Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites by metastasis. Metastasis is defined as the stage in which cancer cells are transported through the bloodstream or lymphatic system. Cancer may affect people at all ages, but risk tends to increase with age. It is one of the leading causes of death in developed countries.

There are many types of cancer. Severity of symptoms depends on the site and character of the malignancy and whether there is metastasis. A definitive diagnosis usually requires the histologic examination of tissue by a pathologist. This tissue is obtained by biopsy or surgery. Most cancers can be treated and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for the type of cancer pathology. Drugs that target specific cancers already exist for several cancers. If untreated, cancers may eventually cause illness and death, though this is not always the case.

The unregulated growth that characterizes cancer is caused by damage to DNA, resulting in mutations to genes that encode for proteins controlling cell division. Many mutation events may be required to transform a normal cell into a malignant cell. These mutations can be caused by chemicals or physical agents called carcinogens, by close exposure to radioactive materials, or by certain viruses that can insert their DNA into the human genome. Mutations occur spontaneously, or are passed down generations as a result of germ line mutations.

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WHO news

New drug being tested in Africa for river blindness
Wed, 01 Jul 2009 10:00:00 -0000
1 July 2009 -- The clinical trial of a drug that could eliminate river blindness is being launched in three African countries. Also known as onchocerciasis, this disease is one of the leading infectious causes of blindness across Africa.
Working relationship between the Russian Federation and WHO strengthened
Fri, 26 Jun 2009 00:00:00 -0000
26 June 2009 -- Dr Margaret Chan, Director-General of WHO, today met Mr Vladimir Putin, Prime Minister of the Russian Federation, during an official visit to the country. The visit has seen the strengthening of the working relationship between the Russian Federation and WHO.
Call to protect hospitals, schools from impact of disasters
Thu, 18 Jun 2009 10:00:00 -0000
18 June 2009 -- WHO and UNICEF today called on governments to strengthen risk reduction measures so that health and education systems are able to cope with disasters.
WHO welcomes sanofi-aventis's donation of vaccine
Wed, 17 Jun 2009 19:15:00 -0000
17 June 2009 -- WHO Director-General Dr Margaret Chan has welcomed the announcement by sanofi-aventis to donate 100 million doses of vaccine against the pandemic H1N1 2009 virus.
Pedestrians, cyclists among main road traffic crash victims
Mon, 15 Jun 2009 17:00:00 -0000
15 June 2009 -- The first global assessment of road safety finds that almost half of the estimated 1.27 million people who die in road traffic crashes every year are pedestrians, motorcyclists and cyclists. While progress has been made towards protecting people in cars, the needs of these vulnerable groups of road users are not being met.
Greater equity in health should be a progress indicator
Mon, 15 Jun 2009 16:00:00 -0000
15 June 2009 -- Greater equity in the health status of populations, within and between countries, should be regarded as a key measure of how we are making progress, said WHO Director-eneral Dr Margaret Chan today, speaking at the UN Headquarters in New York.

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