Page 40 - Noninvasive Diagnostic Techniques for the Detection of Skin Cancers

Summary and Implications

The present technology brief assessed the current state of science regarding noninvasive
diagnostic techniques for the detection of skin cancers, particularly BCC, SCC, and melanoma.
In addition, we sought to assess the clinical application of these modalities and their diffusion
across specialty/subspecialty groups.
Based on these objectives, we found that the use of photography to capture suspicious skin
lesions of the entire body for monitoring purposes is commonly used in dermatology practices,
but not typically in a primary care setting. Photographic surveillance is recommended for
patients at high risk of skin cancer, based on family history, history of dysplastic nevi, or history
of prior malignant lesions. 48,49 However, the age of onset and frequency at which it should be
performed is unclear. The affordability and adaptability of digital imaging permit the increased
ease of electronic image storage and allow for side-by-side comparisons at future visits. The
evolution of computerized imaging systems has also enhanced the ability to convey these lesions
from patients to providers and across provider types. The available data are limited on the role of
photography in changing clinical outcomes, including confirmation that baseline photographs in
specialty clinics improve the detection of melanoma, resulting in detection of earlier stage
lesions, or recurrent lesions. While there are some studies, principally from Australia, about the
impact of photography in primary care settings, no similar studies have been conducted in the
United States.
In addition, we found that approximately half of recently surveyed U.S. dermatologists use
some form of dermoscopy (polarized light noncontact, polarized light contact, and nonpolarized
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light immersion). Except for anecdotal information describing the use of dermoscope in
primary care settings, it is not routinely used in non-dermatologist settings. A handheld
dermoscope can provide at least a 10-fold magnification of skin lesions and aid in the assessment
of pigmented or papulosquamous lesion morphology. Almost all the primary studies on
dermoscopy were non-randomized. The non-randomized studies tended to focus on features of
dermoscopic image that would be of diagnostic interest. We did not identify any controlled
studies examining the use of dermoscopy to increase the detection rate of early stage melanoma.
The primary studies that reported patient outcomes largely focused on number of new lesions
and how lesions had evolved. No study reported on how the addition of dermoscopy affected
survival from melanoma.
One RCT did compare dermoscopic evaluation and naked-eye examination in primary care
physicians in Italy and Spain and inferred the effect of the addition of dermoscopy on the
likelihood that a primary care physician would fail to refer a patient with suspicious skin lesions
for a second expert opinion. A second RCT of patients in Italy examined the downstream effect
on the number of skin lesion excised for diagnostic verification with the addition of dermoscopy
in a pigmented lesion clinic. Whether the findings from the two European RCTs are applicable to
the U.S. population and whether they could be further translated into actual detection of different
forms of skin cancer and/or affecting survival in afflicted patients are uncertain as the practice
patterns are different between the two countries and no trials that examined the effects of the
addition of dermoscopy to naked eye examinations reported on these outcomes. Based on the
abstracts reviewed, we surmise that the actual conduct of dermoscopy as practiced in a U.S.
dermatology setting must be quite heterogeneous owing to the different available algorithms,
devices, training, and practitioner’s experience and belief about the benefits of this technology.

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