Molecular Testing Increasingly Adopted for Skin Cancer Diagnosis

Dermatopathologists are increasingly using molecular testing for diagnosis of skin cancer samples. Yet, this adoption remains more concentrated in academic medical centers and high-volume clinical practices, according to a study published in the Journal of Clinical Pathology. Additionally, the study found that expanded adoption is stymied by test costs, a deficiency in physician training, and a lack of evidence-based clinical practice guidelines.

Researchers used a 15-question online survey in 2017 to assess how dermatopathologists are employing molecular testing and their opinions of the broader role and utility of molecular technologies in clinical practice.

Based on responses from 136 fellows of the American Society of Dermatopathology, the researchers found that the vast majority of respondents (94 percent) reported using one or more of the 10-queried molecular tests. Nearly two-thirds of dermatopathologists order 12 or more molecular tests per year, while 5 percent report ordering two or less assays per year.

The most commonly used molecular tests are T-cell and B-cell clonality studies (92 percent of respondents), BRAF gene mutation testing in melanoma (66 percent), and fluorescence in situ hybridization testing of melanocytic tumors (57 percent). The authors note that responses could not assess whether it was the dermatopathologist or a referring physician that ordered BRAF testing. Next-generation sequencing was amongst the least frequently used tests (16 percent).

The majority of respondents (87 percent) report using the test in order to “obtain a more objective and reproducible diagnosis,” while approximately one quarter report malpractice or litigation concerns as a reason for ordering molecular tests.

Just over half of respondents (53 percent) report feeling either extremely or very confident incorporating the results of molecular tests into histopathological assessments. When asked about training in molecular technologies, just under one-third received education in medical school, while approximately two-thirds received instruction during residency and fellowship.

More frequent use of molecular testing was significantly associated with relevant instruction during residency training, primary board certification in pathology, affiliation with an academic medical center, higher volume clinical practice, and presence of on-site clinical molecular pathology/cytogenetics laboratory. Use of molecular testing was significantly lower for dermatopathologists at “in-office” settings, compared to those practicing in a private lab or a department of pathology or dermatology. Interestingly, there was no association between numbers of molecular tests ordered and the provider’s age.

Respondents’ cited barriers to wider adoption of molecular testing in the practice of dermatopathology include: test costs (86 percent of respondents), physician knowledge and training (76 percent), and a lack of evidence-based clinical practice guidelines (70 percent). Additionally, logistical concerns, such as the amount of paperwork required and test turnaround times, were also reported as challenges.

“Dermatopathologists are ideally suited to play a supportive role in translating molecular and genomic data into clinical care,” write the authors led by Kristin Torre, from the University of Connecticut in Farmington. “In order to provide guidance to dermatologists and other clinicians, dermatopathologists must acquire a broad working knowledge of available technologies, including their clinical utility, advantages, limitations, cost-effectiveness, and evolving applications in the management of skin diseases.”

Takeaway: Adoption of molecular testing for the diagnosis of skin cancers is more heavily concentrated in academic and high-volume practice settings.