What Happens
Melanoma develops when normal pigment-producing skin
cells called
melanocytes become abnormal, grow uncontrollably, and
invade surrounding tissues. Usually only one melanoma develops at a time.
Although melanomas can begin in an existing
mole or other skin growth, most start in previously
unmarked skin. Melanoma is classified as primary or metastatic.
Primary melanoma
Primary melanoma
usually follows a predictable
pattern
of growth
through the
skin
layers. Early detection and surgery to remove the melanoma cure most
cases of primary melanoma.
If not treated, most melanomas
eventually spread to other parts of the body. Melanomas rarely disappear
without treatment.
Your long-term survival, or prognosis, with
primary melanoma depends on:6
- How deeply the melanoma penetrates the skin
(melanoma thickness).
- Whether an open sore is present over the
primary tumor (ulceration).
Metastatic melanoma
Metastatic melanoma
has spread through the
lymph system to nearby skin, lymph nodes, or through
the bloodstream to other organs such as the brain or the liver. Metastatic
melanoma usually cannot be cured. Early detection and removal of primary
melanomas before they metastasize offer the best hope for cure.
Experts talk about prognosis in terms of "5-year survival rates." The
5-year survival rate means the percentage of people who are still alive 5 years
or longer after their cancer was discovered. It is important to remember that
these are only averages. Everyone's case is different, and these numbers do not
necessarily show what will happen to you. The estimated 5-year survival rate
for melanoma is:4
- 98% if cancer is found early and treated
before it has spread.
- 64% if the cancer has spread to close-by
tissue.
- 16% if the cancer has spread farther away, such as to the
liver, brain, or bones.