Non-melanoma skin cancer

Non-melanoma skin cancer is the commonest malignant tumour there is and also the most forgiving: it is nearly always cured, and a small operation is nearly always enough. The name covers two separate diseases, basal cell carcinoma and squamous cell carcinoma. Both start in the top layer of the skin, both are the work of ultraviolet light collected over a lifetime, and both appear where the sun has been falling for years. The one bad part of the story is that people take such a tumour for a scratch or a patch of irritation and turn up a year or two later, by which time a small mark has had time to destroy the side of a nose or an eyelid.

What the tumour looks like

There is no single appearance, but there are recognisable features.

Basal cell carcinoma most often looks like a shiny, translucent lump with a rolled edge and fine vessels showing through it. Sometimes it is a flat pink or brownish patch, sometimes a sore that crusts over, bleeds when touched, seems to heal and opens again a week later. It grows over years and almost never spreads elsewhere, but it is reluctant to go deep only at first: on the nose, the eyelid and the ear it can destroy cartilage and bone.

Squamous cell carcinoma is firmer and in more of a hurry: a lump or plaque with a rough horny crust, often tender, growing over weeks and months. This one can spread to nearby lymph nodes, particularly when it sits on the lip, the ear, an old scar, or on the skin of someone taking medicines that suppress the immune system.

There are forerunners too. Actinic keratoses are dry, rough little patches on a bald scalp, the forehead, the ears and the backs of the hands, easier to feel with a fingertip than to see. They are not cancer in themselves, but some of them turn into it in time, which is why they are treated.

All these tumours favour the same places: the face, the ears, a bald head, the neck, shoulders, back, forearms, the backs of the hands and the lower legs.

What should take you to a doctor

Any of these is a reason to book an appointment:

• a mark on the skin that is growing, hardening or changing colour;
• a sore or ulcer that has not healed in four weeks, bleeds and crusts over;
• a rough patch that will not go away for months, flakes and comes back;
• a small lump that itches or hurts for no obvious reason.

Moles are a separate matter. A new mole in an adult, or an old one that has changed, belongs to melanoma rather than to non-melanoma skin cancer, and that will not wait. What is worrying is an asymmetrical shape, an irregular blurred edge, several colours in one mark, a size bigger than a pencil rubber, and any change over recent months — growth, itching, bleeding.

Skin cancer does not need an ambulance, but there is no sense in waiting six months either. Show anything on the eyelid, the nose, the lip or the ear soonest: there the reckoning is in millimetres of tissue that will have to come out.

Why it develops

There is one main cause: ultraviolet light, from the sun and from sunbeds. It damages the DNA in skin cells, and that damage piles up over decades, which is why the disease is commoner in older people, in those who work outdoors and in dedicated sunbathers. Sunburn in childhood and youth counts separately: it punishes the skin more than an even tan does.

Your risk is higher if you have:

• fair skin that burns rather than tans, red or blond hair, blue or green eyes, plenty of freckles;
• a suppressed immune system — after an organ transplant the risk of squamous cell carcinoma rises many times over, which is why these patients are seen by a dermatologist on a set schedule;
• past radiotherapy to that area of skin, old scars, burns and ulcers that never close;
• a skin cancer or actinic keratoses already treated;
• rare inherited conditions such as xeroderma pigmentosum or Gorlin syndrome;
• medicines that make the skin more sensitive to sunlight — ask your doctor about this if you spend a lot of time outdoors.

On brown and black skin this cancer is far less common, but it happens, and there it arises more often on covered areas and in scars, so it tends to be noticed later.

How to protect yourself from the sun

Protection still counts once a tumour has been treated: it lowers the chance of the next one.

• Get into the shade in the middle of the day. A simple rule: if your shadow is shorter than you are, the sun is too high.
• Clothing protects better than any cream. A long-sleeved shirt, a wide-brimmed hat that covers the ears and the back of the neck, sunglasses with an ultraviolet filter.
• Sunscreen of at least factor 30 with UVA protection on everything left uncovered. Put it on generously and repeat every two hours, and after swimming and towelling dry.
• Do not use sunbeds at all: there is no safe dose of artificial ultraviolet light.
• Take particular care of children: their skin is more delicate, and burns in childhood affect the risk decades later.

If you avoid the sun completely, talk to your doctor about a vitamin D supplement, since covered skin does not make enough of it.

How the diagnosis is made

The doctor asks how long the lesion has been there and how it has changed, examines not only that spot but the whole skin including the scalp, and feels the nearby lymph nodes. A dermatoscope is used to look at it — a lit magnifier that reveals the pattern of vessels and structures the naked eye cannot see.

No examination, though, replaces the essential step: only a biopsy makes the diagnosis. A small lesion is usually taken out whole straight away with a margin of healthy skin; from a large one a piece is taken. The pathologist studies the material, works out the type of cancer, how aggressive it is and how deep it has gone, and, if the whole lesion was removed, whether the edges are clear.

From this follows something very practical. If a suspicious lesion is simply burned off, frozen or vaporised with a laser and nothing is sent for examination, the tissue disappears along with the answer. On the surface everything looks settled, but a year later the tumour comes back from underneath and by then nobody knows what it was. Cosmetic removal of "moles and growths" without histology is the commonest reason a diagnosis arrives late.

Blood tests do not detect skin cancer; they are ordered for other purposes.

Are more tests needed?

Usually not. Basal cell carcinoma almost never leaves the spot it started in, so once the diagnosis is confirmed treatment is planned straight away.

Squamous cell carcinoma is a different matter, especially when it is large, deep, recurrent or sitting on the lip or ear. Then the doctor checks the lymph nodes carefully and, where there is doubt, arranges an ultrasound, a CT or MRI scan and sometimes a biopsy of a node. All of this is to know how much surgery is needed, not a sign that things are going badly.

How it is treated

The choice depends on the type of tumour, its size and site, and on whether it is the first one or has come back.

• Excision. The main approach: the tumour is cut out together with a rim of healthy skin around it and sent for examination. If the gap left is large, it is covered with a skin flap or a graft.
• Mohs micrographic surgery. The tumour is removed in the thinnest of layers and each layer is checked under the microscope there and then, until the edges come back clear. This takes everything out while sparing the greatest amount of tissue — irreplaceable on the nose, eyelids, lips and ears, in recurrences and where the borders are indistinct.
• Curettage with cautery, and cryotherapy, for small superficial lesions and for actinic keratoses.
• Creams with an anti-tumour or immune action, applied over several weeks for superficial basal cell cancers and pre-cancerous changes.
• Photodynamic therapy: a substance is put on the skin that gathers in the tumour cells, the area is then lit with a lamp of a particular wavelength, and those cells die.
• Radiotherapy, when surgery is impossible because of the site or your general health, and also after surgery where the risk of return is high.
• Targeted medicines and immunotherapy, for the rare advanced cases in which the tumour has grown deep or has spread.

What to do after treatment

Anyone who has had a skin cancer joins the group in which a second one is an ordinary event. That is why follow-up runs for years, and half the work falls to the patient.

Once a month look over the whole skin in good light, with a mirror or with help from someone close: the back, behind the ears, the back of the neck, a bald scalp, the backs of the hands, the lower legs and the feet. Watch for a lump or thickening inside a scar, for a sore that will not heal and for an enlarged lymph node near where the tumour was.

After that it is the same as before the illness, only stricter: shade, clothing, sunscreen, no sunbeds. If you take medicines that suppress the immune system, dermatology reviews should be regular and diarised rather than occasional. And do not keep quiet about the cosmetic result: scars on the face can be revised, and asking about it is a legitimate reason to consult, not a vanity.

Online consultation with a doctor

A remote appointment helps decide how urgently a face-to-face visit is needed and with whom: showing the lesion, telling its history, going through a pathology report in which half the words mean nothing, discussing wound care, healing times, sun protection and follow-up after treatment.

The limits are obvious. Neither a phone camera nor a description replaces dermatoscopy, let alone a biopsy: a photograph can neither make a diagnosis nor rule one out. So anything that is growing, bleeding or failing to heal will in the end have to be shown to a doctor in person.

This material is for information only and does not replace medical advice.