Large Skin Lesions More Likely to be Melanomas;
Scalp, Neck Cancers More Deadly
Screening becomes increasingly critical as rate of
melanomas increases
April
21, 2008 - Skin lesions larger than 6 millimeters (.236 inch) in
diameter are more likely to be melanomas than smaller skin growths,
according to a report in the April issue of Archives of Dermatology, one
of the JAMA/Archives journals. The researchers support the diameter
guidelines currently used by dermatologists in searching for this skin
cancer that likes to strike older men.
Many clinicians use the ABCDE method to screen for
melanoma. The criteria are evidence-based guidelines that remind
physicians of the features characteristic of melanoma: A... asymmetry (lopsided), B... border irregularity (edges
are ragged, blurred or irregular), C... color variegation (color
uneven, may include shades of black, brown and tan ), D... diameter larger than 6
millimeters and E... evolution, or changes in
the lesion.
However, some researchers argue that strict
adherence to the diameter guideline will cause physicians to miss
smaller melanomas. It is also worrisome because melanoma rates continue
to increase while rates for most other cancers decline.
Naheed R. Abbasi, M.P.H., M.D., of the New York
University School of Medicine, New York, and colleagues studied 1,323
patients undergoing biopsies of 1,657 pigmented skin lesions or markings
suggestive of melanoma. The maximum diameter of each lesion was
calculated before biopsy using a computerized skin imaging system.
Of the lesions, 804 (48.5 percent) were larger than
6 millimeters in diameter and 138 (8.3 percent) were diagnosed as
melanoma.
Conversion Chart
Millimeters
Inches
.50
.01969
1.00
.03937
1.50
.05906
2.00
.07874
2.50
.09843
3.00
.11811
3.50
.13780
4.00
.15748
4.50
.17717
5.00
.19685
5.50
.21654
6.00
.23622
6.50
.25591
7.00
.27559
7.50
.29528
8.00
.31496
8.50
.33465
9.00
.35433
9.50
.37402
10.00
.39370
20.00
.78740
30.00
1.18110
Invasive melanoma, which has penetrated deeper into
the skin, was diagnosed in 13 of 853 lesions (1.5 percent) that were 6
millimeters or smaller in diameter and in 41 of 804 (5.1 percent)
lesions that were larger than 6 millimeters in diameter.
In situ melanomas, which remain in the skin’s outer
layers, were diagnosed in 22 of 853 (2.6 percent) lesions 6 millimeters
or smaller in diameter and in 62 of 804 (7.7 percent) lesions larger
than 6 millimeters in diameter.
“Within each 1-millimeter diameter range from 2.01
to 6 millimeters, the proportion of melanomas did not vary
significantly, remaining stable at 3.6 percent to 4.5 percent,” the
authors write.
“However, we observed a nearly 100-percent increase
in the proportion of melanomas when comparing the 5.01- to 6-millimeter
category (4.3 percent) to the 6.01- to 7-millimeter category (8.3
percent).”
“We recommend that a diameter criterion of larger
than 6 millimeters remain a part of the ABCDE criteria,” the authors
conclude.
“We do not recommend downward revision of the D
criterion at this time. In the United States, rates of melanoma and
nonmelanoma skin cancers have markedly increased, and skin biopsy rates
have more than doubled in 20 years.
"In an era that demands greater data to support
clinical decision making, the ABCDE criteria are valuable evidence-based
guidelines to aid physicians in decisions regarding the biopsy of
pigmented lesions of the skin.”
Editor's Note: Co-author Dr.
Gutkowicz-Krusin is an employee of Electro-Optical Science Inc. (EOS);
Drs. Mihm, Googe, King and Prieto are dermatopathologists for the
MelaFind Study, sponsored by EOS; Dr. Friedman is a consultant for and
shareholder in EOS; Dr. Rigel is a consultant for EOS; Drs. Kopf and
Polsky are investigators for the MelaFind Study sponsored by EOS; and
Dr. Polsky is a consultant for EOS.
Melanomas on the Scalp and Neck More Deadly
A second study in this issue of Archives of
Dermatology says melanoma screening should be more careful on the scalp
and neck after they discovered patients with skin cancers in these areas
are less likely to survive for five or ten years than people with
melanomas on other areas of the body.
About Melanoma
Melanoma is the most
serious type of
skin cancer. 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 "ugly looking."
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.
“Understanding the role of anatomic site in
melanoma survival is important for public health messages on skin
awareness and sun protection,” the authors say. It is also important to
consider in screening for melanoma, since early detection can be
critical.
Anne M. Lachiewicz, M.P.H., of the University of
North Carolina School of Medicine, Chapel Hill, and colleagues analyzed
data from U.S. cancer registries for 51,704 individuals first diagnosed
with melanoma between 1992 and 2003.
More
elderly dying from Squamous Cell and Merkel
Cell Carcinomas
April 14, 2008 – Skin cancer is the most common
cancer in the U.S. – more than a million are diagnosed annually – but it
is the melanoma skin cancer that older Americans fear most, because of
the high death rate. There is a new skin cancer worry for senior
citizens emerging in Australia, however, where deaths from non-melanoma
skin cancer (NMSC) are increasing rapidly among older Australians.
Read more...
Of those, 43 percent had melanomas on their arms or
legs, 34 percent on the trunk, 12 percent on the face or ears, 6 percent
on the scalp or neck and 4 percent at an unspecified site.
Survival rates were lower among those with scalp
and neck melanoma than among those with melanoma at other sites both
five years (83.1 percent vs. 92.1 percent) and 10 years (76.2 percent
vs. 88.7 percent) after diagnosis.
“Fourteen percent of those with scalp/neck melanoma
and 44 percent of those with melanomas at unknown sites died compared
with only 6 percent of those with extremity [arm or leg] melanoma, 8
percent with trunk melanomas and 6 percent with face/ear melanomas,” the
authors write.
After controlling for other factors—including age,
tumor thickness and sex—patients with melanoma on their neck or scalp
died at 1.84 times the rate of those with melanoma on their arms or
legs.
The blood supply and lymphatic drainage systems
serving these areas are rich and complex, which may make it easier for
melanoma cells to penetrate and circulate. In addition, such patients
are more likely to have cancer that spreads into their brain than those
with melanoma on their arms, legs or trunk. Finally, the skin lesions
may be hidden by hair and therefore diagnosed later than those at other
sites.
“We suggest that all full-skin examinations and
future screening studies include a careful inspection of the
scalp/neck,” the authors conclude.
Editor's Note: This study was funded in part
by National Cancer Institute grants. Ms. Lachiewicz is supported by the
Holderness Medical Foundation Fellowship Program at the University of
North Carolina.
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