Best Margins for MIS Undefined
So far, there are no randomized trials yet to guide surgical margins or depth for many melanoma subtypes, including melanoma in situ (MIS). These are the types of data, when they become available, that change guidelines.
The list of procedures often performed, but for which there is no specific guidance from NCCN or other organizations, is long. Numerous examples were provided during the AAD symposium on guidelines, during which Dr. Swetter spoke. The bedside diagnosis of cutaneous melanoma with noninvasive testing was one.
Describing the 2-gene molecular assay for the evaluation of a suspected melanoma, Caroline C. Kim, MD, director of the Melanoma and Pigmented Lesion Program at Tufts University in Boston, explained that this tool, which is based on the presence of the LINC00158 gene and the preferentially expressed antigen in melanoma (PRAME), has limited utility as a tool for establishing a diagnosis of melanoma. But, she said, it has reasonably good reliability for ruling out melanoma, thereby providing a basis to avoid or delay further diagnostic steps, such as biopsy.
Skin biopsy, as established in the guidelines, “is still the gold standard,” but there are numerous studies indicating that patients negative for both LINC00158 and PRAME have a low risk for melanoma, she said.
“A double negative result is not 100% effective, but it is high,” said Dr. Kim, who provided several examples whereby she employed the test to follow the patient rather than do invasive testing.
This test is gaining popularity, according to Dr. Kim, who cited several surveys suggesting growing use among clinicians, but she characterized it as an adjunctive approach that should be considered in the context of guidelines. It is an example of an approach that is not yet standard practice but can be helpful if used appropriately, she noted.
Dr. Swetter and Dr. Kim report no relevant financial relationships.
A version of this article appeared on Medscape.com.