THE sky above Glasgow is gunmetal grey, dotted with heavy clouds leaden with the promise of rain. The sun is absent – the culprit absconded from the scene of the crime.
Here, among the labyrinth of corridors at the dermatology department of the
city's Southern General Hospital, in a nexus of nondescript rooms, lies one of its victims.
The patient, who appears to be in her sixties, lies on a bed with a blood-soaked gauze pad over one eye, evidence that the effect of the sun's deadly rays have been defused by a methodical technique that, each week, is quietly and carefully cutting out cancerous growths from a growing number of Scots.
Previously, patients with non-melanoma skin cancers on their faces would have the affected area cut out, with surgeons crossing their fingers in the hope that the cancerous cells had been excised and that a return visit was unnecessary.
However, the Mohs' technique now being used effectively guarantees success by keeping the patient on the table and taking samples that are immediately analysed by a trained technician. If cancerous cells are found, more skin and tissue is removed until the area is completely clear.
The principle pioneer of Mohs' technique in Scotland is Dr Robert Herd, a consultant dermatologist and lead clinician for the West of Scotland Managed Clinical Network for Skin Cancer. He trained for Mohs' surgery during a one-year fellowship at Harvard Medical School in Boston.
Taking a short break, Herd explains his medical methodology: "It should be emphasised that Mohs' is used only for facial cancers and only for those that are difficult in some way. For instance, there is a type of basal cell carcinoma that is described as 'morphoeic' and these are always much bigger than they appear (to be] on the skin.
"Also, I think all those that are incompletely excised or recurrent should be removed by Mohs' surgery."
It should come as no surprise to us pale-skinned Scots that the sun is no friend of ours. The rate of skin cancer caused by over-exposure has risen by 350 per cent over the past 30 years as Scots have traded dreich holidays at home to flock abroad, and abandoned worship at the Kirk for weekly worship at the sunbed salon.
The tumours removed using Mohs' technique are the result of chronic, long-term exposure to the sun, with those who enjoy an outdoor lifestyle, such as farmers, at greater risk. Melanomas, meanwhile, are thought to be the result of acute sunburns.
At the moment there is 12-week waiting list for Mohs' surgery, and there is concern that Scots are falling behind in the practice of this valuable technique.
"We are behind England in terms of numbers performing Mohs' surgery, and the UK is far behind the US," explains Dr Herd. "There are dermatologists in Scotland trained to do this procedure but there is very little funding."
Despite this, the number of referrals from other specialities such as plastic surgeons, ENT surgeons and occuloplastic surgeons grows apace, keeping Herd – who was the first in Scotland to adopt the technique and remains the only person in the West of Scotland performing Mohs' – rather busy.
The success rate of Mohs' surgery is above that of any other technique, at 99 per cent for a primary tumour versus 95 per cent by conventional surgery. For recurrent tumours it is 90 per cent versus 83 per cent. And it not only maximises the likelihood of clearing the tumour, but it minimises the size of the resultant defect. "It is the gold standard," says Herd.
Before surgery, the diagnosis has to be confirmed by taking a sample for pathology. This can usually be done by taking a thin "shave" biopsy from the tumour.
"Once we have the result of this biopsy we arrange a date for Mohs'," says Dr Herd. "Patients are told in advance that it is a long procedure with a 30-minute turnaround for each stage. Usually the whole procedure, including the repair, is complete by lunchtime but occasionally it lasts the whole day."
On the day, patients arrive early, usually at 8am. Local anaesthetic is given, and the bulk of the tumour removed. A thin layer is taken from the base and peripheral margins of the wound in such a way that it can be mounted on a slide after being frozen and all the margins are seen in one plane.
The wound is cauterised and a long-acting local anaesthetic is administered to keep it numb while the patient is waiting for their section to be prepared.
The technician – who is a very important part of this process – sections and stains the specimen and looks at it under the microscope. If it's clear, the wound can be repaired.
If there is tumour remaining, it is mapped on a diagram and a further section taken from the residual part. The cycle is repeated until the tumour is cleared.
This surgical technique was developed in the 1930s at the University of Wisconsin by Dr Frederic Mohs, a general surgeon. He was its solitary practitioner for decades until the mainstream medical establishment began to recognise the benefits and adopted it.
While Scotland's future climate is expected to become hotter – and wetter – it will be a while, if ever, before we experience the levels of skin cancer found in California.
In Los Angeles, Dr Jonathan Hoenig performs more than 60 Mohs' procedures a month.
"I think there is an overall rise in skin cancer as the ozone disappears, as light-skinned individuals move to sun exposed regions, and probably genetics," he says. "Melanoma rates have skyrocketed in the last 50 years. I think one has to look at Australia to look at the trends. The skin cancer rates (there] are probably 20 years ahead of the US rates."
Despite all this, Herd explains that some patients aren't frightened enough by their experience.
He talks of one who returned for a check-up after having a skin cancer removed who had a suntan the colour of mahogany: "Some people come back with deep tans and I read them the riot act; others don't ever want to go on holiday again. It's all about getting the balance right."
