Osteoporosis is the most common type of bone disease. It develops when the body breaks down more bone tissue than it can replace. As a result, bones become weak and fragile. This makes them more likely to fracture or break.

Cancer can contribute to bone weakness and fracture risk when it starts in the bone or spreads to the bone. Cancer treatments, such as chemotherapy or hormone therapy, can also cause osteoporosis. If you already have osteoporosis, some cancer treatments can make it worse.