The following section is on a treatment of cancer, it is not a guide on how to perform it, nor is it a guide as to the side effects or how to prepare for treatment. The following section is designed to give readers an in-depth understanding of the treatment, how it functions, and why it functions. Please note that researchers are constantly working to find new treatments or improve current ones, this means the subject(s) discussed below are likely to change as medicine improves.
Most people are familiar with hormone therapy in the form of HRT (hormone replacement therapy) which is most commonly used to treat symptoms of menopause or in gender affirming care, however hormone therapy for cancer is distinct. Hormone therapy can be used to treat cancers as a form of targeted therapy, there is a section on targeted therapy however this is slightly distinct in its functioning and use case.
Hormone therapy can also be referred to as hormonal therapy, hormone treatment, or endocrine therapy.
Hormones are substances that naturally occur in the body, some commonly known ones include oestrogen progesterone and testosterone. Hormones are used as messengers, different levels of different hormones can affect how cells function. For example testosterone is produced in males as early as 7 weeks past conception, testosterone levels increase in puberty causing the changes in a body associated with male puberty, eg hair growth, sperm production, muscle mass etc.
As hormones can affect how cells function and cancer cells are descended from healthy cells, it is possible cancerous cells still need hormones in order to replicate, or may replicate faster with these hormones present. As the basis of cancer is mutation it can be hard to predict whether cancers will still require hormones to grow, even if the original healthy cell had the receptors that bound to the hormone it is possible that as the cancer has grown it has mutated further and no longer has those receptors. Tests can be done in order to check if cancer cells still have the receptors that bind with these hormones.
The objective of hormone therapies in cancer is to keep the hormones that may be stimulating growth away from the cancerous cells. This can be done by removing the glands that produce the hormone, but is more often a drug. Some drugs can bind to the receptors on the cells without activating them to make it impossible for the hormones to bind with the cancerous cells, while others affect the glands producing the hormones and reduce the hormones from the source.
By removing the hormones or the hormones ability to bind with receptors this can slow or stop the growth of cancerous cells. As hormones do not usually regulate vital functions within the cell, hormone therapy does not kill or get rid of cancer cells, this means it is common to combine hormone therapy with another treatment to actually kill the cancerous cells such as radiotherapy, surgery, chemotherapy etc.
The most common types of cancers that can be treated with hormones are cancers originating from tissues in the breast and prostate, however any areas that normally have growth stimulated by hormones could be affected by hormone therapy.
| Mayo Clinic. Hormone therapy for breast cancer – Mayo Clinic. Mayoclinic.org. Published 2019. Accessed July 12, 2026. https://www.mayoclinic.org/tests-procedures/hormone-therapy-for-breast-cancer/about/pac-20384943 |