-negative (TNBC) (ER-negative, PgR-negative, HER2-negative); and basal core phenotype (BCP) (TNBC, CK5-positive and/or EGFR-positive).

Results

After a median follow-up time of 105.4 months the 5-year disease-free survival (DFS) and overall survival (OS) rates were 73.1% and 86.1%, respectively. Among patients with HER2-enriched tumors there was a significant benefit in both DFS and OS (log-rank test; p = 0.021 and p = 0.006, respectively) for those treated with paclitaxel. The subtype classification was found to be of both predictive and prognostic value. Setting luminal A as the referent category, the adjusted for prognostic factors HR for relapse for patients with TNBC was 1.91 (95% CI: 1.31–2.80, Wald's p = 0.001) and for death 2.53 (95% CI: 1.62–3.60, p<0.001). Site of and time to first relapse differed according to subtype. Locoregional relapses and brain metastases were more frequent in patients with TNBC, while liver metastases were more often seen in patients with HER2-enriched tumors.

Conclusions

Triple-negative phenotype is of adverse prognostic value for DFS and OS in patients treated with adjuvant dose-dense sequential chemotherapy. In the pre-trastuzumab era, the HER2-enriched subtype predicts favorable outcome following paclitaxel-containing treatment.

Extended benefit from sequential administration of docetaxel after standard fluorouracil, epirubicin, and cyclophosphamide regimen for node-positive breast cancer: the 8-year follow-up results of the UNICANCER-PACS01 trial

PURPOSE

The initial report from the Programme Action Concertée Sein (PACS) PACS01 trial demonstrated a benefit at 5 years for disease-free survival (DFS) and overall survival (OS) rates with the sequential administration of docetaxel after FEC100 (fluorouracil 500 mg/m(2), epirubicin 100 mg/m(2), and cyclophosphamide 500 mg/m(2)) for patients with node-positive, operable breast cancer. We evaluate here the impact of this regimen at 8 years.

PATIENTS AND METHODS

Between June 1997 and March 2000, a total of 1,999 patients (age <65) with localized, resectable, non-pretreated, unilateral breast cancer were randomly assigned to receive either standard FEC100 for 6 cycles or 3 cycles of FEC100 followed by 3 cycles of 100 mg/m(2) docetaxel (FEC-D), both given every 21 days. Radiotherapy was mandatory after conservative surgery and tamoxifen was given for 5 years to hormone receptor (HR)-positive patients. Five-year DFS was the trial's main endpoint. Updated 8-year survival data are presented.

RESULTS

With a median follow-up of 92.8 months, 639 patients experienced at least one event. A total number of 383 deaths were registered. Eight-year DFS rates were 65.8% with FEC alone and 70.2% with FEC-D. OS rates at 8 years were 78% with FEC alone and 83.2% with FEC-D. Cox regression analysis adjusted for age and number of positive nodes showed a 15% reduction in the relative risk of relapse and a 25% reduction in the relative risk of death in favor of FEC-D. Significant relative risk reductions were observed in the HR-positive, HER2-positive, and Ki67 ≥20% subpopulations.

CONCLUSION

Benefits for DFS and OS rates with the sequential FEC-D regimen are fully confirmed at 8 years.

The microtubule-stabilizing agent, epothilone D, reduces axonal dysfunction, neurotoxicity, cognitive deficits, and Alzheimer-like pathology in an interventional study with aged tau transgenic mice

Neurodegenerative tauopathies, such as Alzheimer's disease (AD), are characterized by insoluble deposits of hyperphosphorylated tau protein within brain neurons. Increased phosphorylation and decreased solubility has been proposed to diminish normal tau stabilization of microtubules (MTs), thereby leading to neuronal dysfunction. Earlier studies have provided evidence that small molecule MT-stabilizing drugs that are used in the treatment of cancer may have utility in the treatment of tauopathies. However, it has not been established whether treatment with a small molecule MT-stabilizing compound will provide benefit in a transgenic model with pre-existing tau pathology, as would be seen in human patients with clinical symptoms. Accordingly, we describe here an interventional study of the brain-penetrant MT-stabilizing agent, epothilone D (EpoD), in aged PS19 mice with existing tau pathology and related behavioral deficits. EpoD treatment reduced axonal dystrophy and increased axonal MT density in the aged PS19 mice, which led to improved fast axonal transport and cognitive performance. Moreover, the EpoD-treated PS19 mice had less forebrain tau pathology and increased hippocampal neuronal integrity, with no dose-limiting side effects. These data reveal that brain-penetrant MT-stabilizing drugs hold promise for the treatment of AD and related tauopathies, and that EpoD could be a candidate for clinical testing.

Taxane resistance in breast cancer: mechanisms, predictive biomarkers and circumvention strategies

BACKGROUND

Taxanes are established in the treatment of metastatic breast cancer (MBC) and early breast cancer (EBC) as potent chemotherapy agents. However, their therapeutic usefulness is limited by de-novo refractoriness or acquired resistance, which are common drawbacks to most anti-cancer cytotoxics. Considering that the taxanes will remain principle chemotherapeutic agents for the treatment of breast cancer, we reviewed known mechanisms of resistance in with an outlook of optimizing their clinical use.

METHODS

We searched the PubMed and MEDLINE databases for articles (from inception through to 9th January 2012; last search 10/01/2012) and journals known to publish information relevant to taxane chemotherapy. We imposed no language restrictions. Search terms included: cancer, breast cancer, response, resistance, taxane, paclitaxel, docetaxel, taxol. Due to the possibility of alternative mechanisms of resistance all combination chemotherapy treated data sets were removed from our overview.

RESULTS

Over-expression of the MDR-1 gene product Pgp was extensively studied in vitro in association with taxane resistance, but data are conflicting. Similarly, the target components microtubules, which are thought to mediate refractoriness through alterations of the expression pattern of tubulins or microtubule associated proteins and the expression of alternative tubulin isoforms, failed to confirm such associations. Little consensus has been generated for reported associations between taxane-sensitivity and mutated p53, or taxane-resistance and overexpression of Bcl-2, Bcl-xL or NFkB. In contrary sufficient in vitro data support an association of spindle assembly checkpoint (SAC) defects with resistance. Clinical data have been limited and inconsistent, which relate to the variety of methods used, lack of standardization of cut-offs for quantitation, differences in clinical endpoints measured and in methods of tissue collection preparation and storage, and study/patient heterogeneity. The most prominent finding is that pharmaceutical down-regulation of HER-2 appears to reverse the taxane resistance.

CONCLUSIONS

Currently no valid practical biomarkers exist that can predict resistance to the taxanes in breast cancer supporting the principle of individualized cancer therapy. The incorporation of several biomarker analyses into prospectively designed studies in this setting are needed.

Pericardial Breast Cancer Metastasis 25 Years after Mastectomy

Pericardial effusion in a patient with a history of cancer should always prompt a hypothesis of malignant involvement. We report the case of a 66-year-old white woman presenting with pericardial effusion 25 years after a mastectomy for ductal breast carcinoma. This is one of the cases with the latest recurrence ever reported.

Protein expression, survival and docetaxel benefit in node-positive breast cancer treated with adjuvant chemotherapy in the FNCLCC-PACS 01 randomized trial

INTRODUCTION

The PACS01 trial has demonstrated that a docetaxel addition to adjuvant anthracycline-based chemotherapy improves disease-free survival (DFS) and overall survival of node-positive early breast cancer (EBC). We searched for prognostic and predictive markers for docetaxel's benefit.

METHODS

Tumor samples from 1,099 recruited women were analyzed for the expression of 34 selected proteins using immunohistochemistry. The prognostic and predictive values of each marker and four molecular subtypes (luminal A, luminal B, HER2-overexpressing, and triple-negative) were tested.

RESULTS

Progesterone receptor-negativity (HR = 0.66; 95% CI 0.47 to 0.92, P = 0.013), and Ki67-positivity (HR = 1.53; 95% CI 1.12 to 2.08, P = 0.007) were independent adverse prognostic factors. Out of the 34 proteins, only Ki67-positivity was associated with DFS improvement with docetaxel addition (adjusted HR = 0.51, 95% CI 0.33 to 0.79 for Ki67-positive versus HR = 1.10, 95% CI 0.75 to 1.61 for Ki67-negative tumors, P for interaction = 0.012). Molecular subtyping predicted the docetaxel benefit, but without providing additional information to Ki67 status. The luminal A subtype did not benefit from docetaxel (HR = 1.16, 95% CI 0.73 to 1.84); the reduction in the relapse risk was 53% (HR = 0.47, 95% CI 0.22 to 1.01), 34% (HR = 0.66, 95% CI 0.37 to 1.19), and 12% (HR = 0.88, 95% CI 0.49 to 1.57) in the luminal B, HER2-overexpressing, and triple-negative subtypes, respectively.

CONCLUSIONS

In patients with node-positive EBC receiving adjuvant anthracycline-based chemotherapy, the most powerful predictor of docetaxel benefit is Ki67-positivity.

Discovery of 7-hydroxy-6-methoxy-2-methyl-3-(3,4,5-trimethoxybenzoyl)benzo[b]furan (BNC105), a tubulin polymerization inhibitor with potent antiproliferative and tumor vascular disrupting properties

A structure-activity relationship (SAR) guided design of novel tubulin polymerization inhibitors has resulted in a series of benzo[b]furans with exceptional potency toward cancer cells and activated endothelial cells. The potency of early lead compounds has been substantially improved through the synergistic effect of introducing a conformational bias and additional hydrogen bond donor to the pharmacophore. Screening of a focused library of potent tubulin polymerization inhibitors for selectivity against cancer cells and activated endothelial cells over quiescent endothelial cells has afforded 7-hydroxy-6-methoxy-2-methyl-3-(3,4,5-trimethoxybenzoyl)benzo[b]furan (BNC105, 8) as a potent and selective antiproliferative. Because of poor solubility, 8 is administered as its disodium phosphate ester prodrug 9 (BNC105P), which is rapidly cleaved in vivo to return the active 8. 9 exhibits both superior vascular disrupting and tumor growth inhibitory properties compared with the benchmark agent combretastatin A-4 disodium phosphate 5 (CA4P).

Developing therapeutic approaches to tau, selected kinases, and related neuronal protein targets

A hallmark of the Alzheimer disease (AD) brain is the presence of inclusions within neurons that are comprised of fibrils formed from the microtubule-stabilizing protein tau. The formation of misfolded multimeric tau species is believed to contribute to the progressive neuron loss and cognitive impairments of AD. Moreover, mutations in tau have been shown to cause a form of frontotemporal lobar degeneration in which tau neuronal inclusions observed in the brain are similar to those seen in AD. Here we review the more compelling strategies that are designed to reduce the contribution of misfolded tau to AD neuropathology, including those directed at correcting a possible loss of tau function resulting from sequestration of cellular tau and to minimizing possible gain-of-function toxicities caused by multimeric tau species. Finally, we discuss the challenges and potential benefits of tau-directed drug discovery programs.

Eribulin (Halaven): a new, effective treatment for women with heavily pretreated metastatic breast cancer

Although metastatic breast cancer remains essentially incurable, many patients previously treated with an anthracycline, taxane, and capecitabine are relatively fit and keen to receive further therapy. Several drugs are used in this setting, but with little evidence of clinically relevant benefit, and none have previously shown improved survival. Eribulin (Halaven®) is a nontaxane tubulin-binding agent with a novel mode of action, and was recently approved by the European Medicines Agency and US Food and Drug Agency as a single agent for patients with heavily pretreated metastatic breast cancer. This review provides an overview of the discovery, and preclinical and clinical development of eribulin, culminating in the recently published EMBRACE metastatic breast cancer study.

18F-fluorodeoxyglucose positron emission tomography optimizes neoadjuvant chemotherapy for primary breast cancer to achieve pathological complete response

BACKGROUND

To assess the usefulness of positron emission tomography combined with computed tomography using (18)F-fluorodeoxyglucose (FDG PET/CT) for optimizing chemotherapy during neoadjuvant chemotherapy for primary breast cancer.

METHODS

One hundred and eight patients (110 tumors) with breast cancer (≥2 cm, stages II and III) received neoadjuvant chemotherapy consisting of an anthracycline-based regimen and taxane. The maximal value of the baseline standardized uptake value (SUV) and the change in SUV after four cycles of an anthracycline-based regimen relative to baseline SUV were assessed for predicting pathological complete response (pCR) after sequential taxane.

RESULTS

Tumors with pCR had significantly higher baseline SUV (9.3 ± 3.7 SD) compared to those with non-pCR (7.2 ± 3.8 SD) (p = 0.02), but there was a considerable overlap between two groups. On PET scan after four cycles of chemotherapy, thirty-three patients (33.7%) with a 72.1% or greater reduction in SUV were considered as responders and the performance in predicting pCR had a sensitivity of 88.9% and specificity of 78.7%.

CONCLUSION

The baseline SUV could not be a useful indicator for predicting pCR due to the wide range in sensitivity. On the other hand, a relative change in SUV after completion of an anthracycline-based regimen could be useful for predicting pCR.

Breast cancer medications and vision: effects of treatments for early-stage disease

This review concerns the effects on vision and the eye of medications prescribed at three phases of treatment for women with early-stage breast cancer (BC): (1) adjuvant cytotoxic chemotherapy, (2) adjuvant endocrine therapy, and (3) symptomatic relief. The most common side effects of cytotoxic chemotherapy are epiphora and ocular surface irritation, which can be caused by any of several different regimens. Most notably, the taxane docetaxel can lead to epiphora by inducing canalicular stenosis. The selective-estrogen-receptor-modulator (SERM) tamoxifen, long the gold-standard adjuvant-endocrine-therapy for women with hormone-receptor-positive BC, increases the risk of posterior subcapsular cataract. Tamoxifen also affects the optic nerve head more often than previously thought, apparently by causing subclinical swelling within the first 2 years of use for women older than ∼50 years. Tamoxifen retinopathy is rare, but it can cause foveal cystoid spaces that are revealed with spectral-domain optical coherence tomography (OCT) and that may increase the risk for macular holes. Tamoxifen often alters the perceived color of flashed lights detected via short-wavelength-sensitive (SWS) cone response isolated psychophysically; these altered perceptions may reflect a neural-response sluggishness that becomes evident at ∼2 years of use. The aromatase inhibitor (AI) anastrozole affects perception similarly, but in an age-dependent manner suggesting that the change of estrogen activity towards lower levels is more important than the low estrogen activity itself. Based on analysis of OCT retinal thickness data, it is likely that anastrozole increases the tractional force between the vitreous and retina. Consequently, AI users, myopic AI users particularly, might be at increased risk for traction-related vision loss. Because bisphosphonates are sometimes prescribed to redress AI-induced bone loss, clinicians should be aware of their potential to cause scleritis and uveitis occasionally. We conclude by suggesting some avenues for future research into the visual and ocular effects of AIs, particularly as relates to assessment of cognitive function.

In vivo MRI of early stage mammary cancers and the normal mouse mammary gland

Since the advent of screening mammography, approximately one-quarter of newly diagnosed breast cancers are at the earliest preinvasive stage of ductal carcinoma in situ (DCIS). Concomitant with this improvement in early detection has been a growing clinical concern that distinguishing aggressive from indolent DCIS is necessary to optimize patient management. Genetically engineered mouse models offer an appealing experimental framework in which to investigate factors that influence and predict progression of preinvasive neoplasias. Because of the small size of early stage carcinomas in mice, high-resolution imaging techniques are required to effectively observe longitudinal progression. The purpose of the present study was to evaluate the feasibility of MRI for assessment of in situ mammary neoplasias and early invasive mammary cancers that stochastically arise in mammary glands of C3(1) SV40 Tag transgenic mice. Additionally, images of normal mammary glands from wild-type FVB/N mice were acquired and compared with those from transgenic mice. Sixteen mice underwent MR examinations employing axial two-dimensional multi-slice gradient recalled echo scans (TR/TE =∼1000/5.5 ms) with fat suppression in a two-step process targeting both the upper and lower mammary glands. MRI successfully detected in situ and early invasive neoplasias in transgenic mice with high sensitivity and specificity. The average signal-to-noise ratio (SNR) of in situ lesions on fat-suppressed high-resolution T(1) -weighted images was 22.9, which was lower than that of invasive tumors, lymph nodes and muscle (average SNR of 29.5-34.9, p < 0.0001) but significantly higher than that of normal mammary tissue (average SNR = 5.5, p < 0.0001). Evaluation of wild-type mammary glands revealed no cancerous or benign lesions, and comparable image contrast characteristics (average SNR = 5.2) as compared with normal tissue areas of transgenic mice. This present study demonstrates that MRI is an excellent candidate for performing longitudinal assessment of early stage mammary cancer disease progression and response to therapy in the transgenic model system.

Selective targeting of breast cancer cells through ROS-mediated mechanisms potentiates the lethality of paclitaxel by a novel diterpene, gelomulide K

Defects in apoptotic pathways confer resistance to tubulin-binding agents via downregulation of caspases or overexpression of antiapoptotic factors, urging the need for novel agents acting on an alternative pathway. The purpose of this study was to investigate whether induction of ROS can induce caspase-independent cell death in breast cancer cells and thereby enhance the activity of paclitaxel. Here, we report that gelomulide K acts as a caspase-independent cell death-inducing agent that synergizes with paclitaxel in breast cancer cells and has low toxicity in normal cells. Treatment with gelomulide K induced PARP-1 hyperactivation, AIF nuclear translocation, and cytoprotective autophagy. These effects were associated with increased ROS production and a decrease in cellular GSH levels in cancer cells. Furthermore, pretreatment with NAC, a precursor of intracellular GSH, effectively abrogated gelomulide K-induced caspase-independent cell death and autophagy, suggesting that ROS-mediated downstream signaling is essential to the anticancer effects of gelomulide K. Additionally, in a xenograft model, gelomulide K induced PARP-1 activation and reduced tumor growth. In terms of structure-activity relationships, analysis not only showed a correlation between ROS levels and drug activity but also highlighted the importance of the 8,14-epoxy group. Taken together, our results show that enhancement of paclitaxel activity can be achieved with gelomulide K and that the structurally relevant pharmacophore provides important insight into the development of new caspase-independent cell death-inducing agents.

Zoledronic acid for adjuvant use in patients with breast cancer

Zoledronic acid, a nitrogen-containing bisphosphonate, is firmly established in the management of metastatic bone disease. It inhibits farnesyl diphosphonate synthase within the mevalonate pathway and, through this mechanism, is a potent inhibitor of osteoclast-mediated bone resorption. In addition, there are preclinical data suggesting that farnesyl diphosphonate synthase inhibition by zoledronic acid has anti-tumor effects in breast cancer. Adjuvant therapies for early breast cancer are associated with substantial decreases in bone mineral density. Results from three clinical trials, ABCSG-12, Z-FAST and ZO-FAST, indicate that the addition of twice-yearly zoledronic acid to standard adjuvant endocrine therapy in premenopausal and postmenopausal patients with hormone receptor-positive breast cancer prevents cancer treatment-induced bone loss. Moreover, it is becoming evident that it may also exert anticancer effects in an estrogen-deprived state in the adjuvant and neoadjuvant setting. However, long-term side effects need to be taken into consideration for treatment decisions.

Taxane-based regimens as a risk factor for chemotherapy-induced amenorrhea

OBJECTIVE

The objective of our study was to show the impact of different chemotherapy regimens on the incidence of amenorrhea (chemotherapy-induced amenorrhea [CIA]) in premenopausal women of various ages with breast cancer.

METHODS

This is a follow-up study of 226 premenopausal women with breast cancer who had received one of three chemotherapy regimens: conventional (cyclophosphamide/methotrexate/5-fluorouracil), anthracycline based, and anthracycline-taxane based. They were evaluated for the incidence of CIA in the follow-up clinic of the Iranian Center for Breast Cancer. A statistical analysis using SPSS software was performed, and logistic regression and Cox regression model were used to determine the risk factors for CIA.

RESULTS

Of the 226 women with a median age of 40 years (range, 26-56 y) who participated in this study, 154 (68.1%) developed CIA. In 101 (65.6%) of these women, CIA was established. CIA was present in 52.5% of the women who had been treated with conventional regimens (cyclophosphamide/methotrexate/5-fluorouracil), 66.7% of the women who had been treated with anthracycline, and 78.7% of the women who had been treated with anthracycline-taxane. Therefore, the frequency of CIA was significantly higher in the taxane-based chemotherapy group than in the other groups (P = 0.015). Although a slightly higher incidence of CIA in women with hormone-insensitive tumors (estrogen receptor negative and progesterone receptor negative) versus hormone-sensitive tumors (estrogen receptor positive and progesterone receptor positive) who had been treated with combination regimens was observed, no statistically significant difference was found (P = 0.629). Of all of the risk factors that were evaluated in the study, anthracycline-taxane-based regimens (odds ratio, 4.059; 95% CI, 1.6-9.8) and age older than 40 years (odds ratio, 3.5; 95% CI, 1.9-6.6) were the most important factors in the development of CIA.

CONCLUSIONS

The type of chemotherapy and the age of the woman at the onset of breast cancer are the most important risk factors in CIA. Taxane-based regimens induced more CIA than did other regimens.

Adjuvant Systemic Therapy of Breast Cancer

The first procedure in primary breast cancer is usually the surgical excision of the tumor. However, a medical therapy is necessary in almost all patients to treat the systemic component of the disease. Which medical approach is recommended depends on the biology of the tumor itself. Endocrine-responsive tumors must be treated by an endocrine therapy according to their menopausal status. In HER2/neu-overexpressing tumors, the monoclonal antibody trastuzumab is part of the standard treatment in combination with chemotherapy. Hormone receptor-negative and non-HER2/neu-overexpressing tumors as well as endocrine-responsive tumors with a high proliferation index or additional risk factors must be treated with chemotherapy as well. This review article gives further information about the available agents and schedules.

Prospective evaluation of prognostic factors uPA/PAI-1 in node-negative breast cancer: phase III NNBC3-Europe trial (AGO, GBG, EORTC-PBG) comparing 6×FEC versus 3×FEC/3×Docetaxel

BACKGROUND

Today, more than 70% of patients with primary node-negative breast cancer are cured by local therapy alone. Many patients receive overtreatment by adjuvant chemotherapy due to inadequate risk assessment. So far, few clinical trials have prospectively evaluated tumor biology based prognostic factors. Risk assessment by a biological algorithm including invasion factors urokinase-type plasminogen activator (uPA) and its inhibitor plasminogen activator inhibitor type 1 (PAI-1) will assess up to 35-55% of node-negative patients as low-risk and thus avoid chemotherapy. In contrast, a clinical-pathological algorithm will only classify 20-40% of patients as low-risk. High-risk node-negative patients should receive chemotherapy. Anthracycline-based regimens are accepted as a standard, the additional benefit of taxanes remains an open question.

METHODS/DESIGN

The international NNBC3 ("Node Negative Breast Cancer 3-Europe") trial compares biological risk assessment (UP) using invasion factors uPA/PAI-1 with a clinical-pathological algorithm (CP). In this trial, the type of risk assessment (CP or UP) was chosen upfront by each center for its patients. Fresh frozen tissue was obtained to determine uPA/PAI-1 using an enzyme-linked immunosorbent assay (ELISA). Patients assessed as high-risk were stratified by human epidermal growth factor receptor 2 (HER2) status and then randomised to receive anthracycline-containing chemotherapy 5-Fluorouracil (F)/Epirubicin (E)/Cyclophosphymide (C) or an anthracycline-taxane sequence (FE(100)C*6 versus FE(100)C*3 followed by Docetaxel(100)*3).

DISCUSSION

In this trial, 4,149 node-negative patients with operable breast cancer from 153 centers in Germany and France were included since 2002. Measurement of uPA/PAI-1 by ELISA was performed with standardised central quality assurance for 2,497 patients (60%) from 56 "UP"-centers. The NNBC 3-Europe trial showed that inclusion of patients into a clinical phase III trial is feasible based on biological testing of fresh frozen tumor material. In addition, 2,661 patients were classified as high-risk and thus received chemotherapy. As adjuvant chemotherapy, 1,334 high-risk patients received FE(100)C-Docetaxel(100), and 1,327 received French FE(100)C. No unexpected toxicities were observed. Chemotherapy efficacy and comparison of UP with CP will be evaluated after longer follow-up.

TRIAL REGISTRATION

clinical Trials.gov NCT01222052.

Breast cancer and fertility preservation

OBJECTIVE

To review the benefits of adjuvant systemic therapy given to women with breast cancer of reproductive age, its effects on fertility, and options for fertility preservation.

DESIGN

Publications relevant to fertility preservation and breast cancer were identified through a PubMed database search.

CONCLUSION(S)

Most women who develop invasive breast cancer under age 40 will be advised to undergo adjuvant chemotherapy with or without extended antihormonal therapy to reduce the risk of recurrence and death from breast cancer. Adjuvant chemotherapy particularly with alkylating agents such as cyclophosphamide is gonadotoxic and markedly accelerates the rate of age-related ovarian follicle loss. Although loss of fertility is an important issue for young cancer survivors, there is often little discussion about fertility preservation before initiation of adjuvant therapy. Greater familiarity with prognosis and effects of different types of adjuvant therapy on the part of infertility specialists and fertility preservation options such cryopreservation of embryos, oocytes, and ovarian tissue on the part of oncologists would facilitate these discussions. Establishment of rapid fertility consultation links within cancer survivorship programs can help ensure that every young woman who is likely to undergo gonadotoxic cancer treatment is counseled about the effects of therapy and options available to her to increase the likelihood of childbearing after cancer treatment.

Prognostic utility of β-tubulin isotype III and correlations with other molecular and clinicopathological variables in patients with early breast cancer: a translational Hellenic Cooperative Oncology Group (HeCOG) study

We evaluated the prognostic and predictive utility of β-tubulin isotype III (TUBB3) tumour gene transcription in early breast cancer patients enrolled in a randomised study. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was applied for assessment of TUBB3, ER, PgR, HER2 and MAPT messenger RNA and immunohistochemistry (IHC) for protein expression in 314 patients enrolled in trial HE10/97, evaluating epirubicin-alkylator adjuvant chemotherapy with or without paclitaxel. High TUBB3 mRNA status was associated with advanced T stage, high histological grade, low mRNA and protein levels of ER, PgR and MAPT, and high levels of HER2 (p < 0.001). At a median follow-up of 98 months, multivariate analysis showed high TUBB3 mRNA status to have prognostic significance for DFS (HR = 1.83, 95% CI 1.25-2.68, p = 0.002) and OS (HR = 1.71, 95% CI 1.03-2.83, p = 0.038), along with the number of involved axillary nodes, PgR mRNA status and tumour grade. TUBB3 mRNA levels did not predict benefit from inclusion of paclitaxel in adjuvant chemotherapy (test for interaction p = 0.96 for OS, p = 0.46 for DFS). Transcriptional activity of β-tubulin isotype III in early breast cancer is an adverse prognostic factor, though not a predictive one for taxane efficacy.

High estrogen receptor expression in early breast cancer: chemotherapy needed to improve RFS?

One of the most controversial questions in early breast cancer treatment is the need of chemotherapy in patients with estrogen receptor positive disease. Therefore, we analyzed a group of patients with high estrogen receptor (ER) expression to scrutinize the role of chemotherapy in this situation. To gauge the effect of chemotherapy on recurrence free survival (RFS) three treatment modalities were compared: endocrine treatment only, chemoendocrine treatment, and chemotherapy. 3,971 breast cancer patients whose treatment modalities as well as ER level were known, were included in this retrospective analysis. Their level of ER expression was documented as immunoreactive score (IRS). A high ER group was defined as ER IRS ≥ 9; primary endpoint was RFS. RFS was associated with ER, with the best outcome for strong and the worst result for negative expression. Adjusted to Nottingham prognostic index (NPI), RFS did not differ between the treatment cohorts of endocrine treatment and chemoendocrine treatment (P = 0.828) in the high ER group. Patients with chemotherapy alone fared significantly worse (P = 0.003). Even in high risk patients (according to NPI) the chemoendocrine and the endocrine treatment only groups did not differ significantly (HR = 1.15; 95% CI (0.56-2.34), P = 0.709). Omission of endocrine treatment led to significantly worse outcome (P = 0.013). In conclusion, RFS was significantly longer in patients with high ER expression than with weak or no ER expression. In the high expression group, there was no significant difference in RFS between endocrine treatment only and chemoendocrine therapy-even in high risk patients, for whom chemoendocrine treatment is routinely indicated. It seems insufficient for high ER patients to only consider tumor size, nodal status, and grading in order to decide which patient will benefit from adding chemotherapy to endocrine treatment.

The characterization of microtubule-stabilizing drugs as possible therapeutic agents for Alzheimer's disease and related tauopathies

Tau, a protein that is enriched in neurons of the central nervous system (CNS), is thought to play a critical role in the stabilization of microtubules (MTs). Several neurodegenerative disorders referred to as tauopathies, including Alzheimer's disease and certain types of frontotemporal lobar degeneration, are characterized by the intracellular accumulation of hyperphosphorylated tau fibrils. Tau deposition into insoluble aggregates is believed to result in a loss of tau function that leads to MT destabilization, and this could cause neurodegeneration as intact MTs are required for axonal transport and normal neuron function. This tau loss-of-function hypothesis has been validated in a tau transgenic mouse model with spinal cord tau inclusions, where the MT-stabilizing agent, paclitaxel, increased spinal nerve MT density and improved motor function after drug absorption at neuromuscular junctions. Unfortunately, paclitaxel is a P-glycoprotein substrate and has poor blood-brain barrier permeability, making it unsuitable for the treatment of human tauopathies. We therefore examined several MT-stabilizing compounds from the taxane and epothilone natural product families to assess their membrane permeability and to determine whether they act as substrates or inhibitors of P-glycoprotein. Moreover, we compared brain and plasma levels of the compounds after administration to mice. Finally, we assessed whether brain-penetrant compounds could stabilize mouse CNS MTs. We found that several epothilones have significantly greater brain penetration than the taxanes. Furthermore, certain epothilones cause an increase in CNS MT stabilization, with epothilone D demonstrating a favorable pharmacokinetic and pharmacodynamic profile which suggests this agent merits further study as a potential tauopathy drug candidate.

Shared and separate functions of polo-like kinases and aurora kinases in cancer

Large numbers of inhibitors for polo-like kinases and aurora kinases are currently being evaluated as anticancer drugs. Interest in these drugs is fuelled by the idea that these kinases have unique functions in mitosis. Within the polo-like kinase family, the emphasis for targeted therapies has been on polo-like kinase 1 (PLK1), and in the aurora kinase family drugs have been developed to specifically target aurora kinase A (AURKA; also known as STK6) and/or aurora kinase B (AURKB; also known as STK12). Information on the selectivity of these compounds in vivo is limited, but it is likely that off-target effects within the same kinase families will affect efficacy and toxicity profiles. In addition, it is becoming clear that interplay between polo-like kinases and aurora kinases is much more extensive than initially anticipated, and that both kinase families are important factors in the response to classical chemotherapeutics that damage the genome or the mitotic spindle. In this Review we discuss the implications of these novel insights on the clinical applicability of polo-like kinase and aurora kinase inhibitors.

Epothilone D improves microtubule density, axonal integrity, and cognition in a transgenic mouse model of tauopathy

Neurons in the brains of those with Alzheimer's disease (AD) and many frontotemporal dementias (FTDs) contain neurofibrillary tangles comprised of hyperphosphorylated tau protein. Tau normally stabilizes microtubules (MTs), and tau misfolding could lead to a loss of this function with consequent MT destabilization and neuronal dysfunction. Accordingly, a possible therapeutic strategy for AD and related "tauopathies" is treatment with a MT-stabilizing anti-cancer drug such as paclitaxel. However, paclitaxel and related taxanes have poor blood-brain barrier permeability and thus are unsuitable for diseases of the brain. We demonstrate here that the MT-stabilizing agent, epothilone D (EpoD), is brain-penetrant and we subsequently evaluated whether EpoD can compensate for tau loss-of-function in PS19 tau transgenic mice that develop forebrain tau inclusions, axonal degeneration and MT deficits. Treatment of 3-month-old male PS19 mice with low doses of EpoD once weekly for a 3 month period significantly improved CNS MT density and axonal integrity without inducing notable side-effects. Moreover, EpoD treatment reduced cognitive deficits that were observed in the PS19 mice. These results suggest that certain brain-penetrant MT-stabilizing agents might provide a viable therapeutic strategy for the treatment of AD and FTDs.

Chemotherapy resistance in metastatic breast cancer: the evolving role of ixabepilone

Resistance to chemotherapy is a major obstacle to the effective treatment of many tumor types. Although many anticancer therapies can alter tumor growth, in most cases the effect is not long lasting. Consequently, there is a significant need for new agents with low susceptibility to common drug resistance mechanisms in order to improve response rates and potentially extend survival. Approximately 30% of the women diagnosed with early-stage disease in turn progress to metastatic breast cancer, for which therapeutic options are limited. Current recommendations for first-line chemotherapy include anthracycline-based regimens and taxanes (paclitaxel and docetaxel). They typically give response rates of 30 to 70% but the responses are often not durable, with a time to progression of 6 to 10 months. Patients with progression or resistance may be administered capecitabine, gemcitabine, vinorelbine, albumin-bound paclitaxel, or ixabepilone, while other drugs are being evaluated. Response rates in this setting tend to be low (20 to 30%); the median duration of responses is <6 months and the results do not always translate into improved long-term outcomes. The present article reviews treatment options in taxane-resistant metastatic breast cancer and the role of ixabepilone in this setting.

Anthracycline and concurrent radiotherapy as adjuvant treatment of operable breast cancer: a retrospective cohort study in a single institution

Background

Concurrent chemoradiotherapy (CCRT) after breast surgery was investigated by few authors and remains controversial, because of concerns of toxicity with taxanes/anthracyclines and radiation. This treatment is not standard and is more commonly used for locally advanced breast cancer. The aim of our study was to evaluate the efficacy and safety of the concomitant use of anthracycline with radiotherapy (RT).

Findings

Four hundred women having operable breast cancer, treated by adjuvant chemotherapy (CT) and RT in concomitant way between January 2001 and December 2003, were included in this retrospective cohort study. The study compares 2 adjuvant treatments using CCRT, the first with anthracycline (group A) and the second with CMF (group B). The CT treatment was repeated every 21 days for 6 courses and the total delivered dose of RT was 50 Gy, divided as 2 Gy daily fractions. Locoregional recurrence free (LRFS), event free (EFS), and overall survivals (OS) were estimated by the Kaplan-Meier method. The log-rank test was used to compare survival events. Multivariate Cox-regression was used to evaluate the relationship between patient characteristics, treatment and survival.

In the 2 groups (A+B) (n = 400; 249 in group A and 151 in group B), the median follow-up period was 74.5 months. At 5 years, the isolated LRFS was significantly higher in group A compared to group B (98.7% vs 95.3%; hazard ratio [HR] = 0.258; 95% CI, 0.067 to 0.997; log-rank P = .034). In addition, the use of anthracycline regimens was associated with a higher rate of 5 years EFS (80.4% vs 75.1%; HR = 0.665; 95% CI, 0.455 to 1.016; log-rank P = .057). The 5 years OS was 83.2% and 79.2% in the anthracycline and CMF groups, respectively (HR = 0.708; 95% CI, 0.455 to 1.128; log-rank P = .143). Multivariate analysis confirmed the positive effect of anthracycline regimens on LRFS (HR = 0.347; 95% CI, 0.114 to 1.053; log-rank P = .062), EFS (HR = 0.539; 95% CI, 0.344 to 0.846; P = 0.012), and OS (HR = 0.63; 95% CI, 0.401 to 0.991; P = .046). LRFS, EFS and OS were significantly higher in the anthracycline group where the patients (n = 288) received more than 1 cycle of concurrent CT (P = .038, P = .026 and P = .038, respectively). LRFS and EFS were significantly higher in the anthracycline group within the BCT subgroup (P = .049 and P = .04, respectively). There were more hematologic, and more grade 2/3/4 skin toxicity in the anthracycline group.

Conclusions

After mastectomy or BCT, the adjuvant treatment based on anthracycline and concurrent RT reduced breast cancer relapse rate, and significantly improved LRFS, EFS and OS in the patients receiving more than 1 cycle of concurrent CT. There were more hematologic and non hematologic toxicities in the anthracycline group.

RHAMM promotes interphase microtubule instability and mitotic spindle integrity through MEK1/ERK1/2 activity

An oncogenic form of RHAMM (receptor for hyaluronan-mediated motility, mouse, amino acids 163-794 termed RHAMM(Delta163)) is a cell surface hyaluronan receptor and mitotic spindle protein that is highly expressed in aggressive human cancers. Its regulation of mitotic spindle integrity is thought to contribute to tumor progression, but the molecular mechanisms underlying this function have not previously been defined. Here, we report that intracellular RHAMM(Delta163) modifies the stability of interphase and mitotic spindle microtubules through ERK1/2 activity. RHAMM(-/-) mouse embryonic fibroblasts exhibit strongly acetylated interphase microtubules, multi-pole mitotic spindles, aberrant chromosome segregation, and inappropriate cytokinesis during mitosis. These defects are rescued by either expression of RHAMM or mutant active MEK1. Mutational analyses show that RHAMM(Delta163) binds to alpha- and beta-tubulin protein via a carboxyl-terminal leucine zipper, but in vitro analyses indicate this interaction does not directly contribute to tubulin polymerization/stability. Co-immunoprecipitation and pulldown assays reveal complexes of RHAMM(Delta163), ERK1/2-MEK1, and alpha- and beta-tubulin and demonstrate direct binding of RHAMM(Delta163) to ERK1 via a D-site motif. In vitro kinase analyses, expression of mutant RHAMM(Delta163) defective in ERK1 binding in mouse embryonic fibroblasts, and blocking MEK1 activity collectively confirm that the effect of RHAMM(Delta163) on interphase and mitotic spindle microtubules is mediated by ERK1/2 activity. Our results suggest a model wherein intracellular RHAMM(Delta163) functions as an adaptor protein to control microtubule polymerization during interphase and mitosis as a result of localizing ERK1/2-MEK1 complexes to their tubulin-associated substrates.