Winter sun hazards

17 December 2024

Phil Silver discusses the link between UV rays and oral cancer.

Cancer represents one of the leading causes of morbidity and mortality worldwide, and oral cancer is one of the more prevalent types. It is paramount that risk-factors for oral cancer are identifiable to both patients and practitioners, as this ensures a swifter diagnosis and treatment.

Ninety per cent of oral cancers are caused by squamous cell carcinomas (SCC), a form of skin cancer that can be found inside the mouth or on the lips. Alongside tobacco and alcohol consumption, one of the most notable risk-factors for lip cancer is chronic exposure to sunlight and UV radiation. But UV does not just cause damage in the hotter periods of the year – it is easy to overlook the winter months as a time for skin protection, with clouds only reducing UV levels by 50 per cent. Protecting the body from harmful rays year-round can reduce the chance of developing oral cancer, and practitioners can help by determining the causes of it.

Solar power

Squamous cell carcinomas on the lips is 11 times as likely to metastasise than SCC on other parts of the body, increasing the risk of spreading into the oral cavity. Ultraviolet radiation – from sunlight or tanning beds – increases the risk of developing SCC. When a photon of UV light hits the DNA in a cell, it makes the DNA more reactive, and the longer the cell is exposed to the UV, the more likely the DNA will undergo a harmful reaction and mutate. If the mutation effects the coding that repairs enzymes or tumour suppressing proteins, it turns the cell malignant. These cells then continue to grow and divide, accumulating into a tumour that may spread into the mouth or onto other areas of the head and neck.

Melanin, the polymer that defines eye, hair and skin colour, is less reactive to UV radiation and therefore is able to protect DNA molecules from mutation. Those with fairer and pale skin have less melanin and are more vulnerable to UV exposure and cell mutation; such patients should be educated on the importance of protecting themselves from this risk.

Early stages

Actinic cheilitis is a precursor to SCC, caused by ongoing exposure to UV. It is informally known as ‘Sailor’s Lip’ or ‘Farmer’s Lip’ due to the association between those professions and being out in the sunlight for large amounts of time. Patients in these jobs, as well as other notable outdoor roles such as construction workers, landscapers, lifeguards or athletes, may be more likely to develop lip (and therefore oral) cancer, with the bottom lip being most exposed to sunlight. Early symptoms include rough lips that may feel like sandpaper, burning, pain or numbness, and indurated plaque. Those who display such symptoms may need to be assessed for cancer.

Men are more likely to get lip cancer than women. This is attributed to a higher proportion of men working outdoor jobs whilst also being less likely to wear SPF lip balm or sunscreen to guard their skin cells. Patients who spend a lot of time outside should be encouraged to take the necessary measures to protect themselves, such as applying SPF, wearing wide-brimmed hats or caps that provide shade over the mouth and lips, and seeking shade when possible.

Winter holiday risks

Cold days do not stop UV radiation from reaching the skin, and those at a high altitude, such as patients on a skiing trip, can be vulnerable – 80 per cent of the sun’s UV light is reflected by snow, giving those around it a double dosage of harmful rays.

For those heading to the warmer southern hemisphere for Christmas, such as trips to Australia or New Zealand, the summer season there comes with some of the highest UV rays in the world, able to cause sunburn in as little as 11 minutes. At home or abroad, UV can be damaging year-round and conversing with at-risk patients about UV protection can better prepare them.

Stepping in

Practitioners can help patients stay healthy by providing educational materials on the link between UV rays and oral cancer and ways to protect themselves. For those at-risk, using the latest technological innovations can help detect the likelihood of oral cancer. For example, the BeVigilant OraFusion System from Vigilant Bioscience identifies the presence of biomarkers that are associated with oral cancer. Able to detect these in 15 minutes or less, the system’s speed is complemented by the non-invasive saliva test required, ensuring a comfortable experience for the patient. Reliably accurate, the system offers a ‘Monitor’ or ‘Investigate Further’ outcome, making it easy for practitioner and patient to plan the next step in containing the threat of cancer.

Due to the damaging nature of sunlight and UV rays, it is essential to detect and manage malignant lesions early so that patients have the best possible chance to beat cancer.

For more information visit www.vigilantbiosciences.com