Hormonal therapy

Hormonal therapies| work by altering the levels of particular hormones in the body. Some cancers depend on certain hormones in order to divide and grow. By altering the level of hormones in the body, or blocking the hormones from attaching to the cancer cells the cancer can be controlled.

Biological therapy

Biological therapies use substances that occur naturally in the body to destroy cancer cells. There are several types of biological therapy, including: monoclonal antibodies, cancer growth inhibitors, vaccines and gene therapy.

Monoclonal antibodies

Monoclonal antibodies are drugs that can 'recognise' and find specific cells in the body. They can be designed to find a particular type of cancer cell, attach itself to them and destroy them. They can also carry a radioactive molecule, which then delivers radiation directly to the cancer cells.

Cancer growth inhibitors| interfere with the way cancer cells use 'chemical messengers' to help the cell to develop and divide.

Immunotherapy

Immunotherapy aims to get the body's immune system to fight the tumor. Local immunotherapy injects a treatment into an affected area, for example, to cause inflammation that causes a tumor to shrink. Systemic immunotherapy treats the whole body by administering an agent such as the protein interferon alpha that can shrink tumors. Immunotherapy can also be considered non-specific if it improves cancer-fighting abilities by stimulating the entire immune system, and it can be considered targeted if the treatment specifically tells the immune system to destroy cancer cells. These therapies are relatively young, but researchers have had success with treatments that introduce antibodies to the body that inhibit the growth of breast cancer cells. Bone marrow transplantation (hematopoetic stem cell transplantation) can also be considered immunotherapy because the donor's immune cells will often attack the tumor or cancer cells that are present in the host.

Gene therapy

The goal of gene therapy is to replace damaged genes with ones that work to address a root cause of cancer: damage to DNA. For example, researchers are trying to replace the damaged gene that signals cells to stop dividing (the p53 gene) with a copy of a working gene. Other gene-based therapies focus on further damaging cancer cell DNA to the point where the cell commits suicide. Gene therapy is a very young field and has not yet resulted in any successful treatments.

Radiation

Radiation treatment, also known as radiotherapy, destroys cancer by focusing high-energy rays on the cancer cells. This causes damage to the molecules that make up the cancer cells and leads them to commit suicide. Radiotherapy utilizes high-energy gamma-rays that are emitted from metals such as radium or high-energy x-rays that are created in a special machine. Early radiation treatments caused severe side-effects because the energy beams would damage normal, healthy tissue, but technologies have improved so that beams can be more accurately targeted. Radiotherapy is used as a standalone treatment to shrink a tumor or destroy cancer cells (including those associated with leukemia and lymphoma), and it is also used in combination with other cancer treatments.


Research is trying to see whether vaccines| and gene therapy| can be given to treat a cancer that has come back or has spread. Vaccines may also be able to reduce the chance of a cancer coming back, but this type of research is in the very early stages.