The hormonal therapy is used in Patients not qualifying for radical treatment, and is a main conservative treatment method in prostate cancer patients.
It is also used as a therapy supplementing the radical treatment during radiotherapy. It eliminates endogenous androgens and blocks androgen receptors in cell nuclei. The hormonal therapy is based on assuming primary hormonal dependence of prostate cancer, that is, its susceptibility to stimulation of its development through androgen receptors.
Prostate cancer is a hormone-dependant cancer. Its development is promoted by testosterone, or rather, its biologically active metabolite - dihydrotestosterone (DHT). Dihydrotestosterone acts by binding to specific androgen receptors in cells, Ars. Elimination or reduction in androgen access to the prostate by reducing their levels in blood and/or by blocking Ars so they cannot bind DHT and testosterone inhibits prostate cancer growth.
The hormonal therapy slows disease development, however, it does not cure the disease. It also plays a role in preventing severe complications and relieving disease symptoms. Some patients may be covered by strict monitoring at the beginning, followed by the hormonal therapy when disease progression is found. At its initial stage, use of the hormonal therapy is characterised by a significant improvement in patient's condition and, usually, a dramatic drop in PSA levels.
This androgen "blockade" may be effective even for a few years. However, at the next stage PSA biochemical progression occurs, because cancer becomes independent of androgens (androgen-independent prostate cancer), and then hormone-resistant, and it grows even when determined testosterone levels are low. This is a castrate-resistant cancer, because cancer grows despite the pharmacological castration. In those cases Xtandi ® (Enzaltumid) is used.
What does the hormonal therapy involve?
The hormonal therapy involves taking pills or injections with substances blocking secretion or effects of androgens. The most commonly used form of the hormonal therapy inhibits testosterone production in the testicles by blocking LH and FSH secretion by the pituitary gland following injection of the LHRH analogue (e.g., Eligard®). Treatment with LHRH antagonist or use of a combined therapy with antiandrogens are other forms of this therapy.
At our centre we use Xtandi® (Enzalutamid) for treatment of castrate-resistant prostate cancer, offering yet another hope for significant prolonging of survival in patients, in whom a previous hormonal blockade was "broken".
Treatment of prostate cancer with metastases to bones
There are many methods for treatment of metastatic cancer, and new therapeutic methods emerge constantly. At the HIFU CLINIC Prostate Cancer Treatment Centre metastases to bones can be treated with monoclonal antibody Xgeva® (denosumab) and with a revolutionary medicine using radiopharmaceutical Xofigo® (radium Ra 223 dichloride), significantly reducing a risk of pathological bone fractures. Complications of advanced disease forms (e.g., pathological fractures, anaemia, or pain) are also treated symptomatically.
Primary hormonal therapy
American studies in prostate cancer patients showed that in some cases early initiation of the hormonal therapy contributes to significant reduction in a risk of cancer progression and complications related to the disease, however, it did not improved cancer-specific survival and only slightly improved the overall survival (reports Veterans Administration Co-operative Urological Research Group (VACURG I and VACURG II), Medical Research Council (MRC) and Eastern Cooperative Oncology Group (EOCG)). Therefore, use of palliative HTH in patients with advanced prostate cancer without clinical symptoms is not always justified. One of the possible conditions for initiation of delayed hormonal therapy is its implementation in a Patient when symptoms or complications of prostate cancer develop.
Hormonal therapy after radical treatment
When cancer cells are found in removed lymph nodes after radical treatment - radical prostatectomy with lymphadenectomy, a supplementary hormonal therapy may be necessary. It was demonstrated in Patients who underwent radical prostatectomy for asymptomatic locally advanced prostate cancer that use of HTH during and/or directly after the procedure is correlated with prolonged time to disease progression and/or prolonged overall survival, versus the delayed therapy initiated when progression was found.
Side effects related to the hormonal therapy in treatment of prostate cancer The hormonal therapy aims at reducing blood testosterone levels. This may result in a number of complications. They include:
- erectile disorders and loss of libido;
- hot flashes;
- complications from the skeletal and the cardiovascular systems;
metabolic syndrome.
Consequences of androgen blockade may have a relatively adverse effect on life, particularly in young men, and may result in serious consequences to health in older Patients. In young patients, for whom maintaining their sex life is an important aspect, specialists initiate a monotherapy with non-steroidal antiandrogen (e.g., bicalutamide).