With incidence rates of melanoma rising for at least 30 years, it is not surprising that new research suggests that five or more blistering sunburns experienced before the age of 20 could increase melanoma risk by 80%.
A study published in the journal Cancer Epidemiology, Biomarkers & Prevention (CEBP) proposes that in a cohort of 108,916 white women, those who had a minimum of 5 severe sunburn incidents between the ages of 15 and 20 had an increased risk of all skin cancers.
With a lifetime risk of 2% (1 in 50), melanoma is more than 20 times more common in white Americans than African-Americans.
Skin cancer is the most common cancer, accounting for nearly half of all cancer cases in the US. Although melanoma skin cancer accounts for less than 2% of these cases, it is more aggressive than other skin cancers and accounts for more than 9,700 of the nearly 13,000 skin cancer deaths each year.
The American Cancer Society estimates that 76,100 new melanomas (about 43,890 in men and 32,210 in women) will be diagnosed in the US in 2014 and 9,710 people (about 6,470 men and 3,240 women) are expected to die of the disease.
Women from the study who had a minimum of 5 severe sunburn incidents between the ages of 15 and 20 had an increased risk of all skin cancers.
The study, funded by the National Institutes of Health and the Brigham and Women's Hospital in Boston, MA, uses 20 years of collected data from the Nurses' Health Study II, which targeted female nurses between the ages of 25 and 42 years across 14 states in 1989.
The baseline questionnaire of the study asked participants about the number of severe sunburns experienced that blistered between the ages 15-20, together with personal history of melanoma, basal or squamous cell skin cancer, family history of melanoma and number of moles between the knees and ankles on both legs.
Participants received a follow-up questionnaire every 2 years with questions about disease and health-related topics, some relating to possible skin cancer risk factors - such as family history disease updates, frequency of tanning bed use, smoking habits, alcohol consumption and body mass index (BMI).
Dr. Abrar A. Qureshi, professor and chair of the Department of Dermatology at Warren Alpert Medical School of the Brown University and Rhode Island Hospital, both in Providence, RI, says: "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." He adds:
"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 color, a higher number of moles and high sunburn susceptibility should pay more attention to avoid excessive sun exposure, especially early in life."
Skin cancer etiology is linked to age, sex, skin type, hair and eye color, family history and genetic conditions. However, the highest percentage of cases are considered to be linked to lifestyle choices including ultraviolet (UV) radiation from sun exposure, UV radiation from tanning beds, obesity, exposure to coal tar pitch, soot, mineral oils and shale oils, arsenic and inorganic arsenic compounds.
80% increased risk for melanoma for teenagers severely burned
After data was analyzed from the 20-year study, researchers found that the individuals with 5 or more blistering sunburns when they were 15 to 20 years old had a 68% increased risk for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), with a colossal 80% increased risk of melanoma. This was compared with those exposed to the greatest quantities of cumulative UV radiation in adulthood who had no increased risk for melanoma, but a 2.35-fold and 2.53-fold increased risk for BCC and SCC.
Dr. Qureshi reports:
"Our results suggest that sun exposures in both early life and adulthood were predictive of non-melanoma skin cancers, whereas melanoma risk was predominantly associated with sun exposure in early life in a cohort of young women."
Of the 108,916 participating nurses, around 24% had experienced painful blisters from sun exposure early in life, 10% had experienced blistering 5 or more times and 24% had used tanning beds. There were 6,955 diagnosed with BCC, 880 with SCC and 779 diagnosed with melanoma. Of the contributors with melanoma, 445 had invasive cancer.
"Parents may need to be advised to pay more attention to protection from early-life sun exposure for their kids in order to reduce the likelihood of developing melanoma as they grow up," says Dr. Qureshi. "Older individuals should also be cautious with their sun exposure because cumulative sun exposure increases skin cancer risk as well."
Recent regulations from the US Food and Drug Administration (FDA) on sunscreen products propose that sunscreen labeling be expanded to include a 4-star rating system to inform consumers how well a product protects them against ultraviolet A (UVA) light and provide information on alternative ways people can limit their risks to sunlight overexposure, such as limiting the time in direct light or wearing protective clothing.
The steps are being taken to help protect consumers from sun damage, prevent sunburn, and reduce the risks of skin cancer and early skin aging.
The FDA also want to make changes regarding protection against ultraviolet B (UVB) light with a proposal for amending their existing rule on UVB products to increase the maximum sunburn protection factor from SPF 30+ to SPF 50+.