1) Intermittent Hormonal Therapy: Prostate cancer is often kept “under control” by depriving the cancer cells of their “fuel”, namely androgens such as testosterone or dihydrotestosterone. Androgen deprivation (hormonal) therapy (ADT) is often applied on an intermittent basis the goal of which is to minimize potentially harmful side effects. The May 11th edition of the Johns Hopkins Prostate Disorders Health Alerts contained an excellent overview of intermittent androgen suppression.
2) Why Androgen Deprivation Enhances Radiation Therapy: It has been known since 2011 that adding a short course of androgen deprivation therapy (ADT) to radiation therapy in prostate cancer patients increased their chances for survival. Recent research indicates that the rationale for this combination treatment lies in the fact that ADT retards the ability of cancer cells to repair DNA damage caused by the radiation therapy thus leading to their programmed cell death or apoptosis. One such DNA repair enzyme is called DNAPK which may be a good target for antitumor drug development. Inhibitors of a similar single-strand DNA repair enzyme, PARP1 [(polyADP-ribose) polymerase], are currently being evaluated in Phase III clinical trials involving breast and ovarian cancers. (PARP1 inhibitors seem to have a beneficial effect on women with a specific BRCA breast cancer genetic mutation.) The relationship between the androgen receptor (AR) and DNA repair proteins such as DNAPK is also summarized in the March 31st issue of the Prostate Cancer Foundation (PCF) NewsPulse.
3) A Study Comparing “Watchful Waiting” versus Surgery in Younger Prostate Cancer Patients: A joint Swedish – Harvard life expectancy study of 700 men with early prostate cancer and published in the March 6th New England Journal of Medicine concluded that surgery (radical prostatectomy) may “trump” watchful waiting in younger men diagnosed with prostate cancer. A summary of this study and comments by other researchers was published in the March 31st issue of the Prostate Cancer Foundation (PCF) NewsPulse.
4) The Effects of Statin Drugs On Prostate Cancer: The March 31st PCF NewsPulse also contained a review of various studies related to the effects of cholesterol-lowering statin drugs on prostate cancer. Researchers conclude that statins do not have an effect on the incidence of prostate cancer however prolonged use may lower the risk of advanced disease and death. No protective effects from statins have been observed and there does not seem to be any association between statin use and early incidence of prostate cancer. Current research is focused on where statins may play a role in the overall prostate cancer cycle.