The use of one or more cytotoxic drugs to systemically treat cancer. These drugs work by targeting and destroying rapidly dividing cells, a hallmark of cancer cells. They interfere with critical cellular processes like DNA replication or cell division. Chemotherapy can be curative (aiming for cure), adjuvant (given after surgery to eliminate residual disease), neoadjuvant (given before surgery to shrink tumors), or palliative (to alleviate symptoms and prolong life when a cure is not possible). A significant drawback is that it also affects some healthy, rapidly dividing cells, leading to side effects like myelosuppression, alopecia, and gastrointestinal mucositis.