Skin Cancers

Dr Kingsley’s comments

Cancer of the Skin.

Cancer of the skin can be divided effectively into two quite different types, so I will describe separately.

A. Malignant Melanoma.

This is the type that nearly always involves the dark pigment melanin, although occasionally it is amelanotic, that is, is without the pigment, although in all other respects it behaves the same. As there is a rising incidence of malignant melanoma, it is assumed that the main risk factor is exposure to ultraviolet light in association with a reduction in the ozone layer.

I feel that, while there may be a measure of truth in this, people are also putting a lot of chemicals into their skin from their food, drink and environmental chemical exposures, so generating free radicles in their skin. So malignant melanoma is probably the result of a combination of factors.

Symptoms and Signs.

One should be suspicious if there is a sudden appearance of a freckle or a mole. If a mole has been there for a long time, however, and it starts to itch, bleed, change in colour or shape, i.e. if it alters in any way, then there is a distinct likelihood that that mole has turned nasty, or is turning nasty.

Malignant melanomas tend to occur on the trunk in men and on the legs in women. Once they are dealt with in the early stages, it can take twenty or more years before a secondary appears. Spread is to local lymph nodes, and, more distantly to the lungs, brain, bones and liver.

Investigations.

In the early stages, a biopsy sample is the only likely investigation, although, if there is a suspicion that secondaries have already developed somewhere in the body, the appropriate scans will be done.

As a standard, routine blood tests will be done, but it is most unlikely that they will reveal anything of specific significance to malignant melanoma, although they might, of course, reveal something completely coincidental, such as anaemia or diabetes, for example.

Conventional Treatment.

There are effectively six stages that doctors use to describe the seriousness of the condition, and surgery to remove the tumour (plus a wide margin of normal tissue around it) is the mainstay of treatment, which can be quite successful.

If the sixth stage has been reached, which means that distant metastases have developed, it is accepted that there is no chance of a cure. Nevertheless, it is sometimes possible to remove a secondary tumour.

While occasionally some surgeons like to remove any local lymph glands that seem to be involved, there does not seem to be any benefit from this, nor is there any value in giving radiotherapy to them.

On the contrary, radiotherapy increases the risk of developing lymphoedema, where the limb becomes swollen because the flow of lymph from it is blocked by the fibrosis in the glands that can result from radiotherapy. The initial skin melanoma tends to be resistant to radiotherapy, so there is little point in giving it and considerable risk from the process.

Malignant melanoma metastases are relatively resistant to chemotherapy, although it can sometimes be helpful. There is no place for it for the primary tumour. A variety of new approaches is being tried, including thalidomide, but the toxic effects can be quite bad in some people.

B. Squamous Cell/Basal Cell Carcinomas.

Although these two are considered as cancers of the skin, they are quite different from malignant melanoma in many ways, and should possibly not be described in the same section. They rarely have any pigment in them, they tend to be slow growing and they seldom spread to other parts of the body, only growing locally, although they can grow into the deeper tissues beneath the skin.

In addition some of them seem to develop scaly, wart-like appearances, which makes me think they might be warts that have additionally gone wrong. Others have a smooth, slightly raised appearance, and may develop a central ulcerated crater with a rolled edge around it.

There is certainly an increased risk in fair-skinned people who live in, or expose themselves to, more sunlight than may be sensible for them, and I know a number of people to whom this applies. Because of this, it can take many years to develop, and tends to occur in people over the age of 60 years, although very fair-skinned people may develop it by 30 years of age.

Perhaps such people should have taken large doses of anti-oxidants to quench the free radicles they were slowly forming in their skin, as well as avoiding as much direct exposure to sunlight as possible. In any case, they usually do not turn brown in the sun, and merely burn, so there is no point in sunbathing.

Mucous membranes, such as the lips, inside the mouth, or in the vagina, can develop a condition called leukoplakia, which can turn into a squamous cell carcinoma. Risk factors for developing this are chronic irritation from smoking, poor hygiene, and rarely nowadays, syphilis.

Investigations.

Apart from a normal thorough examination of the person and routine blood tests, the only investigation is a biopsy of the suspicious lesion and its examination under a microscope.

Conventional Treatment.

Surgical removal of the lesion, plus a clear margin of normal skin around it, is the standard approach, but, in some people, it becomes almost a never-ending round of surgery, leading to multiple scars on certain parts of the body.

In squamous cell carcinoma, involved local glands may be surgically removed or irradiated, but this is almost never used in basal cell carcinoma. Chemotherapy is never used for either of these skin cancers.

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