Certain types of cancer, such as breast and prostate cancer, rely on hormones to grow and develop. These types of cancerous cells have receptors that attach to hormones, allowing them to divide and spread. The growth of these cancers can be halted if the hormones are blocked or modified. Hormone cancer therapy accomplishes this by blocking specific hormones as well as changing how they behave. Especially when combined with other cancer therapies, hormone therapy can successfully eradicate specific types of cancers.
The idea behind hormone therapy arose in 1874 when English doctor Thomas Beatson discovered that by removing the ovaries from rabbits stopped the rabbits from producing milk. This basic idea, that the hormones produced by one organ could influence other organs, fascinated Beatson. He discovered that this principle could be used to treat breast cancer in humans. By removing the ovaries of patients with advanced breast cancer through a surgical procedure, Beatson was able to improve patient outcomes.
Beatson’s work was later improved and refined by other scientists. In 1945, University of Chicago Urologist Dr. Charles B. Huggins discovered that removal of the testicles had a similar effect on improving outcomes of patients with breast cancer. Huggins further experimented with the injection of certain hormones into rats, altering the hormonal balance of the animals without resorting to physical surgery. Huggins’ work is the foundation for modern-day hormone therapy, where injections of certain compounds can be used to treat breast and prostate cancer. In 1966, Huggins was awarded the Nobel Prize for his work.
For modern-day breast cancer treatment, hormone therapy is generally used after surgical removal of the tumor to prevent the cancer from returning. It can also be used before surgery to reduce the growth of the tumor. In the 2 out of 3 breast cancers that are hormone-receptor-positive, meaning they can bind to estrogen, hormone therapy can work by stopping estrogen from connecting to receptors on the cancerous cells or lowering estrogen production. Drugs that block the production of estrogen entirely by removing or shutting down the ovaries are sometimes given to post-menopausal women.
Hormone therapy for prostate cancer focuses on the suppression of male hormones. As prostate cancer expands, hormones such as testosterone bind with cancerous cells and allow them to grow. As with breast cancer, hormone therapy is used a supplement to other forms of therapy such as surgery and radiation. Hormone therapies generally block the production of male hormones by both the testicles and the adrenal glands. The testicles can also be removed to permanently stop testosterone production. An alternative option is giving patients estrogen, which can counteract the effects of male hormones.
Hormone therapy can have wide-ranging side effects by blocking or altering hormones that regulate bodily functions. These can range from lesser effects such as temporary nausea and fatigue to more pronounced ones including weight gain, loss of sexual libido, and bone weakening. However, hormone therapy can also significantly reduce the risk of cancer remission, by up to 50%. Due to its effectiveness, therapy remains an essential tool in treating and preventing the remission of breast and prostate cancers.
Sources:
https://www.mayoclinic.org/tests-procedures/hormone-therapy-for-breast-cancer/about/pac-20384943
https://www.mayoclinic.org/tests-procedures/hormone-therapy-for-prostate-cancer/about/pac-20384737
https://www.cancer.gov/types/breast/breast-hormone-therapy-fact-sheet
https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=p07236