A phase 2 trial of whole-brain radiotherapy combined with intravenous chemotherapy in patients with brain metastases from breast cancer

Loadability and Releasing Profiles In Vitro and Pharmacokinetics In Vivo of Vinorelbine and Raltitrexed by CalliSpheres Beads

Background: This study investigated the loadability and releasing profiles of vinorelbine and raltitrexed from CalliSpheres® Beads (CB) in vitro, and further explored the pharmacokinetic features of vinorelbine and raltitrexed eluting CB in vivo. Materials and Methods: Ten milligrams vinorelbine and 0.2 mg raltitrexed were mixed with 0.15 g CB at two sizes (100-300 and 300-500 μm) for 24 h, respectively, to measure the loadability. Then vinorelbine/raltitrexed loading CBs were placed in 20% phosphate-buffered saline for 24 h to measure the release profiles. Transcatheter arterial chemoembolization (TACE) with 1 mg vinorelbine eluting CBs (two sizes respectively) and transcatheter arterial hepatic infusion (TAI) with 1 mg vinorelbine were performed in 9 rabbits (3 rabbits in each group). The above experiments were repeated with 0.2 mg raltitrexed. Results: Vinorelbine loading efficiency quickly reached 90% within 10 min with maximum loadability >90% by CB with both two sizes, and vinorelbine release rate gradually increased to ∼100% within 1 h. Raltitrexed loading efficiency gradually increased to >40% within 15 min, then slowly increased to >60% within 24 h, with maximum loadability <70% by CB with both sizes, and raltitrexed release rate gradually increased to >90% within 1 h. Besides, vinorelbine/raltitrexed eluting CB showed greatly decreased maximum serum concentration (Cmax) of the drug compared with TAI in rabbits with similar area under the curve (0-t), mean residence time (0-t), and half-time (T1/2). Conclusion: CB exhibits good loadability and an acceptable releasing profile for eluting vinorelbine and raltitrexed, and shows lower Cmax and numerically stable concentration than TAI.

Systemic treatments for breast cancer brain metastasis

Breast cancer (BC) is the most common cancer in females and BC brain metastasis (BCBM) is considered as the second most frequent brain metastasis. Although the advanced treatment has significantly prolonged the survival in BC patients, the prognosis of BCBM is still poor. The management of BCBM remains challenging. Systemic treatments are important to maintain control of central nervous system disease and improve patients' survival. BCBM medical treatment is a rapidly advancing area of research. With the emergence of new targeted drugs, more options are provided for the treatment of BM. This review features currently available BCBM treatment strategies and outlines novel drugs and ongoing clinical trials that may be available in the future. These treatment strategies are discovered to be more efficacious and potent, and present a paradigm shift in the management of BCBMs.

Investigational chemotherapy and novel pharmacokinetic mechanisms for the treatment of breast cancer brain metastases

In women, breast cancer is the most common cancer diagnosis and second most common cause of cancer death. More than half of breast cancer patients will develop metastases to the bone, liver, lung, or brain. Breast cancer brain metastases (BCBM) confers a poor prognosis, as current therapeutic options of surgery, radiation, and chemotherapy rarely significantly extend life and are considered palliative. Within the realm of chemotherapy, the last decade has seen an explosion of novel chemotherapeutics involving targeting agents and unique dosage forms. We provide a historical overview of BCBM chemotherapy, review the mechanisms of new agents such as poly-ADP ribose polymerase inhibitors, cyclin-dependent kinase 4/6 inhibitors, phosphatidyl inositol 3-kinaseinhibitors, estrogen pathway antagonists for hormone-receptor positive BCBM; tyrosine kinase inhibitors, antibodies, and conjugates for HER2+ BCBM; repurposed cytotoxic chemotherapy for triple negative BCBM; and the utilization of these new agents and formulations in ongoing clinical trials. The mechanisms of novel dosage formulations such as nanoparticles, liposomes, pegylation, the concepts of enhanced permeation and retention, and drugs utilizing these concepts involved in clinical trials are also discussed. These new treatments provide a promising outlook in the treatment of BCBM.

Systemic therapy of brain metastases: non-small cell lung cancer, breast cancer, and melanoma

Brain metastases (BM) occur frequently in many cancers, particularly non-small cell lung cancer (NSCLC), breast cancer, and melanoma. The development of BM is associated with poor prognosis and has an adverse impact on survival and quality of life. Commonly used therapies for BM such as surgery or radiotherapy are associated with only modest benefits. However, recent advances in systemic therapy of many cancers have generated considerable interest in exploration of those therapies for treatment of intracranial metastases.This review discusses the epidemiology of BM from the aforementioned primary tumors and the challenges of using systemic therapies for metastatic disease located within the central nervous system. Cumulative data from several retrospective and small prospective studies suggest that molecularly targeted systemic therapies may be an effective option for the treatment of BM from NSCLC, breast cancer, and melanoma, either as monotherapy or in conjunction with other therapies. Larger prospective studies are warranted to further characterize the efficacy and safety profiles of these targeted agents for the treatment of BM.

Cancer and the metastatic substrate

Seventy percent of cancer patients have detectable metastases when they receive a diagnosis and 90% of cancer deaths result from metastases. These two facts emphasise the urgency for research to study the mechanisms and processes that enable metastasis. We need to develop a greater understanding of the cellular and molecular mechanisms that cause metastasis and also we need to do more. We must also consider the micro- and macro-environmental factors that influence this disease. Studying this environmental context has led us to update the ‘seed and soil’ hypothesis which dates back to the 19th century. This theory describes cancerous cells as seeds and the substrate as the soil in target organs though this may seem antiquated. Nonetheless, the tissue specificity that researchers have recently observed in metastatic colonisation supports the validity of the seed and soil theory. We now know that the metastatic potential of a tumour cell depends on multiple, reciprocal interactions between the primary tumour and distant sites. These interactions determine tumour progression. Studies of metastasis have allowed us to develop treatments that focus on therapeutic effectiveness. These new treatments account for the frequent metastasis of some tumours to target organs such as bones, lungs, brain, and liver. The purpose of this review is first to describe interactions between the cellular and molecular entities and the target organ tumour environment that enables metastasis. A second aim is to describe the complex mechanisms that mediate these interactions.

[Systemic treatment of brain metastases from breast cancer: cytotoxic chemotherapy and targeted therapies]

Prevalence of brain metastases is increasing in breast cancer. Brain metastases represent a poor-prognosis disease for which local treatments continue to play a major role. In spite of the presence of a physiological blood-brain barrier limiting their activity, some systemic treatments may display a significant antitumor activity at the central nervous system level. In HER2-positive metastatic breast cancer with brain metastases not previously treated with whole brain radiotherapy, capecitabine and lapatinib combination obtains a volumetric reponse in two thirds of patients (LANDSCAPE study). If confirmed, these results could modify in selected patients the layout of therapeutic strategies. Promoting novel targeted approaches and innovative therapeutic combinations is a critical need to improve survival of breast cancer patients with brain metastases.

Emerging treatment options for the management of brain metastases in patients with HER2-positive metastatic breast cancer

The widespread use of trastuzumab in the past decade has led to a significant and measureable improvement in the survival of patients with human epidermal growth factor receptor-2 (HER2) overexpressing breast cancer, and in many ways has redefined the natural history of this aggressive breast cancer subtype. Historically, survival in patients with HER2-positive disease was dictated by the systemic disease course, and what appears to be the central nervous system (CNS) tropism associated with HER2-amplified tumors was not clinically evident. With improved systemic control and prolonged survival, the incidence of brain metastases has increased, and CNS disease, often in the setting of well-controlled extracranial disease, is proving to be an increasingly important and clinically challenging cause of morbidity and mortality in patients with HER2-positive advanced breast cancer. This review summarizes the known clinical data for the systemic treatment of HER2-positive CNS metastases and includes information about ongoing clinical trials of novel therapies as well as emerging strategies for early detection and prevention.

Brain metastases from breast cancer: prognostic significance of HER-2 overexpression, effect of trastuzumab and cause of death

Background

To access the prognostic significance of HER-2 overexpression, the effect of trastuzumab and the cause of death in patients with brain metastases (BM) from breast cancer (BC).

Methods

We analyzed the outcome of 130 patients with BM from BC who received whole-brain radiotherapy (WBRT) (without surgery or radiosurgery) between January 1998 and April 2006. Demographic data, tumor characteristics, and treatments were prospectively recorded. The impact of HER-2 overexpression and trastuzumab-based therapy on overall survival (OS) and the cause of death were evaluated.

Results

The median follow-up for the whole population was 6.25 months (mean: 9.15; range: 0.23-53). The median survival time and 1-year survival rates after BM diagnosis were 7.43 months and 35.8% (95% CI: 28-45.7) respectively. The median survival time for HER-2 negative patients (n = 78), HER-2 positive patients not treated with trastuzumab (n = 20) and HER-2 positive patients treated with trastuzumab (n = 32) were 5.9 months, 5.6 months and 19.53 months, respectively. The 1-year survival rates were 26.1%, 29.2% and 62.6% respectively, (p < 0.004). Among the 18 HER-2 positive patients treated with trastuzumab who died, 11 (61%) apparently succumbed from CNS progression, in the face of stable or responsive non-CNS disease. Trastuzumab-based therapy was associated with a 51% reduction in the risk of death (multiadjusted hazard ratio: 0.49; 95% CI, 0.29-0.83).

Conclusions

In our experience, trastuzumab-based therapy for HER-overexpressing tumors was associated with improved survival in BM BC patients. This subgroup of patients may benefit from innovative approaches, in order to obtain better intra cerebral control.

Uptake of ANG1005, a novel paclitaxel derivative, through the blood-brain barrier into brain and experimental brain metastases of breast cancer

PURPOSE

We evaluated the uptake of angiopep-2 paclitaxel conjugate, ANG1005, into brain and brain metastases of breast cancer in rodents. Most anticancer drugs show poor delivery to brain tumors due to limited transport across the blood-brain barrier (BBB). To overcome this, a 19-amino acid peptide (angiopep-2) was developed that binds to low density lipoprotein receptor-related protein (LRP) receptors at the BBB and has the potential to deliver drugs to brain by receptor-mediated transport.

METHODS

The transfer coefficient (K(in)) for brain influx was measured by in situ rat brain perfusion. Drug distribution was determined at 30 min after i.v. injection in mice bearing intracerebral MDA-MB-231BR metastases of breast cancer.

RESULTS

The BBB K(in) for (125)I-ANG1005 uptake (7.3 +/- 0.2 x 10(-3) mL/s/g) exceeded that for (3)H-paclitaxel (8.5 +/- 0.5 x 10(-5)) by 86-fold. Over 70% of (125)I-ANG1005 tracer stayed in brain after capillary depletion or vascular washout. Brain (125)I-ANG1005 uptake was reduced by unlabeled angiopep-2 vector and by LRP ligands, consistent with receptor transport. In vivo uptake of (125)I-ANG1005 into vascularly corrected brain and brain metastases exceeded that of (14)C-paclitaxel by 4-54-fold.

CONCLUSIONS

The results demonstrate that ANG1005 shows significantly improved delivery to brain and brain metastases of breast cancer compared to free paclitaxel.