New Tools Available to Help Diagnose Skin Cancer

NEW YORK — More technologies are becoming available that are expected to help improve early detection of skin cancer, while reducing the need for unnecessary biopsies, according to Jonathan Ungar, MD, associate professor of dermatology at the Icahn School of Medicine at Mount Sinai Hospital, New York City.

Improving skin cancer diagnostics remains a priority because early detection is key for reducing morbidity and mortality from melanoma. The 5-year overall survival rate (OS) for patients with melanoma is roughly 92%, falling to 65% when there is lymph node involvement and 25% when the disease spreads to other organs.

Skin cancer screening is largely based on pattern recognition, including consideration of family history, visual inspection, and dermoscopy, but skin biopsy remains the gold standard for detecting malignancy. Although histopathology delivers the most accurate skin cancer diagnoses, biopsies can result in scarring in cosmetically sensitive areas and leave room for human error because of differences in opinion between pathologists.

“Several new technologies have arisen that can improve diagnosis and monitoring for skin cancer, while at the same time minimizing the need for unnecessary biopsies,” Ungar said at the annual Mount Sinai Winter Symposium on Advances in Medical and Surgical Dermatology, where he presented an update on noninvasive skin cancer screening techniques.

These improvements have largely been driven by advancing technology and, in some cases, existing technologies that have become more attractive for dermatologists and patients alike. Total body photography, in which anatomical locations of all lesions on body surfaces are documented, is more accurate than clinical memory/recall but its use has been limited because it is time consuming to take, store, catalog, map, and compare images, said Ungar, medical director of the Waldman Melanoma and Skin Cancer Center at Mount Sinai.

New technologies like the VECTRA WB180/360 systems (Canfield Scientific), a whole-body imaging system, have addressed many of these issues, he noted. This device utilizes many cameras simultaneously, does not require patients to change position, and constructs a 3D avatar of each patient, which catalogs images and their location, making it easy to track lesions over time. A patient spends less than a minute being photographed and the clinical avatar is generated in about 15 minutes.

The machine is integrated with advanced dermoscopy and software in which serial images are clearly displayed for physicians to analyze. According to Ungar, this tool is effective at helping clinicians determine if there have been concerning dermoscopic changes over time in a more seamless way but still requires the subjective analysis of a clinician.

Electrical impedance spectroscopy (EIS) devices provide dermatologists with more objective data than photos. These devices measure electrical resistance of skin and are sensitive to changes in cellular shape, size, type, and membrane composition.

As an example, Ungar gave an overview of the Nevisense EIS device (SciBase AB), which is US Food and Drug Administration (FDA) approved for early melanoma detection, and is painless and has no adverse events associated with its use. The tool provides an EIS score from 0-10 that is based on objective data rather than qualitative inspection. “It’s important to note that this score does not tell the clinician ‘biopsy’ or ‘don’t biopsy,’ but rather provides additional data about a lesion quickly and painlessly,” explained Ungar.

In a study published in 2014, the device was found to have a sensitivity of 96.6% and a Negative Predictive Value (NPV) of 98.2% for melanoma. “Given the ease of performing the measurement and an NPV of 99% [with updated software] this tool can be extremely useful to the clinician to decide what to do with any given lesion,” Ungar said.

Optical coherence tomography (OCT) is a noninvasive, in vivo imaging modality that provides information about the skin’s architecture. Although it provides low-resolution images, it has a high depth of penetration. OCT has been shown to be superior to dermoscopy for detecting cancerous vs noncancerous lesions, with a sensitivity of 91.8% and a specificity of 86.7% compared with 83.2% and 85.8%, respectively, for dermoscopy. “Since the most common locations for nonmalignant skin cancer are cosmetically sensitive, OCT can help to avoid unnecessary biopsies,” Ungar said.

Reflectance confocal microscopy (RCF) is a tool similar to OCT but provides higher resolution images with the tradeoff that it does not penetrate as deeply into the skin. Ungar noted that RCF is particularly useful in diagnosing melanocytic lesions, citing a study which found that not only were fewer biopsies needed to detect cancer with the use of RCF than with dermoscopy, but that RCF alone actually performed better at identifying when a patient had cancer than the use of the tool in conjunction with dermoscopy.

This again highlights the fact that human error in image analysis can sometimes be mitigated by the use of these new technologies, he noted.

“All these tools may be very helpful in more cosmetically sensitive areas to avoid biopsy,” said Theodore James Daly, MD, director of Garden City Dermatology, who was at the meeting and was asked to comment. “Ultimately if I am concerned about a lesion, I would opt not only for a biopsy but genetic testing as well,” he added. Daly noted that although genetic testing of lesions is not widespread, he sees it as a tool, which, like those described by Ungar, will become a more standard part of dermatological practice as practice advances.

Ungar and Daly report no relevant financial relationships.

Myles Starr is a medical journalist based in New York City.

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