A systematic review of bevacizumab efficacy in breast cancer

Pharmacogenetics and breast cancer management: current status and perspectives

INTRODUCTION

Breast cancer has benefited from a number of innovative therapeutics over the last decade. Cytotoxics, hormone therapy, targeted therapies and biologics can now be given to ensure optimal management of patients. As life expectancy of breast cancer patients has been significantly stretched and that several lines of treatment are now made available, determining the best drug or drug combinations to be primarily given and the best dosing and scheduling for each patient is critical for ensuring an optimal toxicity/efficacy balance.

AREAS COVERED

Defining patient's characteristics at the tumor level (pharmacogenomics) and the constitutional level (pharmacogenetics) is a rising trend in oncology. This review covers the latest strategies based upon the search of relevant biomarkers for efficacy, resistance and toxicity to be undertaken at the bedside to shift towards precision medicine in breast cancer patients.

EXPERT OPINION

In the expanding era of bioguided medicine, identifying relevant and clinically validated biomarkers from the plethora of published material remains an uneasy task. Sorting the variety of genetic and molecular markers that have been investigated over the last decade on their level of evidence and addressing the issue of drug exposure should help to improve the management of breast cancer therapy.

Novel antiangiogenic drugs for the management of breast cancer: new approaches for an old issue?

Since angiogenesis plays an important role in cancer growth, infiltration and metastasis, many agents targeting this pathway have been developed over the last decade. Antiangiogenic drugs interfere with this process and may inhibit neoplastic growth or induce tumor dormancy by blocking the expanding network of newly formed capillaries. Despite the initial promise, targeting angiogenesis in breast cancer has not reached major breakthroughs. Nevertheless, the immunologic role of VEGF deserves to be further explored. We aim to describe the biological mechanisms which underlie the role of angiogenesis in breast cancer carcinogenesis, to depict its contribution to the metastatic process and to review the most important clinical trials testing angiogenic inhibitors in breast cancer, including monoclonal antibodies and novel small molecules.

Phase III study on efficacy of taxanes plus bevacizumab with or without capecitabine as first-line chemotherapy in metastatic breast cancer

Taxanes (T) plus bevacizumab (B) and taxanes plus capecitabine (X) showed better progression-free survival (PFS) compared to taxanes alone. Since life-threatening or highly symptomatic situations require polychemotherapy in metastatic breast cancer (MBC), combination of taxanes, capecitabine plus bevacizumab appears reasonable. TABEA (NCT01200212), a prospectively randomized, open-label, phase III trial compares taxanes (paclitaxel 80 mg/m(2) i.v. d1,8,15 q22 or docetaxel 75 mg/m(2) i.v. d1 q22) plus bevacizumab (15 mg/kg i.v. d1 q22) with (TBX) or without capecitabine (TB, 1800 mg/m(2) daily d1-14 q22) as first-line therapy in MBC. Histologically confirmed HER2-negative, locally advanced or MBC patients with a chemotherapy indication and measurable or non-measurable target lesions (RECIST criteria) were included. Primary objective was PFS. Secondary objectives were response rate and duration, clinical benefit rate (complete response, partial response, stable disease ≥24 weeks), 3-year overall survival, PFS in patients ≥65 years, toxicity, and compliance. We assumed 10 and 13.3 months PFS for TB and TBX, respectively (HR = 0.75), requiring 432 patients and 386 events. Preplanned interim futility and safety analyses after 100 events in 202 patients showed no efficacy benefit and higher toxicity for TBX. Recruitment and therapy were stopped following advice from the IDMC. Final analysis revealed a HR 1.13 [95 %CI 0.806-1.59], P = 0.474, for PFS. Overall grade 3-4 adverse event (77.3 vs. 62.1 %, P = 0.014) and serious adverse event (40.0 vs. 30.2 %, P = 0.127) rates were higher for TBX after 26.1 months median follow-up, with six deaths for TBX versus 1 for TB. Adding capecitabine to TB cannot be recommended as first-line therapy in MBC.

Conquests and perspectives of cardio-oncology in the field of tumor angiogenesis-targeting tyrosine kinase inhibitor-based therapy

INTRODUCTION

Angiogenesis is fundamental for tumor development and progression. Hence, anti-angiogenic drugs have been developed to target VEGF and its receptors (VEGFRs). Several tyrosine kinase inhibitors (TKIs) have been developed over the years and others are still under investigation, each anti-VEGFR TKI showing a different cardiotoxic profile. Knowledge of the cardiac side-effects of each drug and the magnitude of their expression and frequency can lead to a specific approach.

AREAS COVERED

This work reviews the mechanism of action of anti-VEGFR TKIs and the pathophysiological mechanisms leading to cardiotoxicity, followed by close examination of the most important drugs individually. A literature search was conducted on PubMed selecting review articles, original studies and clinical trials, with a focus on Phase III studies.

EXPERT OPINION

Side-effects on the cardiovascular system could lead both to the worsening of general health status of cancer patients and to the discontinuation of the cancer treatment affecting its efficacy. Cardiologists often have to face new triggers of heart disease in these patients. They need a specific approach, which must be carried out in cooperation with oncologists. It must start before cancer treatment, continue during it and extend after its completion.