Antiandrogenic therapy is a type of endocrine therapy
Endocrine therapy is an important treatment for advanced prostate cancer. Prostate tumors are highly androgen-dependent tumors, and endocrine therapy can be used to control the tumor by cutting off the source of androgens or antagonizing the effects of androgens.
Endocrine therapy can be divided into two categories: depot treatment and anti-androgen therapy (referred to as anti-androgen therapy). If you compare prostate cancer to a bad guy who eats, the principle of homeopathic treatment is to deny the bad guy food, and the principle of anti-androgen treatment is to gag the bad guy, both of which are aimed at “starving the bad guy”.
- Destructive therapy is surgical destructive (removal of the testicles), pharmacological destructive (goserelin, treprostinil, leuprolide, etc.), and estrogenic.
- Antiandrogen therapy drugs are called androgen receptor antagonists. There are two types of androgen receptor antagonists commonly used in clinical practice, steroids and nonsteroids.
- The steroidal androgen receptor antagonists commonly used are cyproterone acetate (CPA);
- Nonsteroidal androgen receptor antagonists are more diverse, such as flutamide and bicalutamide. The anti-androgenic activity of nonsteroidal drugs has less impact on sexual function and is therefore relatively commonly used.
Flutamide
The clinical oral dose of flutamide is 250 mg per dose, 3 times daily.
In addition to the common side effects of nausea, vomiting, and diarrhea, there is some hepatotoxicity, so it is clinically recommended that patients taking flutamide have their liver function tested regularly.
Bicalutamide
Bicalutamide is a novel nonsteroidal androgen receptor antagonist administered as 50 mg once daily.
It has the advantage of minimal hepatotoxicity, good patient tolerance of the drug, only once daily dosing, and somewhat better patient compliance.
But there are side effects such as breast tenderness, feminization of the male breast, and skin flushing.
Why does anti-androgen therapy fail after a period of treatment?
Endocrine therapy, an important treatment for advanced, metastatic prostate cancer, can, to some extent, improve patients’ symptoms, reduce their pain, and slow down the progression of the disease. But after all, it is only a palliative treatment; it cannot achieve a radical cure.
Because some prostate cancer cells gradually adapt to the low-androgen state after a phase of endocrine therapy, they can grow and proliferate without androgens, and clinically they enter the hormone-non-dependent stage of prostate cancer, when anti-androgen therapy is no longer effective and the disease continues to progress and the PSA continues to rise.
For patients who have failed anti-androgen therapy, the disease can be managed by:
- Discontinuation of anti-androgens. In some patients, the elevated PSA will drop after discontinuation of the anti-androgen, a medical term for “slow withdrawal syndrome.
- Switch to an anti-androgen drug.
- Switching to an antiandrogen can sometimes provide relief;
- For patients with bone pain, it can be controlled by local external radiation radiotherapy and particle implantation radiotherapy;
- Chemotherapy regimens based on docetaxel and mitoxantrone are also effective for advanced prostate cancer;
- Traditional Chinese herbal medicine is also useful for advanced prostate cancer.