TUESDAY, April 22 (HealthDay News) -- Skin lesions larger than
six millimeters in diameter are more likely than smaller lesions to
be melanoma skin cancer, a new study suggests.
The finding supports the current widespread use of diameter
guidelines to screen for melanoma, researchers say.
This "ABCDE" screening method is based on five features
characteristic of melanoma: asymmetry, border irregularity, color
variegation, diameter larger than six millimeters, and changes in a
lesion.
However, some experts have argued that strict adherence to the
diameter guideline will cause doctors to miss smaller melanomas,
according to background information in the study.
In this study, researchers at the New York University School of
Medicine, New York City, studied more than 1,300 patients
undergoing biopsies for 1,657 pigmented skin lesions or markings
suggestive of melanoma. Of those lesions, 804 (48.5 percent) were
larger than six millimeters in diameter and 138 (8.3 percent) were
diagnosed as melanoma.
Invasive melanomas (which have penetrated deeper into the skin)
were diagnosed in 13 of 853 lesions (1.5 percent) that were six
millimeters or smaller in diameter and in 41 of the 804 (5.1
percent) of lesions that were larger than six millimeters. In situ
melanomas (those that remain in the skin's outer layers) were
diagnosed in 22 of the 853 (2.6 percent) of lesions six millimeters
or smaller and in 62 of the 804 (7.7 percent) of lesions larger
than six millimeters.
"With each one-millimeter diameter range from 2.01 to six
millimeters, the proportion of melanomas did not vary
significantly, remaining stable at 3.6 percent to 4.5 percent," the
study authors wrote. "However, we observed a nearly 100-percent
increase in the proportion of melanomas when comparing the 5.01- to
six-millimeter category (4.3 percent) to the 6.01- to
seven-millimeter category (8.3 percent)."
The study was published in the April issue of the journal
Archives of Dermatology.
"We recommend that a diameter criterion of larger than six
millimeters remain a part of the ABCDE criteria," the researchers
concluded. "We do not recommend downward revision of the D criteria
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."
More information
The American Academy of Dermatology has more about
skin cancer.
