ANN ARBOR, MI - Popular Internet sites devoted to melanoma may seem trustworthy, but the information they provide is often only skin-deep, a new University of Michigan study finds. In fact, the majority of sites studied had incomplete facts about the increasingly common and potentially deadly form of skin cancer, and about one in eight had an inaccuracy.
The results from the first study of its kind, published in the January Journal of Clinical Oncology, suggest that Web users should beware when searching for information on melanoma, and that their physicians should guide them toward sites that give full and correct details on the disease.
With more people turning to the Web for health information, especially after diagnosis, the researchers warn that incomplete sites could raise anxiety for those diagnosed with melanoma, mislead those at risk, and even undermine the relationship between doctors and patients.
"No one expects every Web site on a given topic to include every bit of information available, but the lack of even basic preventive, diagnostic, treatment and risk factor data on so many sites amazed us," says lead author Christopher Bichakjian, M.D., a lecturer in dermatology at the U-M Health System. "The fact that melanoma so often strikes young adults, who might be most likely to turn to the Internet for medical information, gives Web-site quality even more importance."
The study's authors - most of them dermatologists in the melanoma clinic of the U-M Health System's Comprehensive Cancer Center - often encounter skin cancer patients who come to appointments clutching printouts from Web sites, some of them misleading or inaccurate. So, the researchers conducted their study by putting themselves in their patients' shoes. They typed the word "melanoma" into six of the most popular commercial search engine services, as well as two well-known medical search engines.
After discarding more than 160 dead links, duplicates and pages with many links but no facts, they found 74 web sites that could be assessed against a "gold standard" checklist of 35 factors, from basic definitions and incidence rates to specific risk factors and treatment options.
Only eight of the factors were included on at least half the sites, and no one piece of information appeared on more than 62 percent of the sites.
Fourteen percent of sites had erroneous information. Most inaccuracies were relatively minor, but some were considerably more dangerous. "Some sites recommended unnecessary tests and more invasive, unnecessary surgery," says co-author Timothy M. Johnson, M.D., director of the U-M melanoma clinic and the William B. Taylor Professor of Dermatology.
Only 62 percent of sites even defined melanoma, while 59 percent correctly stated that the prognosis for someone diagnosed with it can range from death to disease-free survival, depending on what stage it's in when treated. Statistics on melanoma's incidence were also often missing - just 47 percent of sites included such information.
Skin cancers of all kinds are easy to spot because they appear on the surface of the body. Early detection can improve treatment effectiveness and survival. But surprisingly, less than a third of sites included images of melanomas, which could be powerful tools for those wondering if a spot on their skin might be dangerous. Just over half the sites listed signs and symptoms of melanoma, and 38 percent mentioned the importance of screening by oneself or a physician.
Prevention techniques and risk factors, which are key to avoiding melanoma or a recurrence, were also scarce. Sunscreen, hats or clothing, and avoidance of the midday sun were only mentioned on a third of sites. And the increased risks of melanoma that come with a history of sunburn, fair skin or hair, moles on the skin, or a personal or family history of the disease, were raised on less than half of sites.
For those seeking knowledge about diagnostic techniques and treatments for melanoma, the results weren't much better. About half the sites mentioned surgery to remove lesions, but less than a quarter mentioned diagnostic workups or sentinel lymph node biopsies, which can tell whether the cancer has begun to spread beyond the skin.
The sites evaluated in the research included offerings from government agencies, nonprofit organizations, medical professional societies, academic medical centers, companies and individual patients. Most were found using the commercial search engines Yahoo, MSN, Lycos, Netscape, Go and Excite, while the medical search engines Med Hunt and Medical World Search yielded surprisingly few.
Bichakjian and his colleagues cross-checked each others' evaluations of the sites, to ensure accuracy of their results. Their "gold standard" checklist came from National Comprehensive Cancer Center Network guidelines and multidisciplinary consensus expert guidelines.
The new study follows in the footsteps of a pioneering 1999 assessment of Internet health information accuracy, led by UMHS orthopaedic surgeon Sybil Biermann, M.D. Biermann - who is a co-author on the new paper and shared her methodology with the dermatologists - found many inaccuracies on sites dealing with Ewing's sarcoma, a rare bone cancer she treats.
"Unlike Ewing's sarcoma, there are things people can do to reduce their risk of melanoma - both to cut the chance their cancer will come back, and to help their relatives who are also at risk," she says. "That's why it's so important that the Internet help disseminate the information. Unfortunately, complete prevention information was found on less than a third of the sites."
Bichakjian and his colleagues note that the sites they found were perhaps not the best available, but that they are the most likely to come up in a basic Internet search. The use of special computer coding and registration with search engine companies can boost a site into the ranks of the most easily found, regardless of the quality of the information on the site.
Besides Bichakjian, Johnson and Biermann, the study's authors include clinical assistant dermatology professor Timothy Wang, M.D., dermatology lecturer Jennifer Schwartz, M.D., and senior research associate Janette Hall, M.S..
Journal
Journal of Clinical Oncology