No, deodorant does not cause cancer. There is no scientific evidence that deodorant is dangerous to your health. However, certain ingredients in deodorant products can be irritants, and if used incorrectly or in too high of a concentration, may cause skin irritation or allergic reactions. Additionally, certain types of deodorant can contain aluminum, which has been linked to breast cancer, but the research is inconclusive. It is always best to check the ingredients list on the product before use and consult with a medical professional if you have any questions or concerns.