Study Suggests Awareness Alone Will Not Solve Skin Cancer Overdiagnosis Issue

Many dermatopathologists understand that overdiagnosis of skin cancer is a significant problem, according to a new study, but that does not translate into significant alterations in how they diagnose potential cases.

Although melanoma is becoming more prevalent, mortality from the cancer is not. The study investigators wrote in JAMA Dermatology that this imbalance suggests melanoma is often being diagnosed unnecessarily.

“Previous research has shown that different pathologists who examine the same skin biopsy will sometimes give different diagnoses—to a very surprising degree,” said Kathleen Kerr, PhD, MS, MA, professor of biostatistics, University of Washington, and lead author, in a statement announcing the findings.“The same pathologist examining the same case on 2 different occasions might even give 2 substantially different diagnoses.”

Yet, while the issue of overdiagnosis itself has been studied at an epidemiological level, the perceptions and practices of clinicians have not been the subject of significant study. The authors turned to 115 board-certified or fellowship-trained dermatopathologists and asked them to give their perceptions of overdiagnosis. They also asked them to give diagnostic interpretations of 18 skin biopsy cases, made up of 5 slide sets with 90 melanocytic skin lesions.

The authors found awareness of overdiagnosis, but to differing degrees. Sixty-eight percentg of the dermatopathologists agreed that overdiagnosis is a public health issue for atypical nevi, 47% said the same thing about melanoma in situ, and 35% identified overdiagnosis of invasive melanoma as a public health issue.

“Also, a majority of the dermatologists agreed that they see cases that should not have been biopsied in the first place,” Kerr said in the statement. “This points to overdiagnosis as a system-wide issue—a problem that may be rooted in too many skin biopsies.”

The study investigators found that dermatopathologists with more experience were less likely to see overdiagnosis as a problem. For instance, although 93% of dermatopathologists with 1 to 4 years of experience said atypical nevi are overdiagnosed, just 46% of dermatopathologists with 20 or more years of experience agreed.

The investigators then examined how those perceptions affected diagnosis of the skin biopsy samples. However, this analysis found differences in diagnostic rates between the groups did not reach statistical significance.

“We thought that those who think invasive melanoma is overdiagnosed might be more reserved in making this diagnosis, but this was not true,” Kerr noted. “In fact, those who think invasive melanoma is overdiagnosed were slightly more likely to diagnose invasive melanoma compared to other dermatopathologists examining the identical cases.”

The investigators highlighted that the overdiagnosis problem is multifaceted. On the one hand, patients tend to assume that any skin abnormality should be biopsied and that the results of biopsies are definitive. Moreover, both doctors and physicians are wary of missing cancer, perhaps creating a bias toward positive diagnosis.

Unfortunately, they added, the solution is equally complicated; awareness of the problem does not by itself appear to significantly impact diagnostic patterns.

“It isn’t surprising that such a complicated problem won’t have a simple solution,” Kerry concluded said. “Reducing overdiagnosis will need to involve patients and primary care doctors having more restraint with obtaining skin biopsies and pathologists exercising restraint in diagnosing cases as melanoma.”

Reference

Kerr KF, Eguchi MM, Piepkorn MW, et al. Dermatopathologist perceptions of overdiagnosis of melanocytic skin lesions and association with diagnostic behaviors. JAMA Dermatol. Published online April 20, 2022. doi:10.1001/jamadermatol.2022.0489