Effect of gene expression profile (GEP) testing on clinical management in 19% of consecutively treated patients with stage IB/IIA melanoma at a single institution.

Abstract

e21080 Background: A 31-GEP test is predictive of metastasis in cutaneous melanoma. We hypothesized that GEP testing would “upgrade” surveillance to routine imaging in at least 16% of stage IB/IIA patients, similar to the upgrade rate from sentinel node biopsy. Methods: A GEP score was obtained for consecutive patients with Stage IB/IIA melanoma treated between 6/2014-6/2016. A retrospective review of a prospectively collected database was performed. Results: 67 patients with Stage IB/IIA melanoma met inclusion criteria. In four cases, a GEP result was not available. Of the 63 tested cases, 68% were Stage IB (N = 43), and 32% were Stage IIA (N = 20). A high-risk result was seen in 12% of stage IB (5/43) and 42% of stage IIA (8/19) patients. Insurance denied coverage of scans in 1/13 patients with a high-risk GEP result. The remaining 12 Stage IB/IIA patients with high-risk scores were “upgraded” to high-intensity surveillance. With a median follow-up of 14 months, 1/13 patients with a high-risk GEP result developed distant metastases 21 months after diagnosis of a Stage IIA melanoma. Conclusions: Results from this retrospective single institution study show that GEP testing altered patient management in 19% of Stage IB/IIA patients. Early detection in 1/13 patients with high-risk scores in this series supports further investigation into stratifying traditionally low-risk patients by GEP testing.