Chemotherapy is the treatment of cancer with cytotoxic drugs. Chemotherapy is a systemic therapy; it usually treats the whole body, as opposed to radiotherapy or surgery that provides focused treatment to a specific area of the body.
Chemotherapy Can Be
- Adjuvant therapy - Used after primary treatment such as surgery, to prevent metastases.
- Neoadjuvant therapy - Used to reduce the amount or size of a tumor before surgery.
- Primary therapy - Used when surgery is not indicated or possible.
- Radiosensitizer - Used along with radiation therapy to enhance the effectiveness of the radiation.
How Chemotherapy Works
Chemotherapy works by preventing cells from completing the duplication process, known as mitosis. If the cancer cells cannot multiply, they cannot spread into adjacent organs or migrate to develop into metastatic tumors. Chemotherapy is given on a schedule over a prescribed period of time that will maximize cell kill and allow normal cells to recover.
How Chemotherapy Is Administered
Chemotherapy is usually administered through an intravenous (IV) access. There are several other ways to administer chemotherapy:
- Instillation – for example, into the bladder.
- Directly to the area where a tumor has been removed – such as biodegradable chemotherapy wafers used for some brain tumors.
- Topically – directly on the skin.
- Orally - as a tablet or capsule.
Chemotherapy drugs are selected specific to each cancer cell type. Combination chemotherapy can increase the effectiveness of single agent drugs in the treatment of some cancers. Different drugs are often used in combinations given on the same or different days of a chemotherapy cycle.
What to Expect
Chemotherapy is usually administered by specially trained Registered Nurses in an outpatient setting, such as an infusion center, a physician’s office or even in the home. Some chemotherapy regimens require inpatient hospital stays for several days of infusion. The side effects of chemotherapy drugs can include hair loss (alopecia), nausea, fatigue, constipation and dramatic changes in blood cell counts such as anemia, leukopenia (low white cell count) and thrombocytopenia (low platelet count). Some drugs can cause toxicities in the liver, kidneys, heart, lungs and affect nerve function. Some treatments result in reproductive dysfunction and temporary metabolic alterations.
Benefits of Chemotherapy
The goals of cancer treatment include longer survival, higher cure rates and better disease control, which can offer longer intervals between recurrences. The benefits of chemotherapy are likely to increase as newer drugs are developed and more advanced combinations of treatments are researched.