Teenagers who have experienced at least five blistering sunburns before the age of 20 increase their risk of developing the most deadly form of skin cancer, melanoma, by 80 percent, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

The study has “critical” implications for Bermudians, who in 2012 developed melanoma at a rate six percent higher than that of the United States, according to the 2012 Bermuda National Tumour Registry report.

While the study showed strong links between sun exposure in early life and adulthood for non-melanoma skin cancer, melanoma was predominantly associated with sun exposure in young Caucasian women between the ages of 15 and 20.

The study followed 108,916 women — Caucasian registered nurses — for more than 20 years, finding that those who suffered at least five blistering sunburns when they were 15-20 years old faced a 68 percent increased risk for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin, and an 80 percent increased risk for melanoma. Those women who faced the most sun exposure in adulthood, however, had no increased risk of developing melanoma but were more than twice as likely to develop BCC and SCC of the skin.

“Pattern of sun exposure was not uniformly associated with the risk for all the three main skin cancers we see in the United States, suggesting that there are some differences in the pathophysiology of these skin cancers. An individual’s risk of developing skin cancer depends on both host and environmental risk factors. Persons with high host-risk traits, such as red hair colour, higher number of moles, and high sunburn susceptibility, should pay more attention to avoid excessive sun exposure, especially early in life,” said the report’s author, Dr Abrar Qureshi, professor and chair of the Department of Dermatology at Warren Alpert Medical School of the Brown University and Rhode Island Hospital in Providence.

“These statistics highlight the importance of educating the public about the dangers of UV exposure and awareness about the risks of developing skin cancer in Bermuda,” said Deborah Titterton Narraway, Marketing Manager at Bermuda Cancer and Health Centre, highlighting the increasing number of skin cancer patients on the Island.

Though the report only highlighted the increased risk faced by Caucasian women, they are not the only ones who should take caution, said Azuree Williams, coordinator for the Bermuda Cancer and Health Centre’s public-awareness branch, the SunSmart Programme.

“Our message to the public is critical as we continue to see a rise in skin cancer diagnosis in Bermuda, and it is a colour blind disease,” said Ms Williams.

Dr Qureshi and Brown University researchers took nurses between the ages of 25 and 42 from across 14 states, who were first required to a fill out baseline questionnaire about their medical histories and potential risk factors for skin cancers, including number of moles on legs, number of blistering sunburns between age 15 and 20, and family history of melanoma.

Health information was updated every two years for about 20 years, during which time participants answered additional questions related to skin cancer risk, including updated family history, tanning bed use, smoking and alcohol consumption habits, as well as body mass index.

Researchers accounted for the duration participants spent residing at different locations in the US during follow-up interviews to calculate the cumulative ultraviolet (UV) radiation exposure for each individual. The participants were then grouped into three categories of UV exposure — low, medium, and high baseline annual UV flux.

Some 24 percent of participants experienced painful blisters as a child or adolescent, about 10 percent had more than five blistering sunburns between ages 15 and 20, and around 24 percent had used tanning beds.

Of the study participants, 6,955 were diagnosed with BCC, 880 were diagnosed with SCC of the skin, and 779 were diagnosed with melanoma. Of those with melanoma, 445 had invasive cancer.

“Skin cancer is largely preventable,” said Ms Titterton Narraway, and the study’s author, Dr Qureshi, agreed.

“Parents may need to be advised to pay more attention to protection from early-life sun exposure for their children in order to reduce the likelihood of developing melanoma as they grow up,” said Dr Qureshi. “Older individuals should also be cautious with their sun exposure, because cumulative sun exposure increases skin cancer risk as well.”

The SunSmart Programme is supported through a partnership with The St. Baldrick’s Foundation, whose focus is on funding childhood cancer research. For more information, contact the SunSmart coordinator at sunsmart@chc.bm or 236-1001 ext. 1005.