Although UV rays are not the sole cause of lip cancers, they are a significant contributing factor. This is true for people working outdoors, such as roofers, farmers, sailors, and horticulturists. Protecting the lips from the sun is therefore more than a comfort measure: it is a public health action that can prevent serious lesions.
Chronic exposure to ultraviolet rays promotes the development of actinic cheilitis. This precancerous lesion, called lip actinic keratosis, results from the abnormal proliferation of keratinocytes after repeated sun exposure. Symptoms vary: dryness, scaling, erythema, atrophy, even ulceration. Over time, these lesions can progress to invasive squamous cell carcinoma, an aggressive lip cancer with prognosis that worsens as diagnosis is delayed. Precancerous lip lesions may go unrecognised due to lack of information.
Protecting the lips from UV exposure is essential to prevent cancerous lesions.
Several studies have highlighted the importance of photoprotection. Research in Brazil with 404 adults showed a 47.1 % prevalence of actinic cheilitis in the population, in individuals exposed to sunlight for more than four hours per day. In these participants, using physical protection such as a broad-brimmed hat, with or without sunscreen, was associated with a significant 33 % reduction in the risk of actinic cheilitis. This study underscores the need for lip sun protection, a neglected area. Despite this, a separate survey of 119 beach workers in Brazil found that 7.5 % used a lip balm with SPF and fewer than one third applied body protection. These figures reveal a concerning lack of awareness of sun risks for the lips.