Someone
told me we have Cancer cells in are bodies often and our bodies just
get rid of it and one day they
don’t. That sounded weird to me. So I looked it up for plain people
like me and found this explanation if anyone is interested. ( So now we
know the truth- it ain’t because I am a Medical Social Worker- I am just
naturally curious and want to understand medical
things- I guess that is why I am good at my job)
How do healthy cells become cancerous?
A
healthy cell does not turn into a cancer cell overnight. Its behavior
gradually changes, a result of damage
to between three and seven of the hundreds of genes that control cell
growth, division and life span. First, the cell starts to grow and
multiply. Over time, more changes may take place. The cell and its
descendants may eventually become immortal, escape destruction
by the body's defenses, develop their own blood supply and invade the
rest of body.
What Is Cancer?
Cancer is the general name for a group of more than 100 diseases. Although there are many kinds of cancer, all
cancers start because abnormal cells grow out of control. Untreated cancers can cause serious illness and death.
How normal cells act
The
body is made up of trillions of living cells. Normal body cells grow,
divide to make new cells, and die
in an orderly way. During the early years of a person’s life, normal
cells divide faster to allow the person to grow. After the person
becomes an adult, most cells divide only to replace worn-out or dying
cells or to repair injuries.
How cancer starts
Cancer
starts when cells in a part of the body start to grow out of control.
Cancer cell growth is different
from normal cell growth. Instead of dying, cancer cells continue to
grow and form new, abnormal cells. Cancer cells can also invade (grow
into) other tissues, something that normal cells can’t do. Growing out
of control and invading other tissues are what
makes a cell a cancer cell.
Cells become cancer cells because of changes to their DNA (deoxyribonucleic acid). DNA is in every cell and
it directs all its actions. In
a normal cell, when DNA is damaged the cell either repairs the damage
or dies. In cancer cells, the damaged DNA is not repaired, but the cell
doesn’t die like it should. Instead, the cell goes on making new cells
that the body doesn’t need. These new cells all have the same damaged DNA as the first cell does.
People can inherit abnormal or faulty DNA (it’s passed on from their parents), but most DNA damage is
caused by mistakes
that happen while a normal cell is reproducing or by something in the
environment. Sometimes DNA damage may be caused by something obvious
like
cigarette smoking or
sun exposure. But it’s rare to know exactly what caused any one person’s cancer.
In most cases, the cancer cells form a tumor. Over time, the tumors can invade nearby normal tissue, crowd it
out, or push it aside. Some cancers, like
leukemia, rarely form tumors.
Instead, these cancer cells involve the blood and blood-forming organs
and circulate through other tissues where they grow.
How cancer spreads
Cancer
cells often travel to other parts of the body where they can grow and
form new tumors that crowd out
normal tissue. This happens when the cancer cells get into the body’s
bloodstream or lymph vessels. The process of cancer spreading is called
metastasis.
No
matter where a cancer may spread, it’s always named based on the place
where it started. For instance, colon
cancer that has spread to the liver is called metastatic colon cancer,
not liver cancer. In this case, cancer cells taken from the liver would
be the same as those in the colon. They would be treated in the same
ways, too.
How cancers differ
Different types of cancer can behave very differently. For instance,
lung cancer and
skin cancer
are very different diseases. They grow at different rates and respond
to different treatments. This is why people with cancer need treatment
that’s aimed at their kind of cancer.
Tumors that are not cancer
A tumor is an abnormal lump or collection of cells, but not all tumors are cancer. Tumors that aren’t cancer
are called benign. Benign tumors can cause problems – they can
grow very large and press on healthy organs and tissues. But they can’t
grow into (invade) other tissues. And they can’t spread to other parts
of the body (metastasize). These tumors are
seldom life threatening.
Lymph Nodes and Cancer
What is the lymph system?
Our
bodies have a network of lymph vessels and lymph nodes. (Lymph is
pronounced limf.) This network is a part
of the body’s immune system. It collects fluid, waste material, and
other things (like viruses and bacteria) that are in the body tissues,
outside the bloodstream.
Lymph vessels are a lot like the veins that collect and carry blood through the body. But instead of carrying
blood, these vessels carry the clear watery fluid called lymph.
The lymph system
Lymph fluid flows out from capillary walls to bathe the body’s tissue cells. It carries oxygen and other nutrients
to the cells, and carries away waste products like carbon dioxide (CO2) that flow out of the cells. Lymph fluid also contains white blood cells, which help fight infections.
Lymph
fluid would build up and cause swelling if it were not drained in some
way. That’s the role of the lymph
vessels. Lymph vessels draw up the lymph fluid from around the cells to
send it towards the chest. There, lymph fluid collects into a large
vessel that drains into a blood vessel near the heart.
Lymph nodes and what they do
Lymph
vessels route lymph fluid through nodes throughout the body. Lymph
nodes are small structures that work
as filters for harmful substances. They contain immune cells that can
help fight infection by attacking and destroying germs that are carried
in through the lymph fluid.
There
are hundreds of lymph nodes throughout the body. Each lymph node
filters the fluid and substances picked
up by the vessels that lead to it. Lymph fluid from the fingers, for
instance, works its way toward the chest, joining fluid from the arm.
This fluid may filter through lymph nodes at the elbow, or those under
the arm. Fluid from the head, scalp, and face
flows down through lymph nodes in the neck. Some lymph nodes are deep
inside the body, such as between the lungs or around the bowel, to
filter fluid in those areas. The lymph fluid slowly flows in from all
around the body, making its way back to the chest.
At the end of its journey, the filtered fluid, salts, and proteins are
dumped back into the bloodstream.
Swollen lymph nodes
When there’s a problem, such as infection, injury, or cancer, the node or the group of lymph nodes in that area
may swell or enlarge as they work to filter out the “bad” cells. This may be called
lymphadenopathy (LIMF-ad-uh-NOP-uh-thee). Swollen lymph
nodes tell you that something is not right, but other symptoms help
pinpoint the problem. For instance, ear pain, fever, and enlarged lymph
nodes near your ear are clues that you may have
an ear infection or cold.
Some areas where lymph nodes commonly swell are in the neck, groin, and underarms. In most cases, only one area
of nodes swells at a time. When more than one area of lymph nodes is swollen it’s called
generalized lymphadenopathy. Some infections (such as strep throat and chicken pox), certain medicines, immune system diseases, and cancers like
lymphoma and
leukemia
can cause this kind of swelling. The health care provider will look for
more information to figure out the cause of the swelling. Lymph node
swelling
is often caused by something other than cancer.
Cancer in the lymph nodes
Cancer can appear in the lymph nodes in 2 ways: it can either start there or it can spread there from somewhere
else.
More often, cancer starts somewhere else and then spreads to lymph nodes. That is the focus of this section.
How does cancer spread to lymph nodes?
Cancer can spread from where it started (the primary site) to other parts of the body.
When
cancer cells break away from a tumor, they can travel to other areas of
the body through either the bloodstream
or the lymph system. Cancer cells can travel through the bloodstream to
reach distant organs. If they travel through the lymph system, the
cancer cells may end up in lymph nodes. Either way, most of the escaped
cancer cells die or are killed before they can
start growing somewhere else. But one or two might settle in a new
area, begin to grow, and form new tumors. This spread of cancer to a new
part of the body is called
metastasis.
In
order for cancer cells to spread to new parts of the body, they have to
go through several changes. They
first have to become able to break away from the original tumor and
then attach to the outside wall of a lymph vessel or blood vessel. Then
they must move through the vessel wall to flow with the blood or lymph
to a new organ or lymph node.
When cancer grows inside lymph nodes, it usually affects the lymph nodes near the tumor itself. These are the
nodes that have been doing most of the work to filter out or kill the cancer cells.
How is cancer in lymph nodes found?
Normal
lymph nodes are tiny and can be hard to find, but when there’s
infection, inflammation, or cancer, the
nodes can get larger. Those near the body’s surface often get big
enough to feel with your fingers, and some can even be seen. But if
there are only a few cancer cells in a lymph node, it may look and feel
normal. In that case, the doctor must check for cancer
by removing all or part of the lymph node.
When a surgeon operates to remove a primary cancer, one or more of the nearby (regional) lymph nodes may be
removed as well. Removal of one lymph node is called a biopsy. When many lymph nodes are removed, it’s called
lymph node sampling or lymph node dissection. When cancer
has spread to lymph nodes, there’s a higher risk that the cancer might
come back after surgery. This information helps the doctor decide
whether more
treatment, like
chemo or
radiation, might be needed after
surgery.
Doctors may also take samples of one or more nodes using needles. Usually, this is done on lymph nodes that
are enlarged. This is called a needle biopsy. The tissue that’s
removed is looked at under the microscope by a pathologist (a doctor who
diagnoses illness using tissue samples) to find out if there are cancer
cells in it
Under
the microscope, any cancer cells in the nodes look like the cancer
cells from the primary tumor. For instance,
when breast cancer spreads to the lymph nodes, the cells in the nodes
look like breast cancer cells. The pathologist prepares a report, which
details what was found. If a node has cancer in it, the report describes
what it looks like and how much was seen.
Doctors may also use scans or other imaging tests to look for enlarged nodes that deep in the body. For more
on this, see
Imaging (Radiology) Tests. Often, enlarged lymph nodes near a cancer are assumed to contain cancer.
What does it mean if there’s cancer in my lymph node?
It depends. Sometimes there are so few cancer cells in the node that the pathologist must use special tests
to find them. In the case of a very few cancer cells in a lymph node, it may not change the treatment plan at all.
If there’s a lot of cancer in a node, the large mass can be seen easily. If the cancer is growing out of the
lymph node through the layer of connective tissue on the outside (called the
capsule), it’s called extracapsular extension.
More
cancer in the nodes may mean that the cancer is fast growing and/or
more likely to spread to other places
in the body. But if nearby lymph nodes are the only other place cancer
is found beyond the main (primary) site, surgery to remove the main
tumor and the nearby lymph nodes may be able to get rid of it all.
Cancer that has spread to nodes further away from the primary cancer will more likely need extra treatment with
chemo or radiation.
Cancer in nodes affects cancer stage
Treatment
of cancer is based on the type of cancer a person has, and the stage of
the cancer. Doctors use a
system to assign a stage to the cancer. The most common staging system
is the TNM system. The T in TNM stands for tumor, the M stands for
metastasis, and the N stands for lymph nodes. If there’s no cancer found
in the lymph nodes near the cancer, the N is
assigned a value of 0. If nearby or distant nodes show cancer, the N is
assigned a number such as 1, 2 or sometimes 3, depending on how many
nodes are affected, how much cancer is in them, how large they are, and
where they are.
A
cancer with lower TNM numbers is usually easier to treat and has a
better outlook for survival. For instance,
a cancer with T1, N0, M0, would be a cancer that was found very early,
before it spread. The T1 would mean a small tumor, the N0 means that no
nodes are involved, and the M0 means that no metastases were found. For
more information on staging, see information
about
your cancer type, or read
Staging.
Effects of removing lymph nodes
Nodes
that have been removed during cancer surgery can leave part of the body
without a way to drain off the
lymph fluid in the affected area. Many of the lymph vessels now run
into a dead end where the node used to be, and fluid can back up. This
is called
lymphedema,
and it can become a life-long problem. The more lymph nodes that are
removed, the more likely it is to occur. For more on lymphedema,
see “To learn more.”
