Cancer describes a wide range of diseases characterized by uncontrolled growth of malignant cells that invade neighboring tissue and can spread to other parts of the body. There are more than 100 types of cancer. According to the World Health Organization, in 2008:

  • Cancer was the leading cause of death worldwide, accounting for 7.6 million deaths (around 13 percent of all deaths).
  • Nearly 12.7 million people were diagnosed with cancer.
  • About 70% of all cancer deaths occurred in low- and middle-income countries.

Oncology is the branch of medicine that covers all phases of cancer treatment: diagnosis, therapy, follow-up care after treatment, and palliative care of patients with terminal malignancies. Cancer treatments include surgery and hormone manipulation, as well as chemotherapy and radiotherapy that are used to destroy tumors, prevent tumor recurrence, and improve or prolong patient life.

Learn about chemotherapy.