Metastatic Prostate Cancer 편집하기 (부분)

=== Androgen deprivation therapy ===
- Basics of hormonal control of the prostate

- Therapeutic approaches to androgen deprivation therapy

1) Bilateral orchiectomy
: : Within 24hours of surgical castration, testosterone levels are reduced by more than 90%
2) Inhibition of LHRH
: (1) LHRH agonist
: synthetic analogs of native LHRH
: initial exposure to agonists of LHRH results in a flare of LH testosterone levels
: : known as the ‘testosterone surge’ or ‘flare up’ phenomenon (begins within 2-3days of the first injection and lasts through approximately the first week of therapy)
: : result in a severe, life-threatening exacerbation of symptoms
: → co-administration of an antiandrogen (for only 21-28 days)
: Goserelin acetate (Zoladex): 3.6mg sc monthly
: Leuprorelin acetate (Leuplin): 3.75mg sc monthly
: Leuprolide acetate: 7.5mg sc monthly
3) Antiandrogens
: Compete with testosterone and DHT for binding sites on their receptors in the prostate cell nucleus: promoting apoptosis and inhibiting prostate cancer growth
: - Steroidal antiandrogens
: : Cyproterone Acetate, Megesterol acetate, medroxyprogesterone acetate
: - Non-steroidal or pure antiandrogen
: : Flutamide (250mg tid), bicalutamide (50mg po daily), nilutamide (150mg daily)
4) Antiandrogen withdrawal phenomenon
: 정의: experience a decline in PSA level, objective
: responses with the withdrawal of the antiandrogen from the combination with LHRH agonist
: - Declines in PSA level are seen
: → within 4weeks with flutamide withdrawal
: → within 6weeks with bicalutamide, nilutamide withdrawal
: - Declines in PSA level of more than 50% (15-30%), and median duration of 3.5-5months