Chemotherapy
Chemotherapy can be used as a primary curative treatment for cancer, generally for highly sensitive germ cell tumors, high-grade lymphomas or solid childhood tumors.
It can also be utilized as an adjuvant treatment whereby systemic chemotherapy is applied in addition to local treatment of the primary lesion in order to try and destroy disseminated, undetectable micro-metastases. Adjuvant chemotherapy is most commonly used for breast cancer. The direct administration of cytotoxic agents to the tumor can also help shrink tumors in the liver or kidney.
Additionally, chemotherapy can be a general palliative treatment in cases where there is unlikely to be a full cure, but chemotherapy can improve the patient’s quality of life and in some cases prolong lifespan. Moreover, cytotoxic chemotherapy can help with palliation of distressing local symptoms.
Success with chemotherapy in curing hematologic and childhood malignancies has spurred on the use of this treatment modality to treat solid tumors, which were previously only treated using surgery or radiotherapy.
Unfortunately, chemotherapy is also associated with unwanted effects as it is not only toxic to cancerous cells but also to normal cells that have a rapid turnover rate e.g., bone marrow and the gastrointestinal epithelium. Toxic effects include bone marrow suppression, immunosuppression, nausea, vomiting, disruption of the gastrointestinal epithelial turnover, hair loss, gonadal effects such as loss of libido/ sterility as well as renal failure.
Types of chemotherapeutic agents are antimetabolites, alkylating agents, drugs that crosslink DNA (e.g., cisplatin) and drugs that disrupt the mitotic spindle. For treating cancer, the best clinical results and the least toxic effects are obtained by using a combination of different cytotoxic drugs.