Cancer is a disease in which some body cells with genetic or epigenetic changes become capable of replicating and invading other regions of the body uncontrollably. Numerous functional abilities and features are acquired by these cells during this multistage neoplastic process. In the last 20 years, many agents have been discovered and used in the fight against cancer. However, the use of these drugs in appropriate patient groups is still a serious problem. Many cancer types are on the way to becoming chronic diseases; conscientious physicians who are unable to provide appropriate treatment due to economic factors and other reasons face an additional burden.