By Dr. Ralph Moss
from CancerDecisions.com Newsletter
A. Bernard Ackerman, MD, is an exceptionally distinguished dermatologist and one of the world's foremost authorities on the subject of skin cancer. In 1999, after a long career in academic medicine, he founded and became director of the Ackerman Academy of Dermatopathology in New York.
Largely because of his leadership and high standards, Dr. Ackerman's institution quickly became the world's largest training center in the field of dermatopathology. (Dermatopathology is the study of the disease processes that affect the skin. It involves detailed knowledge of the microscopic anatomy of the skin's structure in health and disease.) Dr. Ackerman and his six associates examine more than 100,000 skin specimens and do more than 4,000 consultations per year. Dr. Ackerman has published 625 research papers and his list of honors and awards includes this year's Master Award, given to one person a year by the American Academy of Dermatology.
What makes this accomplished scientist particularly interesting is not just his distinguished career in academic medicine but the fact that he challenges some of the dermatology profession's most cherished dogmas. According to an article in the New York Times (July 20, 2004), at age 67, Dr. Ackerman "continues to teach and write, and also to ask for data and question his field's conventional wisdom."
"The field is just replete with nonsense," he told the Times. For instance:
Dr. Ackerman does not believe that the link between melanoma and sun exposure (a central dogma of dermatology) has been proven. He himself is deeply tanned and unafraid to expose his body to the sun.
He does not believe that sunburns, even the painful or blistering kind sustained early in life, necessarily lead to cancer. While some studies do show a small association, he says, others show none. Even those studies that show some such correlation "disagree on when the danger period for sunburns is supposed to be," writes Gina Kolata, author of the New York Times article. Taken as a whole, "the research is inconsistent and fails to make the case."
He doesn't buy the argument that sunscreens protect against melanoma. He points to a recent editorial in an orthodox journal, Archives of Dermatology, which also concludes that there is scant evidence to support this crucial dogma (Bigby 2004).
Finally, while the incidence of basal cell and squamous cell carcinoma have been shown to be closely linked to lifetime sun exposure, Dr. Ackerman challenges the tenet that the more intense a person's exposure to the sun, the greater their risk of melanoma. He believes that the data for this also is not compelling. Although we are told that the incidence of melanoma increases in populations that live nearer the equator, the correlation is not that simple. Epidemiological data on melanoma, says Dr. Ackerman, are imprecise and inaccurate. The data simply "cannot demonstrate cause and effect."
Indeed, a recent case-control study of 966 patients (Kennedy, 2003) studying the effect of painful sunburns and lifetime sun exposure on the incidence of several types of skin cancer concluded that lifetime sun exposure is predominantly linked to an increased risk of squamous cell carcinoma and to a lesser degree with two common types of basal cell carcinoma. By contrast, this study found that lifetime sun exposure appeared to be associated with a lower risk of malignant melanoma.
Dr. Ackerman advises people to stay out of the sun in order to avoid premature aging of their skin. He also says that if you are very fair, you can prevent squamous cell carcinoma, a less dangerous cancer, by avoiding sunlight. (Squamous cell carcinomas, although they can be disfiguring, are rarely life-threatening.) But don't make the mistake of thinking that by avoiding sunlight or using sunscreen you will be protected against deadly melanoma. This, he says, is a myth.
Other knowledgeable researchers agree that sunscreens fail to protect against melanoma. Dr. William B. Grant, for example, who heads the Sunlight, Nutrition and Health Research Center (SUNARC) in San Francisco, points out that sunscreens primarily block the shorter wavelength ultraviolet (UV) radiation, whereas it is the longer wavelength UV that poses the greater risk for melanoma.
Dr. Grant feels that while there is some evidence pointing to a link between sunlight and melanoma, it is not a simple cause and effect relationship. There are many other factors that have to be taken into account. For example, Dr. Grant points out that while it is true that melanoma rates increase with increasing latitude, it is also true that even as far north as Canada, Denmark and the Netherlands, occupational exposure to solar UV radiation is associated with a reduced risk of melanoma. Conversely, for those of northern European ancestry living south of their latitude of origin, such as in Australia, New Zealand and the US, melanoma rates are much higher than they are in their countries of origin.
In addition, Dr. Grant points out that there is substantial evidence that dietary factors, particularly vitamin D, can have a significant effect on the risk of developing melanoma. He points to the work of Millen and colleagues, of the National Institutes of Health, showing that diets rich in vitamin D and carotenoids, and low in alcohol, may be associated with a reduction in risk for melanoma (Millen, 2004). Therefore, Dr. Grant feels that diverse factors including diet, skin type, the presence, number and type of moles, and ethnic, ancestral and geographic origin also have a major influence on melanoma risk. To say that sunlight causes melanoma is at best an oversimplification and at worst a distortion of the scientific evidence (Grant, 2004).
A Melanoma `Epidemic'
Dr. Ackerman is a questioning sort of person. He even debates whether the much-vaunted "epidemic" of melanoma actually exists. The definition of melanoma, he points out, has changed over the past few decades, leading doctors to diagnose, remove and cure lesions that until recently would not have been called melanoma at all.
"The criteria today, clinically and histopathologically, are diametrically different from those 30 years ago," he said. In medical school, he told the Times, "we were taught that melanoma is a big, black, fungating tumor that kills. Who would have believed then that you can recognize melanoma for what it is when it is small and flat and the size of the fingernail on your pinky? You would have said they were insane" (Kolata 2004).
As noted, a central dogma of the dermatology profession is that sun exposure promotes melanoma. The American Academy of Dermatology's website states that it is clear that excessive sun exposure can promote the development of melanoma. But if this is correct why do African-Americans and Asians develop melanoma precisely on those parts of the skin that are not exposed to sunlight - the palms, soles, nails and mucous membranes? Even among whites, the most common melanoma sites are the leg (in women) and the trunk (in men). These are hardly the most sun-exposed body parts. Why not on the face and arms, which are much more frequently exposed to Old Sol?
Ackerman's arguments (and he is by no means alone in feeling this way) leave conventional dermatologists sputtering with frustration. One leader in the field told the New York Times that "it was perverse of Dr. Ackerman to pick the data apart." But is it perverse to question dogmatic beliefs? This official further claimed that melanoma can occur in unexposed places because "sunlight suppresses immune cells in the skin's surface that ordinarily hold cancer at bay." While many would undoubtedly disagree with him, Dr. Ackerman does not accept this `immune surveillance' argument. He sees it as a tenuous theory manufactured in order to support a dubious hypothesis.
This insightful interview with Dr. Ackerman comes at a crucial moment in the history of dermatology. In my opinion, the dermatologists have painted themselves into a corner on the issue of sun exposure, sunscreens and melanoma. The best that can be said is that they are trying to stem what they perceive to be a rising tide of preventable melanoma cases with a public health campaign. But the science behind this campaign is shaky, at best.
Some leaders of the field, such as Dr. Ackerman, are now trying to help their profession find its way back into the light. Although it is not mentioned in this interview, the recent forced resignation of Michael Holick, MD, PhD, from his dermatology professorship at Boston University has overshadowed this debate and moved it from the back rooms of Academe squarely into the medico-political realm. As readers of this newsletter may remember, Holick was asked to resign after he expressed opinions that were essentially identical to those of Dr. Ackerman. But Dr. Holick took his arguments directly to the laypeople in a popular book (The UV Advantage) and-unlike the retired Dr. Ackerman-was in a position that was vulnerable to retaliation.
I believe the dermatology profession should reconsider its dogmatic positions on the relationship of sunlight to melanoma. It should also reexamine its embrace of the sunscreen industry, whose sales have grown from $18 million in 1972 to almost a half billion dollars today. The supposedly protective effect of sunscreen against the development of melanoma is a major reason for that boom. According to medical writer Michael Castleman, writing in Mother Jones magazine:
"...[D]ermatologists get much of their information from the SCF [Skin Cancer Foundation, ed.], and the SCF, in turn, is heavily supported by the sunscreen industry. (A sunscreen manufacturer even funded SCF's quarterly consumer publication, "Sun and Skin News.") No wonder the foundation doesn't give much credence to the growing number of studies showing that even so-called broad-spectrum sunscreen doesn't prevent melanoma. Like the road-destroying trucks that guaranteed work for the concrete company, rising melanoma rates scare people into using more sunscreen" (Castleman 1998).
The Skin Cancer Foundation has dozens of members of the sunscreen industry, such as Pfizer, Johnson & Johnson and Procter & Gamble, on its "Corporate Council." In return, the SCF awards its Seal of Recommendation to many of these same companies' products. It is a cozy relationship indeed.
To restore their collective good name, dermatologists need to come clean with the public about what is scientifically proven and what is merely speculative about the relationship between cancer and sunlight. In particular, truth-seekers in the field need to band together and demand that B.U. reinstate Dr. Holick. Nothing less will convince the public of the dermatology profession's intellectual honesty.
--Ralph W. Moss, PhD