White marathon runners seem to face an increased risk of skin cancer because of long sun exposure, Austrian researchers report.
The research team, all dermatologists at the Medical University of Graz, Austria, grew interested because they had treated eight ultramarathon runners with malignant skin cancer over a 10-year period.
“...We were concerned by this observation because all of us are enthusiastic runners and two of us ... regularly participate in marathons,” the authors write in Monday’s Archives of Dermatology.
They recruited 210 marathon runners for their study and matched them for age and sex with 210 other people they signed up at five recreation centers in Austria. All 420 people were screened by a dermatologist.
More abnormal moles and lesions
The marathon runners had more abnormal moles and lesions, and 24 were referred for surgical treatment, while there were 14 treatment referrals among the non-marathoners.
The highest rate of referral for treatment, 19 percent, was among the marathoners who trained the most, more than 43.5 miles per week.
Since the research was on white marathoners, it’s unclear if the findings would apply to blacks, who are less prone to skin cancer than whites.
“Personally, I recommend sunscreen use for everybody,” said Dr. Scott B. Phillips, a Chicago dermatologist.
Only 56 percent of the runners reported wearing sunscreen regularly.
Study co-author Dr. Christina Ambros-Rudolph said most marathoners are unaware of the risk to their skin, and even the running researchers found it “good to be reminded to keep wearing the right gear and use sunscreen.”
Runners can lower their risk by training during morning or evening hours and wearing water-resistant sunscreen, said Phillips, who has run 37 marathons and three Ironman triathlons, an endurance event that includes swimming, cycling and running.
He finds hope in a growing awareness of the sun’s danger at races, with volunteers offering to quickly apply sunscreen on athletes, who hate to lose precious seconds from their finish times, Phillips said.
Running clothing made of new fabrics that screen harmful ultraviolet rays also can help, but most runners race with lots of skin exposed.
“Sometimes your training clothing covers different areas than your race clothing,” Phillips said. “You may train in a regular shirt, but for the race you put your singlet on,” leaving shoulders, covered during training, exposed and more likely to a burn. “And for a triathlon, you’re doing the whole thing in a bathing suit.”
Weakened immune systems?
In their report, the researchers cite other studies that have shown suppressed immunity in endurance athletes, caused by repeated tissue damage. Weakened immune systems could leave the marathoners more vulnerable to skin cancer, they speculate.
However, other experts like David Nieman of Appalachian State University, who has documented suppressed immunity in marathon runners, says that link is just a guess at this point.
“There’s just no data to indicate there’s a relationship between the immune changes that occur and cancer risk,” Nieman said.
Nieman said some marathon runners take pride in bronzed, leathery skin — proof that they put in their training miles.
“If someone shows up at a race and they’re lily white, I’ve seen other runners make fun of those guys,” he said.