Skin cancer – what to look for, when to act

Per hall smPer Hall has been a consultant plastic surgeon in Cambridge since 1995. He has been a pioneer in the early detection of skin cancer using computer imaging for over 20 years, and oversees the SkinCheck service as Clinical Advisor for SkinHealth UK. He is also committed to helping children in developing countries and regularly trains surgeons in cleft lip and palate surgery to facilitate this. What tends to happen is that there are surges of media activity that remind people to think about their skin and moles in particular. These naturally tend to come in the summer months, which are the time of year when people take off more of their clothes and see their skin a bit more, as well as being exposed to the sun. That's good, because early detection is potentially life-saving, so awareness months – or weeks or days – are good to keep people thinking, and over the last 20 years we can see earlier detection and better outlook prognosis melanomas being picked up in the summer months. But there is a seasonal variation. People may well be growing a melanoma during winter and may not pick it up until summer, at which point it will be significantly more advanced, so we need to get into a ritual of looking at our skin every two or three months.

Are there potential dangers in the winter months that perhaps are being overlooked?

Yes, ultra-violet light is very intense on ski resorts, partly because of the high altitude and partly due to reflection from the surface of the snow. It's also something we're concerned about with sportspeople in general who are out in the sun all year round. Check4Cancer are currently involved with the Lawn Tennis Association, and are going to Eastbourne to do some educational work with young athletes and their coaches. Awareness is also about knowing what we are looking for, of course. So, it is important to remind people to think about whether a mole has appeared or changed, or whether there's something new growing on the skin that might need checking.

What should we be looking for?

The first thing is for people to be aware of signs that might help them tell the difference between a normal mole and something potentially dangerous. The key things to look for relate to change.  Change in Size, Shape or Colour.  In addition, important signs will include inflammation, itch or altered sensation, if the lesion is larger than other lesions or if there is oozing or crusting. The American system of ABCDE – Area Border, Colour, Diameter, Elevation – is another way of thinking of it, again relating to change, but either if these are a good start for people when self-checking. One major advantage with regard to skin cancer detection is that anomalies are visible, unlike most other cancers... The advantage of the skin being the largest organ in the body is that it is entirely examinable, as long as you know what you're looking for. But change is the key, so if you are a very moley person you could actually take a series of photos on a phone or iPad – perhaps with the help of a partner or relative if they are on your back – and keep them to refer to two or three months later, then these can be compared. The human eye is really good at spotting changes in things, so people who have some anxiety about their skin can use this idea of archiving images to detect change, and seek immediate help if they have any concerns. It's very easy to ignore things and not seek advice, and perhaps think that because it's not bleeding or hurting it must be OK. But these are very late signs for skin cancer. I also want to add a note of caution here about apps for detecting suspect moles. Although it's a nice idea, I would be very wary of any app that makes out it can detect whether something is friendly or not. They're just not sophisticated enough to do that. I would recommend that any app you use is one that allows images taken over time to be compared side by side, where the user is the judge of whether they have changed rather than relying on unvalidated software. One would hope that one day it might be possible for an app to detect what is outside the normal range – that's the kind of research I've been doing for the last 20 years – but we're not there yet.

There are several different types of skin cancer. Are they all life-threatening?

Skin cancer is one of the most common cancers in the world. While the most common forms – non-melanoma (such as basal cell carcinoma and squamous cell carcinoma) – should still receive prompt treatment, they have a relatively low risk of spreading to other parts of the body. Melanoma is less common, but has the potential to be life threatening. What we know is that if we can find them just as they're beginning to grow, we can deal with them much more effectively. Melanomas start in the top layer of the skin, and they can spend a bit of time there before they start to burrow into the leathery part. If we remove the melanoma and measure how thick it is in the skin, that correlates precisely to the risk of recurrence. So if it's less than 0.76mm then the five-year chance of recurrence is only about 3-5%. But if it's more than 4mm thick – in other words, if it's grown through the skin and out the other side – then the chance of serious problems returning within five years is about 50%. Hence the importance of early detection, awareness and skin checking.

Are there any breakthroughs happening with regard to early detection?

Because melanoma isn't a common cancer, there isn't a national screening programme – there's no equivalent of the mammogram at the age of 55 to check for breast cancer. But what I am involved with is work that helps identify people who are at higher risk for melanoma. At Check4Cancer, for example, we go through a series of simple questions with people that they can even answer over the phone, about their skin type, their hair colour before the age of 15, whether they were freckly before 18, whether they have previously had a non-melanoma skin carcinoma and so on. This allows us to identify those who are in a higher risk group, and these are the people who really need to be checking their skin regularly. While we can't justify a national campaign, we might be able to justify targeting groups of people for closer scrutiny. There is also some very encouraging work on immune therapies that at last offer some treatment hope to people who have advanced melanoma, so that is an encouraging new area. One problem with sun exposure is that it in the recent past it was thought to be healthy, and is still seen as is still seen as beautiful and desirable. Has that created a cancer legacy that is now coming to fruition? Yes, there is a legacy that catches up with people. For that we have to blame Coco Chanel for going for a suntan rather than being pale and interesting! We think that cancer actually develops as a two hit thing, so you prime your skin cells by damaging them with UV light, and then perhaps decades later you give it another hit by going skiing in the Alps and that second hit tips something that was already damaged into becoming cancerous.

Do we need a fundamental change of attitude?

We do. Even I, knowing it's completely wrong, feel healthier with a bit of a tan... But this is a legacy we hope to avoid by working with children and teenagers. People who are in their 40s and 50s have already done the damage to themselves. Now they have an obligation to themselves to keep an eye in their skin, but they also have an obligation to their children to make sure they don't get sunburned.