Skin checks detecting high proportion of ‘not harmful’ melanomas

Matt Woodley

9/06/2022 5:00:52 PM

But does this mean GPs should change their clinical practice?

GP conducting skin check
New research indicates up to 29% of the melanomas detected during skin checks may ‘never have come to light’ if that person had not been screened.

Nearly one third of melanomas detected during routine skin checks may not be harmful, new research out of QIMR Berghofer suggests.
The observational study, which tracked nearly 44,000 Queenslanders aged 40–69 years with no prior history of melanoma over seven years, found detections were significantly higher among those who had routinely had their skin examined by a doctor before enrolling in the study.
It concluded that people who undergo skin screening subsequently experience higher rates of biopsies and melanoma (especially in situ melanoma), even after adjusting for all known risk factors, ‘consistent with overdiagnosis’.
Professor David Whitemen, who led the study, said the findings indicate that up to 29% of the melanomas detected during skin checks may ‘never have come to light’ if that person had not been screened.
‘It suggests that skin examinations and biopsies are picking up things that look and feel just like melanomas, but they don’t always behave like them or cause harm,’ he said.
‘Melanoma can be a very dangerous cancer and our study does not lessen the importance of good prevention, screening and treatment at all.
‘But it does open up some exciting research possibilities to improve diagnosis and treatment of the disease.’
According to the paper’s authors, the results offer the first estimate of potential melanoma overdiagnosis using individual patient data, and highlight the need for further research to determine why some melanomas appear to stay dormant and undetected for long periods of time.
But if nearly one third of detected melanomas may not have proved harmful, what does this mean for GPs who are regularly the first port of call for people wanting to have their skin checked?
For Dr Jeremy Hudson, Chair of RACGP Specific Interests Dermatology, the message is ‘keep calm and carry on’.
‘Overdiagnosis is a broad term that is difficult to define,’ he told newsGP.
‘In this context it means 29% of the in-situ melanomas were “overdetected” as theoretically they were never going to cause harm. But practically, we can’t tell which 29% of melanomas are “not harmful”.
‘We don’t know why some melanomas behave this way, for example, whether it is immune or genetic factors … [so] this study makes no difference to skin checks or screening at this time.’
One outcome the researchers hope will stem from this study is the development of more accurate diagnostic tools that can spare patients from the anxiety associated with a melanoma diagnosis.
Professor Whiteman says these more accurate tools would benefit patients, doctors and the health system.
‘Patients diagnosed with melanoma have to live with the fact they have a potentially fatal cancer, and endure ongoing check-ups and scans. It’s a life-changing event,’ he said.
‘Fortunately, most people diagnosed with melanoma in Australia can expect an excellent prognosis, as doctors in this country are world leaders in the detection and treatment of this disease.
‘If we can find a way to distinguish the melanomas with a good prognosis from the very nasty melanomas, we might be able offer patients better information about their condition and more appropriate treatment options.
‘It would also help alleviate pressure on the healthcare system as melanoma treatment is very, very costly.’
QIMR Berghofer’s QSkin Study Team will reportedly continue the research by investigating whether there are particular genes that influence the behaviour of melanoma and the development of more serious disease.
Log in below to join the conversation.

melanoma overdiagnosis skin cancer skin checks

newsGP weekly poll What area of medicine do you find most difficult to stay across the changing clinical evidence?

newsGP weekly poll What area of medicine do you find most difficult to stay across the changing clinical evidence?



Login to comment

Dr Matt Harvey   10/06/2022 6:26:27 AM

So if I find a lesion on a patient and say “Look, there’s a spot here that I think is a melanoma. But if I’m right, there’s a 30 percent chance this one won’t hurt you. What should you like to do?” How many patients in reality are going to take that chance and decide to leave it rather than remove it? I certainly wouldn’t. I’d rather read about clinical research outcomes that alter clinical practice.

Dr Ian Rivlin   10/06/2022 8:37:33 AM

One of my patients, aged 16, went to a "skin cancer clinic" about twenty years ago. She was told by the clinic "nothing to worry about". Her father took her back, after three months and was given the same advice. The father brought her in to see me three months after that. The lesion looked benign but had some minor anomalies. Thankfully, I always remember the words told to me, as a medcial student... "If the patient's worried about it, you should be worried about it", I biopsied the benign looking lesion. - It came back as an amelanotic melanoma. The young, vivacious, attractive girl died shortly after her 17th birthday.
So, never use those two dangerous words; "watchful waiting". I'll continue biopsing lesions with even minimally concerning features. I'll never fob off a patient with "Non worrying melanoma". That is the very definition of an oxymoron.

Dr Mileham Geoffrey Hayes   10/06/2022 8:57:10 AM

Then again, of the original 399 men not treated in the infamous Tuskegee Experiment or Tuskegee Syphilis Study, only 28 died of syphilis while 100 died of related complications.
May I ask, then, if these Researchers were diagnosed with a melanoma, would they do "watchful waiting" or 'do a Tuskegee' i.e. not receive treatment - after all, according to them, they have a good 30% chance of their melanomas not progressing.

Dr Ross Phillip Taylor   10/06/2022 12:09:18 PM

I recall a mid-40's teacher who played tennis regularly sent by his wife about a lesion in posterior cervical region.Clinically it looked like a typical BCC. At the same time I had recieved a " nudge" letter from Medicare advising less histology referrals. I excised the lesion and sent to pathology never-the-less. - It turned out to be a amelanotic melanoma and this delightful physics teacher was dead 3 years later with brain 2's. I still remove any suspicious or worrying lesions.

Dr David Alan Wallace   10/06/2022 2:41:06 PM

I don't see anything in this study to change my two guiding principles when dealing with pigmented lesions. "Can I confidently state that this lesion is benign?" and "Would I leave this lesion on my daughter?" Leaving a melanoma on somebody and hoping that it is one of the 29% which do not progress makes no sense.

Dr Scott David Arnold   10/06/2022 6:53:17 PM

I agree with Dr Jeremy Hudson. What is not presented in this article is other data presented by Professor David Whitemen (SCCA Congress 2019 i think) that has shown that south east Queensland with the highest rate of over diagnosis has a lower rate of mortality. Tell me which ones not to cut off and I'll stop. Until them carry on.

A.Prof Christopher David Hogan   12/06/2022 9:30:46 PM

This study merely confirms that the more research we do, the more we find out.
The existence of non harmful malignancies has been detected in prostate & breast screening & will probably be found in others.
The difficulty lies -as the authors state- in developing ways to definitely being to prove a cancer is a cancer that is “not harmful “

Dr Kylie Fardell   13/06/2022 6:02:20 PM

I think this may change practice. My understanding is that the study was not about excising lesions patients had detected or were concerned about; it was about routine skin screening in patients with no history of melanoma. If replicated, it could mean that we should warn about patients about the risk of over-diagnosis if they present requesting a routine skin check.