Cancers and Tumors

Cancer is any of more than 100 diseases characterized by excessive, uncontrolled growth of abnormal cells, which invade and destroy other tissues. Cancer develops in almost any organ or tissue of the body, but certain types of cancer are more lethal than others. Cancer is the leading cause of death in Canada and second only to heart disease in the United States. Each year, more than 1.2 million Americans and 132,000 Canadians are diagnosed with cancer, and more than 1,700 people die from cancer each day in the United States and Canada. For reasons not well understood, cancer rates vary by gender, race, and geographic region. For instance, more males have cancer than females, and African Americans are more likely to develop cancer than persons of any other racial and ethnic group in North America. Cancer rates also vary globally--residents of the United States, for example, are nearly three times more likely to develop cancer than are residents of Egypt.

English: Gross appearance of the cut surface of a ...

Cancer cure

Birmingham Children's Hospital, Steelhouse Lane, B...

Although people of all ages develop cancer, most types are more common in people over the age of 50. Cancer usually develops gradually over many years, the result of a complex mix of environmental, nutritional, behavioral, and hereditary factors. Scientists do not completely understand the causes of cancer, but they know that certain lifestyle choices can dramatically reduce the risk of developing most types of cancer. Not smoking, eating a healthy diet, and exercising moderately for at least 30 minutes each day reduce cancer risk by more than 60 percent.

Cancer begins in genes, bits of biochemical instructions composed of individual segments of the long, coiled molecule deoxyribonucleic acid (DNA). Genes contain the instructions to make proteins, molecular laborers that serve as building blocks of cells, control chemical reactions, or transport materials to and from cells. The...