Chemotherapy is a cancer treatment that uses (injectable or oral) drugs to destroy cancer cells. It works by stopping or slowing the growth of cancer cells that grow and divide rapidly but it can also affect healthy cells. Damage to healthy cells can cause side effects, but often side effects disappear when chemotherapy is over.
Depending on the type of cancer and its stage, chemotherapy can:
Cure cancer – when chemotherapy destroys cancer cells to the point that the doctor can no longer detect them in the body and no longer regrow
Control cancer – when chemotherapy prevents the spread of cancer, slows growth or destroys cancer cells that have spread to other parts of the body
Relieve cancer-related symptoms (palliative care) – when chemotherapy reduces tumours that cause pain or pressure.
How is chemotherapy used?
Sometimes chemotherapy is the only treatment used in cancer care. But most often, chemotherapy is used in combination with surgery, radiotherapy or hormone therapy.
Reduce a tumour before surgery or radiation therapy. This is called neoadjuvant chemotherapy
Destroy cancer cells that may remain after surgery or radiation therapy. This is adjuvant chemotherapy.
Help improve radiation therapy. This is chemotherapy in combination with radiotherapy.
Destroy recurrent cancer cells (recurrent cancer) or stops the spread to other parts of the body (metastatic cancer)