Risk of second melanoma higher than thought

Patients with one melanoma are at greater risk than previous studies suggest of developing a second, according to a paper published in the April Archives of Dermatology.

Researchers contacted more than 300 melanoma patients listed in the New Hampshire State Cancer Registry. While previous research has estimated the risk of a second melanoma to be about 3% or 4%, this investigation found that about 8% of those patients diagnosed with this cancer would have a second within two years; 6% would be diagnosed within one year of the initial diagnosis.

The authors also found that a third of these repeat melanomas were deeper and more dangerous than the first and that the more abnormal moles a person had, the higher the risk for a second brush with the disease.

Paradoxically, although sun exposure has been implicated repeatedly in melanoma's initial development, it did not appear to be a factor in the ensuing cases. The authors say this does not exonerate the sun as a contributing factor but rather suggests that genetics might have a stronger role in repeat occurrences.

A need for vigilance

Physicians responded that this study indicates the critical need to pay close attention to the skin of melanoma patients even after the cancer has been removed.

"This should cause more physicians to be much more vigilant," said Daniel Van Durme, MD, chair of the Dept. of Family Medicine and Rural Health at Florida State University College of Medicine in Tallahassee.

But while this research indicates the need for close follow-up, an editorial in the same issue of the journal also suggests a screening strategy for detecting this disease in the first place.

Skin cancer screening is one of the least-used modalities, with studies usually finding that only about one-fifth of the population ever has had a total body skin exam. "We've made pretty good progress with other cancers, but melanoma falls short," said Alan Geller, MPH, RN, the paper's lead author and a research associate professor at Boston University School of Medicine. "We need a national plan to find these cancers early."

Currently, the U.S. Preventive Services Task Force says there is insufficient evidence to recommend regularly conducting full body skin exams. The American Cancer Society is reviewing its skin cancer screening guidelines, although the organization notes that these exams can be part of a cancer-related checkup.

The Archives editorial specifically urges the development of a screening program to target those who comprise half of all melanoma deaths: white men older than 50. The writers note that a full body exam is preferred but acknowledge that it is also not always possible. They suggest that doctors ask patients and family members about any unusual moles and keep the skin in mind during a checkup.

"Ideally, it would be a full body skin exam, but a third of all melanomas in men are on the back," Geller said. "And the back is very visible to physicians when they are listening to a person's lungs. This is the only cancer that is visible to a doctor's eye, and they're looking at the skin anyway."

Response to the proposal was mixed. On one hand, those who work in this area strongly support increasing skin cancer screening for people of all ages and praised the strategies outlined in this paper. This perspective was balanced out, though, by concerns that more such screening would overburden primary care physicians as well dermatologists.

"It's an elegant plan," said Anna Pavlick, DO, director of the melanoma program at the New York University Cancer Institute. "But it's asking primary care physicians to do a skin check in addition to whatever else they need to do. It's probably not going to happen. It's just going to make the demand on dermatologists much higher."