Drug therapy options for advanced prostate cancer
Prostate carcinoma is treated curatively in the early and organ-limited stage either surgically or by means of radiation.
However, metastasized prostate car cinoma should be treated with medication. We will be happy to advise you on this in our oncology consultation hours(always Wednesdays 9:00 - 15:00).
As prostate tumor cells are primarily androgen-sensitive, hormone ablation has traditionally been performed by surgical castration. However, following the pharmacological development of LHRH analogs, GnRH antagonists and androgen receptor antagonists, irreversible orchiectomy with its associated psychological side effects is now generally avoided.
As a rule, the first step is to block the androgen receptors for 1-2 weeks and then discontinue the treatment. The next step is to initiate injection therapy with LHRH analogs, which are available in various depot forms, e.g. monthly, every 3 months and every 6 months.
In the first few weeks of therapy with LHRH analogs, there is an excessive and undesirable release of male hormones. For this reason, the androgen receptors are primarily blocked with medication for 1-2 weeks. In the case of therapy with GnRH antagonists, the simultaneous administration of androgen receptor antagonists is not necessary. Unfortunately, the androgen-sensitive disease develops over time into a castration-resistant situation. From this stage, therapy is palliative.
Further information can be found under Clinical studies .
Information on the drugs
In 2004, a taxane-based chemotherapy was introduced for the treatment of castration-resistant prostate cancer (CRPC). Docetaxel in combination with prednisolone improved the median survival rate to approx. 2.9 months. It is recommended that testosterone levels be checked before starting chemotherapy.
Four newly developed substances (cabazitaxel, abiraterone, MDV 3100 and Tak-700) have dramatically changed the therapeutic landscape of CRPC after taxane failure or even before the start of taxane therapy:
In2010, cabazitaxel (Jevtana®) was approved as a semisynthetic taxane derivative after taxane failure in America and one year later in Germany. The approval study showed a significant survival benefit of around 2.4 months compared to the control group, albeit with severe side effects.
In2011, abiraterone acetate (Zytiga®), a selective inhibitor of androgen biosynthesis in adrenal, testicular and prostate tumor cells, was presented in patients with CRPC following taxane therapy. The pivotal study demonstrated a significant prolongation of overall survival with an acceptable side effect profile.
MDV 3100, a so-called "small-molecule" drug, indirectly achieves an antagonistic effect of androgens by translocating the androgen receptors in the nucleus. A phase I/II study with 140 patients showed a PSA drop of 50% in 56% of patients. Imaging examinations showed 22% tumor regression and stable disease in almost 50% of patients.
Following antiandrogenic therapy before or after chemotherapy with docetaxel, the use or availability of the new substances in CRPC offers promising options.
As many of the new substances do not yet have sufficient clinical experience, affected patients should seek detailed information in an oncologically specialized Clinical Department and be presented with the full range of treatment options in accordance with the guidelines. Ideally, patients can be included in a clinical trial program.