What is Chemotherapy?

Chemotherapy (also referred to as "chemo") is a mode of cancer treatment, which uses certain drugs to treat cancer. The drugs used for chemotherapy are referred to as "anti-cancer" drugs or "antineoplastics."  This treatment was used by the ancient Greeks, but modern chemotherapy for treatment of cancer started and developed from 1940s with the use of nitrogen mustard. Since then, many new drugs have been added to the armamentarium for treatment of cancer.

Currently, there are about 100 drugs to treat cancer. Many newer kinds of chemo drugs such as biologic response modifiers, hormone therapy and monoclonal antibodies are also used for the treatment of many types of cancer. Research is being carried out to develop newer and more effective chemo drugs.

First line and second line chemotherapy

The goal of the treatment of cancer is to cure the disease. Chemotherapy drugs used for the treatment can be categorised as first line and second line chemotherapy.

• First line chemotherapy drugs: consuming these drugs is the first option for the treatment of cancer, which responds to chemotherapeutic drugs. Efficacy of these drugs in the treatment of the particular cancer has been documented by intensive research and studies.
• Second line chemotherapy drugs: These drugs are used as back-up treatment options when the main or first line of the treatment option fails to deliver expected results.

Difference between chemotherapy and other treatments for cancer

The two main modes of treatment of cancer i.e. radiation and surgery are considered as local treatments. These treatments act in one area of the body such as the breast, lung or prostate and target the cancer directly. Chemotherapy is different from surgery or radiation as it mostly acts as a systemic treatment (whether given orally or in the vein). The drugs after administration get distributed throughout the body and reach the cancer cells.

What is Chemotherapy used for?

Chemotherapy is used to treat many different types of cancer and for a variety of purposes such as to:

• Cure a specific type of cancer.
• Control the growth of cancer if it cannot be cured.
• Shrink or reduce the size of tumours before surgery or radiation therapy (to increase the efficacy of these treatments). Chemotherapy that is given before surgery is known as neoadjuvant chemotherapy. It shrinks the tumour so that the surgery is not as complicated and extensive as it could have been.
• Relieve symptoms (such as pain) and improve the quality of life when the cancer cannot be treated or cured.
• Destroy any remaining microscopic cancer cells after surgery for a cancer (called adjuvant therapy).  Adjuvant therapy is given to prevent the possibility of a cancer’s recurrence. This can also decrease the chance of the recurrence of tumour.

The doctor decides on the chemotherapy drug/s needed based on many factors such as the stage of disease, type of tumour, overall health etc.