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MELANOMA
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MELANOMA
The melanocytes are special cells that produce a pigment, called melanin, which
gives us our coloring. Black people have more melanin production in their skin, while
Caucasians have less. Albinos have none at all. Their skin is pure white and their eyes
are light blue or pink. Besides for the skin, melanin-producing cells are also found in
the mouth, eye, gut and vaginal areas.
A cancer starting in the melanocytes is called a "melanoma." If someone develops melanoma, it is critical to get prompt diagnosis and proper treatment; this can literally make the difference between life and death. Fortunately, newer treatments give greater hope for melanoma patients than before. Understanding your options will give you the peace-of-mind of knowing you have done everything possible to ensure a successful outcome for yourself or a loved one.
The skin is a tissue, meaning that it is a collection of cells organized as a unit. Cells are the smallest level of animal life, and are controlled
by the genetic material called "genes" within thi. Initially all human cells start out from the fusion of the sperm and
egg cells; at the time of fertilization there is only one type of cell ("zygote")
containing genetic information for constructing the entire human body. As the body
is formed, cells specialize ("differentiate") into all sorts of specific subtypes, such as
nerve, muscle, liver and heart cells. As they do so, part of the genetic material
in thi is "masked" so that it becomes unavailable; we do not need information on
how to form a bone cell when we are making a stomach cell! However, every cell still retains,
at some level in its genes, the total information necessary ("totipotential") for
constructing an entirely new body. This is how scientists are able to clone a cheek
cell, for instance, into a whole new animal.
Normally, skin cells divide very quickly in womb life, early childhood and through
puberty to form the covering surface ("integument") of our bodies. In adulthood, they divide more slowly to replace cells that have
died either from old age or injury. New skin cells arise at the deepest level of
the skin, and gradually push their way upwards toward the surface as they mature.
The main types of cells found within the skin are basal cells, which form the bottom layer, squamous cells, which push toward the surface to form the skin we see, and melanocytes, which produce melanin pigment that colors the skin. If specific types of gene damage
occurs in a cell, it can start dividing out of control. When cells divide quickly,
they tend to pile up to form a lump, called a "tumor". A tumor merely means an abnormal swelling; it can be caused by infection, inflammation,
or just about anything and is usually not cancer. A "benign" tumor only grows in its local area (albeit quite large), it cannot spread distantly
and is not cancer. In contrast, a "malignant" tumor has the ability to spread to anywhere in the body, and this is cancer. This
process of spread is called "metastasis", and is what makes cancer so dangerous. Ultimately, cancer starts in a single cell
and and is a disease of its genes. Any type of skin cell can give rise to skin cancer, when their reproduction goes out
of control, and they divide in a disorganized way. When basal or squamous cells become cancerous, they are called carcinomas, while when the melanocytes become cancerous, this is called melanoma, which has such a different character that it is a different topic from other skin
cancers.
How Common is Melanoma?
In 1997 in the United States 38,000 new cases of melanoma were diagnosed, and 7,300 deaths were attributed to the disease. The number of new cases of melanoma has tended to rise each year. In 1935, the lifetime risk of getting melanoma was only 1 in 1500, but had increased
to 1 in 135 by 1990. It is expected to effect 1 in 90 people by the year 2002. While it is rare in young children, it begins to occur in puberty, and then increases
each year through age 70, afterwhich it decreases. The more fair skinned a person
is, the higher their risk to develop melanoma, of any body area. Conversely, it is
very rare in dark black individuals. It is more common in predominantly fair-skinned
countries, such as Australia.
What Causes or Increases the Risk for Melanoma?
Like any cancer, no one knows exactly why one individual gets melanoma and another
does not. The exact cause of any cancer is currently unknown. However, several risk-factors have been discovered by studying groups of patients, it is vanishingly rare in people with none of the following factors:
1) Sun Exposure increases the risk of all skin cancers, including melanoma. One of the reasons that
melanoma has increased over the years is thought to be people spending more time
"sun worshiping" on the beach. More melanoma
is noted in people living in sunny climates (i.e. Florida) than weak-sun areas
(i.e. Alaska). Ocular (eye) melanoma is also more common in sunny areas,
but not melanomas occurring deeper within the body.
2) Heredity-- People with a family history of certain conditions make up about 10%
of melanoma patients. These "melanoma families" have genes of "dominant"
heredity, which means that if one parent has it, it will most likely be passed
to
their children. However, it is "incompletely penetrant", which means it won't
necessarily be expressed in the offspring, even if they have it. Family mibers
of those with these hereditary genes will tend to get melanoma at a younge
age
than the other 90% of individuals who develop melanoma sporadically. They
are also more likely to have multiple sites of melanoma, which occurs in 5%
of
all patients. Particular syndromes associated with high risk for melanoma are
"Dysplastic Nevus Syndrome" and "Atypical Mole Syndrome". A "nevus" is a
pigmented area of skin, which may be raised, often called a "mole". Patients
may have hereditary conditions where they have large or unusually shaped
moles, which are filled with melanocytes. The odder shaped ("dysplastic") or more abnormal ("atypical") they appear, the more likely to become cancerous.
Also, the more the moles are irritated by sunlight or chiicals, the greater
the
chance that they will undergo "malignant degeneration" to become cancerous.
3) Nevi ("moles") in thiselves will increase the risk for skin melanoma. About
70% of skin melanoma have a pre-existing mole at the cancer site; this is
one
reason why one of the famous "7 signs of cancer" includes a change in a wart
or mole. Interestingly, people continue to develop nevi throughout life. By
age
age 30, men have about 40 nevi that were not present at birth, mostly on the
trunk and arms. This is one reason why the incidence of melanoma increases
with age. Fortunately, only one of a million moles moles becomes malignant.
4) Chronic Irritation is a the underlying the development of many types of
cancer. Irritants include chiicals ("carcinogens"), ultraviolet light, radiation, and trauma causing scars to form in an area. Anything that damages cells
over time will cause specific ones in damaged area to divide and try to repair
damage. The more divisions, the more chance of something going awry in the
division mechanism leading to uncontrolled growth -- this is cancer and starts
with a "screw-up" in just a single cell. Thus anything which is continuously
irritating (i.e. cigarette smoke, b sunlight) should be avoided to minimize
the risk of developing any type of cancer over time.
5) Poor Immune Systi Function or "immunosuppression" raises the risk for
many cancers, including melanoma. There is a theory called "immunosurveill-
ance" which says that we are developing cancerous cells all the time, but
that
a healthy immune systi recognizes and destroys thi before they can start
to divide, take root and spread. Many factors are associated with decreased
immune systi function, including viruses like HIV, EBV, CMV and Hepatitis,
certain medications ("immunosuppressants"), poor nutrition, diabetes, and
even feeling iotionally depressed over time. These conditions can "promote"
the development of cancer, especially in genetically predisposed individuals.
The melanocytes are special cells that produce a pigment, called melanin, which
gives us our coloring. Black people have more melanin production in their skin, while
Caucasians have less. Albinos have none at all. Their skin is pure white and their eyes
are light blue or pink. Besides for the skin, melanin-producing cells are also found in
the mouth, eye, gut and vaginal areas.
A cancer starting in the melanocytes is called a "melanoma." If someone develops melanoma, it is critical to get prompt diagnosis and proper treatment; this can literally make the difference between life and death. Fortunately, newer treatments give greater hope for melanoma patients than before. Understanding your options will give you the peace-of-mind of knowing you have done everything possible to ensure a successful outcome for yourself or a loved one.
The Cancer Group Institute's material explains, in plain English, the definition, types, risk factors, frequency, symptoms, evaluation, historical and latest effective treatments for melanoma. We describe surgery, radiation, chemotherapy, and new immune treatments, along with their side-effects and results. While we don't promise a cure, we tell you everything you need to know to help you make the right choices today in dealing with a problem of melanoma.
