hormone therapy

Pre-menopause estrogen

produced by ovary stimulated by FSH and LH

Post-menopause estrogen

produced by adrenal glands and adipose tissue

Synthetic GnRH analogues

continuous administration downregulates GnRH receptors in pituitary, suppressing the release of FSH and LH, preventing follicular maturation in ovary

Synthetic GnRH analogues

goserelin, leuprolide, triptorelin

Synthetic GnRH analogues

in combination with tamoxifen, AIs, or fulvestrant, used for adjuvant therapy of premenopausal ER+ breast cancer

Synthetic GnRH analogues

in combination with antiandrogens or androgen synthesis inhibitors, used for adjuvant therapy of prostate cancer

Synthetic GnRH analogues

administered subq or IM every 1/3/6 months

GnRH antagonists

results in rapid reduction of FSH and LH secretion from pituitary, causing concomitant loss of estrogen/androgen production

GnRH antagonists

approved for advanced and metastatic prostate cancer with no initial disease flare

Degarelix

small peptide GnRH antagonist

Relugolix

oral nonpeptide GnRH antagonist

Degarelix

loading subq dose followed by monthly subq injections

Relugolix

loading PO dose followed by daily PO dose

substrate of P-gp and 3A4

Anastrozole, letrozole

nonsteroidal aromatase inhibitor(s), inhibit aromatase activity, reducing estrogen production

reversible inhibition

Exemestane

steroidal aromatase inhibitor(s), inhibit aromatase activity, reducing estrogen production

irreversible inhibition

Exemestane

in combination with everolimus, used for postmenopausal advanced breast cancer that has progressed on nonsteroidal AIs

Aromatase inhibitors

hypoestrogenism (hot flashes, libido, vag. dryness), increased fracture risk

biphosphonates good for preventing BMD loss

Aromatase inhibitors

used as (neo)adjuvant for postmenopausal women with early to advanced breast cancer

Tamoxifen

partial estrogenic agonist in endometrium, bone metabolism, and coagulation system, estrogenic antagonist in ER+ breast cancer cells

Tamoxifen

used for ER+ metastatic breast cancer or as adjuvant for ER+ breast cancer

Fulvestrant

selective estrogen receptor downregulator (SERD), steroidal antiestrogen that binds to the ER with high affinity

Fulvestrant

used alone or with palbociclib for postmenopausal metastatic ER+ breast cancer (second line)

Fulvestrant

given IM, metabolized by 3A4

1st gen anti-androgens

bicalutamide, flutamide

2nd gen anti-androgen

enzalutamide

Anti-androgens

used with GnRH agonists/antagonists for metastatic prostate cancer

Abiraterone

inhibits biosynthesis of androgens, also some activity as an AR antagonist

Abiraterone

used with prednisone for metastatic prostate cancer