Researchers have confirmed the accuracy of a skin fluorescent imaging (SFI) system for non-invasive, point-of-care molecular testing of difficult-to-characterize moles. Results of the study, published in the Journal of the American Academy of Dermatology, suggest the imaging system has potential to reduce unnecessary biopsies and identify aggressive cancers early compared to current clinical practice.
Here, Catherine Shachaf, Co-founder and Chief Scientific Officer of Orlucent, elaborates on the study results and their implications for melanoma care.
What diagnostic gap does this study address particularly in patients with atypical or “difficult-to-characterize” pigmented lesions?
Dermatologists evaluate lesions to determine if they are benign or at risk of melanoma by visually examining the surface of the mole for color, symmetry, borders, and evolution. Not only is it a subjective process, but it becomes more difficult with gray zone lesions, whose features do not reflect the underlying biology.
The SFI system addresses this uncertainty using in vivo molecular imaging to identify the biological tissue remodeling associated with melanoma development.
How does SFI change decision-making compared with relying on ABCDE criteria and dermoscopy alone?
In current practice, the “when in doubt, cut it out” approach is used for most gray zone lesions. SFI provides molecular information on the remodeling status of a lesion that aligns with melanoma development, allowing physicians to “see” melanoma risk before it becomes visible – thus eliminating some of the “doubt”.
By using molecular information provided by SFI together with the ABCDE criteria, physicians can better determine which lesions are of clinical concern and should be biopsied for additional information.
Can you summarize the pivotal study design and how lesions were classified as melanoma versus low-risk findings?
The pivotal study enrolled 251 subjects with clinically atypical pigmented lesions – those more difficult to assess because they are not overtly benign or melanomas. The SFI test was performed prior to biopsy, then each lesion was biopsied and evaluated by an expert panel of dermatopathologists, which served as the ground truth.
The SFI cutoff scores were compared to non-concerning lesions (no and low dysplasia) versus concerning lesions (high-grade dysplasia, melanoma in situ, or invasive melanoma) as determined by the pathology panel.
Your results report that SFI detected oncogenic activity in 100 percent of melanoma cases. How should clinicians interpret that signal diagnostically?
Oncogenic activity refers to the tissue remodeling and neoangiogenesis that occurs as a tumor grows and seeks nourishment. The biotag used in the SFI test identifies a byproduct of this process. If there is a signal detected and associated with a high score, that means that the lesion has a high likelihood that it will develop into melanoma and should be treated accordingly.
SFI showed an AUC of 0.907 in this study. What does that level of accuracy suggest about how the tool could fit into lesion triage?
AUC of 0.907 is considered solid discriminatory performance. At 0.907, the SFI system reliably distinguishes lesions that are undergoing tissue remodeling associated with melanoma development from those that are not. With both high sensitivity and specificity, and taking into account visual assessment and patient history, SFI can help physicians determine which lesions should be biopsied for further evaluation and those that can be monitored.
For those lesions that are biopsied, pathologists may find the additional biological information provided by SFI to be helpful in their assessments.
Compared with dermoscopy, SFI showed higher sensitivity and specificity in this trial. In your view, what explains this performance difference, and how should SFI be positioned alongside dermoscopy?
While dermoscopy has improved clinical performance, as a visual method it remains subjective. Being limited to assessment of structural features can make evaluation of borderline lesions, such as early melanoma, challenging.
SFI provides noninvasive molecular information using a fluorescent biotag that complements standard visual assessment by providing biological activity. When used alongside current practice at the point of care, this added biological information may help physicians determine better whether biopsy is warranted or if lesions without evidence of tissue remodeling activity can be monitored.
What are the next steps for this research?
We are conducting several clinical studies in preparation for submission filing to FDA. We are also working with prominent pathologists to clarify the features that are important in qualifying borderline lesions and validating their correlation with the SFI output.
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