"Melanoma writes its message on the skin with its own ink, and it is there for all of us to see. Unfortunately, some see but do not comprehend." This was written some years ago by Dr. Neville Davis, chairman of the Queensland Australia Melanoma Project, and is reproduced today by the Skin Cancer Foundation on a new brochure.
It typifies the frustration still felt by skin cancer experts who know that the mortality rate of this most deadly skin cancer can be significantly reduced.
Because when melanoma is found in its early stages, it is curable by simple surgery, virtually always in the doctor's office.
Once it spreads, however, it spreads virulently through the blood stream sewing its deadly seeds in visceral organs like the lung or the liver, or even in the brain. So far the metastatic cancer is mostly resistant to radiation or various forms of chemotherapy, although there is some early promise in work with Vitamin A-related chemicals.
The incidence of this cancer is increasing rapidly. A baby born in 1930 had one chance in 1,500 of developing a melanoma, says the Skin Cancer Foundation. A baby born today has a lifetime risk of one in 150.
The American Cancer Society estimates that 22,000 Americans will develop melanoma this year -- a jump of 25 percent from last year alone. Some 5,500 Americans will die this year from the disease.
The mortality rate from malignant melanoma, says ACS, is increasing faster than that of any other cancer except lung cancer. However, in sunny Queensland, Australia, where the risk of melanoma is high, a comprehensive public education project actually has caused the death rate to begin to decrease, even though the incidence has soared.
Dr. Douglas Robins, a Washington area dermatologist designated as a spokesman for his colleagues, issued an annual warning about the relationship between the sun and skin cancer. The less lethal forms of skin cancer -- basal cell and squamous cell carcinomas -- seem more directly associated with cumulative damage from exposure to the sun or tanning parlor exposure over a long period.
The relationship between chronic exposure to the sun and melanoma is less well established.
One recent study suggests that even a single childhood or adolescent episode of blistering sunburn can create a risk for later developing malignant melanoma, even if overall exposure is less than that of victims of the less serious cancers. And, says Robins: "There have been many melanomas in which we feel the sun does play a role. Not all, but many. And I would include tanning parlors as part of the sun exposure."
Within the past decade or so, researchers have become convinced that the existence of so-called dysplastic nevi -- benign moles with irregular borders, varied colorations and usually larger than normal shapes -- may suggest a risk of eventual melanoma. Studies have shown that these are common in families where more than one member has developed a melanoma. For the most part, says Robins, "the moles themselves do not become malignant, but malignant lesions may occur independently. Some of these moles do become malignant, however, so that although it is not recommended necessarily that all of them be removed, they should be followed very carefully."
Normal moles, which most people start acquiring in early childhood, are made up of pigment-producing cells called melanocytes. They rarely become cancerous -- even when they are in places where they are rubbed or irritated.
But moles, especially very large ones, which are present in newborn babies, may pose a risk. Whether or not they should be automatically removed at birth is still a matter of some disagreement among the experts. Scientists are also investigating other factors -- exposure to toxic chemicals, for example, that may interact with sun to produce this dangerous cancer.
Taking a page from the Australian experience, dermatologists, the ACS and the Skin Cancer Foundation have targeted early detection as the best way to approach the problem at this time. They do, of course, emphasize the dangers of the sun, especially to children and adolescents, people with fair skin, blue or green eyes and those who tan with difficulty. Blacks are not immune, especially to melanomas on the soles of the feet and sometimes on the hands. But most current efforts are designed to help both physicians and patients distinguish between benign lesions -- moles (or nevi), warts, and other more or less normal skin lesions and skin cancers.
Pathologists now know that the depth of the melanoma can often predict the outcome of the disease. If the lesion is thin, penetrating only the top skin surfaces, the cancer is almost certainly curable. The deeper it penetrates and the thicker it is, the poorer the prognosis. It is almost a case of a complete cure or an eventual death sentence.
"The importance of early detection," ACS says, "cannot therefore be overemphasized."