Chemotherapy uses medications that are also known as "anti-cancer" drugs or "anti-neoplastics" to treat cancer. Cancer is caused due to the loss of the ability of the cells to divide and grow in an orderly manner. This inability leads to the growth of more cells than required and the excess cells form a mass of tissue called growth or tumour. Cancer cells tend to divide rapidly and the anticancer or anti-neoplastic drugs work by attacking the cells that are dividing quickly. Therefore, they attack and kill the cancer cells.
Currently, more than 100 drugs are used for the treatment of 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. The drug/drugs to be used for chemotherapy are decided by many factors such as:
Methods of administration: Chemotherapy medication/s can be given systemically or administered locally (regional).
Systemic chemotherapy: The different ways of giving systemic chemotherapy medications include:
Regional chemotherapy: Some cancers may be treated by regional chemotherapy if high dose of chemotherapy medication/medications are needed for a specific area of the body. In regional chemotherapy, the drug is directly administered into the part of the body where the cancer is growing. The advantage of this treatment is that it achieves high concentration at the site of cancer while minimizing the side effects on the entire body. Side effects, however, still occur as most of the medications are partly absorbed into the bloodstream and spread throughout the body. Some examples of regional chemotherapy include:
Combination Therapy: Many cancer patients need treatment with more than one type of therapy (surgery, chemotherapy or radiotherapy). If needed, chemotherapy can be given along with other cancer treatments such as radiation therapy or surgery. The patient may receive chemotherapy before or after radiation therapy or surgery. Combining the therapies improves the chances of cure and survival. Another important strategy while treating cancer includes administration of repeated courses of chemotherapy. This helps to improve the chances of cure and survival.
The oncologist (specialist doctor, who treats cancer) decides on the type of chemotherapy treatment that is best for you after a discussion with other health care professionals.