Hormones in Cancer

• the two hormone-sensitive cancers are breast (~50%) and prostate (> 90%)

• tamoxifen

  • mechanism: antiestrogenic in breast; proestrogenic in uterus and bone

  • toxicities

    • thromboembolic events

    • uterine cancer (low incidence, but risk is still increased 2-3x)

    • postmenopausal events: hot flashes and uterine bleeding

• aromatase inhibitors: anastazole, letrozole, exemestane

  • used in ER+ breast cancer

  • toxicities

    • postmenopausal events: hot flashes and uterine bleeding

    • osteoporosis

• gonadotropin-releasing hormone agonists

  • used in prostate cancer

  • mechanism: acts on pituitary to inhibit gonadotropin release, hence decreasing testosterone production to castrated levels. prevents normal pulsatile secretion of gonadotropins

  • toxicities

    • initial surge in LH/FSH, so initial disease flare

    • loss of sexual function

    • fatigue, anemia, osteoporosis

• androgen receptor blockers

  • used in combination with GnRH agonists

Category: Pharmacology Notes