Basic Cancer Facts

What Is Cancer? 

 

Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells. If the spread is not controlled, it can result in death. Cancer is caused by external factors, such as tobacco, infectious organisms, and an unhealthy diet, and internal factors, such as inherited genetic mutations, hormones, and immune conditions. These factors may act together or in sequence to cause cancer. Ten or more years often pass between exposure to external factors and detectable cancer. Treatments include surgery, radiation, chemotherapy, hormone therapy, immune therapy, and targeted therapy (drugs that specifically interfere with cancer cell growth)

Can Cancer Be Prevented?  

A substantial proportion of cancers could be prevented. All cancers caused by tobacco use and heavy alcohol consumption could be prevented completely. In 2015, almost 171,000 of the estimated 589,430 cancer deaths in the US will be caused by tobacco smoking. In addition, the World Cancer Research Fund has estimated that up to one-third of the cancer cases that occur in economically developed countries like the US are related to overweight or obesity, physical inactivity, and/or poor nutrition, and thus could also be prevented. Certain cancers are related to infectious agents, such as human papillomavirus (HPV), hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and Helicobacter pylori (H. pylori). Many of these cancers could be avoided by preventing infection, either through behavioral changes or vaccination, or by treating the infection. Many of the more than 3 million skin cancer cases that are diagnosed annually could be prevented by protecting skin from excessive sun exposure and avoiding indoor tanning. Screening can prevent colorectal and cervical cancers by allowing for the detection and removal of precancerous lesions. Screening also offers the opportunity to detect cancer early, before symptoms appear, which usually results in less extensive treatment and better outcomes. Screening is known to reduce mortality for cancers of the breast, colon, rectum, cervix, and lung (among long-term and/or heavy smokers). A heightened awareness of changes in the breast, skin, or testicles may also result in the early detection of cancer. For complete cancer screening guidelines,