The ABCDEs of melanoma: an evolving concept

Journal of Drugs in Dermatology, May-June, 2005 by David Polsky

In 1985, (1,2) clinicians working in the Melanoma Clinical Cooperative Group at New York University (NYU) School of Medicine sought to develop easily memorizable, readily usable guidelines to alert both laypersons and primary care providers to the clinical features of melanoma. They found that in a database of over 1,100 melanomas, 3 features--Asymmetry, Border irregularity, and Color variegation--were consistently associated with lesions > 6 mm in Diameter. This observation led them to create the "ABCD" acronym, which has since been embraced by most cancer groups and countless individuals as an aid to early diagnosis of melanoma.

The initial analysis excluded ulcerated lesions because the goal was to elucidate features of early melanoma. Pigmented skin lesions that are ulcerated without antecedent trauma are highly suspicious for advanced melanoma and require biopsy regardless of other features, justifying their exclusion from the analysis.

The ABCDs were thus meant to describe a melanoma subset--early, thin tumors that might otherwise be confused with benign pigmented skin lesions. The main point was to alert non-dermatologist health professionals and laypersons to the key clinical features that help in differentiating common moles from melanoma--not to present a list of all melanoma characteristics.

Now, researchers at NYU have published a review of the ABCDs in which they recommend expanding the acronym to ABCDE, with "E" for Evolving. (3) Several factors support this proposed change.

The Case for E

Since the inception of the ABCDs, evidence has accumulated that adding "E" for "Evolving" would substantially enhance the ability of physicians and laypersons to recognize melanomas in early growth phases. "Evolving" recognizes the dynamic nature of melanoma. This is extremely important, for example, in the diagnosis of nodular melanoma (NM), which frequently presents at more advanced stages (ie, thicker tumors), contributing significantly to melanoma mortality rates. (4) NMs frequently lack asymmetry, border irregularity, color variegation, and diameter > 6mm. (5) However, in one series of 125 patients, lesion change (ie, evolution) was noted in 78% of NMs. (5)

Evolution also has proven to be a significant warning sign for superficial spreading melanoma (SSM). In a study of 92 patients with this more common melanoma, 71% noted evolution of their lesions. (5) These data are consistent with previous data from the NYU group showing that 615/696 SSM patients (88%) noted evolution in their melanomas prior to their removal. (6)

These and other observations spurred the NYU researchers to expand their ABCD criteria to include the E for "Evolving" (meaning lesion change over time). (3) "Evolving lesions" are those that have significantly changed in size, shape, symptoms (eg, itching, tenderness), surface (eg, crusting, bleeding), or shades of color. The importance of such evolution as a cardinal feature of cutaneous melanoma and as a frequent cause of biopsy leading to a melanoma diagnosis and excision is well supported. (3) Though patient reports have been criticized for their subjectivity compared to more objective assessments of asymmetry, border, and color, Grichnik's 2001 review of "difficult early melanomas" supports soliciting a history of lesion changes in differentiating melanoma from atypical nevi. (7)

In addition, a study by Cassileth et al of presenting symptoms in melanoma found that changes in "size, elevation, and color" were the most frequent cluster of symptoms precipitating medical evaluation. (8) Additional symptoms noted to be significant were bleeding, itching, tenderness, elevation, and ulceration. (8)

Three other studies also support the importance of lesion evolution in diagnosing melanoma. In their proposed ABCDEs, Thomas et al (9) actually used an "E" to represent horizontal Enlargement (one of the features of an evolving lesion), concluding that enlargement was a more specific warning sign for melanoma than anything in the existing ABCDs. Lucas et al, using dermoscopy, found that lesions noted by dermatologists to be both nonuniform (ie, sharing some of the ABC criteria) and changed had at least 4 times greater risk of being melanomas than lesions without these characteristics. (10) And Healsmith et al's study of the sensitivity of ABCDE criteria (with their E representing Elevation) in diagnosing 65 melanomas revealed that the 5 lesions missed by physicians using these ABCDEs had been noted by the patient to have evolved (changed in size over time). (11) Lesion evolution also has a prominent place in the well-known Glasgow "7-point checklist," which highlights changes in size, shape, and color as major signs of early melanoma. (11)

Additional evidence suggests that expansion to ABCDE would improve the early diagnosis of melanoma. In 2001, Harris et al published an Internet-based study of skin cancer education, (12) which included modules on recognition of melanoma using an algorithm that combines the ABCD criteria with the importance of a changing lesion. The study population consisted of 354 physicians, 346 (92%) of whom were non-dermatologists. The authors observed a statistically significant improvement in proper management of pigmented lesions when the module was applied. Specificity--the correct diagnosis--increased from 69% to 89% (p < .001), with a small decrease in sensitivity from 95% to 91% (p < .001). The authors commented that a single case--a small melanoma that changed in color but was not biopsied by many physicians--accounted for this insignificant decrease in sensitivity.

Conclusions

The ABCD criteria for assessment of pigmented cutaneous lesions should be expanded to ABCDE, to include E for "Evolving." This proposal emphasizes the importance of lesion change as an additional criterion for differentiating melanoma from benign pigmented lesions. Although not all changes in moles indicate melanoma, lesions that have significantly changed warrant further examination and possible biopsy. Clearly, more research is needed to define benign versus malignant changes more precisely. However, in the interim, educational programs and literature should emphasize history of change (evolution) in assessing pigmented lesions. Organizations including the American Cancer Society and The Skin Cancer Foundation have promoted lesion change in their educational materials; however, adding an "E" for "Evolving" to the well-established ABCD acronym would greatly reinforce this message. ABCDE is a simple, succinct, helpful tool to educate the public, as well as the dermatology and non-dermatology medical communities, about the key features of melanoma.