Systematic chemotherapy is administered throughout the entire body, regional chemotherapy is localized treatment, combination chemotherapy involves multiple drugs, neoadjuvant chemotherapy is used before other treatment, and adjuvant chemotherapy is used after other treatments. Chemotherapy is a cancer treatment designed to stop the production of cancer cells by use of chemicals. Each cancer cell divides into 2 daughter cells, they then grow, rest, and the divide again. Similar to the drugs used to treat HIV/AIDS, chemotherapy uses powerful chemicals to interrupt this cycle and stop the cells from growing. Different drugs kill at different stages of the life cycle of the cell.