Prostate cancer - the most common cancer in men in the United States. Because the prostate is sensitive to testosterone, androgen deprivation (ADT) therapy is the cornerstone of the treatment of these men, with about 50 percent of patients with prostate cancer begin to ADT in the year after diagnosis. This therapy works by suppressing the production of testosterone, which in turn slows down the growth of cancer. Although ADT leads to improved survival in a subgroup of these patients, it has many side effects, including an increased risk of cardiovascular disease and sudden death. The mechanisms by which the ADT can cause an increased risk of sudden death, were unclear. Now a group of researchers at BWH shed light on this issue, and the results published in the Journal of the Endocrine Society.
"We have shown that ADT results in electrophysiological changes in the heart" - said the first author of Thiago Gagliano Juka, MD, a researcher at the Section of men BWH health. "The time required for these cells to shrink again after each stroke, increased after the ADT, and the extension of this period is a known risk factor for ventricular arrhythmias."
It is known that testosterone reduces the time required to cardiac cells (cardiomyocytes) could be reduced again after the previous reduction. Reduced testosterone levels as a result of ADT prolongs the time that called QTc interval on the electrocardiogram. This study of more than 70 patients showed that men who receive the ADT, experiencing prolongation of the QTc interval compared with men with prostate cancer who did not receive ADT. QTc prolongation is well established to be associated with a higher risk of developing arrhythmia, suggesting that the prolongation of the QTc interval during the ADT may be a mechanism underlying some of these cardiac events.
"Oncologists should monitor the QTc interval in patients receiving the ADT, especially for those patients who are taking medications that prolong the QTc interval», - Gagliano Juka said.