Cancer is caused
by a group of cells ( but usually begins with one cell) that become
defective and begin growing out of control. Healthy cells become
transformed into cancerous cells in a very complex way. The first
stage is the initiation stage in which a change in the cell's genetic
material sets the stage for a cell to become cancerous. Initiation is
believed to be caused by various cancer-causing agents (carcinogens),
such as tobacco, chemicals or radiation. The second stage is called
the promotion stage in which a cell that has been initiated then comes
cancerous. Promotion may be caused by substances in an individual’s
environment.
Cancers can begin
anywhere in the body, but some are more common than others. They can
also develop at any age, but are much more common in older people.
Over half of all cancer diagnoses and half of all cancer deaths occur
in people over the age of 65. Older people are especially more prone
to lung, breast, prostate and colon cancer.
Cancer is believed
to be more common in older people for a variety of reasons. The
longer a person is alive, the more exposure they have to
cancer-causing agents. The immune system is believed to become less
active and less effective with increasing age, which reduces its
protective ability against cancer. Also, the body's ability to repair
damage to genetic material inside the cell declines with age, allowing
for more opportunity for cancer cell initiation. Fortunately, there
is some evidence that certain types of cancer are actually less
aggressive in older people.
Cancers are
damaging in a number of ways. As they grow they are known to invade
and damage nearby organs and other parts of the body. The cancer may
also interfere with the function of organs and tissues simply by
pressing up against them. They can also spread to distant tissues
producing collections of cells (called metastases) that may then
invade and damage tissues and blood vessels in these new areas.
Cancers may also produce hormones or similar chemical substances,
which can travel throughout the bloodstream wreaking havoc throughout
the entire body.
Cancer is that
dreaded word and diagnosis feared by all. Some types of cancer can be
treated successfully in the elderly, sometimes with a cure, at other
times with a very prolonged remission. It is frequently believed at
this point in time, that a cancer diagnosis is not necessarily an
eminent death sentence. Even when cancer is relatively advanced ,
many symptoms may be effectively managed, although it is still true
that many if not most older people with advanced cancer may eventually
die from the disease.