The skin cancer we all fear the most is malignant melanoma, which kills about 8,000 Americans a year. However, the incidence of stage one (less than 1 mm in size without spreading) malignant melanoma has tripled over the past forty years in spite of the fact that more and more people now avoid the sun and use sunblock. Why is melanoma increasing if so many people are now taking sun precautions?
While getting frequent severe sunburns, especially as a child, clearly increases the risk of malignant melanoma, few people know that frequent sun exposure, without burning, actually decreases the melanoma risk.
Indoor workers, for example, are at higher risk than outdoor workers are. Nor do most people know that melanomas are most likely to occur on areas of the body not chronically exposed to sunlight, such as the back and upper legs. However, although the diagnosis of melanoma has been steadily increasing, melanoma death rates have not.
Dermatologists will tell you that’s because they are doing such a good job, detecting early melanoma and curing it. However, before you congratulate them, consider this. The only type of melanoma that has been increasing is stage one melanoma. The more advanced cases of melanoma, such as those that spread to the local skin, to a lymph node, or to other organs, has increased little, if at all.
Say I told you there was an epidemic of pneumonia in the country and that pneumonia has increased ten-fold in forty years. Wow, that’s bad! However, I add that death rates have not changed, hospitalization rates have not changed, and fever and cough have not changed. The only thing that changed is that radiologists were diagnosing ten times more pneumonia on chest x-rays. You might ask how that could be, as many people will not go to a doctor unless they are near death, so certainly some people stricken with this new epidemic would not come in to see a doctor until they were sick. How could pneumonia rates on chest x-rays be increasing so dramatically, while clinical pneumonia is not increasing at all? It couldn’t.
I have blogged before on a paper from researchers from the Dermatology Department of the Norfolk and Norwich University Hospital in England, led by Dr. Lovell.
In this study, they analyzed 3,971 cases of melanoma over a 13-year period and found the increase in melanoma was almost entirely due to stage one disease. The diagnosis of melanoma has increased dramatically, but there is no increase in regional metastasis, no increase in distant metastasis, and almost no increase in death rates. The authors point out that such an epidemic is impossible and they called for a re-evaluation of the role of sunshine in melanoma and for scientists to look in a new direction when looking for the cause of melanoma.
This is not a new idea. In 1997, researchers from Emery University in Atlanta analyzed similar American data and issued the same warning, contending, “little available evidence suggests the presence of an actual increase in the frequency of melanoma.”
What is happening is simple. People are more concerned about melanoma, so they go to their dermatologist more often when they see a change in one of their moles. The dermatologists know about the “melanoma epidemic,” so they biopsy the mole more often, take their fee, and send it to the pathologist. The pathologists know about the “melanoma epidemic” so they ask themselves a simple question, What happens if I say this is benign? Will I be sued if I’m wrong? So the pathologists then diagnose microscopic melanoma more often, take their fee, and large numbers of Americans are walking around with an unsightly scar, proving the “melanoma epidemic” is real. As Dr. Levell said, “compensation has outbid apology.”
Dermatologists could easily test this idea by getting slides of possible melanoma from the 1960s and compare them, in a blinded manner, to slides from today. More and more scientists think such a study would show that more and more benign lesions are currently being diagnosed as melanoma. In other words, in the 1960s, it would be a diagnosis of “normal mole” and today it would be “melanoma.” Dermatologists could so easily conduct such a study; it makes one wonder why they have not.
Don’t misunderstand me; sunburns clearly increase the risk of melanoma, especially blistering sunburns. However, as with other cancers, genetics play an important role in causing malignant melanoma, especially the number of moles you have.
However, malignant melanoma can occur inside the mouth, on the penis, or inside the vagina, hardly areas of the body exposed to the sun. So much for the idea that prudent ultraviolet light is causing the “melanoma epidemic.”