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What Is Cancer?
Cancer is a group of diseases characterized by
uncontrolled growth and spread of abnormal cells. If the spread is not
controlled, it can result in death. Cancer is caused by both external
factors (tobacco, chemicals, radiation, and infectious organisms) and
internal factors (inherited mutations, hormones, immune conditions,
and mutations that occur from metabolism). These causal factors may
act together or in sequence to initiate or promote carcinogenesis. Ten
or more years often pass between exposure to external factors and
detectable cancer. Cancer is treated by surgery, radiation,
chemo-therapy, hormones, and immunotherapy.
Can Cancer Be Prevented?
All cancers caused by cigarette smoking and heavy
use of alcohol could be prevented completely. The American Cancer
Society estimates that in 2008 about 170,000 cancer deaths are
expected to be caused by tobacco use.
Scientific evidence suggests that about one-third of the 564,830
cancer deaths expected to occur in 2008 will be related to nutrition,
physical inactivity, and overweight or obesity, and thus could also be
prevented. Certain cancers are related to infectious agents, such as
hepatitis B virus (HBV), human papillomavirus (HPV), human
immunodeficiency virus (HIV), helicobacter, and others, and could be
prevented through behavioral changes, vaccines, or antibiotics. In
addition, many of the more than 1 million skin cancers that are
expected to be diagnosed in 2008 could have been prevented by
protection from the sun’s rays. |
