Dermatologists have long promoted the ABCDs of melanoma detection — A for asymmetry, B for border irregularity, C for color variation and D for diameter larger than six millimeters. But a recent study on nodular melanoma — an aggressive subtype of the skin cancer — forced Martin Weinstock, professor of dermatology and epidemiology, to suggest a few more letters for the alphabet.
The EFG — elevated, firm, growing — criteria were developed by Weinstock to describe the unique features of nodular melanoma, which is difficult to catch early. The study was published in print in the Archives of Dermatology this January.
Weinstock and his associates spent months sifting through the Surveillance, Epidemiology and End Results Program, a database managed by the National Cancer Institute. They analyzed 111,478 invasive melanoma cases that occurred between 1978 and 2007. They grouped each case by subtype and compared the incidence, survival and ultimate fatality rates of each subtype.
What they found was a statistical red flag, signaling nodular melanoma's disproportionately large fatality rate.
Though nodular melanoma accounted for only 14 percent of total melanoma cases, it was the cause of 37 percent of ultimately fatal melanomas. While only one in 19 cases of the common melanoma is ultimately fatal, one in five cases of nodular melanoma ends in death.
"It's nice to be able to analyze the data and get definitive numbers," said Michael Xiong MD'14, who worked closely with Weinstock on the study.
Nodular melanoma accounts for a large proportion of deaths because it is difficult to detect early. The melanoma initially grows deep into the skin instead of spreading laterally across the skin's surface. If the melanoma remains undetected, it is more likely to metastasize, spreading to other areas of the body.
"Catching it early and surgically removing it early is critically important to surviving the melanoma," Weinstock said. "We need to pay more attention to catching the nodular melanomas early."
Nodular melanomas resemble blisters and are most often found on the sun-exposed head and neck. Males over the age of 50 are most susceptible, according to the study.
Nodular melanoma rates of incidence, survival and fatality remain grudgingly static. In analyzing long-term trends, Weinstock's team found nodular melanoma rates have not budged for 30 years. These stagnant rates "underscore the importance of making progress against nodular melanoma," the authors wrote. "Public health efforts should include a focus on (nodular melanoma) for maximum reduction of melanoma mortality."
The study has been met with positive response from other professionals in the field.
"This study confirmed what a lot of dermatologists suspected," said Keri Chaney, instructor of dermatology at Harvard Medical School.
The study's authors recognized that their statistics were subject to variability due to remaining controversy about whether nodular melanoma is a distinct subtype. Some dermatologists may not specifically record nodular melanoma when they turn in their pathology reports, the study reported.
But dermatologists remain hopeful that future research might target nodular melanoma specifically with the goal of detecting it in its early stages.
As research progresses, dermatologists will continue to work through the alphabet.
"Once we get to ‘Z' we'll have to go to Greek letters," joked Robert Kirsner, professor and vice-chairman of dermatology and cutaneous surgery at the University of Miami School of Medicine.