Sometimes I wonder about the things that medical researchers argue about. Just last month, Darrell S. Rigel, MD, clinical professor of dermatology at New York University Medical Center in New York City and a past president of the American Academy of Dermatology, published an argument that the significant rise in rates of melanoma is real. This was a response to researchers who argue that the detection and reporting of more melanoma reflects better and more available diagnostic techniques. Either way, it seems to me the real issue should be how to improve prevention.
But if I had to weigh in on the debate at hand, I'd say that Dr. Rigel's statistics make a strong case. According to Rigel, the average American's risk of melanoma in his or her life time increased from one in 1,500 in 1930, to one in 250 in 1980 and one in 74 in 2000. The rate increased again to one in 65 by 2004, and now that risk is one in 58. "If this rate continues to rise at the same pace, the risk will be one in 50 by 2015," he says. That's a lot of deadly skin cancer.
Rigel says that there are a number of factors that make it clear that this is a real increase. First, if the increase merely reflected more and better screening for cancer, "you would expect cases to pop up earlier, and then suddenly drop off." With a disease like prostate cancer, for example, when "better" screening (in the form of testing for prostate specific antigens, or PSAs) became available in the 1990's, there was a short-term up-tick in the number of cases reported, and then the numbers went back down. Clearly this is not the case with melanoma, where better screenings became available in the 1980s. Instead, the numbers of cases reported has continued to skyrocket. Then again, maybe that's not such a great comparison since recent studies have indicated PSA testing is highly inaccurate and may, in fact, actually be harmful. But that's a different blog topic.
In any case, those who maintain that the upswing in cases simply reflects better diagnostics say the proof is in the fact that all sorts of skin cancers -- not just melanoma -- have been increasing. It's a rather tautological argument -- akin to saying if I document the world's population increasing, it proves I've become better at recording all births, rather than that more babies are actually being born. Again, the fact that all sorts of cancers are on the rise doesn't prove that diagnosis is better or that better diagnosis has caused the rise in cases. It merely proves that more cancer exists than was previously recorded. In fact, a whole lot more.
In fact, among Medicare patients, the incidence of non-melanoma skin cancers increased by 16% from 2002 to 2006. According to Dr. Howard Rogers, a dermatologist in Norwich, Connecticut and lead author of a study on the incidence of non-melanoma skin cancer, "The number has kept going up and up at a rate of 4.2 percent every year, on average, from 1992 to 2006." The most common skin cancers are basal and squamous cell cancer. More than 250,000 new cases are diagnosed each year, of which about 2,500 will be fatal.
Even more alarming, according to WEBMD, is the fact that an estimated 40% to 50% of fair-skinned people who live to be 65 will develop at least one skin cancer. To put it into perspective, five times more people were diagnosed with non-melanoma skin cancer in 2007 than were diagnosed with breast or prostate cancers.
The good news is that both basal and squamous cell cancers respond well to treatment. Melanomas, on the other hand, which account for about five percent of all skin cancers, are difficult to treat in later stages. Plus, melanoma is generally under-reported because the National Cancer Institute bases its counts on reports from hospitals and many melanoma patients get treatment right in the doctor's office instead. And, melanoma, once it develops, is by far the most deadly skin cancer.
National Cancer Institute statistics show that in 2009, 12.6 percent of melanoma cases ended in death, a much higher proportion than for basal and squamous cell cancers, which had a .01 percent mortality rate. Melanoma is slightly more common in men than in women, but recently, the most pronounced increases have been in older white men and young women.
What's causing the increase, if not "better diagnostics"? Dr. Catherine Harwood, consultant dermatologist for Cancer Research UK, thinks she at least knows why the incidence is higher in men. She says, "The thickness of a melanoma, at diagnosis, is very important in determining the outcome of the cancer. Men seem to be generally less aware of mole changes than women and as a result they often present when the melanoma is already quite thick. Detecting a melanoma in its early stages means earlier treatment with a much better chance of survival." The UK saw an astounding 31% increase in melanoma deaths among men in 2006.
Another cause of skin cancers is tanning, which is a relatively new phenomenon. Throughout most of history, Caucasian people dreaded sun exposure, using compounds like arsenic to whiten their skin and carrying parasols for protection. The tanning craze didn't start until 1923, when socialite Coco Channel accidentally stayed on her cruise ship in the sun too long. The incident made the press and others soon imitated her, hoping perhaps that if they got tan, they'd also be considered glamorous and get rich. And so, the increase in cases may be that all those children of the 50s, 60s, and 70s who had carefree fun in the sun without sunscreen are now reaping the results of that early exposure. Dr. Rigel says "We know the cause of melanoma is too much exposure to ultraviolet (UV) radiation, whether from the sun or indoor tanning beds and lamps. Simple behavior changes can lower your risk." That's why use of a heavy-duty sunscreen is advised along with wearing hats and protective clothing and avoiding exposure when the sun is strongest, between the hours of 10 AM to 3 PM. (And while I agree with the protective clothing, I consider heavy use of sunscreen problematic -- both because of the chemicals it contains and the fact that it severely limits vitamin D production.)
But what if you grew up in the "decades of the sun," before anyone thought of prevention? Then your primary concern becomes one of detection. You have to keep an eye on your moles and freckles. Harold S. Rabinovitz, MD, a dermatologist at the University of Miami Miller School of Medicine, says that you should look at your moles and check for what he calls the ABCs--asymmetry (one half unlike the other half); border (irregular, scalloped or poorly defined); color (varies from one area to another), shades of tan and brown, black; sometimes white, red or blue; diameter (the size of a pencil eraser or larger); evolving (changing in size, shape or color).
In either case, melanoma is on the rise, and not a statistical fluke. If you can, prevent it. If you can't prevent it, then detect it and eliminate it. It's easily treatable if detected early.