Important Facts Cancer is a leading cause of death worldwide, causing 7.6 million deaths in 2008 (about 13 percent of all deaths). Each year, most cancer deaths are caused by lung, stomach, liver, colon and breast cancers. The most common types of cancer differ between men and women. Approximately 30% of cancer deaths result from five major behavioral and dietary risk factors: high body mass index, low fruit and vegetable intake, physical inactivity, tobacco use, and alcohol consumption. Tobacco use is the most significant carcinogenic risk factor, contributing to 22% of cancer deaths worldwide and 71% of lung cancer deaths worldwide. Cancer-causing infections such as hepatitis B and C viruses and human papillomavirus cause up to 20 percent of deaths in low- and middle-income countries. The number of cancer deaths worldwide is expected to continue to rise and will exceed 13.1 million by 2030. Cancer is a generic term for a group of multiple diseases that can affect any part of the body. Other terms used are malignant tumors and superfluous organisms. A defining characteristic of cancer is the rapid production of abnormal cells that grow beyond their usual boundaries and can invade adjacent parts of the body and spread to other organs. This process is known as metastasis. Metastasis is the leading cause of death from cancer.