Hormone Therapy for Cancer: How It Works, Types and Side Effects
Updated: 6 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026 · How we review
Quick Answer: What is hormone therapy for cancer?
Hormone therapy for cancer is a treatment that stops hormone-sensitive cancer cells from getting the hormones they need to grow. It is used mainly for prostate, breast, ovarian and uterine cancers, delivered through tablets, injections or surgery, often alongside surgery, chemotherapy or radiation, and can lower the chance of cancer returning. [1]
What the research says
Aromatase inhibitors lower breast cancer deaths more than tamoxifen after menopause. In a pooled analysis of 31,920 postmenopausal women with estrogen receptor-positive early breast cancer, 5 years of an aromatase inhibitor cut 10-year breast cancer mortality to 12.1%, compared with 14.2% on 5 years of tamoxifen (rate ratio 0.85). Bone fractures were more common (5-year risk 8.2% vs 5.5%), while endometrial cancer was less common (0.4% vs 1.2%). (EBCTCG, Lancet, 2015) [2]
Adding hormone therapy to radiation helps men with localized prostate cancer live longer. Individual data from 10,741 patients in 11 trials showed that adding short-term androgen deprivation therapy (ADT) to radiotherapy improved overall survival (hazard ratio 0.91), and making ADT longer improved it further (hazard ratio 0.86). (Roy et al., J Clin Oncol, 2023) [3]
Hormone therapy, not a higher radiation dose, lowers the risk of prostate cancer spreading. A network meta-analysis of 11,862 patients from 13 trials (median follow-up 8.8 years) found that adding short- or long-term ADT to radiotherapy consistently improved metastasis-free survival, while raising the radiation dose alone did not (hazard ratio 0.97). (Kishan et al., Eur Urol, 2022) [4]
Key takeaways
Hormone therapy only works for cancers that use hormones to grow.
It works in three ways: it stops hormone production, blocks hormones from reaching cancer cells, or replaces natural hormones with lab-made versions cancer cells cannot use.
Prostate cancer and estrogen-dependent cancers (breast, ovarian and uterine) are the main cancers treated.
Side effects depend on the cancer and the medicine, and commonly include hot flashes, weight gain, lower sex drive and bone loss.
You will see your care team regularly throughout treatment.
How does hormone therapy for cancer work?
Hormone therapy for cancer works by cutting off cancer cells' access to the hormones they need to grow, multiply and spread. [1]
Hormones are chemical messengers. Your glands release them into your bloodstream, and they travel to your organs to coordinate how your body works. Your body cannot function without them. But some cancer cells depend on these same hormones as fuel. [1]
Treatment takes away that fuel in one of three ways:
Approach | What it does | Example |
Stop production | Lowers how much of the hormone the body makes | LHRH agonists; surgery to remove the testicles (orchiectomy) |
Block access | Keeps the hormone from attaching to cancer cells | SERMs such as tamoxifen |
Replace | Gives lab-made hormones, such as progestins, that slow the growth of some cancers | Progestins (for uterine cancer) |
Your care team may combine hormone therapy with surgery, chemotherapy or radiation therapy. It may also be used after treatment to lower the risk of the cancer coming back. [1] Learn more about how chemotherapy works.
Which cancers does hormone therapy treat?
Hormone therapy treats prostate cancer and estrogen-dependent cancers, which include breast, ovarian and uterine cancer. [1]
Cancer | Hormone involved | Main hormone therapy options |
Prostate cancer | Androgens such as testosterone | LHRH agonists, antiandrogens, abiraterone acetate, orchiectomy |
Breast cancer (ER-positive) | Estrogen | Aromatase inhibitors, SERMs, estrogen receptor down regulators |
Ovarian cancer (a rare form) | Estrogen | LHRH agonists, tamoxifen, aromatase inhibitors |
Uterine cancer | Progesterone-like drugs slow growth | Progestin (most common), tamoxifen, LHRH agonists, aromatase inhibitors |
How is hormone therapy used for prostate cancer?
Hormone therapy for prostate cancer mostly uses medicines that keep androgens, such as testosterone, from fueling prostate cancer cells; in some cases it involves surgery to remove one or both testicles (orchiectomy). [1]
LHRH agonists: Signal the pituitary gland to stop making luteinizing hormone. Without this hormone, the testicles stop releasing testosterone, and testosterone-dependent cancer cells stop growing.
Antiandrogens: Reduce testosterone's ability to drive prostate cancer cell growth.
Abiraterone acetate: Stops prostate cancer cells from making androgens. It may help when cancer has not responded to other hormone therapy or is likely to come back after treatment.
Hormone therapy is often combined with radiation therapy for prostate cancer. [1] Read more about how the prostate works, seed-implant radiation (brachytherapy) and prostate cancer recurrence.
How is hormone therapy used for breast cancer?
Hormone therapy for breast cancer lowers estrogen levels or blocks estrogen from attaching to breast cancer cells, and it is used for hormone receptor-positive (ER-positive) tumors. [1]
About 8 in 10 breast cancers are hormone receptor-positive. These cells carry receptor proteins that estrogen in the bloodstream can attach to, which boosts their growth. [1] If you want to understand your pathology report, see our guide to hormone receptor-positive breast cancer.
Medicine group | How it works | Who it is for |
Aromatase inhibitors | Block the enzyme aromatase, which turns other hormones into estrogen | People with ER-positive breast cancer who have gone through menopause |
SERMs (selective estrogen receptor modulators) | Keep estrogen from connecting with cancer cells | ER-positive breast cancer |
Estrogen receptor down regulators | Block estrogen and make it harder for estrogen to connect with cancer cells | ER-positive breast cancer |
When it is given:
After surgery (adjuvant): The most common use, to lower the risk of the cancer coming back.
Before surgery (neoadjuvant): To shrink the tumor first.
For cancer that has spread: To treat breast cancer in other parts of the body. [1]
Related reading: breast cancer symptoms, causes and treatment and types of breast cancer surgery.
How is hormone therapy used for ovarian and uterine cancer?
Hormone therapy for ovarian cancer is used for a rare form of the disease, while for uterine cancer it is used after surgery, for advanced or recurring cancer, or as palliative care to ease pain. [1]
Ovarian cancer: Options include LHRH agonists, tamoxifen and aromatase inhibitors. Learn more about ovarian cancer.
Uterine cancer: Progestin is the most common choice. These drugs act like the hormone progesterone and slow uterine cancer cell growth. Tamoxifen, LHRH agonists or aromatase inhibitors may also be used. [1]
How is hormone therapy for cancer given?
Hormone therapy for cancer is given as oral medicines (tablets) or as hormone injections, and for prostate cancer it can also mean surgery to remove the testicles. [1]
Your treatment plan decides how often you take or receive it. Because hormone therapy is often part of a wider plan, you may receive it before, during or after other treatments. [1]
What are the side effects of hormone therapy for cancer?
The side effects of hormone therapy for cancer vary from person to person and depend on your overall health and the type of hormone therapy you receive. [1]
Cancer | Common side effects |
Prostate | Weight gain, lower interest in sex, erectile dysfunction, bone loss (osteoporosis) |
Breast | Joint pain or stiffness, fatigue, nausea and vomiting, weight gain, lower interest in sex, hot flashes, tender or swollen breasts |
Ovarian | Hot flashes, vaginal dryness, osteoporosis, joint and muscle pain |
Uterine | Hot flashes, weight gain, night sweats |
Ask your care team which side effects to expect from your specific treatment, including any that could lead to serious complications. [1] For more on two common concerns, read about osteoporosis and erectile dysfunction.
What are the benefits of hormone therapy for cancer?
The main benefit of hormone therapy for cancer is that it can slow or stop cancer growth, especially when combined with other treatments. [1]
Benefits | Things to weigh |
Can slow or stop cancer growth | Side effects such as hot flashes, weight gain and bone loss |
Can lower the risk of the cancer coming back after treatment | Works only for hormone-sensitive cancers |
Works alongside surgery, chemotherapy and radiation | Requires regular follow-up visits |
How well does hormone therapy for cancer work?
How well hormone therapy for cancer works depends on your situation; for many people it keeps the cancer from growing or slows its growth. [1]
It is one of several tools used to treat hormone-sensitive cancers. Your care team is the best source for how much difference it can make in your specific case. [1]
When should you contact your doctor during hormone therapy?
During hormone therapy for cancer, you will see your care team regularly according to your treatment plan. [1]
Between visits, contact your care team if a side effect is affecting your daily life, or if you have questions about a new symptom.
Conclusion
Hormone therapy for cancer takes away the fuel that hormone-sensitive cancers need. It is a core treatment for prostate cancer and for estrogen-dependent breast, ovarian and uterine cancers. It can be given as tablets, injections or, for prostate cancer, surgery, and it often works alongside other treatments to slow growth and lower the chance of the cancer returning. Side effects are real but differ between people and treatments, so open, regular conversations with your care team matter.
Next step: Bring this guide to your next appointment and ask your oncologist which hormone therapy fits your cancer, how long you will take it, and which side effects to watch for. Then keep learning with our guide to hormone receptor-positive breast cancer or prostate cancer recurrence. You can also search for open studies on ClinicalTrials.gov.
FAQ
What is hormone therapy for cancer?
Hormone therapy for cancer is a treatment that cuts off hormone-sensitive cancer cells from the hormones they need to grow. It may stop the body from making the hormone, block the hormone from reaching cancer cells, or replace natural hormones with lab-made ones that cancer cells cannot use.
Which cancers are treated with hormone therapy?
Hormone therapy is used for prostate cancer and estrogen-dependent cancers, including breast, ovarian and uterine cancer. For ovarian cancer, it is used for a rare hormone-sensitive form.
Is hormone therapy for cancer given as pills or injections?
Hormone therapy for cancer can be given as oral medicines or as hormone injections. For prostate cancer, surgery to remove one or both testicles (orchiectomy) is another form of hormone therapy.
What are the most common side effects of hormone therapy for cancer?
Common side effects of hormone therapy include hot flashes, weight gain, lower interest in sex and bone loss. Others depend on the cancer, such as erectile dysfunction with prostate cancer treatment or joint pain with breast cancer treatment.
What is the difference between aromatase inhibitors and SERMs?
Aromatase inhibitors lower estrogen levels by blocking the enzyme that makes estrogen, and they are used after menopause. SERMs keep estrogen from attaching to cancer cells.
Can hormone therapy be used with chemotherapy or radiation?
Hormone therapy is often combined with surgery, chemotherapy or radiation therapy. In prostate cancer, it is commonly paired with radiation therapy.
Can hormone therapy stop cancer from coming back?
Hormone therapy can lower the risk of cancer coming back when it is used after main treatment. In breast cancer, this after-surgery use is the most common reason it is prescribed.
How often will I see my doctor during hormone therapy?
During hormone therapy, you will see your care team regularly based on your treatment plan. Contact them sooner if a side effect affects your daily life.
How is hormone therapy used for prostate cancer?
For prostate cancer, hormone therapy lowers testosterone or blocks its effects, which slows the cancer's growth. It may be given as injections, pills or, less often, surgery to remove the testicles.
Can hormone therapy for cancer affect fertility?
Yes, some hormone therapies can affect your ability to have children. If you may want children in the future, ask your care team about fertility options before treatment starts.
Related Reading
Adjuvant Therapy: What It Is, Types and Why It's Used explains adjuvant cancer therapy.
References
Cleveland Clinic. Hormone Therapy for Cancer. Cleveland Clinic. Last updated November 22, 2022. https://my.clevelandclinic.org/health/treatments/17108-hormone-therapy-to-treat-cancer
Early Breast Cancer Trialists' Collaborative Group (EBCTCG). Aromatase inhibitors versus tamoxifen in early breast cancer: patient-level meta-analysis of the randomised trials. Lancet. 2015;386(10001):1341-1352. PMID 26211827. https://doi.org/10.1016/S0140-6736(15)61074-1
Roy S, Romero T, Michalski JM, et al. Biochemical Recurrence Surrogacy for Clinical Outcomes After Radiotherapy for Adenocarcinoma of the Prostate. J Clin Oncol. 2023;41(32):5005-5014. PMID 37639648. https://doi.org/10.1200/JCO.23.00617
Kishan AU, Wang X, Sun Y, et al. High-dose Radiotherapy or Androgen Deprivation Therapy (HEAT) as Treatment Intensification for Localized Prostate Cancer: An Individual Patient-data Network Meta-analysis from the MARCAP Consortium. Eur Urol. 2022;82(1):106-114. PMID 35469702. https://doi.org/10.1016/j.eururo.2022.04.003
Disclaimer
This article is for general education and does not replace advice from your doctor. Hormone therapy decisions depend on your cancer type, test results and overall health. Always talk with your oncology team before starting, changing or stopping any treatment.
Comments