A group of over a hundred diseases that occur when malignant forms of abnormal cell growth develop in one or more body organs.
Cancer arises after a series of genetic mutations remove the normal checks on cell growth. These cancer cells continue to divide and grow to produce tumours. Cancer cells can invade adjacent structures and spread via the lymph or blood to distant organs.
It is estimated that about 80 percent of cancers are due to environment or lifestyle, and therefore are potentially preventable. The risk factors for some cancers have been clearly identified, but for others further research is needed.
The cancer treatment that a patient receives is determined by the stage of cancer at diagnosis, the type and location of the cancer, the standard medical practices in the patient’s country, and the ability of the patient to pay for treatment (through national or private insurance or otherwise).
Cancer treatment is a challenge to the sustainability of health care system.