31-GEP testing should be considered in new melanoma patients

Dermatologists should consider ordering a 31-gene expression profile test to determine metastasis risk in patients with newly diagnosed cutaneous malignant melanoma, according to a study.

“A 31-gene expression profile (31-GEP) test that predicts metastatic risk in patients with cutaneous malignant melanoma (CMM) has previously been validated and is available for clinical use,” Alexander Witkowski, MD, PhD, of the department of dermatology at Oregon Health & Science University, and colleagues wrote.

They noted that the test allows clinicians to assign patients to a low- or high-risk group based on differences corresponding to unique genetic expression patterns, according to the findings.

Previous studies have investigated the effect of this test on how dermatology providers make decisions in the clinic. However, potential associations between clinical features such as dermoscopy and 31-GEP results have yet to be explored.

In the retrospective analysis, Witkowski and colleagues included data for 17 31-GEP test results ordered by dermatology providers. The researchers used a three-point checklist to assess for the frequency of dermoscopic features and compared these findings with a number of other clinicopathologic features such as tumor thickness, ulceration and mitotic rate. They also assessed how the dermatologist incorporated GEP testing as part of clinical decision-making in melanoma overall.

Patients who had undergone 31-GEP testing were assigned to one of four groups. Groups 1A and 1B were those at low risk for metastasis or recurrence, whereas 2A and 2B were at a high risk for those outcomes.

The analysis included 15 patients in group 1A and one each in groups 1B and 2B.

Findings for the frequency of dermoscopic features showed that 100% of lesions that underwent analysis were asymmetrical. Round structures were observed in 47%, whereas 70.6% were blue-white in color.

Clinicians spent an average duration of 15 minutes (range, 10-20) explaining and ordering 31-GEP testing.

“This study represents our experience and understanding of the dermatologist’s role ordering 31-GEP in the care pathway of melanoma patients,” the researchers concluded. “We recommend that dermatology providers consider ordering the test for newly diagnosed CMM patients.”