It is very complicated- and the understanding of the genetics is an evolving area of research.

Other examples include radio-iodine therapy. prostate cancer) 'beads' of radioactive material can be placed inside the cancer and irradiate it from within. external beam radiotherapy is the most common. There are many different forms of radiotherapy (internal versus external). Radiotherapy delivers energy to the tissue in the form of ionising radiation. There are now more 'targeted' regimens that we can use such as the tyrosine kinase inhibitors.

The problem is that it is a systemic treatment and so actually damages all cells in the body. As Khan has alluded to- it works on the prinicple that DNA will be dividing fastest in the cancer cells. They work in a variety of ways: (1) promoting DNA damage, (2) inhibit DNA repair, (3) work against cell metabolism, (4) work against tubulin. It kills cells by promoting apoptosis (regulated cell death) and sometimes frank necrosis (disordered cell death).

People 'recover' from cancer when no malignant cells are found within the body- this is termed 'remission.' Cancer may return after 'remission'- but the longer a patient has been in 'remission' the less likely the cancer is to return.Ĭhemotherapy consits of systemically administered drugs that directly damage cellular DNA and RNA. Treatment either has curative intent or paliative intent. It depends very much on the type of cancer, the stage of the disease, the health of the patient. It is not true that there is not a cure for cancer.

Khan academy molecular biology