Early-life skin cancer risks
Excess sun exposure in youth boosts melanoma risk, says study
As summer approaches each year, media headlines call out the risks of UV exposure and the sun’s damaging effect on the skin. But skin cancer rates are still rising—improvements in public education is key, particularly among young people. Recent research has focused on the link between sun exposure during adolescence and skin cancer.
One such study, published in Cancer Epidemiology, Biomarkers & Prevention, suggests that five or more severe sunburn incidents between the ages of 15 and 20 could increase the risk of melanoma by 80% in later years. In the UK alone, over 13,000 cases are diagnosed with malignant melanoma each year.
The US study used 20 years of data from 108,916 female nurses, documenting the number of blistering sunburns experienced as teenagers as well as personal and family history of skin cancers. Every two years, participants completed a follow-up questionnaire, covering skin cancer risk factors such as familial disease updates, tanning bed use, smoking habits, alcohol consumption and body mass index.
Researchers found that those with five or more severe sunburns between 15–20 years old had a 68% increased risk of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) and an 80% increased risk of melanoma.
Corresponding author, Dr Abrar Qureshi, says: “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. 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,”.
While general sun exposure can—to some extent—be controlled, artificial light emitted from tanning bed lamps presents a different problem. While an increased risk of skin cancer from indoor tanning has been widely reported, few studies have focused on the effects on younger populations. Young people exposed to UV radiation from tanning beds may have a greater risk of developing BCCs at a young age, according to research published in Pediatrics journal.
Researchers noted that UV from indoor tanning devices can be up to 10–15 times stronger than radiation from the midday sun. The study involved 657 patients with newly diagnosed BCC and 452 controls, documenting historical use of indoor tanning devices, skin sensitivity to the sun and proportion of time spent outdoors in childhood. More BCC patients than controls reported using tanning beds, and had skin that was more likely to burn than tan.
The researchers echoed the importance of education, noting that their findings “underscore the importance of counselling adolescents and young adults about the risks of indoor tanning and discouraging parents from consenting minors to this practice.”
But what if sun exposure had “addictive” properties, similar to the effects of opiate drugs such as heroin or morphine? Sunbathing increases natural endorphin production which, according to research published in Cell journal, triggers feelings of euphoria or opiate-like highs.
Researchers at Massachusetts General Hospital and Havard Medical School exposed shaven mice to daily UVB exposure for six weeks, equivalent to 30 minutes of midday sun. Results showed that UV radiation led to the production of the protein proopiomelanocortin—which is then broken down into melanin—but the UV exposure also produced endorphins. Following the six-week study, the mice showed withdrawal symptoms such as tremors, chattering teeth and shaking. A second experiment on mice genetically-engineered to block the production of beta endorphins did not produce the same effects.
Critics of the study comment that social pressures may be behind the “addict-like behaviour” rather than a physical dependency, as well as an aesthetic preference for tanned skin.