Few health messages sound simpler than “get your skin checked.” For decades, the public has been urged to have moles examined and suspicious spots removed in the hope of catching melanoma early. The reasoning makes intuitive sense, but whether the results have lived up to it is a separate question.
Dr. Michael Piepkorn, a clinical dermatologist, dermatopathologist, and longtime melanoma researcher, has spent years looking into it. As he sees it, the debate over skin cancer screening guidelines comes down to a familiar tradeoff in medicine, where the benefits of screening have to be weighed against its risks.
What Every Screening Guideline Has to Balance
Any guideline for screening healthy populations involves a balance of benefits and risks. Because a screening program examines people who have no symptoms, even a modest error rate can affect a large number of people.
Screening doctrine also depends on an assumption about the tools being used. The methods used to screen must be both sensitive and specific for the early stages of the cancer being targeted. A sensitive method reliably catches the disease when it’s present, and a specific one doesn’t flag disease when it isn’t there.
Both matter. A test that misses early cancer offers little benefit to the people being screened. A test that labels harmless findings as cancer causes harm of its own, and across a program that reaches millions of people, that harm can pile up quickly.
Dr. Michael Piepkorn frames the melanoma debate around that second requirement. When screening turns up lesions that can’t be diagnosed reliably, the balance between benefit and risk begins to shift.
The Difficulty With Early and Precursor Lesions
The lesions screening tends to find include dysplastic nevi and melanomas in situ. They’re considered possible precursors or early forms of melanoma, which is why screening programs try to catch them.
They’re also among the hardest lesions for pathologists to interpret consistently. Michael Piepkorn, PhD, and his colleagues have documented substantial disagreement among pathologists reviewing these kinds of lesions. If independent observers often come to different conclusions about the same tissue, the diagnosis at the core of a screening program is less reliable than it looks.
These lesions sit in the histological gray zone between an ordinary common nevus and a well-developed melanoma, the same territory where his research on reproducibility has found agreement among pathologists to be weakest.
This matters because a screening program can only be as accurate as the diagnosis that comes after the biopsy. A skin exam may find a lesion, but the pathology report determines what it’s called.
Overdiagnosis and the Mortality Question
According to Piepkorn, the limits of diagnosis in this gray zone of precursors and early melanoma have led to overdiagnosis. Epidemiological studies of national databases show the pattern starting around the time national dermatology organizations began recommending screening for the general public, roughly half a century ago.
Overdiagnosis means diagnosing a condition that would never have gone on to cause symptoms or death. With melanoma, it means some patients receive a cancer diagnosis for a lesion that was never going to threaten their lives.
Over that same period, he points out, there’s no credible evidence that public screening has reduced melanoma mortality in the population at large. Finding more lesions hasn’t been shown to save more lives.
It appears instead that many lesions diagnosed as melanoma during formal screening programs would likely never have caused harm if they had gone undetected.
When the Label Itself Causes Harm
That’s a quieter cost of screening. A patient who’s told they have cancer carries the diagnosis forward, along with the procedures, follow-up visits, and worry attached to it. If the lesion was never going to threaten their health, the diagnosis is where the harm comes from.
In Piepkorn’s assessment, screening has contributed to that outcome by labeling some patients as having cancer where no cancer exists. He has laid out his perspective on melanoma screening in published research, including a paper titled “Skin Cancer Screening: Recommendations for Data-driven Screening Guidelines and a Review of the U.S. Preventive Services Task Force Controversy.”
None of this means skin exams have no value. How much an exam is worth depends heavily on who’s being examined.
A Shift Toward Risk-Based Screening
Screening strategies have evolved to bring the balance of benefit and risk back in line. Many now focus screening by stratifying patient populations according to their perceived level of risk, so the same approach isn’t applied to everyone.
Piepkorn offers a clear example. A person from a melanoma-prone family is more likely to benefit from regular skin examinations than a member of the general public with no objective risk factors. For the higher-risk patient, the improved benefit-risk ratio makes routine screening more worthwhile.
For someone without objective risk factors, the same exam offers less potential benefit and still carries the risk of an ambiguous biopsy result and an unnecessary cancer label.
His view has been shaped by decades of melanoma research and diagnosis, including his role on the research team that identified the major familial melanoma gene known as p16, or CDKN2A. Families who carry that kind of inherited risk are the people a risk-based approach is designed to serve.
For patients, the practical step is a conversation with a clinician about personal risk, including family history and other objective risk factors. Dr. Michael Piepkorn’s work suggests that screening does the most good when it’s matched to the people most likely to benefit, and that the ongoing debate over guidelines is largely a debate about where to draw that line.