Acute and Long-term Cardiovascular Toxicity After Modern Radiotherapy for Breast Cancer

Overview

In Europe, breast cancer is by far the most common form of cancer diagnosed in women today, accounting for 29% of all cases. The 5-year survival rate is approximately 90%. Surgery is usually combined with radiotherapy (RT), anthracyclines, aromatase inhibitors and/or trastuzumab (Herceptin) which all have improved the life expectancy and survival in breast cancer patients. Unfortunately, RT is associated with a broad spectrum of cardiovascular diseases, which includes coronary artery disease, valvular dysfunction, congestive heart failure and stroke, and is the most common non-malignancy cause of death. During the last two decades, RT regimens for breast cancer have changed and the doses of radiation to which the heart is exposed are now potentially lower due to new and improved RT techniques. However, there are no data on whether these new regimes decrease the risk of cardiovascular disease. In this study the incidence and prevalence of cardiovascular diseases will be estimated 8 and 15 years after both conventional and laser assisted breath controlled RT, and compared with cardiovascular diseases in the general female population. A further aim is to evaluate signs and prevalence of acute cardiotoxicity from RT with the use of cardiac magnetic resonance imaging, coronary fractional flow reserve, ECG and inflammatory and cardiac biomarkers and to investigate whether these signs can predict later cardiovascular disease. The importance of traditional cardiovascular risk factors (age, hypertension, hypercholesterolemia, smoking habits and physical activity, as registered before RT) will also be evaluated.

The study is an observational study. In 2007-2012 conventional RT was part of the common treatment regime for breast cancer, but has recently been replaced by laser assisted breath controlled RT. Thus, two cohorts of breast cancer patients treated with different modes of RT will be followed for the development of cardiovascular disease for the subsequent 15 years.

Conditions