| SolveYourProblem
Article Series: Cancer
Help Me Understand Cancer
When
Melanoma Metastasizes: What Does It Mean?
When patients are diagnosed with Clark's
level III or higher, there is a good chance that the melanoma cells
may have spread, or metastasized, from the original site into
the lymph and blood systems, even if they cannot be detected
at the time of diagnosis.
Metastases are often classified as regional
or systemic. Regional
metastases are located in the first lymph node area draining
the primary site and anywhere between the primary site and
those lymph nodes. For example, one patient had a primary melanoma
removed from the skin on his right calf. Four years later he
was found to have nodules under the skin of his right upper
leg and enlarged lymph nodes in his right groin that were proved
by fine needle aspiration (FNA) to contain melanoma cells.
Doctors were unable to detect metastases anywhere else in his
body, and his metastases were classified as regional. If this
patient is later found to have melanoma cells in his liver
and lung, these new sites would be classified as systemic metastases.
The terms that are used to describe these two conditions are
regionally advanced disease and advanced systemic disease.
Their treatment may be very different.
More Information About Metastases
Malignant melanoma is unique among cancers in that it will
metastasize to almost any organ in the body; we do not know
why. When most cancers spread, they like to grow in particular
organs. For example, breast cancer cells usually spread to
the bones, and colon cancer cells usually spread to the liver.
Once melanoma cells are in the bloodstream, they pass through
all the organs. To form a metastasis in an organ, melanoma
cells must first adhere to a blood vessel in that organ. Then
they must penetrate the wall of the blood vessel and set up
a kind of nest in the tissue of the organ. Finally, they release
cytokines that bring new blood vessels to them for nourishment.
Once they have developed a blood supply of their own, they
are off and growing.
Each organ has its own chemical environment. Most melanoma
cells will find the environment of a particular organ hostile.
They may be killed or they may simply not be able to perform
one or more of the operations needed for tumor formation. As
the melanoma cells mutate, however, one or more of them may
become adapted to the environment of a particular organ and
can begin to grow there.
Although melanoma cells may metastasize to any part of the
body, metastases in the vast majority of melanoma patients
do follow a pattern. They are most likely to show up first
as subcutaneous (under the skin) nodules, or in the lymph nodes,
and then in the lungs, liver, and brain. It is not unusual,
however, to find that melanoma has metastasized to the spleen,
adrenal glands, intestines, bones, or bone marrow. It is uncommon
for melanoma to invade the heart, the muscles, or any of the
remaining organs, but it is not unheard of. Patients who die
of the disease are most likely to die of brain metastases,
but by this time, they usually have tumors in many other parts
of their bodies as well.
Scientists are working hard to figure out the mechanisms of
melanoma metastases. Such understanding will be key to the
development of new and better treatments. The type of treatment
currently used for metastatic melanoma depends on which organs
are involved. Treatment may include chemotherapy, immunotherapy,
surgery, radiation therapy, or a combination of these. # # # # #
SolveYourProblem.com
: 2006
> Home > Cancer Articles
: Main Page
|
