Derms diagnose melanomas earlier

August 1, 2007

Dermatologists detect melanoma at an earlier stage than do non-dermatologists, a study found, and patients whose skin cancers are detected earlier have better survival rates. This raises concerns relative to prevention, training of physicians and accessibility to dermatologic expertise.

Researchers reached this conclusion in a study published in the Archives of Dermatology in April 2007. In the retrospective analysis, investigators examined data on 2,020 subjects, covering the period from 1991 to 1996, from the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database.

"Our findings raise several issues," says Suephy C. Chen, M.D., M.S., a dermatologist, one of the study's authors and an assistant professor in the department of dermatology, Emory University School of Medicine, Atlanta.

Dermatologic detectives

With the the population aging, it is unrealistic to expect that all see dermatologists, in light of the shortage of physicians in that specialty, Dr. Chen tells Dermatology Times.

"There are not a lot of us out there," she says. "It's not possible from a technical standpoint."

In this study, tumor detection by a dermatologist vs. non-dermatologist was associated with an earlier-stage melanoma (stage 0, stage I, stage II vs. stage III and stage IV; x2 test, p< .01). Dermatologists were also more likely to detect thinner tumors than non-dermatologists: Breslow thickness, 0.86mm vs. 1.00mm; p < .05.

Derm diagnoses, improved survival

At all time points, patients seen by dermatologists had longer survival than those not seen by dermatologists.

At six months, two years and five years, patients whose melanomas were diagnosed by dermatologists had 98 percent, 87 percent and 74 percent survival rates, respectively. By contrast, patients whose melanomas were diagnosed by non-dermatologists had 95 percent, 79 percent and 69 percent survival rates, respectively, at the same three points in time.

Of the 2,020 subjects, dermatologists diagnosed melanomas in 1,467 patients (73 percent), and non-dermatologists diagnosed 553 melanomas (27 percent).

While there were no significant differences based on age, sex, race, marital status or type of insurance between the two patient arms, there was a marked difference in care for urban dwellers. Patients who received their diagnoses from dermatologists were more likely to live in an urban area (p< .001).

"If you look at the breakdown in terms of where dermatologists are located, it's mostly on the bicoastal areas in the urban settings," Dr. Chen says. "There are big pockets of the country where there are not a lot of dermatologists."

Moreover, Dr. Chen notes that she and colleagues published an earlier study on diagnostic accuracy and management strategy in melanoma in the Journal of General Internal Medicine, in which they found dermatologists outperformed non-dermatologists in diagnostic accuracy and management strategy.

Stretching resources, meeting the need

But to expect general practitioners to detect early-stage skin cancers is not realistic given their workloads, according to Dr. Chen.

"They are already working at their maximum as it is, dealing with things like hypertension and diabetes," Dr. Chen says. "I think to expect them to add one more thing on their plate may be not a practical suggestion, and too optimistic."

Many medical schools do not have a mandatory dermatology rotation, with it being only an option, she adds.