Chemotherapy is a treatment method for cancer that utilizes strong chemicals. Because cancer cells are a mutated version of normal body cells, treatment of cancer is difficult. Treatments like antibiotics that target foreign invaders are ineffective against cancer because cancer cells are human cells. However, there are differences in the cellular behavior. Many types of cancer are characterized by cells dividing more quickly than normal cells and growing into a lump of disorganized tissue, a tumor. When chemotherapeutic drugs are put into the body, these toxic chemicals affect all cells within the body. Many chemotherapeutic agents damage the DNA or RNA that enables a cell to divide. As a result, cells that proliferate more quickly such as cancer cells are more likely to be affected. Other cells in the body that proliferate quickly include hair cells, blood cells, and cells in the digestive tract and are therefore also susceptible to chemotherapy. This mechanism enables chemotherapy to target cancer cells while having a lesser effect on many of the normal cells within the body. Chemotherapy is often used in conjunction with other cancer therapies including surgery and radiation therapy. One advantage of chemotherapy is that it affects the entire body, so it is more effective in treating cancer that has metastasized (moved from the primary cancer location to other parts of the body). This systemic effect is also a disadvantage of this type of treatment, because the chemicals can cause nausea, vomiting, fatigue, hair loss, and mouth sores.
