Dermatologists better at detecting melanoma

Dermatologists are significantly better at diagnosing melanoma than non-dermatologist clinicians, according to a study presented at the 89th annual meeting of the Canadian Dermatology Association in Toronto.

Given the incidence of melanoma is rising yearly in Canada in both men and women, that there were 6,000 new cases of melanoma diagnosed in 2013, and that more than 1,000 Canadians died from melanoma in 2013, according to Canadian Cancer Statistics, it's imperative for physicians to be able to detect melanoma, explained Michal Martinka, a medical student at the University of British Columbia in Vancouver, British Columbia, Canada, in an oral presentation here.

"It is essential that they (non-dermatologists) be able to discriminate between benign and malignant lesions," Mr. Martinka told Dermatology Times. "We compared (the ability of) GPs, dermatologists, and other clinicians, who were typically plastic surgeons."

The retrospective review of skin biopsy pathology requisitions with a clinical diagnosis of cutaneous melanoma between January through July 2013. The reports were culled from Vancouver Coastal Health. Study investigators noted if the diagnosis was "listed", meaning melanoma was included in a list of potential diagnoses, or "primary", meaning melanoma was the favored diagnosis.

The total of 225 physicians included in the study consisted of 34 dermatologists and 191 non-dermatologists. Of the 191, 144 were family physicians and 21 were plastic surgeons. Other clinicians included internists, general surgeons, ophthalmologists, nurse practitioners, and dentists."

The total number of cases identified was 922. Of those, 235 were excluded from the study because they were specimens undergoing re-excisional biopsies of previously diagnosed melanoma and excisional biopsies of melanoma that had metastasized.

Of 215 primary melanomas biopsied by dermatologists, 50 were correct clinical diagnoses while 20 of 348 primary melanomas biopsied by non-dermatologists were correct clinical diagnoses, yielding a statistically significant difference, p<0.0001. Similarly, 50 of 300 listed melanomas biopsied by dermatologists were correct clinical diagnoses while 20 of 387 listed melanomas biopsied by non-dermatologists were correct clinical diagnoses, yielding again a statistically significant difference, p<0.0001.

Study investigators then drilled down further amongst the non-dermatologist group. They compared correct clinical diagnoses from dermatologists with those from family physicians and correct clinical diagnoses from dermatologists with those from other non-dermatologists. Dermatologists outperformed both family physicians and other non-dermatologists.

"Dermatologists are significantly more likely to be correct (in diagnosing melanoma) than non-dermatologists," Mr. Martinka says. "Dermatologists are receiving rigorous training in skin lesion identification."

The data underline a need for increased instruction in dermatology for non-dermatologists, he adds.

"There is value in providing more training and education to non-dermatologists as it can have a meaningful impact on patient care," he says. "They play a pivotal role in the overall treatment and care of the patient.

"There is a large disparity between how much training they (non-dermatologists) receive and how often skin-related conditions present to their them," Mr. Martinka says. "Particularly in family medicine, about one out of every four visits to a family physician is a skin-related complaint."

Yet there is a dearth of education about dermatology at the undergraduate level in Canadian medical schools, according to Mr. Martinka. "Some (medical) schools offer only two or three days of dermatology education in the classroom," he says.

Published research in the United States supports the contention about insufficient education about dermatology amongst non-dermatologic clinicians. Forty percent of primary care residents in California who were surveyed reported that they did not feel prepared through their medical school education to respond to dermatologic issues.¹

A retrospective chart review in the United States of 271 consecutive dermatologic consultations from primary care teams demonstrated that the primary care team had a correct diagnosis in less than one out of every four cases (23.9 per cent). Consultation with a dermatologist led to a change in or addition to treatment in the balance of cases.²

Michal Martinka had no relevant disclosures.

1 Hansra NK, O'sullivan P, Chen CL, Berger TG. Medical school dermatology curriculum: are we adequately preparing primary care physicians?. J Am Acad Dermatol. 2009;61(1):23-29.e1.

2 Davila, Manuel; Christenson, Leslie J; & Sontheimer, Richard D. (2010). Epidemiology and outcomes of dermatology in-patient consultations in a midwestern U.S. university hospital.Dermatology Online Journal, 16(2). Retrieved from: https://escholarship.org/uc/item/64h8j3kz