What is the primary action of hormone therapy in cancer treatment?

The primary action of hormone therapy in cancer treatment is to add, block, or remove hormones to interrupt cancer cell division. Hormone-sensitive cancers, such as some types of breast and prostate cancer, rely on hormones to grow and divide. By manipulating hormone levels, hormone therapy can effectively slow down or stop the growth of these cancers.

For instance, in certain breast cancers, estrogen can promote tumor growth. Anti-estrogen medications, such as tamoxifen or aromatase inhibitors, block the action of estrogen or lower its levels in the body, thereby reducing stimulation of the cancer cells and allowing the body to maintain better control over the disease. Similarly, in prostate cancer, hormone therapies can reduce levels of testosterone, which can drive the growth of prostate tumors.

This mechanism of disrupting the hormonal signals that cancer cells depend on distinguishes hormone therapy from other treatment modalities such as chemotherapy, which aims to directly kill rapidly dividing cells, or immunotherapy, which seeks to enhance the body's immune response against cancer.