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There are different types of lung cancer and each type is
treated differently.
The Genetic Basis of Lung
Cancer
All cells in the body contain the genetic material called
deoxyribonucleic acid (DNA). Every time a mature cell divides into two
daughter cells, it replicates its DNA exactly. The daughter cells are
clones of the original cell, identical in every way. It is in this way
that our bodies continually replenish themselves. Old cells die off and
the next generation takes their place.
A cancer begins with an error, or mutation, in a cell's DNA. DNA
mutations can be caused by the normal aging process or through
environmental factors, such as cigarette smoke or breathing in asbestos.
Researchers have found that it takes a series of genetic changes to
create a lung cancer cell. Before becoming fully cancerous, cells can be
precancerous, which means they have some irregularities (mutations) but
still function as lung cells. However, precancerous changes may signify
progression toward cancer. When a cell with a genetic mutation divides,
it passes along its abnormal genes to the two daughter cells, which then
divide into four cells with errors in their DNA and so on. Once a cell
has a genetic mutation, it may develop more. With each new mutation, the
cell becomes more irregular and may not be as effective in carrying out
their function in lung tissue. At a later stage of disease, some cells
can migrate away from the main tumor and start growing in other parts of
the body. These sites are called metastases.
Primary versus Secondary Lung Cancer
Primary lung cancer starts in the lungs. The cancer cells are abnormal
lung cells. Sometimes, people will have cancer from another part of
their body travel, or metastasize, to their lungs. This is called
secondary lung cancer, because the lungs are secondary compared to the
original, primary, location of the cancer. Secondary lung cancer is not
lung cancer, but rather the type of cancer from its original site, such
as breast cancer. Secondary lung cancer will be treated differently than
primary lung cancer, because it is a different disease. This web site
focuses on primary lung cancer.
Lung Cancer Statistics
When you read about statistics, it is always important to remember that
they are compiled from populations, or groups, of people. They do not
represent individual experiences.
Lung cancer is one of the most common cancers. In 2007, lung cancer will
account for approximately 15% of all cancer diagnoses and 29% of all
cancer deaths. It is the second most diagnosed cancer in men and women
(after prostate and breast, respectively), but it is the number one
cause of death from cancer each year in both men and women. Because lung
cancer can take years to develop, it is mostly found in older people.
The average age of a person receiving a lung cancer diagnosis is 69
years.
Overall, lung cancer affects men more than women, but that gap is
closing. In 2007, an estimated 114,760 men and an estimated 98,620 women
will be diagnosed with lung cancer and an estimated 89,510 men and an
estimated 70,880 women will die from lung cancer.
Cigarette smoking is the cause of most lung cancers, but there are other
factors, too. Exposure to asbestos, radon, environmental factors, or
secondhand smoke can cause lung cancer. Sometimes, a person develops
lung cancer and doctors do not know why. There are often internal
factors (inherited or from our genes) as well as external or
environmental factors (from outside of our bodies) involved in the
development of any type of cancer.
Lung cancer is the subject of a great amount of research. Promising
areas of research include the study of chemopreventive agents and
research into targeted therapies, both of which show potential to halt
the progression of the development of a cancer cell. However, lung
cancer does not receive as much attention, both in funding and in public
awareness, compared to other types of cancers that are not as common.
Advocates for lung cancer research are working hard to raise awareness
of this imbalance. Here are some organizations that work to support
people with lung cancer by raising awareness of the disease and offering
information and services to patients and families. |
