Hormones play an important role in certain cancers like breast, prostate, and ovarian cancer. Hormones stimulate the growth of cancerous cells in hormone-dependent cancers. Risk factors for breast cancer include factors affecting hormone levels like early menarche, late menopause, hormone replacement therapy, and oral contraceptive use. Prostate cancer risk is influenced by ethnicity and androgen receptor genes. Hormonal therapies target hormone levels and receptors to slow cancer growth by using medications like anti-androgens and GnRH agonists.