Types of chemotherapy

There are over 100 kinds of anti-cancer medicines. Doctors divide those 100+ drugs into various groups. 

Factors that determine how anti-cancer drugs are grouped and classified

• How they affect chemical substances within the cancer cell
• Which activity or process in the cell the drug interferes
• What part of the cell cycle the drug affects

How chemotherapy affects a cell's DNA and RNA

Chemotherapy affects substances inside the cells called DNA and RNA. DNA, or deoxyribonucleic acid, is a chemical in the cell that is made up of and controls genetic information. RNA, or ribonucleic acid, is another type of nucleic acid found in cells. RNA helps send information from the cell’s DNA to proteins made by the cell. This is how DNA controls how a cell works and behaves.

Using single or multiple anti-cancer drugs

When your cancer treatment team designs a treatment plan for you, they may recommend a single chemotherapy drug or have you take more than one drug at the same time. Using more than one drug to treat cancer is called combination chemotherapy.

Your treatment team will keep in mind the way each drug works and its side effects to make sure the drugs will work well together. The treatment team designs your treatment plan by taking into account the type of cancer, its stage and multiple other factors.

Types of chemotherapy drugs

Alkylating agents

This group of medicines works directly on DNA to keep the cell from reproducing itself. These drugs will kill cells in all phases of the cell cycle. Some examples of alkylating agents are Chlorambucil, Cyclophosphamide, Cisplatin, and Carboplatin.

Nitrosoureas

A group of drugs that act similar to that of alkylating agents. These drugs slow down or stop enzymes that help repair DNA. They do travel into the brain, though many chemotherapy medicines do not. Examples are Carmustine and Lomustine.

Anti-metabolites

Drugs that interfere with a cell’s RNA and DNA. Anti-metabolites work when cells are dividing. Examples are Fluorouracil, Methotrexate and Fludarabine.

Plant alkaloids and natural products

Medicines that are made from natural products. This group of drugs can block a cell’s ability to divide and become two cells, and to repair damage to cells. Examples are Vincristine, Paclitaxel, and Topotecan.

Anti-tumor antibiotics

Anti-neoplastic drugs that are made from micro-organisms. These antibiotics do not act like the antibiotics used to treat infections. They may work in all phases of the cell cycle. They either break up DNA strands or slow down or stop DNA synthesis that cells need to grow. Examples are Bleomycin, Doxorubicin and Mitoxantrone.

Hormonal agents

There are two types of hormonal agents used in the treatment of cancer: Corticosteroid hormones and sex hormones. Corticosteroids are used to treat some cancers (leukemia, multiple myeloma, and lymphoma). Steroids are also used to reduce swelling around tumors of the brain and spinal cord. Steroids are used with other chemotherapy drugs in combination chemotherapy. Examples of corticosteroids are Prednisone and Dexamethasone. Sex hormones change how female and male hormones are made and act. They can be used to control the growth of breast, uterine and prostate cancers, which may grow when around hormones. These drugs do not kill cells, as typical chemo drugs do. They cut off the “food supply” to destroy the cancer cells. Examples of sex hormones are Tamoxifen and Leuprolide.

Biological response modifiers

Drugs that strengthen the bodies’ immune system to fight the growth of cancer. Other agents might stop or slow cancer growth by disrupting processes that are needed to grow or spread. This growing group of anti-cancer medicines is often considered separate from chemotherapy. Examples of biological response modifiers are Herceptin and Avastin, Erbitux and Rituxan.