The researchers found that in the patients with breast cancer being treated with doxorubicin the ones who presented with lower EPC levels were more likely to have higher levels of troponin in their blood by the end of treatment. The researchers found that the treatment was well tolerated and there were no acute indications of damage to heart function. However, there was a trend in physical changes in the heart, including increased water content in heart cells and indications that the heart was working less efficiently.
“I think we often don’t recognize when a cancer survivor’s heart has been affected by cancer treatment. So now we can pick it up earlier before they show up with heart failure,” said study investigator Subha Raman, MD, Professor of Cardiovascular Medicine at Ohio State University, Columbus, Ohio “EPCs and CMR can be tailored to screen those at highest risk, which will be better defined as we use these tools across multiple centers, to detect cardiac problems before patients develop heart failure. Early cardiac damage identified by these techniques allows earlier institution of proven cardioprotective therapies.”
By using these so-called “heart resilience” biomarkers it may be possible to start many types of interventions that could prevent structural damage to the heart, Dr. Raman noted. Studies are currently under way looking at beta blockers and angiotensin receptor blockers to see if they can prevent cardiac dysfunction during early breast cancer therapy.4,5 Trials are also currently exploring how effective it may be to give these agents during postoperative chemotherapy and radiotherapy.
Dr. Raman and her colleagues presented their latest findings with these biomarkers this past December at the San Antonio Breast Cancer Symposium. They now plan to reassess their patients at 12 and 24 months and they hope to follow the study group for as long as 5 years in order to capture more data and to refine how these biomarkers may be incorporated into the management of patients with breast cancer.
Protecting the Heart Before Chemotherapy
Survival rates after a cancer diagnosis are now higher than they have ever been. Subsequently, clinical practice needs to change with these trends. This burgeoning area of cardio-oncology is of paramount importance due to the success of current cancer therapies and the enhanced long-term survival from contemporary treatment.
There are many potential cardiovascular complications that can result from cancer therapy, but researchers believe they can be categorized into three major groups: vascular conditions (atherosclerosis, thrombosis and hypertension), cardiac structural problems (valvular degeneration), and cardiac dysfunction and heart failure.6 Investigators are now starting to closely look at late cardiac effects from cancer therapy and investigating various cardiac imaging techniques, biomarkers, and genetic determinants of response to cancer treatment.
Cardiologists at Virginia Commonwealth University (VCU) School of Medicine in Richmond, Virginia recently reported that combining either sildenafil (Viagra) or rapamycin (Sirolimus) with the cancer medication doxorubicin protected the heart from damage and improved doxorubicin’s ability to kill cancer cells.7 Combining all three (sildenafil, rapamycin, and doxorubicin) increased these protective benefits. Researchers believe the combination therapy could potentially improve the life expectancy of patients with cancer.
The investigators used cell models and animal models and found that sildenafil alone in combination with rapamycin significantly improved the anti-cancer effects of doxorubicin while protecting the heart. However, the combination of all three medications showed the most powerful effect. Lead study author David Durrant, PHD, with the VCU School of Medicine, said this trio of medications led to a dramatic protection of heart muscle from apoptosis, and to a lesser extent necrosis. Dr. Durrant also indicated this treatment strategy has excellent potential to move forward into clinical trials and eventually could help improve life expectancy in patients with cancer.