Chemotherapy

Here’s how chemotherapy works.

Chemotherapy affects the DNA and RNA of cancer cells, reducing their ability to multiply. Your care team may recommend a single chemotherapy drug or a combination of drugs to account for the type of cancer, its stage, and other factors.

Anti-cancer drugs are grouped by:

• How they affect chemical substances inside the cancer cell
• Which process in the cell the drug disrupts
• What part of the cell cycle the drug affects

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.

Nitrosoureas

These are a group of drugs that act similar to alkylating agents. They slow down or stop enzymes that help repair DNA.

Anti-metabolites

These drugs interfere with a cell’s RNA and DNA. Anti-metabolites work when cells are dividing.

Plant Alkaloids and Natural Products

These medicines are made from natural products. They can block a cell’s ability to divide and become two cells, and to repair damage to cells.

Anti-tumor Antibiotics

These are 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.

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. 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.

Biological Response Modifiers

These are drugs that strengthen the body’s 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 expanding group of anti-cancer medicines is often considered separate from chemotherapy.