Oncology (cancer)

One in three people will get cancer at some time in their life. Cancer isn’t one disease. There are over two hundred different types of cancer, the most common of which are cancers of the lung, breast, bowel and prostate.

Cancer is a disease where cells grow out of control. They can form a solid growth, called a tumour, or they can multiply in the blood or bone marrow, where blood cells are made.

Cancers can become malignant. If they do, they can spread around the body, and invade, damage and destroy normal tissue.

Cancers grow and spread with the help of substances, such as growth factors, which the body makes. Some of these growth factors help cancerous cells to multiply, while others, called angiogenic factors, help tumours to grow new blood vessels, so they can get oxygen and food from the bloodstream.

Research into new treatments for cancer is looking for better ways to destroy cancer cells and to block growth factors, so that cancers can’t grow.

Treating cancer

Most of the medicines that are currently used to treat cancer are designed to kill cells, usually by interfering with the way that they multiply. This means that anti-cancer medicines (also called chemotherapy) can kill both cancerous and healthy cells. So, although they may be very effective in destroying tumours, they also have unwanted effects on normal cells, especially those that multiply quickly, like lymphocytes or cells that line the intestine.

New medicines for cancer aim to get around this problem by targeting treatment at cancer cells, and not affecting normal cells.

Scientists are trying to identify changes in cancer cells that could make them sensitive to new small molecule drugs, and spare the normal cells. Unlike most chemotherapeutics, these new drugs are often taken orally and are better tolerated. Another approach is to attach antibodies to powerful anti-cancer drugs. The antibodies are designed to recognise and bind to markers that are only found on cancer cells, so they keep anti-cancer drugs away from healthy cells. Antibodies alone can also be used to kill cancer cells by binding to markers on cancer cells, and signalling to the immune system that these are cells it needs to destroy.

Antibodies can also be used on their own to stop growth factors from getting to cancer cells and helping them to multiply and grow. The antibodies bind to and block places on cancer cells that are normally reserved for growth factors. Some of these growth factors are needed for the cancer to get bigger, while others are needed to help a tumour to grow blood vessels – a process called angiogenesis.

Like all tissues, tumours need a blood supply to provide them with oxygen and nutrients. Using an antibody to block angiogenesis may stop it from growing and spreading, and may even cause it to become smaller.

Research into new treatments for cancer is therefore looking beyond traditional methods of destroying tumours towards novel ways of keeping cancer under control..

More about non-small-cell lung cancer and non-Hodgkins lymphoma.