|
Definition:
Melanoma is a skin cancer of the melanocytes, the cells that
produce skin color and give moles their dark color. Under normal
conditions, moles are benign skin tumors. Sometimes, however, a
mole can develop into melanoma. A new mole may also be an early
melanoma.
Melanoma skin
cancers are less common than carcinoma skin cancers. But melanomas
are more dangerous because they are far more likely to spread to
other parts of the body.
Cancer occurs when
cells in the body (in this case skin cells) divide without control
or order. Normally, cells divide in a regulated manner. If cells
keep dividing uncontrollably when new cells are not needed, a mass
of tissue forms, called a growth or tumor. The term cancer refers
to malignant tumors, which can invade nearby tissues and can
spread to other parts of the body. A benign tumor is unable to
invade or spread.
Causes:
Ultraviolet radiation from the sun is the main cause of skin
cancer. But artificial radiation from sun lamps and tanning booths
can also cause skin cancer.
Risk
Factor: A risk factor is something that increases your
chance of getting a disease or condition:
Certain types of
moles called dysplastic nevi, or atypical moles. These types of
moles look somewhat like melanoma. (See symptoms section for
description of melanoma moles.)
-
Large nevi
present at birth
-
Age: Peak
incidence in early adulthood and again later in life
-
Fair skin
-
Red or blonde
hair
-
Light-colored
eyes
-
Family members
with melanoma
-
Excessive skin
exposure to the sun without protective clothing or
sunscreen
-
Suppression of
the immune system, caused either by disease or treatment
Symptoms:
Melanomas are not usually painful. The first sign of melanoma is
often a change in the size, shape, color, or feel of an existing
mole. Melanomas also may appear as a new, black, discolored or
abnormal mole. It's important to remember that most people have
moles, and almost all moles are benign.
The following are
signs that a mole may be a melanoma:
-
Uneven Shape
-The shape of one half does match the shape of the other
half.
-
Ragged Edges -
The edges are ragged, notched, blurred, or irregular and the
pigment may spread into surrounding skin.
-
Uneven Color -
The color is uneven with shades of black, brown or tan, and
possibly even white, gray, pink, red or blue.
-
Change in Size
- The mole changes in size, usually growing larger. Melanomas
are usually larger than the eraser of a pencil (5 mm or 1/4
inch).
-
Change in
Texture - The mole may begin to have fine scales. In more
advanced cases, a mole may become hard or lumpy.
-
Itching - The
mole may start to itch, or in more advanced cases it may ooze
or bleed.
Diagnosis:
The doctor will ask about your symptoms and medical
history, and perform a physical exam. The doctor will examine your
skin and moles. He or she will take a biopsy (tissue sample) of
any suspicious moles and send them to a laboratory for testing.
Other moles will be watched over time.
The doctor may also
examine lymph nodes in the groin, underarm, neck, or areas near
the suspicious mole. Enlarged lymph nodes may suggest the spread
of a melanoma. The doctor may need to remove a sample of lymph
node tissue to test for cancer cells.
Treatment:
Once melanoma is found, tests are performed to find out if the
cancer has spread and, if so, to what extent. Treatment for
melanoma depends on whether the cancer has spread.
Treatments include:
-
Surgery -
removal of the melanoma and some healthy tissue surrounding
it. If a large area of tissue is removed, a skin graft may be
done at the same time. For this procedure, the skin that was
removed is replaced with skin from another part of the body.
Lymph nodes near the tumor may be removed during surgery
because cancer can spread through the lymphatic system.
-
Chemotherapy -
uses drugs to kill cancer cells. Chemotherapy may be given in
many forms including: pill, injection, and via a catheter. The
drugs enter the bloodstream and travel through the body
killing mostly cancer cells, but also some healthy cells.
-
Biological
Therapy - medications or substances made by the body to
increase or restore the body's natural defenses against
cancer. Also called biological response modifier (BRM)
therapy. Examples include interferon, interleukin 2 and
melanoma vaccines.
-
Radiation
Therapy (Radiotherapy) - The use of radiation to kill cancer
cells and shrink tumors. This is not a cure for melanoma and
is used only in combination with other therapies.
Prevention:
To reduce your chance of getting melanoma:
-
Avoid spending
too much time in the sun.
-
Protect your
skin from the sun with clothing, including a shirt,
sunglasses, and a hat with a broad brim.
-
Use sunscreens
with a sun protection factor (SPF) of 15 or more on skin that
will be exposed to the sun.
-
Avoid exposing
your skin to the sun between 10:00 a.m. and 2:00 p.m. standard
time, or 11:00 a.m. and 3:00 p.m. daylight savings time.
-
Don't use sun
lamps or tanning booths.
Take the following
precautions to find melanoma in its early stages:
-
If you have a
mole that looks similar to the ones described above, have your
skin examined by a doctor.
-
If you have
many moles or a family history of melanoma, have your skin
checked regularly for changes in moles.
-
Ask your doctor
to show you how to do a skin self-exam.
|