Growing Concerns – Skin Cancer

Despite what we now know about the damage that sun does to our skin, the incidence of skin cancer among sun-worshipping Western nations has risen at an alarming rate. In Britain the incidence has doubled in the last 30 years with over 40,000 cases of skin cancer a year being reported (and possibly twice as many again going unreported).

skin cancer

Malignant melanoma (MM)

Learning how to recognize the signs of a potential dangerous melanoma is extremely important because they are the skin cancers which can metastasize, or spread, most rapidly and kill most quickly. As the name implies, melanomas are cancers of the pigment-producing cells, the melanocytes. If you already have lots of moles (40 or more), if anyone in your family has had MM, or if you have every experienced even one severe, blistered sunburn, you are at increased risk of developing MM.

You should watch out for moles with:

• An irregular shape.

• Uneven edges — whether raised and scalloped or flat and diffused.

• Uneven colour — moles which vary in shade from light tan to deep black or red with white streaks.

• Changes in size or shape, including if the mole is beginning to itch, crust or bleed. Any change, however minor, should be reported Immediately to your doctor.

Cause: Although there is clear evidence for a link between the sun and other forms of skin cancer, we are not yet entirely sure how sun causes malignant melanoma. Certainly research has shown that even one severe sunburn can increase your risk of getting it, but because MM occurs in dark-skinned races and often in areas not exposed to sunlight (such as the soles of the feet and inside of the lip) it seems that other factors may be at play — heredity, for instance.

Treatment: A worrisome mole will usually be surgically removed, along with some of the surrounding tissue and sent to the laboratory to see whether the growth is cancerous or benign. If it is cancerous then further investigation will be needed. Treatment will include chemotherapy and/or radiotherapy, interferon drugs and possibly the new melanoma vaccines. Benign moles will need no further treatment but ideally should be checked, along with all others, by a dermatologist once a year.


Non melanoma skin cancer (NMSC)

Basal cell and squamous cell carcinornas account for 90 per cent of all skin cancers. They are most commonly found in pale-skinned people, on the face, neck, ears and shoulders, on the heads of balding men and the lower legs of women. The mortality rate, however, is low (437 per 40,000 incidences in the UK) when compared to MM as NMSCs grow more slowly and are less likely to spread to the lymph nodes or other parts of the body.

Basal cell carcinomas are cancers of the cells of the lowest part of the epidermis. They appear as Small, pale, shiny nodules, (sometimes with a concave centre) where basal cells have burst through to the surface without undergoing the usual keratinization process. They may sometimes bleed and/or become crusty. They grow very slowly over years, and if left untreated can eventually break open into ulcers but are unlikely to metasticize, or spread.

Squamous cell carcinomas are cancers of cells of the upper epidermis and are characterized by red to pinky scaly patches. Squamous tumours grow more rapidly and if untreated can grow into large raised tumours, sometimes with ulcerated centres. Unlike basal cell carcinomas, they can metastasize, but deaths from squamous cell cancer are rare. More often they are disfiguring as if not caught early enough large amounts of tissue will need to be removed.

Causes: There is a strong genetic link in the development of some basal cell carcinomas, but the sun is also an important factor in their development. The development of squamous cell carcinomas, on the other hand, is believed to be caused largely by the sun. The paler the skin and the greater the total sun exposure, then the higher the risk of developing them.

Treatment: Depending on the size and location of your lesion, your physician may choose surgical removal, curettage and electrosurgery, X-ray therapy, cyrosurgery (freezing with liquid nitrogen) or Mohs microscopic surgery. If caught in good time, the cure rate for basal and squamous cell growths is 95 per cent.


Solar keratoses

If you have spent a lot of time sunbathing, or if you have type l or II skin and you notice a tiny, crusty growth, it may well be a solar keratosis.

Cause: They are the result of past UV-damage to the cells’ DNA which renders their command centre incapable of correctly controlling cell growth and maturation. If left untreated, some of these small lesions could become squamous cell carcinomas.

Treatment: Although it may take years for such tiny growths to turn cancerous, it is generally wise to have them removed. Doing so rarely involves more than having a swab of liquid nitrogen held against them for a few seconds. If, for the general sake of your tired complexion, you choose to have a resurfacing procedure, even a very superficial one, you may find that this eliminates the solar keratosis.

Studies in Australia have shown that the use of Retin-A reduces the numbers of new solar keratoses as does the daily use of sunscreens.

Spot check

We have already seen the benefits of ‘safe sun’ campaigns: the incidence of malignant melanoma is no longer climbing. For those who have already developed it the news is also good.