A person may suffer an injury, go to a physician, and the physician may happen to find a tumor. Cancer is a very complex disease. If there were one single cause of cancer, the cure would have been found long ago. Cancer is caused by many factors. No one single cause can explain it.
Cancer can run in families.
If one family member has it, others may get the disease. Cancer in families is usually of one type. It is a myth that too much medication for pain will cause a patient to become addicted. Research has shown that this is not true. People with cancer can take pain medication as long as needed, if used properly, without becoming addicted.