Hormones such as estrogen and progesterone play a crucial role in hormone therapy for breast cancer. Understanding their role helps explain how hormone therapy works and its significance in treating hormone receptor-positive breast cancer.

Hormones and Breast Cancer:

• Hormones like estrogen and progesterone play a role in the growth and development of normal breast tissue.
• Some breast cancers have receptors for these hormones, meaning they can attach to the cancer cells and fuel their growth.

Hormone Receptor-Positive Breast Cancer:

• Breast cancers are classified based on their hormone receptor status.
• Hormone receptor-positive (HR+) breast cancers have receptors for estrogen, progesterone, or both. These receptors can promote cancer growth.

Role of Hormone Therapy:

• Hormone therapy is a targeted treatment that aims to block the effects of hormones on cancer cells.
• For HR+ breast cancer, hormone therapy is used to interfere with hormone receptor activation, slowing down or stopping cancer growth.

Types of Hormone Therapy:

1. Selective Estrogen Receptor Modulators (SERMs):

   • SERMs, like tamoxifen, block the effects of estrogen on breast cancer cells. They can be used in both premenopausal and postmenopausal women.
   • Tamoxifen acts as an estrogen antagonist in breast tissue but has estrogen-like effects in other tissues.

2. Aromatase Inhibitors (AIs):

   • AIs are used in postmenopausal women. They work by reducing the production of estrogen in the body.
   • Examples include anastrozole, letrozole, and exemestane.

3. Luteinizing Hormone-Releasing Hormone (LHRH) Agonists:

   • These drugs are used in premenopausal women to suppress the ovaries' production of estrogen. They include drugs like goserelin and leuprolide.

4. Selective Estrogen Receptor Degraders (SERDs):

   • SERDs, like fulvestrant, bind to the estrogen receptor and also degrade it, leading to reduced signaling.

Impact and Benefits:

• Hormone therapy is effective in reducing the risk of recurrence and improving survival rates in hormone receptor-positive breast cancer.
• It is often used as adjuvant therapy (given after surgery) to prevent cancer recurrence or as neoadjuvant therapy (given before surgery) to shrink tumors.

Side Effects:

• Hormone therapy can have side effects, including hot flashes, vaginal dryness, mood changes, bone thinning, and an increased risk of blood clots.
• Side effects depend on the specific hormone therapy used and individual factors.

Hormone therapy is a vital component in the treatment of hormone receptor-positive breast cancer. It helps prevent the cancer cells from receiving the signals they need to grow, ultimately improving outcomes for many patients with this subtype of breast cancer.