Plaster activated by light to kill skin cancer could help transform battle against the disease 

A bandage that ‘cooks’ tumour cells could help to fight the most deadly form of skin cancer.

The dressing is designed to be worn after a patient has undergone surgery to remove a malignant melanoma — the most dangerous form of skin cancer, which kills more than 2,000 people a year in the UK.

Around 90 per cent of cases are due to exposure to ultraviolet light — mainly from the sun — and numbers are rising.

When surgeons cut out a cancerous mole or patch of skin, most commonly found on the back in men and legs in women, they usually take extra surrounding ‘healthy’ tissue in case a few stray tumour cells have already spread there.

This extra margin can be up to 2cm wide, depending on how far the tumour has penetrated. The larger the tumour, the more likely some cells — invisible to the naked eye — will have migrated just beyond the site of the cancer.

But even removing a portion of healthy tissue does not guarantee that all malignant cells are cleared. Any remaining ones could trigger the cancer months or even years later, and some studies suggest that in around 13 per cent of patients, melanoma returns within two years of the cancerous tissue being removed.

The high-tech bandage could potentially reduce the recurrence rate by destroying all lingering cancer cells after surgery.

It is based on a form of treatment known as photothermal therapy, where a laser beam is used to heat tumour cells to the point where they self-destruct.

Cancer cells are more sensitive to heat damage than healthy cells, so temperatures of 60c can wipe out malignant ones while healthy cells remain mostly intact.

Photothermal therapy, which is available on the NHS, usually involves injecting a light-sensitive chemical into the tumour site and then zapping it for a few minutes with laser light. It is used for skin and liver cancer.

However, this treatment has to be repeated every few days or weeks, normally in hospital.

In addition, tumours often have tangled blood vessels which make it difficult to control the flow of the chemical once it has been injected into the body.

When surgeons cut out a cancerous mole or patch of skin, most commonly found on the back in men and legs in women, they usually take extra surrounding ‘healthy’ tissue in case a few stray tumour cells have already spread there

The experimental bandage, which looks like a plaster, does the same job, but patients can use it at home with an infrared lamp. A chemical in the dressing converts the light into heat.

Shining the light at the bandage for 15 seconds every two days generates enough heat to kill the tumour, according to lab tests on cells. The results were published recently in the journal Advanced Functional Materials.

Now researchers from the University of Nottingham, who developed the dressing, plan to trial it in patients. If successful, it’s hoped that surgeons may be able to remove smaller amounts of tissue — reducing scarring and speeding up healing.

Dr Rupal Mistry, research information manager at Cancer Research UK, says: ‘This surgical dressing could be used to help kill cancer, but we are some way off it being used in the clinic.’

Scientists have identified four genes that determine whether a malignant melanoma is likely to spread rapidly.

Researchers at the University of Arizona extracted genetic material from melanoma tumours in 37 patients and found that in the six patients in whom the cancer had already spread, four genes — CXCL1, CXCL2, c-CBL and CD276 — were more active.

Identifying these genes in a tumour sample could lead to patients being targeted earlier with immunotherapy drugs, which turbocharge the immune system to fight off cancer, reported the Journal of Surgical Research.

Mini muscle might 

Tiny muscles that play big roles. This week: Ciliary muscle in the eye 

This muscle is like a circle around the lens in the eye, and it changes its shape to help us focus. When the muscle contracts, it makes the lens fatter to see things close up; when it relaxes, it makes the lens thinner for distance.

The lens starts to get less flexible from your mid-40s, making the job of the ciliary muscle harder and its impact less effective. That’s when you need reading glasses.

Too much close reading (especially on tiny screens) can also cause the ciliary muscle to spasm, making distance vision blurry.

To keep the ciliary muscle healthy, Clare Roberts, a consultant ophthalmologist at Moorfields Eye Hospital in London, recommends limiting screen time and taking regular brief rests from sustained close work by looking at something far away every 20 minutes.

‘We humans weren’t designed to look at very close objects for long periods,’ she says. ‘Remember to relax — the more you worry the more blurry your vision will get.’