Among patients who used indoor tanning, melanoma was diagnosed nearly 10 years earlier than among those who had never used indoor tanning, according to a Canadian study that surveyed more than 800 patients with melanoma.

Among patients who started to use indoor tanning before age 25, melanoma diagnosis occurred about 17 years earlier than among those who started later.

“Our findings support policies restricting the use of indoor tanning among young people,” first author Meghan Mahoney, MD, a cutaneous medical oncologist at the Arthur JE Child Comprehensive Cancer Centre in Calgary, told Medscape News Canada.

The study was published on March 20 as a brief report in the Journal of the American Academy of Dermatology.

Confirms Earlier Findings

“We previously reported several years before that indoor tanning might be related to younger age at diagnosis, so the current study is a larger follow-up study to see if we could confirm that,” she said.

The researchers recruited 854 patients who were asked to complete a 24-item risk assessment survey on sun behavior and indoor tanning. The survey was conducted under supervision, Mahoney said.

Participants’ median age was 62 years, (range, 19-97 years). About 45% of participants were women, and most (93%) were fair-skinned Fitzpatrick I-II skin type. A third of patients (n = 276) reported indoor tanning use.

Patients who used indoor tanning received a melanoma diagnosis at a median age of 52 years compared with 63 years for those who had never used indoor tanning. After adjusting for gender, skin type, hair color, eye color, sun exposure, and family history, indoor tanning was associated with being diagnosed 9.6 years earlier (P < .001).

Patients who used indoor tanning when they were younger than 25 years were diagnosed 17 years earlier than later users (41 years vs 58 years, P < .001).

Compared with nonusers, indoor tanning users more often developed melanomas on intermittently sun-exposed skin (61% vs 50%, P = .011) and had BRAF V600E mutations (22% vs 18%, P = .001).

“In Ontario and British Columbia, there are bans on young people under age 18 years using tanning beds, and the World Health Organization has moved tanning beds up to the highest cancer risk category, stating that they are carcinogenic to humans,” Mahoney said.

Patients with Fitzpatrick skin type, who are fair skinned and have lighter hair and eyes, are at highest risk, she noted. “It is very important that people understand where they fit in terms of their risk factors. It is also crucial for someone who has ever had exposure to indoor tanning to know the ABCDEs of melanoma and when to ask their primary care provider for a referral to a dermatologist.” 

The Case Against Indoor Tanning

“This study adds clinically meaningful evidence to the existing literature on indoor tanning and melanoma,” Isabelle Vallerand, MD, clinical assistant professor of dermatology and community health sciences at the University of Calgary, Calgary, told Medscape News Canada.

“The most striking aspect is the magnitude of the association with age at diagnosis. That temporal gradient, with earlier exposure linked to earlier disease, adds biologic plausibility and strengthens the case for indoor tanning as a modifiable risk factor that may accelerate melanoma development,” said Vallerand, who was not part of the study.

She noted that the findings from this study will be useful in her practice because they will inform her warnings to patients about the risks for indoor tanning.

“The under-25-years finding gives us a tangible counselling point. Framing risk in terms of decades of life rather than in abstract statistics tends to resonate more with patients, particularly younger individuals who may not perceive themselves to be at risk.”

“I am certainly not surprised by the results of this study because that’s why we worked for years to ban indoor tanning for people 18 years of age and younger in Ontario,” Cheryl Rosen, MD, head of Dermatology at Toronto Western Hospital and University Health Network Hospitals in Toronto, told Medscape News Canada.

“It is still surprising that people think that a tan is attractive, but people don’t necessarily listen to the advice that is given to them by dermatologists and dermatology organizations. And we know people still think a tan looks good, makes them look thinner, or makes them look sexy. These are all comments that people have given, but we know that indoor tanning increases your risk of melanoma,” Rosen said.

“Some places like Brazil and parts of Australia have banned indoor tanning for all ages. We weren’t able to do that. It was quite a struggle just to ban it for age 18 years and under,” she added. “So we have to remind people to take care and, especially now that spring and summer are coming, to use sunscreen, seek shade, wear hats, plan your day so that you are doing your outdoor activities early in the morning or late in the day, all the usual things that dermatologists advise.”

This study was conducted without outside funding. Mahoney and Rosen reported having no relevant financial relationships. Vallerand reported being a cofounder of All Skin and has participated in advisory boards or received honoraria from AbbVie, Sanofi, Pfizer, LEO Pharma, Sun Pharma, and Kenvue.