Can You Trust Skin Cancer Apps

Human error plays a big role

The technology is not perfect, but neither is the user. Ever snapped a bad photo? That's the risk here. Human error can play a crucial role in accuracy. Bad lighting, a slightly blurry image or a photo taken at an awkward angle could distort the size, shape or color of the mole or lesion, leading to a misdiagnosis.

"It's like everything else in medicine – there are false negatives, false positives and user errors," Dr. Doolittle says.

Worst case scenario, let's say a person accepts the app's assessment of a "low-risk" mole and doesn't follow up with a doctor. The false sense of security can be dangerous if he or she actually has an aggressive form of melanoma. Left unchecked, the cancer can spread in a matter of months.

"It can happen," Dr. Doolittle says. "I've seen patients who didn't have moles or lesions that looked anything like melanoma, but they turned out to be melanoma."

As a rule, skin cancer tends not to look like its "neighbors." Smartphone apps may not be programmed to make such comparisons.

For example, amelanotic melanomas have no color. They appear as pink or tan spots and can be very dangerous. Apps based on color and pattern recognition won't pick them up.

"That's why we don't look at photos; we look at people," Dr. Aires says. "Skin cancer is diagnosed by how it looks to the trained eye, how it feels and how it appears under a microscope."

Dr. Aires and his colleagues use a dermoscope, a special noninvasive, handheld microscope that lights up the skin pigment network, giving doctors a much better view of what's going on underneath the skin.

"It's much better than the standard skin exam by eye or by app," Dr. Aires says.

Apps are conversation starters

Dr. Aires and Dr. Doolittle say smartphone apps may have a bright future, but only as a first step in early detection. They want users to see the app for what it is – a conversation starter between patient and doctor, not a replacement for your dermatologist.

"There's no question these apps will raise awareness and encourage people to point out moles or unusual skin findings to their doctors – even if they are going in for a routine exam," Dr. Doolittle says.

Both doctors say the smartphone apps could be most helpful to those people who may not be getting regular skin cancer screenings.

"If you have a history of skin cancer, blistering sunburns, lumps or moles, or skin cancer in your family, you are at an elevated risk and should be receiving regular skin cancer screenings," Dr. Aires says. "The smartphone apps would be especially helpful for everyone else – people who would traditionally be thought of as low-risk for skin cancer and who aren't seeing a doctor regularly."

But for now, it is better to be evaluated in person.

"If you have a funny-looking mole and the phone app says it's no big deal, you still will want to get it checked out by a doctor," Dr. Aires says.

Still, it's an exciting development

Despite the limitations of smartphone app technology, Dr. Aires and Dr. Doolittle agree the potential is exciting.

"Anything that can catch skin cancer farther 'upstream' is going to turn into a cure," Dr. Doolittle says. "A melanoma doctor has to believe image recognition technology and smartphone apps are a positive thing, assuming all the appropriate studies are done before it is released to the general population."

Both doctors say they can imagine a day when their patients will be able to receive an accurate, reliable skin cancer diagnosis with their smartphones.

"But I don't think we're there yet," Dr. Aires says. "For now, smartphone apps have the potential to save lives – but only if people follow through with a visit to their doctor."