Study shows anti-hormone treatment combined with PARP inhibitor may prevent progression of prostate cancer

A commonly prescribed treatment for cancer of the prostate helping to reduce the levels of male hormones may inadvertently activate the DNA repair enzyme, PARP, aiding cancer cells to withstand anti-hormone therapy treatment resulting in cells to develop into a more aggressive form.


“This study from England’s University of Surrey is a very important find showing that the treatment of prostate cancer hormone depletion may in fact, be making a tumor that is more aggressive and deadly,” said Dr. David Samadi. “This is the last thing we want to happen as prostate cancer is the second leading cause of cancer-related deaths in men.  This new and exciting discovery may reduce relapse rate among patients treated in this manner and in the long run, be a much more effective way of preventing aggressive prostate cancer.”

Appearing in the Journal Nature Communications, the study’s aim was to investigate the impact of anti-hormone therapy on samples taken from patients with prostate cancer.  An international team of researchers led by British scientists set up a prospective study of men with the disease.  Participants in the study were split into two groups – one had anti-hormone therapy before radiation treatment, while the other started anti-hormone therapy after radiation.  The group who received hormone depletion before radiation therapy had fewer cancerous cells that were eradicated from the radiation. 

“Specifically the study showed that deprivation of the male sex hormone impacts DNA repair which is linked to greater activity of PARP in the cells,” explained Dr. Samadi.  “The research teams compared PARP levels in the participants before and after hormone therapy.  What they found was that depleting androgens led to increased levels of PARP. When there is a loss of androgen hormones, it activates the DNA repair enzyme PARP which prevents cancer treatment from being effective.   To be more effective in reducing a recurrence of prostate cancer, the researchers found that prescribing PARP inhibitors at the same time when prescribing anti-hormone therapy treatment had a more protective effect.  The PARP inhibitors prevented DNA from repairing cancer cells which could lead to aggressive prostate cancer recurrence, and instead the PARP inhibitors did their job of causing more of the cancerous cells to die.”

Dr. Samadi went on to add, “Cancer treatments work by destroying the malignant tumor cell’s DNA which helps prevent cancer cells from multiplying.  But since PARP activates the system repairing the DNA, it only ends up helping the cancer cells to withstand the effects of treatment.  That’s why using PARP inhibitors, which are commonly used in treating breast cancer, looks promising to help some men with prostate cancer who could benefit from being given PARP inhibitors alongside hormone deprivation.  This could have the potential to increase the chance of survival extending good quality years of life for more men who are diagnosed with prostate cancer each year.”

Patients newly diagnosed with prostate cancer can contact world renowned prostate cancer surgeon and urologic oncologist, Dr. David Samadi, for a free phone consultation and to learn more about prostate cancer risk call 212-365-5000.