Multimodal assessment of acute cardiac toxicity induced by thoracic radiotherapy in cancer patients. Study protocol.

BACKGROUND: Today, cancer ranks as one of the leading causes of death. Despite the large number of novel available therapies, radiotherapy (RT) remains as the most effective non-surgical method to cure cancer patients. In fact, approximately 50% of all cancer patients receive some type of RT and among these 60% receive RT-treatment with a curative intent. However, as occurs with any other oncological therapy, RT treated patients may experience toxicity side effects that range from moderate to severe. Among these, cardiotoxicity represents a significant threat for premature death. Current methods evaluate cardiotoxic damage based on volumetric changes in the Left Ventricle Ejected Fraction (LVEF). Indeed, a 10% drop in LVEF is commonly used as indicator of cardiotoxicity. More recently, a number of novel techniques have been developed that significantly improve specificity and sensitivity of heart's volumetric changes and early detection of cardiotoxicity even in asymptomatic patients. Among these, the Strain by Speckle Tracking (SST) is a technique based on echocardiographic analysis that accurately evaluates myocardial deformation during the cardiac cycle (ventricular and atrial function). Studies also suggest that Magnetic Resonance Imaging (MRI) is a high-resolution technique that enables a better visualization of acute cardiac damage. METHODOLOGY: This protocol will evaluate changes in SST and MRI in cancer patients that received thoracic RT. Concomitantly, we will assess changes in serum biomarkers of cardiac damage in these patients, including: high-sensitivity cardiac Troponin-T (hscTnT), N-Terminal pro-Brain Natriuretic Peptide (NTproBNP) and Circulating Endothelial Cells (CECs), a marker of endothelial dysfunction and vascular damage. DISCUSSION: The presented protocol is to our knowledge the first to prospectively and with a multimodal approach, study serological and image biomarkers off early cardiac damage due to radiotherapy. With a practical clinical approach we will seek early changes that could potentially be in the future be linked to clinical mayor events with consequences for cancer survivors.

Cost-minimization analysis of subcutaneous versus intravenous trastuzumab administration in Chilean patients with HER2-positive early breast cancer.

PURPOSE: Trastuzumab (TZM) improves survival and the risk of recurrence among patients with early-stage HER2+ breast cancer (BC). TZM treatment can be given intravenously (IV-TZM) or subcutaneously (SC-TZM). Although both methods have similar efficacy and safety, they differ in dosage and administration. Previous studies of cost minimization determined that SC-TZM is associated with lower costs than IV-TZM; however, those studies did not include the costs associated with body weight-based dosage and the treatment of adverse drug reactions (ADRs). METHODS/PATIENTS: We performed a model-based cost-minimization analysis. The analysis included direct and indirect medical costs associated with TZM preparation (adjusted by body weight) and administration and also costs due to severe ADRs and non-medical costs that occurred during the total treatment course (18 cycles). We performed a sensitivity analysis to test the robustness of the results across various TZM costs and patient body weights. RESULTS: The overall cost (in USD) of IV-TZM treatment was $83,309.1 per patient compared with $77,067.7 per patient for SC-TZM. Thus, one year of SC-TZM treatment cost $6,241.4 less per patient than one year of IV-TZM treatment. The sensitivity analysis revealed that the results were mainly driven by the price of each TZM vial and body weight. CONCLUSION: SC-TZM is a cost-saving therapy for Chilean patients with early-stage HER2+ BC. Given their similar efficacy and safety, we suggest the use of SC formulations rather than IV formulations. The use of SC-TZM instead of IV-TZM may have a significant economic impact on public/private healthcare systems.