Melanoma Skin Cancer May Be More Treatable with New Discovery
Average age of melanoma diagnosis is 61; over 9,000 expected to die in 2012 - more about this skin cancer below news report
Aug. 15, 2012 - There is a new target that may hold the key to the successful treatment of melanoma, the deadliest skin
cancer that primarily targets older men. Researchers have found a new channel-forming protein called Pannexin (Panx1) that is on the surface
of healthy skin cells. But they found, in melanoma, Panx1 is over-produced to a uncontrolled level. If you reduce it or knock it down, the
cell becomes more normal.
This new research by Silvia Penuela and Dale Laird from Western University, Canada, is published in the August 17 issue
of the Journal of Biological Chemistry.
Malignant melanoma only accounts for four per cent of all skin cancers and yet, it's responsible for 79% of skin
cancer-related deaths. The World Health Organization says there are 200-thousand cases of melanoma diagnosed each year and 65 thousand
melanoma-related deaths (2000 statistics).
"We think this over-production of Panx1, enables the melanoma to become very aggressive. The cells have these extra Panx1
channels and they can leave the primary tumor and invade other tissues," explains Laird, a Professor in the Department of Anatomy and Cell
Biology, and Canada Research Chair in Gap Junctions and Disease.
"And when you find a protein that is highly up-regulated in a disease cell such as a melanoma, the question becomes, is
there therapeutic value in targeting a drug to that protein to reduce its production or block its function. Would that be an effective
"We now want to correlate our discovery to patient samples using the human melanoma bank through our collaboration with
Dr. Muriel Brackstone and other clinicians at the London Health Sciences Centre, to see if this is a cancer marker," says Penuela, a
Postdoctoral Fellow working in the Laird lab.
"So if a melanoma lesion has a lot of this protein, it might be a tool for prognosis, in saying this is more advanced, or
going to be highly metastatic. And because it's on the skin, it would be more accessible for treatment." Penuela suggests potential treatment
might be in the form of a topical medication to use on melanoma lesions.
The scientists also worked with David Litchfield and John Lewis and their teams at Schulich Medicine & Dentistry and the
London Regional Cancer Program on this research. It was funded through the Canadian Institutes of Health Research. The Laird laboratory
recently received a $200,000 Innovation Grant from the Canadian Cancer Society Research Institute to further its studies on Panx1.
is the most serious type of
skin cancer and senior citizens are the usual victims. Often the first sign of melanoma is a change in the size, shape, color or
feel of a mole. Most melanomas have a black or black-blue area. Melanoma may also appear as a new mole. It may be black, abnormal or
Thinking of "ABCD" can help you remember what to watch
● Asymmetry - the shape of one half does not match the other
● Border - the edges are ragged, blurred or irregular
● Color - the color in uneven and may include shades of black, brown and tan
● Diameter - there is a change in size, usually an increase
Melanoma can be cured if it is diagnosed and treated early. If melanoma is not removed in
its early stages, cancer cells may grow downward from the skin surface and invade healthy tissue. If it spreads to other parts of the body it
can be difficult to control.
Melanoma is a form of cancer that
begins in melanocytes (cells that make the pigment melanin). It may begin in a mole (skin melanoma), but can also begin in other
pigmented tissues, such as in the eye or in the intestines.
It is estimated that 76,250 men and women (44,250 men and 32,000 women) will be diagnosed with and 9,180 men
and women will die of melanoma of the skin in 2012.
From 2005-2009, the median age at diagnosis for melanoma of the skin was 61 years of age.
Approximately 0.6% were diagnosed under age 20; 6.8% between 20 and 34; 10.7% between 35 and 44; 18.2%
between 45 and 54; 21.6% between 55 and 64; 18.8% between 65 and 74; 16.7% between 75 and 84; and 6.6% 85+ years of age.
The age-adjusted incidence rate was 21.0 per 100,000 men and women per year.
From 2005-2009, the median age at death for melanoma of the skin was 68 years of age. Approximately 0.1% died
under age 20; 2.6% between 20 and 34; 5.6% between 35 and 44; 13.5% between 45 and 54; 19.9% between 55 and 64; 21.2% between 65
and 74; 24.1% between 75 and 84; and 12.9% 85+ years of age.
The age-adjusted death rate was 2.7 per 100,000 men and women per year. These rates are based on patients who
died in 2005-2009 in the US.
Based on rates from 2007-2009, 1.99% of men and women born today will be diagnosed with melanoma of the skin
at some time during their lifetime. This number can also be expressed as 1 in 50 men and women will be diagnosed with melanoma of
the skin during their lifetime. These statistics are called the
lifetime risk of developing cancer. Sometimes it is more useful to look at the
probability of developing melanoma of the skin between two age groups. For example,
0.99% of men will develop melanoma of the skin between their 50th and 70th birthdays compared to 0.60% for women
On January 1, 2009, in the United States there were approximately 876,344 men and women alive who had a
history of melanoma of the skin - 427,810 men and 448,534 women.
Couples encouraged to examine each other for
suspicious moles that could be skin cancer. Researchers estimate that 40
50% of people in the U.S. who live to age 65 will have nonmelanoma
skin cancer at least once.